WorldWideScience

Sample records for surface receptor family

  1. Proteomic plasma membrane profiling reveals an essential role for gp96 in the cell surface expression of LDLR family members, including the LDL receptor and LRP6.

    Science.gov (United States)

    Weekes, Michael P; Antrobus, Robin; Talbot, Suzanne; Hör, Simon; Simecek, Nikol; Smith, Duncan L; Bloor, Stuart; Randow, Felix; Lehner, Paul J

    2012-03-02

    The endoplasmic reticulum chaperone gp96 is required for the cell surface expression of a narrow range of proteins, including toll-like receptors (TLRs) and integrins. To identify a more comprehensive repertoire of proteins whose cell surface expression is dependent on gp96, we developed plasma membrane profiling (PMP), a technique that combines SILAC labeling with selective cell surface aminooxy-biotinylation. This approach allowed us to compare the relative abundance of plasma membrane (PM) proteins on gp96-deficient versus gp96-reconstituted murine pre-B cells. Analysis of unfractionated tryptic peptides initially identified 113 PM proteins, which extended to 706 PM proteins using peptide prefractionation. We confirmed a requirement for gp96 in the cell surface expression of certain TLRs and integrins and found a marked decrease in cell surface expression of four members of the extended LDL receptor family (LDLR, LRP6, Sorl1 and LRP8) in the absence of gp96. Other novel gp96 client proteins included CD180/Ly86, important in the B-cell response to lipopolysaccharide. We highlight common structural motifs in these client proteins that may be recognized by gp96, including the beta-propeller and leucine-rich repeat. This study therefore identifies the extended LDL receptor family as an important new family of proteins whose cell surface expression is regulated by gp96.

  2. Family C 7TM receptor dimerization and activation

    DEFF Research Database (Denmark)

    Bonde, Marie Mi; Sheikh, Søren P; Hansen, Jakob Lerche

    2006-01-01

    The family C seven transmembrane (7TM) receptors constitutes a small and especially well characterized subfamily of the large 7TM receptor superfamily. Approximately 50% of current prescription drugs target 7TM receptors, this biologically important family represents the largest class of drug...... to be fully defined. This review presents the biochemical support for family C 7TM receptor dimerization and discusses its importance for receptor biosynthesis, surface expression, ligand binding and activation, since lessons learnt here may well be applicable to the whole superfamily of 7TM receptors.......-targets today. It is well established that family C 7TM receptors form homo- or hetero-dimers on the cell surface of living cells. The large extra-cellular domains (ECD) have been crystallized as a dimer in the presence and absence of agonist. Upon agonist binding, the dimeric ECD undergoes large conformational...

  3. A new family of insect tyramine receptors

    DEFF Research Database (Denmark)

    Cazzamali, Giuseppe; Klærke, Dan Arne; Grimmelikhuijzen, Cornelis J P

    2005-01-01

    in the genomic databases from the malaria mosquito Anopheles gambiae and the honeybee Apis mellifera. These four tyramine or tyramine-like receptors constitute a new receptor family that is phylogenetically distinct from the previously identified insect octopamine/tyramine receptors. The Drosophila tyramine...

  4. Recurrent LDL-receptor mutation causes familial ...

    African Journals Online (AJOL)

    1995-05-05

    May 5, 1995 ... 3. eaudet . New. Recurrent LDL-receptor mutation causes familial hypercholesterolaemia in ... amplification refractory mutation system (ARMS)" and single- strand conformation .... Location. Afrikaner. Mixed race. ApaLl.

  5. Minimal families of curves on surfaces

    KAUST Repository

    Lubbes, Niels

    2014-11-01

    A minimal family of curves on an embedded surface is defined as a 1-dimensional family of rational curves of minimal degree, which cover the surface. We classify such minimal families using constructive methods. This allows us to compute the minimal families of a given surface.The classification of minimal families of curves can be reduced to the classification of minimal families which cover weak Del Pezzo surfaces. We classify the minimal families of weak Del Pezzo surfaces and present a table with the number of minimal families of each weak Del Pezzo surface up to Weyl equivalence.As an application of this classification we generalize some results of Schicho. We classify algebraic surfaces that carry a family of conics. We determine the minimal lexicographic degree for the parametrization of a surface that carries at least 2 minimal families. © 2014 Elsevier B.V.

  6. Common structural basis for constitutive activity of the ghrelin receptor family

    DEFF Research Database (Denmark)

    Holst, Birgitte; Holliday, Nicholas D; Bach, Anders

    2004-01-01

    Three members of the ghrelin receptor family were characterized in parallel: the ghrelin receptor, the neurotensin receptor 2 and the orphan receptor GPR39. In transiently transfected COS-7 and human embryonic kidney 293 cells, all three receptors displayed a high degree of ligand......-independent signaling activity. The structurally homologous motilin receptor served as a constitutively silent control; upon agonist stimulation, however, it signaled with a similar efficacy to the three related receptors. The constitutive activity of the ghrelin receptor and of neurotensin receptor 2 through the G...... demonstrated that the epitope-tagged ghrelin receptor was constitutively internalized but could be trapped at the cell surface by an inverse agonist, whereas GPR39 remained at the cell surface. Mutational analysis showed that the constitutive activity of both the ghrelin receptor and GPR39 could systematically...

  7. Familial hypocalciuric hypercalcemia and calcium sensing receptor

    DEFF Research Database (Denmark)

    Mrgan, Monija; Nielsen, Sanne; Brixen, Kim

    2014-01-01

    Familial hypocalciuric hypercalcemia (FHH) is a lifelong, benign autosomal dominant disease characterized by hypercalcemia, normal to increased parathyroid hormone level, and a relatively low renal calcium excretion. Inactivation of the calcium-sensing receptor in heterozygous patients results...... in FHH, while in homozygous patients as well as in compound heterozygous or dominant negative heterozygous patients, it may result in neonatal severe hyperparathyroidism (NSHPT). Parathyroid surgery is not indicated in FHH and does not lower plasma calcium unless total parathyroidectomy is performed...

  8. Receptor-interacting protein (RIP) kinase family

    OpenAIRE

    Zhang, Duanwu; Lin, Juan; Han, Jiahuai

    2010-01-01

    Receptor-interacting protein (RIP) kinases are a group of threonine/serine protein kinases with a relatively conserved kinase domain but distinct non-kinase regions. A number of different domain structures, such as death and caspase activation and recruitment domain (CARD) domains, were found in different RIP family members, and these domains should be keys in determining the specific function of each RIP kinase. It is known that RIP kinases participate in different biological processes, incl...

  9. Receptor-interacting protein (RIP) kinase family

    Science.gov (United States)

    Zhang, Duanwu; Lin, Juan; Han, Jiahuai

    2010-01-01

    Receptor-interacting protein (RIP) kinases are a group of threonine/serine protein kinases with a relatively conserved kinase domain but distinct non-kinase regions. A number of different domain structures, such as death and caspase activation and recruitment domain (CARD) domains, were found in different RIP family members, and these domains should be keys in determining the specific function of each RIP kinase. It is known that RIP kinases participate in different biological processes, including those in innate immunity, but their downstream substrates are largely unknown. This review will give an overview of the structures and functions of RIP family members, and an update of recent progress in RIP kinase research. PMID:20383176

  10. Minimal families of curves on surfaces

    KAUST Repository

    Lubbes, Niels

    2014-01-01

    A minimal family of curves on an embedded surface is defined as a 1-dimensional family of rational curves of minimal degree, which cover the surface. We classify such minimal families using constructive methods. This allows us to compute the minimal

  11. Receptor oligomerization in family B1 of G-protein-coupled receptors

    DEFF Research Database (Denmark)

    Roed, Sarah Norklit; Ørgaard, Anne; Jørgensen, Rasmus

    2012-01-01

    , the glucagon receptor, and the receptors for parathyroid hormone (PTHR1 and PTHR2). The dysregulation of several family B1 receptors is involved in diseases, such as diabetes, chronic inflammation, and osteoporosis which underlines the pathophysiological importance of this GPCR subfamily. In spite of this......, investigation of family B1 receptor oligomerization and especially its pharmacological importance is still at an early stage. Even though GPCR oligomerization is a well-established phenomenon, there is a need for more investigations providing a direct link between these interactions and receptor functionality......The superfamily of the seven transmembrane G-protein-coupled receptors (7TM/GPCRs) is the largest family of membrane-associated receptors. GPCRs are involved in the pathophysiology of numerous human diseases, and they constitute an estimated 30-40% of all drug targets. During the last two decades...

  12. Calcitonin and calcitonin receptor-like receptors: common themes with family B GPCRs?

    Science.gov (United States)

    Barwell, James; Gingell, Joseph J; Watkins, Harriet A; Archbold, Julia K; Poyner, David R; Hay, Debbie L

    2012-05-01

    The calcitonin receptor (CTR) and calcitonin receptor-like receptor (CLR) are two of the 15 human family B (or Secretin-like) GPCRs. CTR and CLR are of considerable biological interest as their pharmacology is moulded by interactions with receptor activity-modifying proteins. They also have therapeutic relevance for many conditions, such as osteoporosis, diabetes, obesity, lymphatic insufficiency, migraine and cardiovascular disease. In light of recent advances in understanding ligand docking and receptor activation in both the family as a whole and in CLR and CTR specifically, this review reflects how applicable general family B GPCR themes are to these two idiosyncratic receptors. We review the main functional domains of the receptors; the N-terminal extracellular domain, the juxtamembrane domain and ligand interface, the transmembrane domain and the intracellular C-terminal domain. Structural and functional findings from the CLR and CTR along with other family B GPCRs are critically appraised to gain insight into how these domains may function. The ability for CTR and CLR to interact with receptor activity-modifying proteins adds another level of sophistication to these receptor systems but means careful consideration is needed when trying to apply generic GPCR principles. This review encapsulates current thinking in the realm of family B GPCR research by highlighting both conflicting and recurring themes and how such findings relate to two unusual but important receptors, CTR and CLR. © 2011 The Authors. British Journal of Pharmacology © 2011 The British Pharmacological Society.

  13. A family of photoswitchable NMDA receptors

    Science.gov (United States)

    Berlin, Shai; Szobota, Stephanie; Reiner, Andreas; Carroll, Elizabeth C; Kienzler, Michael A; Guyon, Alice; Xiao, Tong; Trauner, Dirk; Isacoff, Ehud Y

    2016-01-01

    NMDA receptors, which regulate synaptic strength and are implicated in learning and memory, consist of several subtypes with distinct subunit compositions and functional properties. To enable spatiotemporally defined, rapid and reproducible manipulation of function of specific subtypes, we engineered a set of photoswitchable GluN subunits ('LiGluNs'). Photo-agonism of GluN2A or GluN2B elicits an excitatory drive to hippocampal neurons that can be shaped in time to mimic synaptic activation. Photo-agonism of GluN2A at single dendritic spines evokes spine-specific calcium elevation and expansion, the morphological correlate of LTP. Photo-antagonism of GluN2A alone, or in combination with photo-antagonism of GluN1a, reversibly blocks excitatory synaptic currents, prevents the induction of long-term potentiation and prevents spine expansion. In addition, photo-antagonism in vivo disrupts synaptic pruning of developing retino-tectal projections in larval zebrafish. By providing precise and rapidly reversible optical control of NMDA receptor subtypes, LiGluNs should help unravel the contribution of specific NMDA receptors to synaptic transmission, integration and plasticity. DOI: http://dx.doi.org/10.7554/eLife.12040.001 PMID:26929991

  14. Maturing of the nuclear receptor family.

    Science.gov (United States)

    Lazar, Mitchell A

    2017-04-03

    Members of the nuclear receptor (NR) superfamily of ligand-regulated transcription factors play important roles in reproduction, development, and physiology. In humans, genetic mutations in NRs are causes of rare diseases, while hormones and drugs that target NRs are in widespread therapeutic use. The present issue of the JCI includes a series of Review articles focused on specific NRs and their wide range of biological functions. Here I reflect on the past, present, and potential future highlights of research on the NR superfamily.

  15. Multiple Receptor Subtypes for the CGRP Super-Family

    Directory of Open Access Journals (Sweden)

    R. Quirion

    2001-01-01

    Full Text Available Molecular evidence for the existence of multiple receptors for CGRP has been rather difficult to obtain. Over 10 years after suggesting the existence of at least two classes (CGRP1 and CGRP2 of CGRP receptors on the basis of pharmacological data[1], molecular data on the CGRP2 receptor subtype are still lacking as well as potent and selective antagonists. The situation is somewhat different for the functional CGRP1 subtype which is likely composed of diverse subunits CRLR, RAMP1 and possibly RCP[2]. Moreover, BIBN 4096BS was recently reported as the first nonpeptide highly potent CGRP1 receptor antagonist[3]. However, in situ hybridization and receptor autoradiographic data have clearly shown the existence of major mismatches (e.g., cerebellum between the discrete localization of CRLR, RAMP1, and specific CGRP binding sites supporting the existence of CGRP receptor subtypes. Functional studies have also provided evidence in that regard (for a recent review: [4]. Accordingly, additional studies aiming at cloning additional CGRP receptors are certainly warranted. Similarly, recent evidence from various laboratories including ours suggests the existence of more than one class (CRLR and RAMP2 of adrenomedullin receptors at least in the rat brain. In contrast, most evidence suggests the existence of a single class of amylin receptors. In brief, it appears that multiple receptors or receptor complexes do exist for CGRP and related peptides but their composition is apparently unique among the GPCR super-family and additional data are needed to fully establish the molecular organization of each subtype. Supported by CIHR of Canada.

  16. Genetic diversity of bitter taste receptor gene family in Sichuan

    Indian Academy of Sciences (India)

    Genetic diversity of bitter taste receptor gene family in Sichuan domestic and Tibetan chicken populations. YUAN SU DIYAN LI UMA GAUR YAN WANG NAN WU BINLONG CHEN HONGXIAN XU HUADONG YIN YAODONG HU QING ZHU. RESEARCH ARTICLE Volume 95 Issue 3 September 2016 pp 675-681 ...

  17. Signal transduction through the IL-4 and insulin receptor families.

    Science.gov (United States)

    Wang, L M; Keegan, A; Frankel, M; Paul, W E; Pierce, J H

    1995-07-01

    Activation of tyrosine kinase-containing receptors and intracellular tyrosine kinases by ligand stimulation is known to be crucial for mediating initial and subsequent events involved in mitogenic signal transduction. Receptors for insulin and insulin-like growth factor 1 (IGF-1) contain cytoplasmic tyrosine kinase domains that undergo autophosphorylation upon ligand stimulation. Activation of these receptors also leads to pronounced and rapid tyrosine phosphorylation of insulin receptor substrate 1 (IRS-1) in cells of connective tissue origin. A related substrate, designated 4PS, is similarly phosphorylated by insulin and IGF-1 stimulation in many hematopoietic cell types. IRS-1 and 4PS possess a number of tyrosine phosphorylation sites that are within motifs that bind specific SH2-containing molecules known to be involved in mitogenic signaling such as PI-3 kinase, SHPTP-2 (Syp) and Grb-2. Thus, they appear to act as docking substrates for a variety of signaling molecules. The majority of hematopoietic cytokines bind to receptors that do not possess intrinsic kinase activity, and these receptors have been collectively termed as members of the hematopoietin receptor superfamily. Despite their lack of tyrosine kinase domains, stimulation of these receptors has been demonstrated to activate intracellular kinases leading to tyrosine phosphorylation of multiple substrates. Recent evidence has demonstrated that activation of different members of the Janus family of tyrosine kinases is involved in mediating tyrosine phosphorylation events by specific cytokines. Stimulation of the interleukin 4 (IL-4) receptor, a member of the hematopoietin receptor superfamily, is thought to result in activation of Jak1, Jak3, and/or Fes tyrosine kinases.(ABSTRACT TRUNCATED AT 250 WORDS)

  18. A Family of Invariant Stress Surfaces

    DEFF Research Database (Denmark)

    Krenk, S.

    A family of invariant stress surfaces with a cubic dependence on the deviatoric stress components is expressed as a linear combination of the second and third deviatori stress invariants. A simple geometric derivation demonstrates the convexity of the contours in the deviatoric plane. An explicit...... representation of the deviatoric contours in terms of a size and a shape parameter is given. The shape parameter effects a continuous transition from a triangle to a circle in the deviatoric plane. An explicit format in terms of the triaxial compresson and tension generators is derived, and the plane stress...

  19. MTA family of coregulators in nuclear receptor biology and pathology

    Science.gov (United States)

    Manavathi, Bramanandam; Singh, Kamini; Kumar, Rakesh

    2007-01-01

    Nuclear receptors (NRs) rely on coregulators (coactivators and corepressors) to modulate the transcription of target genes. By interacting with nucleosome remodeling complexes, NR coactivators potentiate transcription, whereas corepressors inhibit transcription of the target genes. Metastasis-associated proteins (MTA) represent an emerging family of novel NR coregulators. In general, MTA family members form independent nucleosome remodeling and deacetylation (NuRD) complexes and repress the transcription of different genes by recruiting histone deacetylases onto their target genes. However, MTA1 also acts as a coactivator in a promoter-context dependent manner. Recent findings that repression of estrogen receptor transactivation functions by MTA1, MTA1s, and MTA2 and regulation of MTA3 by estrogen signaling have indicated the significance of these proteins in NR signaling. Here, we highlight the action of MTA proteins on NR signaling and their roles in pathophysiological conditions. PMID:18174918

  20. Evolution of the vertebrate insulin receptor substrate (Irs) gene family.

    Science.gov (United States)

    Al-Salam, Ahmad; Irwin, David M

    2017-06-23

    Insulin receptor substrate (Irs) proteins are essential for insulin signaling as they allow downstream effectors to dock with, and be activated by, the insulin receptor. A family of four Irs proteins have been identified in mice, however the gene for one of these, IRS3, has been pseudogenized in humans. While it is known that the Irs gene family originated in vertebrates, it is not known when it originated and which members are most closely related to each other. A better understanding of the evolution of Irs genes and proteins should provide insight into the regulation of metabolism by insulin. Multiple genes for Irs proteins were identified in a wide variety of vertebrate species. Phylogenetic and genomic neighborhood analyses indicate that this gene family originated very early in vertebrae evolution. Most Irs genes were duplicated and retained in fish after the fish-specific genome duplication. Irs genes have been lost of various lineages, including Irs3 in primates and birds and Irs1 in most fish. Irs3 and Irs4 experienced an episode of more rapid protein sequence evolution on the ancestral mammalian lineage. Comparisons of the conservation of the proteins sequences among Irs paralogs show that domains involved in binding to the plasma membrane and insulin receptors are most strongly conserved, while divergence has occurred in sequences involved in interacting with downstream effector proteins. The Irs gene family originated very early in vertebrate evolution, likely through genome duplications, and in parallel with duplications of other components of the insulin signaling pathway, including insulin and the insulin receptor. While the N-terminal sequences of these proteins are conserved among the paralogs, changes in the C-terminal sequences likely allowed changes in biological function.

  1. Trace amine-associated receptor 1-Family archetype or iconoclast?

    Science.gov (United States)

    Grandy, David K

    2007-12-01

    Interest has recently been rekindled in receptors that are activated by low molecular weight, noncatecholic, biogenic amines that are typically found as trace constituents of various vertebrate and invertebrate tissues and fluids. The timing of this resurgent focus on receptors activated by the "trace amines" (TA) beta-phenylethylamine (PEA), tyramine (TYR), octopamine (OCT), synephrine (SYN), and tryptamine (TRYP) is the direct result of 2 publications that appeared in 2001 describing the cloning of a novel G protein-coupled receptor (GPCR) referred to by their discoverers Borowsky et al. as TA1 and Bunzow et al. as TA receptor 1 (TAR1). When heterologously expressed in Xenopus laevis oocytes and various eukaryotic cell lines, recombinant rodent and human TAR dose-dependently couple to the stimulation of adenosine 3',5'-monophosphate (cAMP) production. Structure-activity profiling based on this functional response has revealed that in addition to the TA, other biologically active compounds containing a 2-carbon aliphatic side chain linking an amino group to at least 1 benzene ring are potent and efficacious TA receptor agonists with amphetamine (AMPH), methamphetamine, 3-iodothyronamine, thyronamine, and dopamine (DA) among the most notable. Almost 100 years after the search for TAR began, numerous TA1/TAR1-related sequences, now called TA-associated receptors (TAAR), have been identified in the genome of every species of vertebrate examined to date. Consequently, even though heterologously expressed TAAR1 fits the pharmacological criteria established for a bona fide TAR, a major challenge for those working in the field is to discern the in vivo pharmacology and physiology of each purported member of this extended family of GPCR. Only then will it be possible to establish whether TAAR1 is the family archetype or an iconoclast.

  2. The repertoire of olfactory C family G protein-coupled receptors in zebrafish: candidate chemosensory receptors for amino acids

    Directory of Open Access Journals (Sweden)

    Ngai John

    2006-12-01

    Full Text Available Abstract Background Vertebrate odorant receptors comprise at least three types of G protein-coupled receptors (GPCRs: the OR, V1R, and V2R/V2R-like receptors, the latter group belonging to the C family of GPCRs. These receptor families are thought to receive chemosensory information from a wide spectrum of odorant and pheromonal cues that influence critical animal behaviors such as feeding, reproduction and other social interactions. Results Using genome database mining and other informatics approaches, we identified and characterized the repertoire of 54 intact "V2R-like" olfactory C family GPCRs in the zebrafish. Phylogenetic analysis – which also included a set of 34 C family GPCRs from fugu – places the fish olfactory receptors in three major groups, which are related to but clearly distinct from other C family GPCRs, including the calcium sensing receptor, metabotropic glutamate receptors, GABA-B receptor, T1R taste receptors, and the major group of V2R vomeronasal receptor families. Interestingly, an analysis of sequence conservation and selective pressure in the zebrafish receptors revealed the retention of a conserved sequence motif previously shown to be required for ligand binding in other amino acid receptors. Conclusion Based on our findings, we propose that the repertoire of zebrafish olfactory C family GPCRs has evolved to allow the detection and discrimination of a spectrum of amino acid and/or amino acid-based compounds, which are potent olfactory cues in fish. Furthermore, as the major groups of fish receptors and mammalian V2R receptors appear to have diverged significantly from a common ancestral gene(s, these receptors likely mediate chemosensation of different classes of chemical structures by their respective organisms.

  3. Inhibitory effects of two G protein-coupled receptor kinases on the cell surface expression and signaling of the human adrenomedullin receptor

    Energy Technology Data Exchange (ETDEWEB)

    Kuwasako, Kenji, E-mail: kuwasako@med.miyazaki-u.ac.jp [Frontier Science Research Center, University of Miyazaki, Miyazaki, 889-1692 (Japan); Sekiguchi, Toshio [Noto Marine Laboratory, Division of Marine Environmental Studies, Institute of Nature and Environmental Technology, Kanazawa University, Ishikawa, 927-0553 (Japan); Nagata, Sayaka [Division of Circulatory and Body Fluid Regulation, Faculty of Medicine, University of Miyazaki, Miyazaki, 889-1692 (Japan); Jiang, Danfeng; Hayashi, Hidetaka [Frontier Science Research Center, University of Miyazaki, Miyazaki, 889-1692 (Japan); Murakami, Manabu [Department of Pharmacology, Hirosaki University, Graduate School of Medicine, Hirosaki, 036-8562 (Japan); Hattori, Yuichi [Department of Molecular and Medical Pharmacology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, 930-0194 (Japan); Kitamura, Kazuo [Division of Circulatory and Body Fluid Regulation, Faculty of Medicine, University of Miyazaki, Miyazaki, 889-1692 (Japan); Kato, Johji [Frontier Science Research Center, University of Miyazaki, Miyazaki, 889-1692 (Japan)

    2016-02-19

    Receptor activity-modifying protein 2 (RAMP2) enables the calcitonin receptor-like receptor (CLR, a family B GPCR) to form the type 1 adrenomedullin receptor (AM{sub 1} receptor). Here, we investigated the effects of the five non-visual GPCR kinases (GRKs 2 through 6) on the cell surface expression of the human (h)AM{sub 1} receptor by cotransfecting each of these GRKs into HEK-293 cells that stably expressed hRAMP2. Flow cytometric analysis revealed that when coexpressed with GRK4 or GRK5, the cell surface expression of the AM{sub 1} receptor was markedly decreased prior to stimulation with AM, thereby attenuating both the specific [{sup 125}I]AM binding and AM-induced cAMP production. These inhibitory effects of both GRKs were abolished by the replacement of the cytoplasmic C-terminal tail (C-tail) of CLR with that of the calcitonin receptor (a family B GPCR) or β{sub 2}-adrenergic receptor (a family A GPCR). Among the sequentially truncated CLR C-tail mutants, those lacking the five residues 449–453 (Ser-Phe-Ser-Asn-Ser) abolished the inhibition of the cell surface expression of CLR via the overexpression of GRK4 or GRK5. Thus, we provided new insight into the function of GRKs in agonist-unstimulated GPCR trafficking using a recombinant AM{sub 1} receptor and further determined the region of the CLR C-tail responsible for this GRK function. - Highlights: • We discovered a novel function of GRKs in GPCR trafficking using human CLR/RAMP2. • GRKs 4 and 5 markedly inhibited the cell surface expression of human CLR/RAMP2. • Both GRKs exhibited highly significant receptor signaling inhibition. • Five residues of the C-terminal tail of CLR govern this function of GRKs.

  4. Inhibitory effects of two G protein-coupled receptor kinases on the cell surface expression and signaling of the human adrenomedullin receptor

    International Nuclear Information System (INIS)

    Kuwasako, Kenji; Sekiguchi, Toshio; Nagata, Sayaka; Jiang, Danfeng; Hayashi, Hidetaka; Murakami, Manabu; Hattori, Yuichi; Kitamura, Kazuo; Kato, Johji

    2016-01-01

    Receptor activity-modifying protein 2 (RAMP2) enables the calcitonin receptor-like receptor (CLR, a family B GPCR) to form the type 1 adrenomedullin receptor (AM_1 receptor). Here, we investigated the effects of the five non-visual GPCR kinases (GRKs 2 through 6) on the cell surface expression of the human (h)AM_1 receptor by cotransfecting each of these GRKs into HEK-293 cells that stably expressed hRAMP2. Flow cytometric analysis revealed that when coexpressed with GRK4 or GRK5, the cell surface expression of the AM_1 receptor was markedly decreased prior to stimulation with AM, thereby attenuating both the specific ["1"2"5I]AM binding and AM-induced cAMP production. These inhibitory effects of both GRKs were abolished by the replacement of the cytoplasmic C-terminal tail (C-tail) of CLR with that of the calcitonin receptor (a family B GPCR) or β_2-adrenergic receptor (a family A GPCR). Among the sequentially truncated CLR C-tail mutants, those lacking the five residues 449–453 (Ser-Phe-Ser-Asn-Ser) abolished the inhibition of the cell surface expression of CLR via the overexpression of GRK4 or GRK5. Thus, we provided new insight into the function of GRKs in agonist-unstimulated GPCR trafficking using a recombinant AM_1 receptor and further determined the region of the CLR C-tail responsible for this GRK function. - Highlights: • We discovered a novel function of GRKs in GPCR trafficking using human CLR/RAMP2. • GRKs 4 and 5 markedly inhibited the cell surface expression of human CLR/RAMP2. • Both GRKs exhibited highly significant receptor signaling inhibition. • Five residues of the C-terminal tail of CLR govern this function of GRKs.

  5. Inhibitors for Androgen Receptor Activation Surfaces

    Science.gov (United States)

    2007-09-01

    times and the electron-rich iodine groups of Triac representing particularly good markers. Control soaks with solvent ( DMSO ) reveal no similar...electron-rich iodine groups of Triac represent particu- larly good markers. Control soaks with solvent ( DMSO ) reveal no similar effects on coregulator...3-(dibutylamino)-1-(4-hexylphenyl)propan-1-one DMSO , dimethylsulfoxide DTT, dithiothreitol ER, estrogen receptor GST, glutathione S-transferase

  6. Nuclear functions and subcellular trafficking mechanisms of the epidermal growth factor receptor family

    Science.gov (United States)

    2012-01-01

    Accumulating evidence suggests that various diseases, including many types of cancer, result from alteration of subcellular protein localization and compartmentalization. Therefore, it is worthwhile to expand our knowledge in subcellular trafficking of proteins, such as epidermal growth factor receptor (EGFR) and ErbB-2 of the receptor tyrosine kinases, which are highly expressed and activated in human malignancies and frequently correlated with poor prognosis. The well-characterized trafficking of cell surface EGFR is routed, via endocytosis and endosomal sorting, to either the lysosomes for degradation or back to the plasma membrane for recycling. A novel nuclear mode of EGFR signaling pathway has been gradually deciphered in which EGFR is shuttled from the cell surface to the nucleus after endocytosis, and there, it acts as a transcriptional regulator, transmits signals, and is involved in multiple biological functions, including cell proliferation, tumor progression, DNA repair and replication, and chemo- and radio-resistance. Internalized EGFR can also be transported from the cell surface to several intracellular compartments, such as the Golgi apparatus, the endoplasmic reticulum, and the mitochondria, in addition to the nucleus. In this review, we will summarize the functions of nuclear EGFR family and the potential pathways by which EGFR is trafficked from the cell surface to a variety of cellular organelles. A better understanding of the molecular mechanism of EGFR trafficking will shed light on both the receptor biology and potential therapeutic targets of anti-EGFR therapies for clinical application. PMID:22520625

  7. Purification of family B G protein-coupled receptors using nanodiscs: Application to human glucagon-like peptide-1 receptor.

    Directory of Open Access Journals (Sweden)

    Yingying Cai

    Full Text Available Family B G protein-coupled receptors (GPCRs play vital roles in hormone-regulated homeostasis. They are drug targets for metabolic diseases, including type 2 diabetes and osteoporosis. Despite their importance, the signaling mechanisms for family B GPCRs at the molecular level remain largely unexplored due to the challenges in purification of functional receptors in sufficient amount for biophysical characterization. Here, we purified the family B GPCR human glucagon-like peptide-1 (GLP-1 receptor (GLP1R, whose agonists, e.g. exendin-4, are used for the treatment of type 2 diabetes mellitus. The receptor was expressed in HEK293S GnTl- cells using our recently developed protocol. The protocol incorporates the receptor into the native-like lipid environment of reconstituted high density lipoprotein (rHDL particles, also known as nanodiscs, immediately after the membrane solubilization step followed by chromatographic purification, minimizing detergent contact with the target receptor to reduce denaturation and prolonging stabilization of receptor in lipid bilayers without extra steps of reconstitution. This method yielded purified GLP1R in nanodiscs that could bind to GLP-1 and exendin-4 and activate Gs protein. This nanodisc purification method can potentially be a general strategy to routinely obtain purified family B GPCRs in the 10s of microgram amounts useful for spectroscopic analysis of receptor functions and activation mechanisms.

  8. Purification of family B G protein-coupled receptors using nanodiscs: Application to human glucagon-like peptide-1 receptor.

    Science.gov (United States)

    Cai, Yingying; Liu, Yuting; Culhane, Kelly J; DeVree, Brian T; Yang, Yang; Sunahara, Roger K; Yan, Elsa C Y

    2017-01-01

    Family B G protein-coupled receptors (GPCRs) play vital roles in hormone-regulated homeostasis. They are drug targets for metabolic diseases, including type 2 diabetes and osteoporosis. Despite their importance, the signaling mechanisms for family B GPCRs at the molecular level remain largely unexplored due to the challenges in purification of functional receptors in sufficient amount for biophysical characterization. Here, we purified the family B GPCR human glucagon-like peptide-1 (GLP-1) receptor (GLP1R), whose agonists, e.g. exendin-4, are used for the treatment of type 2 diabetes mellitus. The receptor was expressed in HEK293S GnTl- cells using our recently developed protocol. The protocol incorporates the receptor into the native-like lipid environment of reconstituted high density lipoprotein (rHDL) particles, also known as nanodiscs, immediately after the membrane solubilization step followed by chromatographic purification, minimizing detergent contact with the target receptor to reduce denaturation and prolonging stabilization of receptor in lipid bilayers without extra steps of reconstitution. This method yielded purified GLP1R in nanodiscs that could bind to GLP-1 and exendin-4 and activate Gs protein. This nanodisc purification method can potentially be a general strategy to routinely obtain purified family B GPCRs in the 10s of microgram amounts useful for spectroscopic analysis of receptor functions and activation mechanisms.

  9. One-parameter family of solitons from minimal surfaces

    Indian Academy of Sciences (India)

    solitons arising from a one parameter family of minimal surfaces. The process enables us to generate a new solution of the B–I equation from a given complex solution of a special type (which are abundant). We illustrate this with many examples. We find that the action or the energy of this family of solitons remains invariant ...

  10. Theory and simulations of adhesion receptor dimerization on membrane surfaces.

    Science.gov (United States)

    Wu, Yinghao; Honig, Barry; Ben-Shaul, Avinoam

    2013-03-19

    The equilibrium constants of trans and cis dimerization of membrane bound (2D) and freely moving (3D) adhesion receptors are expressed and compared using elementary statistical-thermodynamics. Both processes are mediated by the binding of extracellular subdomains whose range of motion in the 2D environment is reduced upon dimerization, defining a thin reaction shell where dimer formation and dissociation take place. We show that the ratio between the 2D and 3D equilibrium constants can be expressed as a product of individual factors describing, respectively, the spatial ranges of motions of the adhesive domains, and their rotational freedom within the reaction shell. The results predicted by the theory are compared to those obtained from a novel, to our knowledge, dynamical simulations methodology, whereby pairs of receptors perform realistic translational, internal, and rotational motions in 2D and 3D. We use cadherins as our model system. The theory and simulations explain how the strength of cis and trans interactions of adhesive receptors are affected both by their presence in the constrained intermembrane space and by the 2D environment of membrane surfaces. Our work provides fundamental insights as to the mechanism of lateral clustering of adhesion receptors after cell-cell contact and, more generally, to the formation of lateral microclusters of proteins on cell surfaces. Copyright © 2013 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  11. Reaction and Aggregation Dynamics of Cell Surface Receptors

    Science.gov (United States)

    Wang, Michelle Dong

    This dissertation is composed of both theoretical and experimental studies of cell surface receptor reaction and aggregation. Project I studies the reaction rate enhancement due to surface diffusion of a bulk dissolved ligand with its membrane embedded target, using numerical calculations. The results show that the reaction rate enhancement is determined by ligand surface adsorption and desorption kinetic rates, surface and bulk diffusion coefficients, and geometry. In particular, we demonstrate that the ligand surface adsorption and desorption kinetic rates, rather than their ratio (the equilibrium constant), are important in rate enhancement. The second and third projects are studies of acetylcholine receptor clusters on cultured rat myotubes using fluorescence techniques after labeling the receptors with tetramethylrhodamine -alpha-bungarotoxin. The second project studies when and where the clusters form by making time-lapse movies. The movies are made from overlay of the pseudocolored total internal reflection fluorescence (TIRF) images of the cluster, and the schlieren images of the cell cultures. These movies are the first movies made using TIRF, and they clearly show the cluster formation from the myoblast fusion, the first appearance of clusters, and the eventual disappearance of clusters. The third project studies the fine structural features of individual clusters observed under TIRF. The features were characterized with six parameters by developing a novel fluorescence technique: spatial fluorescence autocorrelation. These parameters were then used to study the feature variations with age, and with treatments of drugs (oligomycin and carbachol). The results show little variation with age. However, drug treatment induced significant changes in some parameters. These changes were different for oligomycin and carbachol, which indicates that the two drugs may eliminate clusters through different mechanisms.

  12. G-Protein Coupled Receptors: Surface Display and Biosensor Technology

    Science.gov (United States)

    McMurchie, Edward; Leifert, Wayne

    Signal transduction by G-protein coupled receptors (GPCRs) underpins a multitude of physiological processes. Ligand recognition by the receptor leads to the activation of a generic molecular switch involving heterotrimeric G-proteins and guanine nucleotides. With growing interest and commercial investment in GPCRs in areas such as drug targets, orphan receptors, high-throughput screening of drugs and biosensors, greater attention will focus on assay development to allow for miniaturization, ultrahigh-throughput and, eventually, microarray/biochip assay formats that will require nanotechnology-based approaches. Stable, robust, cell-free signaling assemblies comprising receptor and appropriate molecular switching components will form the basis of future GPCR/G-protein platforms, which should be able to be adapted to such applications as microarrays and biosensors. This chapter focuses on cell-free GPCR assay nanotechnologies and describes some molecular biological approaches for the construction of more sophisticated, surface-immobilized, homogeneous, functional GPCR sensors. The latter points should greatly extend the range of applications to which technologies based on GPCRs could be applied.

  13. 5D-QSAR for spirocyclic sigma1 receptor ligands by Quasar receptor surface modeling.

    Science.gov (United States)

    Oberdorf, Christoph; Schmidt, Thomas J; Wünsch, Bernhard

    2010-07-01

    Based on a contiguous and structurally as well as biologically diverse set of 87 sigma(1) ligands, a 5D-QSAR study was conducted in which a quasi-atomistic receptor surface modeling approach (program package Quasar) was applied. The superposition of the ligands was performed with the tool Pharmacophore Elucidation (MOE-package), which takes all conformations of the ligands into account. This procedure led to four pharmacophoric structural elements with aromatic, hydrophobic, cationic and H-bond acceptor properties. Using the aligned structures a 3D-model of the ligand binding site of the sigma(1) receptor was obtained, whose general features are in good agreement with previous assumptions on the receptor structure, but revealed some novel insights since it represents the receptor surface in more detail. Thus, e.g., our model indicates the presence of an H-bond acceptor moiety in the binding site as counterpart to the ligands' cationic ammonium center, rather than a negatively charged carboxylate group. The presented QSAR model is statistically valid and represents the biological data of all tested compounds, including a test set of 21 ligands not used in the modeling process, with very good to excellent accuracy [q(2) (training set, n=66; leave 1/3 out) = 0.84, p(2) (test set, n=21)=0.64]. Moreover, the binding affinities of 13 further spirocyclic sigma(1) ligands were predicted with reasonable accuracy (mean deviation in pK(i) approximately 0.8). Thus, in addition to novel insights into the requirements for binding of spirocyclic piperidines to the sigma(1) receptor, the presented model can be used successfully in the rational design of new sigma(1) ligands. Copyright (c) 2010 Elsevier Masson SAS. All rights reserved.

  14. Tissue-type plasminogen activator-binding RNA aptamers inhibiting low-density lipoprotein receptor family-mediated internalisation.

    Science.gov (United States)

    Bjerregaard, Nils; Bøtkjær, Kenneth A; Helsen, Nicky; Andreasen, Peter A; Dupont, Daniel M

    2015-07-01

    Recombinant tissue-type plasminogen activator (tPA, trade name Alteplase), currently the only drug approved by the US Food and Drug Administration and the European Medicines Agency for the treatment of cerebral ischaemic stroke, has been implicated in a number of adverse effects reportedly mediated by interactions with the low-density lipoprotein (LDL) family receptors, including neuronal cell death and an increased risk of cerebral haemorrhage. The tissue-type plasminogen activator is the principal initiator of thrombolysis in human physiology, an effect that is mediated directly via localised activation of the plasmin zymogen plasminogen at the surface of fibrin clots in the vascular lumen. Here, we sought to identify a ligand to tPA capable of inhibiting the relevant LDL family receptors without interfering with the fibrinolytic activity of tPA. Systematic evolution of ligands by exponential enrichment (SELEX) was employed to isolate tPA-binding RNA aptamers, which were characterised in biochemical assays of tPA association to low density lipoprotein receptor-related protein-1 (LRP-1, an LDL receptor family member); tPA-mediated in vitro and ex vivo clot lysis; and tPA-mediated plasminogen activation in the absence and presence of a stimulating soluble fibrin fragment. Two aptamers, K18 and K32, had minimal effects on clot lysis, but were able to efficiently inhibit tPA-LRP-1 association and LDL receptor family-mediated endocytosis in human vascular endothelial cells and astrocytes. These observations suggest that coadministration alongside tPA may be a viable strategy to improve the safety of thrombolytic treatment of cerebral ischaemic stroke by restricting tPA activity to the vascular lumen.

  15. Toward a better understanding of the interaction between TGF-β family members and their ALK receptors

    KAUST Repository

    Romano, Valentina; Raimondo, Domenico; Calvanese, Luisa; D’ Auria, Gabriella; Tramontano, Anna; Falcigno, Lucia

    2012-01-01

    Transforming growth factor-beta (TGF-β) proteins are a family of structurally related extracellular proteins that trigger their signaling functions through interaction with the extracellular domains of their cognate serine/threonine kinase receptors. The specificity of TGF-β/receptor binding is complex and gives rise to multiple functional roles. Additionally, it is not completely understood at the atomic level. Here, we use the most reliable computational methods currently available to study systems involving activin-like kinase (ALK) receptors ALK4 and ALK7 and their multiple TGF-β ligands. We built models for all these proteins and their complexes for which experimental structures are not available. By analyzing the surfaces of interaction in six different TGF-β/ALK complexes we could infer which are the structural distinctive features of the ligand-receptor binding mode. Furthermore, this study allowed us to rationalize why binding of the growth factors GDF3 and Nodal to the ALK4 receptor requires the Cripto co-factor, whilst binding to the ALK7 receptor does not. © Springer-Verlag 2012.

  16. Toward a better understanding of the interaction between TGF-β family members and their ALK receptors

    KAUST Repository

    Romano, Valentina

    2012-02-22

    Transforming growth factor-beta (TGF-β) proteins are a family of structurally related extracellular proteins that trigger their signaling functions through interaction with the extracellular domains of their cognate serine/threonine kinase receptors. The specificity of TGF-β/receptor binding is complex and gives rise to multiple functional roles. Additionally, it is not completely understood at the atomic level. Here, we use the most reliable computational methods currently available to study systems involving activin-like kinase (ALK) receptors ALK4 and ALK7 and their multiple TGF-β ligands. We built models for all these proteins and their complexes for which experimental structures are not available. By analyzing the surfaces of interaction in six different TGF-β/ALK complexes we could infer which are the structural distinctive features of the ligand-receptor binding mode. Furthermore, this study allowed us to rationalize why binding of the growth factors GDF3 and Nodal to the ALK4 receptor requires the Cripto co-factor, whilst binding to the ALK7 receptor does not. © Springer-Verlag 2012.

  17. Theoretical and Computational Studies of Peptides and Receptors of the Insulin Family

    Directory of Open Access Journals (Sweden)

    Harish Vashisth

    2015-02-01

    Full Text Available Synergistic interactions among peptides and receptors of the insulin family are required for glucose homeostasis, normal cellular growth and development, proliferation, differentiation and other metabolic processes. The peptides of the insulin family are disulfide-linked single or dual-chain proteins, while receptors are ligand-activated transmembrane glycoproteins of the receptor tyrosine kinase (RTK superfamily. Binding of ligands to the extracellular domains of receptors is known to initiate signaling via activation of intracellular kinase domains. While the structure of insulin has been known since 1969, recent decades have seen remarkable progress on the structural biology of apo and liganded receptor fragments. Here, we review how this useful structural information (on ligands and receptors has enabled large-scale atomically-resolved simulations to elucidate the conformational dynamics of these biomolecules. Particularly, applications of molecular dynamics (MD and Monte Carlo (MC simulation methods are discussed in various contexts, including studies of isolated ligands, apo-receptors, ligand/receptor complexes and intracellular kinase domains. The review concludes with a brief overview and future outlook for modeling and computational studies in this family of proteins.

  18. Molecular evolution of a chordate specific family of G protein-coupled receptors

    Directory of Open Access Journals (Sweden)

    Leese Florian

    2011-08-01

    Full Text Available Abstract Background Chordate evolution is a history of innovations that is marked by physical and behavioral specializations, which led to the development of a variety of forms from a single ancestral group. Among other important characteristics, vertebrates obtained a well developed brain, anterior sensory structures, a closed circulatory system and gills or lungs as blood oxygenation systems. The duplication of pre-existing genes had profound evolutionary implications for the developmental complexity in vertebrates, since mutations modifying the function of a duplicated protein can lead to novel functions, improving the evolutionary success. Results We analyzed here the evolution of the GPRC5 family of G protein-coupled receptors by comprehensive similarity searches and found that the receptors are only present in chordates and that the size of the receptor family expanded, likely due to genome duplication events in the early history of vertebrate evolution. We propose that a single GPRC5 receptor coding gene originated in a stem chordate ancestor and gave rise by duplication events to a gene family comprising three receptor types (GPRC5A-C in vertebrates, and a fourth homologue present only in mammals (GPRC5D. Additional duplications of GPRC5B and GPRC5C sequences occurred in teleost fishes. The finding that the expression patterns of the receptors are evolutionarily conserved indicates an important biological function of these receptors. Moreover, we found that expression of GPRC5B is regulated by vitamin A in vivo, confirming previous findings that linked receptor expression to retinoic acid levels in tumor cell lines and strengthening the link between the receptor expression and the development of a complex nervous system in chordates, known to be dependent on retinoic acid signaling. Conclusions GPRC5 receptors, a class of G protein-coupled receptors with unique sequence characteristics, may represent a molecular novelty that helped non

  19. Origins of the many NPY-family receptors in mammals

    DEFF Research Database (Denmark)

    Larhammar, D; Wraith, A; Berglund, M M

    2001-01-01

    The NPY system has a multitude of effects and is particularly well known for its role in appetite regulation. We have found that the five presently known receptors in mammals arose very early in vertebrate evolution before the appearance of jawed vertebrates 400 million years ago. The genes Y(1), Y....... These observations pertain to the discussion whether ligands or receptors tend to appear first in evolution. The roles of Y(1) and Y(5) in feeding may differ between species demonstrating the importance of performing functional studies in additional mammals to mouse and rat....

  20. Genetic diversity of bitter taste receptor gene family in Sichuan ...

    Indian Academy of Sciences (India)

    Previous research had revealed that chicken has only three bitter taste receptor genes (Tas2r1, ... Journal of Genetics, DOI 10.1007/s12041-016-0684-4, Vol. ..... between red-winged blackbirds and European starlings. ... Academic Press,.

  1. Regulated internalization of NMDA receptors drives PKD1-mediated suppression of the activity of residual cell-surface NMDA receptors.

    Science.gov (United States)

    Fang, Xiao-Qian; Qiao, Haifa; Groveman, Bradley R; Feng, Shuang; Pflueger, Melissa; Xin, Wen-Kuan; Ali, Mohammad K; Lin, Shuang-Xiu; Xu, Jindong; Duclot, Florian; Kabbaj, Mohamed; Wang, Wei; Ding, Xin-Sheng; Santiago-Sim, Teresa; Jiang, Xing-Hong; Salter, Michael W; Yu, Xian-Min

    2015-11-19

    Constitutive and regulated internalization of cell surface proteins has been extensively investigated. The regulated internalization has been characterized as a principal mechanism for removing cell-surface receptors from the plasma membrane, and signaling to downstream targets of receptors. However, so far it is still not known whether the functional properties of remaining (non-internalized) receptor/channels may be regulated by internalization of the same class of receptor/channels. The N-methyl-D-aspartate receptor (NMDAR) is a principal subtype of glutamate-gated ion channel and plays key roles in neuronal plasticity and memory functions. NMDARs are well-known to undergo two types of regulated internalization - homologous and heterologous, which can be induced by high NMDA/glycine and DHPG, respectively. In the present work, we investigated effects of regulated NMDAR internalization on the activity of residual cell-surface NMDARs and neuronal functions. In electrophysiological experiments we discovered that the regulated internalization of NMDARs not only reduced the number of cell surface NMDARs but also caused an inhibition of the activity of remaining (non-internalized) surface NMDARs. In biochemical experiments we identified that this functional inhibition of remaining surface NMDARs was mediated by increased serine phosphorylation of surface NMDARs, resulting from the activation of protein kinase D1 (PKD1). Knockdown of PKD1 did not affect NMDAR internalization but prevented the phosphorylation and inhibition of remaining surface NMDARs and NMDAR-mediated synaptic functions. These data demonstrate a novel concept that regulated internalization of cell surface NMDARs not only reduces the number of NMDARs on the cell surface but also causes an inhibition of the activity of remaining surface NMDARs through intracellular signaling pathway(s). Furthermore, modulating the activity of remaining surface receptors may be an effective approach for treating receptor

  2. Multiple kisspeptin receptors in early Osteichthyans provide new insights into the evolution of this receptor family

    DEFF Research Database (Denmark)

    Pasquier, J.; Lafont, A._G.; Jeng, S.-R.

    2012-01-01

    Deorphanization of GPR54 receptor a decade ago led to the characterization of the kisspeptin receptor (Kissr) in mammals and the discovery of its major role in the brain control of reproduction. While a single gene encodes for Kissr in eutherian mammals including human, other vertebrates present ...

  3. Syndecans as cell surface receptors: Unique structure equates with functional diversity

    DEFF Research Database (Denmark)

    Choi, Youngsil; Chung, Heesung; Jung, Heyjung

    2011-01-01

    An increasing number of functions for syndecan cell surface heparan sulfate proteoglycans have been proposed over the last decade. Moreover, aberrant syndecan regulation has been found to play a critical role in multiple pathologies, including cancers, as well as wound healing and inflammation....... As receptors, they have much in common with other molecules on the cell surface. Syndecans are type I transmembrane molecules with cytoplasmic domains that link to the actin cytoskeleton and can interact with a number of regulators. However, they are also highly complex by virtue of their external...... glycosaminoglycan chains, especially heparan sulfate. This heterodisperse polysaccharide has the potential to interact with many ligands from diverse protein families. Here, we relate the structural features of syndecans to some of their known functions....

  4. ATAR, a novel tumor necrosis factor receptor family member, signals through TRAF2 and TRAF5.

    Science.gov (United States)

    Hsu, H; Solovyev, I; Colombero, A; Elliott, R; Kelley, M; Boyle, W J

    1997-05-23

    Members of tumor necrosis factor receptor (TNFR) family signal largely through interactions with death domain proteins and TRAF proteins. Here we report the identification of a novel TNFR family member ATAR. Human and mouse ATAR contain 283 and 276 amino acids, respectively, making them the shortest known members of the TNFR superfamily. The receptor is expressed mainly in spleen, thymus, bone marrow, lung, and small intestine. The intracellular domains of human and mouse ATAR share only 25% identity, yet both interact with TRAF5 and TRAF2. This TRAF interaction domain resides at the C-terminal 20 amino acids. Like most other TRAF-interacting receptors, overexpression of ATAR activates the transcription factor NF-kappaB. Co-expression of ATAR with TRAF5, but not TRAF2, results in synergistic activation of NF-kappaB, suggesting potentially different roles for TRAF2 and TRAF5 in post-receptor signaling.

  5. THESEUS 1, FERONIA and relatives: a family of cell wall-sensing receptor kinases?

    Science.gov (United States)

    Cheung, Alice Y; Wu, Hen-Ming

    2011-12-01

    The plant cell wall provides form and integrity to the cell as well as a dynamic interface between a cell and its environment. Therefore mechanisms capable of policing changes in the cell wall, signaling cellular responses including those that would feedback regulate cell wall properties are expected to play important roles in facilitating growth and ensuring survival. Discoveries in the last few years that the Arabidopsis THESEUS 1 receptor-like kinase (RLK) may function as a sensor for cell wall defects to regulate growth and that its relatives FERONIA and ANXURs regulate pollen tube integrity imply strongly that they play key roles in cell wall-related processes. Furthermore, FERONIA acts as a cell surface regulator for RAC/ROP GTPases and activates production of reactive oxygen species which are, respectively, important molecular switches and mediators for diverse processes. These findings position the THESEUS 1/FERONIA family RLKs as surface regulators and potential cell wall sensors capable of broadly and profoundly impacting cellular pathways in response to diverse signals. Copyright © 2011 Elsevier Ltd. All rights reserved.

  6. Human Diversity in a Cell Surface Receptor that Inhibits Autophagy.

    Science.gov (United States)

    Chaudhary, Anu; Leite, Mara; Kulasekara, Bridget R; Altura, Melissa A; Ogahara, Cassandra; Weiss, Eli; Fu, Wenqing; Blanc, Marie-Pierre; O'Keeffe, Michael; Terhorst, Cox; Akey, Joshua M; Miller, Samuel I

    2016-07-25

    Mutations in genes encoding autophagy proteins have been associated with human autoimmune diseases, suggesting that diversity in autophagy responses could be associated with disease susceptibility or severity. A cellular genome-wide association study (GWAS) screen was performed to explore normal human diversity in responses to rapamycin, a microbial product that induces autophagy. Cells from several human populations demonstrated variability in expression of a cell surface receptor, CD244 (SlamF4, 2B4), that correlated with changes in rapamycin-induced autophagy. High expression of CD244 and receptor activation with its endogenous ligand CD48 inhibited starvation- and rapamycin-induced autophagy by promoting association of CD244 with the autophagy complex proteins Vps34 and Beclin-1. The association of CD244 with this complex reduced Vps34 lipid kinase activity. Lack of CD244 is associated with auto-antibody production in mice, and lower expression of human CD244 has previously been implicated in severity of human rheumatoid arthritis and systemic lupus erythematosus, indicating that increased autophagy as a result of low levels of CD244 may alter disease outcomes. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. The under-appreciated promiscuity of the epidermal growth factor receptor family.

    Directory of Open Access Journals (Sweden)

    Sean P Kennedy

    2016-08-01

    Full Text Available Each member of the epidermal growth factor receptor (EGFR family plays a key role in normal development, homeostasis and a variety of pathophysiological conditions, most notably in cancer. According to the prevailing dogma, these four receptor tyrosine kinases (RTKs; EGFR, ERBB2, ERBB3 and ERBB4 function exclusively through the formation of homodimers and heterodimers within the EGFR family. These combinatorial receptor interactions are known to generate increased interactome diversity and therefore influence signalling output, subcellular localization and function of the heterodimer. This molecular plasticity is also thought to play a role in the development of resistance towards targeted cancer therapies aimed at these known oncogenes. Interestingly, many studies now challenge this dogma and suggest that the potential for EGFR family receptors to interact with more distantly related RTKs is much greater than currently appreciated. Here we discuss how the promiscuity of these oncogenic receptors may lead to the formation of many unexpected receptor pairings and the significant implications for the efficiency of many targeted cancer therapies.

  8. Familial Risk for Major Depression is Associated with Lower Striatal 5-HT4 Receptor Binding

    DEFF Research Database (Denmark)

    Madsen, Karine; Torstensen, Eva; Holst, Klaus K

    2014-01-01

    was to determine whether familial risk for MDD is associated with cerebral 5-HT4 receptor binding as measured with [(11)C]SB207145 brain PET imaging. Familial risk is the most potent risk factor of MDD. METHODS: We studied 57 healthy individuals (mean age 36 yrs, range 20-86; 21 women), 26 of which had first......-degree relatives treated for MDD. RESULTS: We found that having a family history of MDD was associated with lower striatal 5-HT4 receptor binding (p = 0.038; in individuals below 40 years, p = 0.013). Further, we found evidence for a "risk-dose effect" on 5-HT4 receptor binding, since the number of first......-degree relatives with a history of MDD binding correlated negatively with 5-HT4 receptor binding in both the striatum (p = 0.001) and limbic regions (p = 0.012). CONCLUSIONS: Our data suggest that the 5-HT4 receptor is involved in the neurobiological mechanism underlying familial risk for depression...

  9. Ligand Activation of TAM Family Receptors-Implications for Tumor Biology and Therapeutic Response.

    Science.gov (United States)

    Davra, Viralkumar; Kimani, Stanley G; Calianese, David; Birge, Raymond B

    2016-11-29

    The TAM family of receptors (i.e., Tyro3, Axl, and Mertk), and their ligands Growth arrest specific factor 6 (Gas6) and Protein S (Pros1) contribute to several oncogenic processes, such as cell survival, invasion, migration, chemo-resistance, and metastasis, whereby expression often correlates with poor clinical outcomes. In recent years, there has been great interest in the study of TAM receptors in cancer, stemming both from their roles as oncogenic signaling receptors, as well as their roles in tumor immunology. As a result, several classes of TAM inhibitors that include small molecule tyrosine kinase inhibitors, monoclonal antibodies, decoy receptors, as well as novel strategies to target TAM ligands are being developed. This paper will review the biology of TAM receptors and their ligands with a focus on cancer, as well as evidence-based data for the continued pursuit of TAM/Gas6 inhibitors in clinical practice.

  10. MRAP and MRAP2 are bidirectional regulators of the melanocortin receptor family

    OpenAIRE

    Chan, Li F.; Webb, Tom R.; Chung, Teng-Teng; Meimaridou, Eirini; Cooray, Sadani N.; Guasti, Leonardo; Chapple, J. Paul; Egertová, Michaela; Elphick, Maurice R.; Cheetham, Michael E.; Metherell, Louise A.; Clark, Adrian J. L.

    2009-01-01

    The melanocortin receptor (MCR) family consists of 5 G protein-coupled receptors (MC1R–MC5R) with diverse physiologic roles. MC2R is a critical component of the hypothalamic–pituitary–adrenal axis, whereas MC3R and MC4R have an essential role in energy homeostasis. Mutations in MC4R are the single most common cause of monogenic obesity. Investigating the way in which these receptors signal and traffic to the cell membrane is vital in understanding disease processes related to MCR dysfunction....

  11. Familial defective apolipoprotein B-100: low density lipoproteins with abnormal receptor binding

    International Nuclear Information System (INIS)

    Innerarity, T.L.; Weisgraber, K.H.; Arnold, K.S.; Mahley, R.W.; Krauss, R.M.; Vega, G.L.; Grundy, S.M.

    1987-01-01

    Previous in vivo turnover studies suggested that retarded clearance of low density lipoproteins (LDL) from the plasma of some hypercholesterolemic patients is due to LDL with defective receptor binding. The present study examined this postulate directly by receptor binding experiments. The LDL from a hypercholesterolemic patient (G.R.) displayed a reduced ability to bind to the LDL receptors on normal human fibroblasts. The G.R. LDL possessed 32% of normal receptor binding activity. Likewise, the G.R. LDL were much less effective than normal LDL in competing with 125 I-labeled normal LDL for cellular uptake and degradation and in stimulating intracellular cholesteryl ester synthesis. The defect in LDL binding appears to be due to a genetic abnormality of apolipoprotein B-100: two brothers of the proband possess LDL defective in receptor binding, whereas a third brother and the proband's son have normally binding LDL. Further, the defect in receptor binding does not appear to be associated wit an abnormal lipid composition or structure of the LDL. Normal and abnormal LDL subpopulations were partially separated from plasma of two subjects by density-gradient ultracentrifugation, a finding consistent with the presence of a normal and a mutant allele. The affected family members appear to be heterozygous for this disorder, which has been designated familial defective apolipoprotein B-100. These studies indicate that the defective receptor binding results in inefficient clearance of LDL and the hypercholesterolemia observed in these patients

  12. Neuro-psychopharmacological perspective of Orphan receptors of Rhodopsin (class A) family of G protein-coupled receptors.

    Science.gov (United States)

    Khan, Muhammad Zahid; He, Ling

    2017-04-01

    In the central nervous system (CNS), G protein-coupled receptors (GPCRs) are the most fruitful targets for neuropsychopharmacological drug development. Rhodopsin (class A) is the most studied class of GPCR and includes orphan receptors for which the endogenous ligand is not known or is unclear. Characterization of orphan GPCRs has proven to be challenging, and the production pace of GPCR-based drugs has been incredibly slow. Determination of the functions of these receptors may provide unexpected insight into physiological and neuropathological processes. Advances in various methods and techniques to investigate orphan receptors including in situ hybridization and knockdown/knockout (KD/KO) showed extensive expression of these receptors in the mammalian brain and unmasked their physiological and neuropathological roles. Due to these rapid progress and development, orphan GPCRs are rising as a new and promising class of drug targets for neurodegenerative diseases and psychiatric disorders. This review presents a neuropsychopharmacological perspective of 26 orphan receptors of rhodopsin (class A) family, namely GPR3, GPR6, GPR12, GPR17, GPR26, GPR35, GPR39, GPR48, GPR49, GPR50, GPR52, GPR55, GPR61, GPR62, GPR63, GPR68, GPR75, GPR78, GPR83, GPR84, GPR85, GPR88, GPR153, GPR162, GPR171, and TAAR6. We discussed the expression of these receptors in mammalian brain and their physiological roles. Furthermore, we have briefly highlighted their roles in neurodegenerative diseases and psychiatric disorders including Alzheimer's disease, Parkinson's disease, neuroinflammation, inflammatory pain, bipolar and schizophrenic disorders, epilepsy, anxiety, and depression.

  13. The nuclear receptor gene family in the Pacific oyster, Crassostrea gigas, contains a novel subfamily group.

    Science.gov (United States)

    Vogeler, Susanne; Galloway, Tamara S; Lyons, Brett P; Bean, Tim P

    2014-05-15

    Nuclear receptors are a superfamily of transcription factors important in key biological, developmental and reproductive processes. Several of these receptors are ligand- activated and through their ability to bind endogenous and exogenous ligands, are potentially vulnerable to xenobiotics. Molluscs are key ecological species in defining aquatic and terrestrial habitats and are sensitive to xenobiotic compounds in the environment. However, the understanding of nuclear receptor presence, function and xenobiotic disruption in the phylum Mollusca is limited. Here, forty-three nuclear receptor sequences were mined from the genome of the Pacific oyster, Crassostrea gigas. They include members of NR0-NR5 subfamilies, notably lacking any NR6 members. Phylogenetic analyses of the oyster nuclear receptors have been conducted showing the presence of a large novel subfamily group not previously reported, which is named NR1P. Homologues to all previous identified nuclear receptors in other mollusc species have also been determined including the putative heterodimer partner retinoid X receptor, estrogen receptor and estrogen related receptor. C. gigas contains a highly diverse set of nuclear receptors including a novel NR1 group, which provides important information on presence and evolution of this transcription factor superfamily in invertebrates. The Pacific oyster possesses two members of NR3, the sex steroid hormone receptor analogues, of which there are 9 in humans. This provides increasing evidence that steroid ligand specific expansion of this family is deuterostome specific. This new knowledge on divergence and emergence of nuclear receptors in C. gigas provides essential information for studying regulation of molluscan gene expression and the potential effects of xenobiotics.

  14. Downregulation of transferrin receptor surface expression by intracellular antibody

    International Nuclear Information System (INIS)

    Peng Jilin; Wu Sha; Zhao Xiaoping; Wang Min; Li Wenhan; Shen Xin; Liu Jing; Lei Ping; Zhu Huifen; Shen Guanxin

    2007-01-01

    To deplete cellular iron uptake, and consequently inhibit the proliferation of tumor cells, we attempt to block surface expression of transferrin receptor (TfR) by intracellular antibody technology. We constructed two expression plasmids (scFv-HAK and scFv-HA) coding for intracellular single-chain antibody against TfR with or without endoplasmic reticulum (ER) retention signal, respectively. Then they were transfected tumor cells MCF-7 by liposome. Applying RT-PCR, Western blotting, immunofluorescence microscopy and immunoelectron microscope experiments, we insure that scFv-HAK intrabody was successfully expressed and retained in ER contrasted to the secreted expression of scFv-HA. Flow cytometric analysis confirmed that the TfR surface expression was markedly decreased approximately 83.4 ± 2.5% in scFv-HAK transfected cells, while there was not significantly decrease in scFv-HA transfected cells. Further cell growth and apoptosis characteristics were evaluated by cell cycle analysis, nuclei staining and MTT assay. Results indicated that expression of scFv-HAK can dramatically induce cell cycle G1 phase arrest and apoptosis of tumor cells, and consequently significantly suppress proliferation of tumor cells compared with other control groups. For First time this study demonstrates the potential usage of anti-TfR scFv-intrabody as a growth inhibitor of TfR overexpressing tumors

  15. Interaction of lectins with membrane receptors on erythrocyte surfaces.

    Science.gov (United States)

    Sung, L A; Kabat, E A; Chien, S

    1985-08-01

    The interactions of human genotype AO erythrocytes (red blood cells) (RBCs) with N-acetylgalactosamine-reactive lectins isolated from Helix pomatia (HPA) and from Dolichos biflorus (DBA) were studied. Binding curves obtained with the use of tritium-labeled lectins showed that the maximal numbers of lectin molecules capable of binding to human genotype AO RBCs were 3.8 X 10(5) and 2.7 X 10(5) molecules/RBC for HPA and DBA, respectively. The binding of one type of lectin may influence the binding of another type. HPA was found to inhibit the binding of DBA, but not vice versa. The binding of HPA was weakly inhibited by a beta-D-galactose-reactive lectin isolated from Ricinus communis (designated RCA1). Limulus polyphemus lectin (LPA), with specificity for N-acetylneuraminic acid, did not influence the binding of HPA but enhanced the binding of DBA. About 80% of LPA receptors (N-acetylneuraminic acid) were removed from RBC surfaces by neuraminidase treatment. Neuraminidase treatment of RBCs resulted in increases of binding of both HPA and DBA, but through different mechanisms. An equal number (7.6 X 10(5) of new HPA sites were generated on genotypes AO and OO RBCs by neuraminidase treatment, and these new sites accounted for the enhancement (AO cells) and appearance (OO cells) of hemagglutinability by HPA. Neuraminidase treatment did not generate new DBA sites, but increased the DBA affinity for the existing receptors; as a result, genotype AO cells increased their hemagglutinability by DBA, while OO cells remained unagglutinable. The use of RBCs of different genotypes in binding assays with 3H-labeled lectins of known specificities provides an experimental system for studying cell-cell recognition and association.

  16. Molecular cloning, expression, and sequence analysis of GPRC6A, a novel family C G-protein-coupled receptor

    DEFF Research Database (Denmark)

    Wellendorph, Petrine; Bräuner-Osborne, Hans

    2004-01-01

    with a significant homology to the human calcium-sensing receptor (CaR, 34% aa sequence identity), the taste receptor 1 (T1R1, 28%), and the metabotropic glutamate receptor 1 (mGluR1, 24%), places GPRC6A in family C of the GPCRs. Interestingly, GPRC6A bears the highest resemblance with an odorant goldfish 5...

  17. CRDB: database of chemosensory receptor gene families in vertebrate.

    Directory of Open Access Journals (Sweden)

    Dong Dong

    Full Text Available Chemosensory receptors (CR are crucial for animals to sense the environmental changes and survive on earth. The emergence of whole-genome sequences provides us an opportunity to identify the entire CR gene repertoires. To completely gain more insight into the evolution of CR genes in vertebrates, we identified the nearly all CR genes in 25 vertebrates using homology-based approaches. Among these CR gene repertoires, nearly half of them were identified for the first time in those previously uncharacterized species, such as the guinea pig, giant panda and elephant, etc. Consistent with previous findings, we found that the numbers of CR genes vary extensively among different species, suggesting an extreme form of 'birth-and-death' evolution. For the purpose of facilitating CR gene analysis, we constructed a database with the goals to provide a resource for CR genes annotation and a web tool for exploring their evolutionary patterns. Besides a search engine for the gene extraction from a specific chromosome region, an easy-to-use phylogenetic analysis tool was also provided to facilitate online phylogeny study of CR genes. Our work can provide a rigorous platform for further study on the evolution of CR genes in vertebrates.

  18. Mutations in the nuclear bile acid receptor FXR cause progressive familial intrahepatic cholestasis

    Science.gov (United States)

    Gomez-Ospina, Natalia; Potter, Carol J.; Xiao, Rui; Manickam, Kandamurugu; Kim, Mi-Sun; Kim, Kang Ho; Shneider, Benjamin L.; Picarsic, Jennifer L.; Jacobson, Theodora A.; Zhang, Jing; He, Weimin; Liu, Pengfei; Knisely, A. S.; Finegold, Milton J.; Muzny, Donna M.; Boerwinkle, Eric; Lupski, James R.; Plon, Sharon E.; Gibbs, Richard A.; Eng, Christine M.; Yang, Yaping; Washington, Gabriel C.; Porteus, Matthew H.; Berquist, William E.; Kambham, Neeraja; Singh, Ravinder J.; Xia, Fan; Enns, Gregory M.; Moore, David D.

    2016-01-01

    Neonatal cholestasis is a potentially life-threatening condition requiring prompt diagnosis. Mutations in several different genes can cause progressive familial intrahepatic cholestasis, but known genes cannot account for all familial cases. Here we report four individuals from two unrelated families with neonatal cholestasis and mutations in NR1H4, which encodes the farnesoid X receptor (FXR), a bile acid-activated nuclear hormone receptor that regulates bile acid metabolism. Clinical features of severe, persistent NR1H4-related cholestasis include neonatal onset with rapid progression to end-stage liver disease, vitamin K-independent coagulopathy, low-to-normal serum gamma-glutamyl transferase activity, elevated serum alpha-fetoprotein and undetectable liver bile salt export pump (ABCB11) expression. Our findings demonstrate a pivotal function for FXR in bile acid homeostasis and liver protection. PMID:26888176

  19. Trace Amine-Associated Receptor 1 – Family Archetype or Iconoclast?

    Science.gov (United States)

    Grandy, David K.

    2009-01-01

    Interest has recently been rekindled in receptors that are activated by low molecular weight, non-catecholic, biogenic amines that are typically found as trace constituents of various vertebrate and invertebrate tissues and fluids. The timing of this resurgent focus on receptors activated by the ‘trace amines’ (TAs) β-phenylethylamine (PEA), tyramine (TYR), octopamine (OCT), synephrine (SYN), and tryptamine (TRYP) is the direct result of two publications that appeared in 2001 describing the cloning of a novel G protein-coupled receptor (GPCR) referred to by their discoverers as TA1 (Borowsky et al., 2001) and TAR1 (Bunzow et al., 2001). When heterologously expressed in Xenopus laevis oocytes and various eukaryotic cell lines recombinant rodent and human TA receptors dose-dependently couple to the stimulation of cAMP production. Structure-activity profiling based on this functional response has revealed that in addition to the TAs, other biologically active compounds containing a 2 carbon aliphatic side chain linking an amino group to at least one benzene ring are potent and efficacious TA receptor agonists with amphetamine, methamphetamine, 3-iodothyronamine, thyronamine, and dopamine among the most notable. Almost 100 years after the search for TA receptors began numerous TA1/TAR1-related sequences, now called Trace Amine-Associated Receptors (TAARs), have been identified in the genome of every species of vertebrate examined to date. Consequently, even though heterologously expressed TAAR1 fits the pharmacological criteria established for a bona fide TA receptor a major challenge for those working in the field is to discern the in vivo pharmacology and physiology of each purported member of this extended family of GPCRs. Only then will it be possible to establish whether TAAR1 is the family archetype or an iconoclast. PMID:17888514

  20. Plant cell surface receptor-mediated signaling - a common theme amid diversity.

    Science.gov (United States)

    He, Yunxia; Zhou, Jinggeng; Shan, Libo; Meng, Xiangzong

    2018-01-29

    Sessile plants employ a diverse array of plasma membrane-bound receptors to perceive endogenous and exogenous signals for regulation of plant growth, development and immunity. These cell surface receptors include receptor-like kinases (RLKs) and receptor-like proteins (RLPs) that harbor different extracellular domains for perception of distinct ligands. Several RLK and RLP signaling pathways converge at the somatic embryogenesis receptor kinases (SERKs), which function as shared co-receptors. A repertoire of receptor-like cytoplasmic kinases (RLCKs) associate with the receptor complexes to relay intracellular signaling. Downstream of the receptor complexes, mitogen-activated protein kinase (MAPK) cascades are among the key signaling modules at which the signals converge, and these cascades regulate diverse cellular and physiological responses through phosphorylation of different downstream substrates. In this Review, we summarize the emerging common theme that underlies cell surface receptor-mediated signaling pathways in Arabidopsis thaliana : the dynamic association of RLKs and RLPs with specific co-receptors and RLCKs for signal transduction. We further discuss how signaling specificities are maintained through modules at which signals converge, with a focus on SERK-mediated receptor signaling. © 2018. Published by The Company of Biologists Ltd.

  1. Mapping of Wnt-Frizzled interactions by multiplex CRISPR targeting of receptor gene families.

    Science.gov (United States)

    Voloshanenko, Oksana; Gmach, Philipp; Winter, Jan; Kranz, Dominique; Boutros, Michael

    2017-11-01

    Signaling pathway modules are often encoded by several closely related paralogous genes that can have redundant roles and are therefore difficult to analyze by loss-of-function analysis. A typical example is the Wnt signaling pathway, which in mammals is mediated by 19 Wnt ligands that can bind to 10 Frizzled (FZD) receptors. Although significant progress in understanding Wnt-FZD receptor interactions has been made in recent years, tools to generate systematic interaction maps have been largely lacking. Here we generated cell lines with multiplex mutant alleles of FZD1 , FZD2 , and FZD7 and demonstrate that these cells are unresponsive to canonical Wnt ligands. Subsequently, we performed genetic rescue experiments with combinations of FZDs and canonical Wnts to create a functional ligand-receptor interaction map. These experiments showed that whereas several Wnt ligands, such as Wnt3a, induce signaling through a broad spectrum of FZD receptors, others, such as Wnt8a, act through a restricted set of FZD genes. Together, our results map functional interactions of FZDs and 10 Wnt ligands and demonstrate how multiplex targeting by clustered regularly interspaced short palindromic repeat (CRISPR)/Cas9 can be used to systematically elucidate the functions of multigene families.-Voloshanenko, O., Gmach, P., Winter, J., Kranz, D., Boutros, M. Mapping of Wnt-Frizzled interactions by multiplex CRISPR targeting of receptor gene families. © The Author(s).

  2. Transmembrane signal transduction by peptide hormones via family B G protein-coupled receptors

    Directory of Open Access Journals (Sweden)

    Kelly J Culhane

    2015-11-01

    Full Text Available Although family B G protein-coupled receptors (GPCRs contain only 15 members, they play key roles in transmembrane signal transduction of hormones. Family B GPCRs are drug targets for developing therapeutics for diseases ranging from metabolic to neurological disorders. Despite their importance, the molecular mechanism of activation of family B GPCRs remains largely unexplored due to the challenges in expression and purification of functional receptors to the quantity for biophysical characterization. Currently, there is no crystal structure available of a full-length family B GPCR. However, structures of key domains, including the extracellular ligand binding regions and seven-helical transmembrane regions, have been solved by X-ray crystallography and NMR, providing insights into the mechanisms of ligand recognition and selectivity, and helical arrangements within the cell membrane. Moreover, biophysical and biochemical methods have been used to explore functions, key residues for signaling, and the kinetics and dynamics of signaling processes. This review summarizes the current knowledge of the signal transduction mechanism of family B GPCRs at the molecular level and comments on the challenges and outlook for mechanistic studies of family B GPCRs.

  3. Dynamic evolution of toll-like receptor multigene families in echinoderms

    Directory of Open Access Journals (Sweden)

    Katherine M Buckley

    2012-06-01

    Full Text Available The genome of the purple sea urchin, Strongylocentrotus purpuratus, was the first to be sequenced from a long-lived large invertebrate. Analysis of this genome uncovered a surprisingly complex immune system in which the moderately sized sets of pattern recognition receptors that form the core of vertebrate innate immunity are encoded in large multigene families. The sea urchin genome contains 253 Toll-like receptor (TLR genes, more than 200 Nod-like receptors and 1095 scavenger receptor cysteine-rich domains, a ten-fold expansion relative to vertebrates. Given their stereotypic structure and simple intron-exon architecture, the TLRs are the most tractable of these families for more detailed analysis. An immune defense role for these receptors is suggested by their sequence diversity and expression in immunologically active tissues, including phagocytes. This complexity of the sea urchin TLR multigene families largely derives from expansions that are independent of those in vertebrates and protostomes, although a small family of TLRs with structure similar to that of Drosophila Toll likely originated in an ancient eumetazoan ancestor. Several other invertebrate deuterostome genomes have been sequenced, including the cephalochordate, Branchiostoma floridae and the sea urchin Lytechinus variegatus, as well as partial sequences from two other sea urchin species. Here, we present an analysis of the invertebrate deuterostome TLRs with emphasis on the echinoderms. Representatives of most of the S. purpuratus TLR subfamilies and homologs of the protostome-like sequences are found in L. variegatus. The phylogeny of these genes within sea urchins highlights lineage-specific expansions at higher resolution than is evident at the phylum level. These analyses identify quickly evolving TLR subfamilies that are likely to have novel functions and other, more stable, subfamilies that may function similarly to those of vertebrates.

  4. Gonadal cell surface receptor for plasma retinol-binding protein

    International Nuclear Information System (INIS)

    Krishna Bhat, M.; Cama, H.R.

    1979-01-01

    A specific membrane receptor for plasma retinol-binding protein has been demonstrated in testicular cells. Prealbumin-2 did not show any specific binding to the membrane. The affinity of retinol-binding protein for receptor drastically decreases upon delivery of retinol and the retinol-binding protein does not enter the cell. The mechanism of delivery of retinol to the target cell by plasma retinol-binding protein has been investigated. The process involves two steps; direct binding of retinol-binding protein to the receptor and uptake of retinol by the target cell with a concomitant drastic reduction in the affinity of the retinol-binding protein to the receptor. Probably the second step of the process needs a cytosolic factor, possibly the cellular retinol-binding protein or an enzyme. The binding of retinol-binding protein to the receptor is saturable and reversible. The interaction shows a Ksub(d) value of 2.1x10 -10 . The specific binding of a retinol-binding protein with great affinity has been employed in the development of a method for radioassay of the receptor. The receptor level of the gonadal cell has been found to vary with the stage of differentiation. The receptor concentrations in 11-week-old birds and adult birds are comparable. Testosterone treatment of 11-week-old birds produced a substantial increase in the receptor concentration over control, while the protein content increased marginally, indicating that, probably, synthesis of the receptor is specifcally induced by testosterone during spermatogenesis, and the concentration of receptor is relatively higher before the formation of the acrosome. (Auth.)

  5. Natural killer cell receptor genes in the family Equidae: not only Ly49.

    Directory of Open Access Journals (Sweden)

    Jan Futas

    Full Text Available Natural killer (NK cells have important functions in immunity. NK recognition in mammals can be mediated through killer cell immunoglobulin-like receptors (KIR and/or killer cell lectin-like Ly49 receptors. Genes encoding highly variable NK cell receptors (NKR represent rapidly evolving genomic regions. No single conservative model of NKR genes was observed in mammals. Single-copy low polymorphic NKR genes present in one mammalian species may expand into highly polymorphic multigene families in other species. In contrast to other non-rodent mammals, multiple Ly49-like genes appear to exist in the horse, while no functional KIR genes were observed in this species. In this study, Ly49 and KIR were sought and their evolution was characterized in the entire family Equidae. Genomic sequences retrieved showed the presence of at least five highly conserved polymorphic Ly49 genes in horses, asses and zebras. These findings confirmed that the expansion of Ly49 occurred in the entire family. Several KIR-like sequences were also identified in the genome of Equids. Besides a previously identified non-functional KIR-Immunoglobulin-like transcript fusion gene (KIR-ILTA and two putative pseudogenes, a KIR3DL-like sequence was analyzed. In contrast to previous observations made in the horse, the KIR3DL sequence, genomic organization and mRNA expression suggest that all Equids might produce a functional KIR receptor protein molecule with a single non-mutated immune tyrosine-based inhibition motif (ITIM domain. No evidence for positive selection in the KIR3DL gene was found. Phylogenetic analysis including rhinoceros and tapir genomic DNA and deduced amino acid KIR-related sequences showed differences between families and even between species within the order Perissodactyla. The results suggest that the order Perissodactyla and its family Equidae with expanded Ly49 genes and with a potentially functional KIR gene may represent an interesting model for

  6. Natural Killer Cell Receptor Genes in the Family Equidae: Not only Ly49

    Science.gov (United States)

    Futas, Jan; Horin, Petr

    2013-01-01

    Natural killer (NK) cells have important functions in immunity. NK recognition in mammals can be mediated through killer cell immunoglobulin-like receptors (KIR) and/or killer cell lectin-like Ly49 receptors. Genes encoding highly variable NK cell receptors (NKR) represent rapidly evolving genomic regions. No single conservative model of NKR genes was observed in mammals. Single-copy low polymorphic NKR genes present in one mammalian species may expand into highly polymorphic multigene families in other species. In contrast to other non-rodent mammals, multiple Ly49-like genes appear to exist in the horse, while no functional KIR genes were observed in this species. In this study, Ly49 and KIR were sought and their evolution was characterized in the entire family Equidae. Genomic sequences retrieved showed the presence of at least five highly conserved polymorphic Ly49 genes in horses, asses and zebras. These findings confirmed that the expansion of Ly49 occurred in the entire family. Several KIR-like sequences were also identified in the genome of Equids. Besides a previously identified non-functional KIR-Immunoglobulin-like transcript fusion gene (KIR-ILTA) and two putative pseudogenes, a KIR3DL-like sequence was analyzed. In contrast to previous observations made in the horse, the KIR3DL sequence, genomic organization and mRNA expression suggest that all Equids might produce a functional KIR receptor protein molecule with a single non-mutated immune tyrosine-based inhibition motif (ITIM) domain. No evidence for positive selection in the KIR3DL gene was found. Phylogenetic analysis including rhinoceros and tapir genomic DNA and deduced amino acid KIR-related sequences showed differences between families and even between species within the order Perissodactyla. The results suggest that the order Perissodactyla and its family Equidae with expanded Ly49 genes and with a potentially functional KIR gene may represent an interesting model for evolutionary biology of

  7. Transcription control and neuronal differentiation by agents that activate the LXR nuclear receptor family.

    Science.gov (United States)

    Schmidt, A; Vogel, R; Holloway, M K; Rutledge, S J; Friedman, O; Yang, Z; Rodan, G A; Friedman, E

    1999-09-10

    LXR and PPAR receptors belong to the nuclear receptor superfamily of transcriptional activating factors. Using ligand-dependent transcription assays, we found that 5-tetradecyloxy-2-furancarboxylic acid (TOFA) transactivates chimeric receptors composed of the glucocorticoid receptor DNA binding domain and the ligand binding regions of PPARalpha, PPARbeta (NUC-1) and LXRbeta (NER) receptors. In the same assays, ligands for PPARs (oleic acid, WY-14643 and L-631,033) and LXRs (hydroxycholesterols) maintain their respective receptor selectivity. TOFA and hydroxycholesterols also stimulate transcription from a minimal fibrinogen promoter that is under the control of AP-1 or NF-kappaB transcription factor binding sites. In addition to their effects on transcription, these LXRbeta activators induce neuronal differentiation in rat pheochromocytoma cells. TOFA and the natural LXR agonist, 22 (R)-hydroxycholesterol, stimulate neurite outgrowth in 55 and 28% of cells, respectively. No neurite outgrowth was induced by the related 22(S)-hydroxycholesterol, which does not activate the LXR family. These results suggest that the hydroxycholesterol signaling pathway has a complex effect on transcription that mediates the activity of TOFA and hydroxycholesterol on neuronal differentiation in pheochromocytoma cells.

  8. Novel skeletal muscle ryanodine receptor mutation in a large Brazilian family with malignant hyperthermia.

    Science.gov (United States)

    McWilliams, S; Nelson, T; Sudo, R T; Zapata-Sudo, G; Batti, M; Sambuughin, N

    2002-07-01

    Malignant hyperthermia (MH) is an autosomal dominant disorder that predisposes susceptible individuals to a potentially life-threatening crisis when exposed to commonly used anesthetics. Mutations in the skeletal muscle calcium release channel, ryanodine receptor (RYR1) are associated with MH in over 50% of affected families. Linkage analysis of the RYR1 gene region at 19q13 was performed in a large Brazilian family and a distinct disease co-segregating haplotype was revealed in the majority of members with diagnosis of MH. Subsequent sequencing of RYR1 mutational hot spots revealed a nucleotide substitution of C to T at position 7062, causing a novel amino acid change from Arg2355 to Cys associated with MH in the family. Haplotype analysis of the RYR1 gene area at 19q13 in the family with multiple MH members is an important tool in identification of genetic cause underlying this disease.

  9. The Role of Nuclear Receptor-Binding SET Domain Family Histone Lysine Methyltransferases in Cancer.

    Science.gov (United States)

    Bennett, Richard L; Swaroop, Alok; Troche, Catalina; Licht, Jonathan D

    2017-06-01

    The nuclear receptor-binding SET Domain (NSD) family of histone H3 lysine 36 methyltransferases is comprised of NSD1, NSD2 (MMSET/WHSC1), and NSD3 (WHSC1L1). These enzymes recognize and catalyze methylation of histone lysine marks to regulate chromatin integrity and gene expression. The growing number of reports demonstrating that alterations or translocations of these genes fundamentally affect cell growth and differentiation leading to developmental defects illustrates the importance of this family. In addition, overexpression, gain of function somatic mutations, and translocations of NSDs are associated with human cancer and can trigger cellular transformation in model systems. Here we review the functions of NSD family members and the accumulating evidence that these proteins play key roles in tumorigenesis. Because epigenetic therapy is an important emerging anticancer strategy, understanding the function of NSD family members may lead to the development of novel therapies. Copyright © 2017 Cold Spring Harbor Laboratory Press; all rights reserved.

  10. Cell surface receptors for signal transduction and ligand transport: a design principles study.

    Directory of Open Access Journals (Sweden)

    Harish Shankaran

    2007-06-01

    Full Text Available Receptors constitute the interface of cells to their external environment. These molecules bind specific ligands involved in multiple processes, such as signal transduction and nutrient transport. Although a variety of cell surface receptors undergo endocytosis, the systems-level design principles that govern the evolution of receptor trafficking dynamics are far from fully understood. We have constructed a generalized mathematical model of receptor-ligand binding and internalization to understand how receptor internalization dynamics encodes receptor function and regulation. A given signaling or transport receptor system represents a particular implementation of this module with a specific set of kinetic parameters. Parametric analysis of the response of receptor systems to ligand inputs reveals that receptor systems can be characterized as being: i avidity-controlled where the response control depends primarily on the extracellular ligand capture efficiency, ii consumption-controlled where the ability to internalize surface-bound ligand is the primary control parameter, and iii dual-sensitivity where both the avidity and consumption parameters are important. We show that the transferrin and low-density lipoprotein receptors are avidity-controlled, the vitellogenin receptor is consumption-controlled, and the epidermal growth factor receptor is a dual-sensitivity receptor. Significantly, we show that ligand-induced endocytosis is a mechanism to enhance the accuracy of signaling receptors rather than merely serving to attenuate signaling. Our analysis reveals that the location of a receptor system in the avidity-consumption parameter space can be used to understand both its function and its regulation.

  11. A survey of the pyrabactin resistance-like abscisic acid receptor gene family in poplar.

    Science.gov (United States)

    Yu, Jingling; Li, Hejuan; Peng, Yajing; Yang, Lei; Zhao, Fugeng; Luan, Sheng; Lan, Wenzhi

    2017-08-03

    The conserved PYR/PYL/RCAR family acts as abscisic acid (ABA) receptors for land plants to adapt to terrestrial environments. Our recent study reported that the exogenous overexpression of poplar PtPYRL1 and PtPYRL5, the PYR/PYL/RCAR orthologs, promoted the sensitivity of transgenic Arabidopsis to ABA responses. Here, we surveyed the PtPYRL family in poplar, and revealed that although the sequence and structure are relatively conserved among these receptors, PtPYRL members have differential expression patterns and the sensitivity to ABA or drought treatment, suggesting that PtPYRLs might be good candidates to a future biotechnological use to enhance poplar resistance to water-stress environments.

  12. The D1 family dopamine receptor, DopR, potentiates hind leg grooming behavior in Drosophila.

    Science.gov (United States)

    Pitmon, E; Stephens, G; Parkhurst, S J; Wolf, F W; Kehne, G; Taylor, M; Lebestky, T

    2016-03-01

    Drosophila groom away debris and pathogens from the body using their legs in a stereotyped sequence of innate motor behaviors. Here, we investigated one aspect of the grooming repertoire by characterizing the D1 family dopamine receptor, DopR. Removal of DopR results in decreased hind leg grooming, as substantiated by quantitation of dye remaining on mutant and RNAi animals vs. controls and direct scoring of behavioral events. These data are also supported by pharmacological results that D1 receptor agonists fail to potentiate grooming behaviors in headless DopR flies. DopR protein is broadly expressed in the neuropil of the thoracic ganglion and overlaps with TH-positive dopaminergic neurons. Broad neuronal expression of dopamine receptor in mutant animals restored normal grooming behaviors. These data provide evidence for the role of DopR in potentiating hind leg grooming behaviors in the thoracic ganglion of adult Drosophila. This is a remarkable juxtaposition to the considerable role of D1 family dopamine receptors in rodent grooming, and future investigations of evolutionary relationships of circuitry may be warranted. © 2016 The Authors. Genes, Brain and Behavior published by International Behavioural and Neural Genetics Society and John Wiley & Sons Ltd.

  13. Receptor-like kinases as surface regulators for RAC/ROP-mediated pollen tube growth and interaction with the pistil

    Science.gov (United States)

    Zou, Yanjiao; Aggarwal, Mini; Zheng, Wen-Guang; Wu, Hen-Ming; Cheung, Alice Y.

    2011-01-01

    Background RAC/ROPs are RHO-type GTPases and are known to play diverse signalling roles in plants. Cytoplasmic RAC/ROPs are recruited to the cell membrane and activated in response to extracellular signals perceived and mediated by cell surface-located signalling assemblies, transducing the signals to regulate cellular processes. More than any other cell types in plants, pollen tubes depend on continuous interactions with an extracellular environment produced by their surrounding tissues as they grow within the female organ pistil to deliver sperm to the female gametophyte for fertilization. Scope We review studies on pollen tube growth that provide compelling evidence indicating that RAC/ROPs are crucial for regulating the cellular processes that underlie the polarized cell growth process. Efforts to identify cell surface regulators that mediate extracellular signals also point to RAC/ROPs being the molecular switches targeted by growth-regulating female factors for modulation to mediate pollination and fertilization. We discuss a large volume of work spanning more than two decades on a family of pollen-specific receptor kinases and some recent studies on members of the FERONIA family of receptor-like kinases (RLKs). Significance The research described shows the crucial roles that two RLK families play in transducing signals from growth regulatory factors to the RAC/ROP switch at the pollen tube apex to mediate and target pollen tube growth to the female gametophyte and signal its disintegration to achieve fertilization once inside the female chamber. PMID:22476487

  14. Demonstration of functional low-density lipoprotein receptors by protein blotting in fibroblasts from a subject with homozygous receptor-negative familial hypercholesterolemia

    International Nuclear Information System (INIS)

    Semenkovich, C.F.; Ostlund, R.E. Jr.; Yang, J.; Reaban, M.E.

    1985-01-01

    We report the detection of low-density lipoprotein (LDL) receptors by the technique of receptor blotting in fibroblasts from a patient with homozygous familial hypercholesterolemia (FHC) previously classified as ''receptor negative.'' Solubilized receptors were electrophoresed, transferred to nitrocellulose paper, treated with LDL followed by radiolabeled antibody to LDL, and visualized by autoradiography. GM 2000 FHC fibroblasts revealed LDL receptors with an apparent molecular weight of approximately 140,000, the same as in normal cells. LDL receptor activity by blotting in GM 2000 cells was greatly diminished in comparison with normal cells, but was calcium dependent. Receptor activity was also detectable by conventional monolayer binding and degradation assays. Thus, GM 2000 cells have profoundly diminished LDL receptor activity, but retain the genetic capacity to make LDL receptor material of normal molecular weight that is capable of binding LDL. Previous studies have demonstrated the presence of trace amounts of immunoreactive LDL receptor protein in fibroblasts from some receptor-negative FHC homozygotes. These studies are extended by demonstrating the ability of this material to bind LDL

  15. Complex Determinants in Specific Members of the Mannose Receptor Family Govern Collagen Endocytosis

    DEFF Research Database (Denmark)

    Jürgensen, Henrik J; Johansson, Kristina; Madsen, Daniel H

    2014-01-01

    Members of the well-conserved mannose receptor (MR) protein family have been functionally implicated in diverse biological and pathological processes. Importantly, a proposed common function is the internalization of collagen for intracellular degradation occurring during bone development, cancer...... invasion, and fibrosis protection. This functional relationship is suggested by a common endocytic capability and a candidate collagen-binding domain. Here we conducted a comparative investigation of each member's ability to facilitate intracellular collagen degradation. As expected, the family members u......PARAP/Endo180 and MR bound collagens in a purified system and internalized collagens for degradation in cellular settings. In contrast, the remaining family members, PLA2R and DEC-205, showed no collagen binding activity and were unable to mediate collagen internalization. To pinpoint the structural elements...

  16. The relaxin family peptide receptors and their ligands : new developments and paradigms in the evolution from jawless fish to mammals

    NARCIS (Netherlands)

    Yegorov, Sergey; Bogerd, Jan; Good, Sara V

    2014-01-01

    Relaxin family peptide receptors (Rxfps) and their ligands, relaxin (Rln) and insulin-like (Insl) peptides, are broadly implicated in the regulation of reproductive and neuroendocrine processes in mammals. Most placental mammals harbour genes for four receptors, namely rxfp1, rxfp2, rxfp3 and rxfp4.

  17. Effectoromics-based identification of cell surface receptors in potato

    NARCIS (Netherlands)

    Domazakis, Emmanouil; Lin, Xiao; Aguilera-Galvez, Carolina; Wouters, Doret; Bijsterbosch, Gerard; Wolters, Pieter J.; Vleeshouwers, Vivianne G.A.A.

    2017-01-01

    In modern resistance breeding, effectors have emerged as tools for accelerating and improving the identification of immune receptors. Effector-assisted breeding was pioneered for identifying resistance genes (R genes) against Phytophthora infestans in potato (Solanum tuberosum). Here we show that

  18. Cell-surface acceleration of urokinase-catalyzed receptor cleavage

    DEFF Research Database (Denmark)

    Høyer-Hansen, G; Ploug, M; Behrendt, N

    1997-01-01

    by a prior incubation of the cells with uPA inactivated by diisopropyl fluorophosphate, demonstrating a requirement for specific receptor binding of the active uPA to obtain the high-efficiency cleavage of cell-bound uPAR. Furthermore, amino-terminal sequence analysis revealed that uPAR(2+3), purified from U...

  19. Using paleogenomics to study the evolution of gene families: origin and duplication history of the relaxin family hormones and their receptors.

    Directory of Open Access Journals (Sweden)

    Sergey Yegorov

    Full Text Available Recent progress in the analysis of whole genome sequencing data has resulted in the emergence of paleogenomics, a field devoted to the reconstruction of ancestral genomes. Ancestral karyotype reconstructions have been used primarily to illustrate the dynamic nature of genome evolution. In this paper, we demonstrate how they can also be used to study individual gene families by examining the evolutionary history of relaxin hormones (RLN/INSL and relaxin family peptide receptors (RXFP. Relaxin family hormones are members of the insulin superfamily, and are implicated in the regulation of a variety of primarily reproductive and neuroendocrine processes. Their receptors are G-protein coupled receptors (GPCR's and include members of two distinct evolutionary groups, an unusual characteristic. Although several studies have tried to elucidate the origins of the relaxin peptide family, the evolutionary origin of their receptors and the mechanisms driving the diversification of the RLN/INSL-RXFP signaling systems in non-placental vertebrates has remained elusive. Here we show that the numerous vertebrate RLN/INSL and RXFP genes are products of an ancestral receptor-ligand system that originally consisted of three genes, two of which apparently trace their origins to invertebrates. Subsequently, diversification of the system was driven primarily by whole genome duplications (WGD, 2R and 3R followed by almost complete retention of the ligand duplicates in most vertebrates but massive loss of receptor genes in tetrapods. Interestingly, the majority of 3R duplicates retained in teleosts are potentially involved in neuroendocrine regulation. Furthermore, we infer that the ancestral AncRxfp3/4 receptor may have been syntenically linked to the AncRln-like ligand in the pre-2R genome, and show that syntenic linkages among ligands and receptors have changed dynamically in different lineages. This study ultimately shows the broad utility, with some caveats, of

  20. Tracking Cell Surface GABAB Receptors Using an α-Bungarotoxin Tag*

    Science.gov (United States)

    Wilkins, Megan E.; Li, Xinyan; Smart, Trevor G.

    2008-01-01

    GABAB receptors mediate slow synaptic inhibition in the central nervous system and are important for synaptic plasticity as well as being implicated in disease. Located at pre- and postsynaptic sites, GABAB receptors will influence cell excitability, but their effectiveness in doing so will be dependent, in part, on their trafficking to, and stability on, the cell surface membrane. To examine the dynamic behavior of GABAB receptors in GIRK cells and neurons, we have devised a method that is based on tagging the receptor with the binding site components for the neurotoxin, α-bungarotoxin. By using the α-bungarotoxin binding site-tagged GABAB R1a subunit (R1aBBS), co-expressed with the R2 subunit, we can track receptor mobility using the small reporter, α-bungarotoxin-conjugated rhodamine. In this way, the rates of internalization and membrane insertion for these receptors could be measured with fixed and live cells. The results indicate that GABAB receptors rapidly turnover in the cell membrane, with the rate of internalization affected by the state of receptor activation. The bungarotoxin-based method of receptor-tagging seems ideally suited to follow the dynamic regulation of other G-protein-coupled receptors. PMID:18812318

  1. Tracking cell surface GABAB receptors using an alpha-bungarotoxin tag.

    Science.gov (United States)

    Wilkins, Megan E; Li, Xinyan; Smart, Trevor G

    2008-12-12

    GABA(B) receptors mediate slow synaptic inhibition in the central nervous system and are important for synaptic plasticity as well as being implicated in disease. Located at pre- and postsynaptic sites, GABA(B) receptors will influence cell excitability, but their effectiveness in doing so will be dependent, in part, on their trafficking to, and stability on, the cell surface membrane. To examine the dynamic behavior of GABA(B) receptors in GIRK cells and neurons, we have devised a method that is based on tagging the receptor with the binding site components for the neurotoxin, alpha-bungarotoxin. By using the alpha-bungarotoxin binding site-tagged GABA(B) R1a subunit (R1a(BBS)), co-expressed with the R2 subunit, we can track receptor mobility using the small reporter, alpha-bungarotoxin-conjugated rhodamine. In this way, the rates of internalization and membrane insertion for these receptors could be measured with fixed and live cells. The results indicate that GABA(B) receptors rapidly turnover in the cell membrane, with the rate of internalization affected by the state of receptor activation. The bungarotoxin-based method of receptor-tagging seems ideally suited to follow the dynamic regulation of other G-protein-coupled receptors.

  2. The role of TAM family receptors and ligands in the nervous system: From development to pathobiology.

    Science.gov (United States)

    Shafit-Zagardo, Bridget; Gruber, Ross C; DuBois, Juwen C

    2018-03-04

    Tyro3, Axl, and Mertk, referred to as the TAM family of receptor tyrosine kinases, are instrumental in maintaining cell survival and homeostasis in mammals. TAM receptors interact with multiple signaling molecules to regulate cell migration, survival, phagocytosis and clearance of metabolic products and cell debris called efferocytosis. The TAMs also function as rheostats to reduce the expression of proinflammatory molecules and prevent autoimmunity. All three TAM receptors are activated in a concentration-dependent manner by the vitamin K-dependent growth arrest-specific protein 6 (Gas6). Gas6 and the TAMs are abundantly expressed in the nervous system. Gas6, secreted by neurons and endothelial cells, is the sole ligand for Axl. ProteinS1 (ProS1), another vitamin K-dependent protein functions mainly as an anti-coagulant, and independent of this function can activate Tyro3 and Mertk, but not Axl. This review will focus on the role of the TAM receptors and their ligands in the nervous system. We highlight studies that explore the function of TAM signaling in myelination, the visual cortex, neural cancers, and multiple sclerosis (MS) using Gas6 -/- and TAM mutant mice models. Copyright © 2018. Published by Elsevier Inc.

  3. The TIM and TAM families of phosphatidylserine receptors mediate dengue virus entry.

    Science.gov (United States)

    Meertens, Laurent; Carnec, Xavier; Lecoin, Manuel Perera; Ramdasi, Rasika; Guivel-Benhassine, Florence; Lew, Erin; Lemke, Greg; Schwartz, Olivier; Amara, Ali

    2012-10-18

    Dengue viruses (DVs) are responsible for the most medically relevant arboviral diseases. However, the molecular interactions mediating DV entry are poorly understood. We determined that TIM and TAM proteins, two receptor families that mediate the phosphatidylserine (PtdSer)-dependent phagocytic removal of apoptotic cells, serve as DV entry factors. Cells poorly susceptible to DV are robustly infected after ectopic expression of TIM or TAM receptors. Conversely, DV infection of susceptible cells is inhibited by anti-TIM or anti-TAM antibodies or knockdown of TIM and TAM expression. TIM receptors facilitate DV entry by directly interacting with virion-associated PtdSer. TAM-mediated infection relies on indirect DV recognition, in which the TAM ligand Gas6 acts as a bridging molecule by binding to PtdSer within the virion. This dual mode of virus recognition by TIM and TAM receptors reveals how DVs usurp the apoptotic cell clearance pathway for infectious entry. Copyright © 2012 Elsevier Inc. All rights reserved.

  4. Familial Risk for Major Depression is Associated with Lower Striatal 5-HT4 Receptor Binding

    DEFF Research Database (Denmark)

    Madsen, Karine; Torstensen, Eva; Holst, Klaus Kähler

    2015-01-01

    was to determine whether familial risk for MDD is associated with cerebral 5-HT4 receptor binding as measured with [(11)C]SB207145 brain PET imaging. Familial risk is the most potent risk factor of MDD. METHODS: We studied 57 healthy individuals (mean age 36 yrs, range 20-86; 21 women), 26 of which had first...

  5. Working memory span capacity improved by a D2 but not D1 receptor family agonist.

    Science.gov (United States)

    Tarantino, Isadore S; Sharp, Richard F; Geyer, Mark A; Meves, Jessica M; Young, Jared W

    2011-06-01

    Patients with schizophrenia exhibit poor working memory (WM). Although several subcomponents of WM can be measured, evidence suggests the primary subcomponent affected in schizophrenia is span capacity (WMC). Indeed, the NIMH-funded MATRICS initiative recommended assaying the WMC when assessing the efficacy of a putative therapeutic for FDA approval. Although dopamine D1 receptor agonists improve delay-dependent memory in animals, evidence for improvements in WMC due to dopamine D1 receptor activation is limited. In contrast, the dopamine D2-family agonist bromocriptine improves WMC in humans. The radial arm maze (RAM) can be used to assess WMC, although complications due to ceiling effects or strategy confounds have limited its use. We describe a 12-arm RAM protocol designed to assess whether the dopamine D1-family agonist SKF 38393 (0, 1, 3, and 10 mg/kg) or bromocriptine (0, 1, 3, and 10 mg/kg) could improve WMC in C57BL/6N mice (n=12) in cross-over designs. WMC increased and strategy usage decreased with training. The dopamine D1 agonist SKF 38393 had no effect on WMC or long-term memory. Bromocriptine decreased WMC errors, without affecting long-term memory, consistent with human studies. These data confirm that WMC can be measured in mice and reveal drug effects that are consistent with reported effects in humans. Future research is warranted to identify the subtype of the D2-family of receptors responsible for the observed improvement in WMC. Finally, this RAM procedure may prove useful in developing animal models of deficient WMC to further assess putative treatments for the cognitive deficits in schizophrenia. Copyright © 2011 Elsevier B.V. All rights reserved.

  6. Ephrinb1 and Ephrinb2 Are Associated with Interleukin-7 Receptor α and Retard Its Internalization from the Cell Surface*

    Science.gov (United States)

    Luo, Hongyu; Wu, Zenghui; Qi, Shijie; Jin, Wei; Han, Bing; Wu, Jiangping

    2011-01-01

    IL-7 plays vital roles in thymocyte development, T cell homeostasis, and the survival of these cells. IL-7 receptor α (IL-7Rα) on thymocytes and T cells is rapidly internalized upon IL-7 ligation. Ephrins (Efns) are cell surface molecules and ligands of the largest receptor kinase family, Eph kinases. We discovered that T cell-specific double gene knock-out (dKO) of Efnb1 and Efnb2 in mice led to reduced IL-7Rα expression in thymocytes and T cells, and that IL-7Rα down-regulation was accelerated in dKO CD4 cells upon IL-7 treatment. On the other hand, Efnb1 and Efnb2 overexpression on T cell lymphoma EL4 cells retarded IL-7Rα down-regulation. dKO T cells manifested compromised STAT5 activation and homeostatic proliferation, an IL-7-dependent process. Fluorescence resonance energy transfer and immunoprecipitation demonstrated that Efnb1 and Efnb2 interacted physically with IL-7Rα. Such interaction likely retarded IL-7Rα internalization, as Efnb1 and Efnb2 were not internalized. Therefore, we revealed a novel function of Efnb1 and Efnb2 in stabilizing IL-7Rα expression at the post-translational level, and a previously unknown modus operandi of Efnbs in the regulation of expression of other vital cell surface receptors. PMID:22069310

  7. Three family members with elevated plasma cobalamin, transcobalamin and soluble transcobalamin receptor (sCD320)

    DEFF Research Database (Denmark)

    Hoffmann-Lücke, Elke; Arendt, Johan F B; Nissen, Peter H

    2013-01-01

    deficiency were found. DNA sequencing of the TCN2 gene revealed several known polymorphisms not associated with highly elevated transcobalamin levels. Upon gel filtration, sCD320 eluted as a larger molecule than previously reported. By incubation with anti-transcobalamin antibodies, we precipitated both...... transcobalamin and part of sCD320. CONCLUSIONS: The high cobalamin levels were mainly explained by high levels of holoTC, possibly caused by complex formation with its soluble receptor, sCD320. The family occurrence points to a genetic explanation....

  8. [Coactivators in energy metabolism: peroxisome proliferator-activated receptor-gamma coactivator 1 family].

    Science.gov (United States)

    Wang, Rui; Chang, Yong-sheng; Fang, Fu-de

    2009-12-01

    Peroxisome proliferator-activated receptor gamma coactivator 1 (PGC1) family is highly expressed in tissues with high energy metabolism. They coactivate transcription factors in regulating genes engaged in processes such as gluconeogenesis, adipose beta-oxydation, lipoprotein synthesis and secretion, mitochondrial biogenesis, and oxidative metabolism. Protein conformation studies demonstrated that they lack DNA binding domains and act as coactivators through physical interaction with transcription factors. PGC1 activity is regulated at transcription level or by multiple covalent chemical modifications such as phosphorylation, methylation and acetylation/deacetylation. Abnormal expression of PGC1 coactivators usually is closely correlated with diseases such as diabetes, obesity, hyperglycemia, hyperlipemia, and arterial and brain neuron necrosis diseases.

  9. Cross-talk between the NR3B and NR4A families of orphan nuclear receptors

    International Nuclear Information System (INIS)

    Lammi, Johanna; Rajalin, Ann-Marie; Huppunen, Johanna; Aarnisalo, Piia

    2007-01-01

    Estrogen-related receptors (NR3B family) and Nurr1, NGFI-B, and Nor1 (NR4A family) are orphan nuclear receptors lacking identified natural ligands. The mechanisms regulating their transcriptional activities have remained elusive. We have previously observed that the members of NR3B and NR4A families are coexpressed in certain cell types such as osteoblasts and that the ability of Nurr1 to transactivate the osteopontin promoter is repressed by ERRs. We have now studied the cross-talk between NR3B and NR4A receptors. We show that NR3B and NR4A receptors mutually repress each others' transcriptional activity. The repression involves intact DNA-binding domains and dimerization interfaces but does not result from competition for DNA binding or from heterodimerization. The activation functions of NR3B and NR4A receptors are dispensable for the cross-talk. In conclusion, we report that cross-talk between NR3B and NR4A receptors is a mechanism modulating the transcriptional activities of these orphan nuclear receptors

  10. International Union of Pharmacology. LXXXIX. Update on the Extended Family of Chemokine Receptors and Introducing a New Nomenclature for Atypical Chemokine Receptors

    Science.gov (United States)

    Bachelerie, Francoise; Ben-Baruch, Adit; Burkhardt, Amanda M.; Combadiere, Christophe; Farber, Joshua M.; Graham, Gerard J.; Horuk, Richard; Sparre-Ulrich, Alexander Hovard; Locati, Massimo; Luster, Andrew D.; Mantovani, Alberto; Matsushima, Kouji; Nibbs, Robert; Nomiyama, Hisayuki; Power, Christine A.; Proudfoot, Amanda E. I.; Rosenkilde, Mette M.; Rot, Antal; Sozzani, Silvano; Thelen, Marcus; Yoshie, Osamu; Zlotnik, Albert

    2014-01-01

    Sixteen years ago, the Nomenclature Committee of the International Union of Pharmacology approved a system for naming human seven-transmembrane (7TM) G protein-coupled chemokine receptors, the large family of leukocyte chemoattractant receptors that regulates immune system development and function, in large part by mediating leukocyte trafficking. This was announced in Pharmacological Reviews in a major overview of the first decade of research in this field [Murphy PM, Baggiolini M, Charo IF, Hébert CA, Horuk R, Matsushima K, Miller LH, Oppenheim JJ, and Power CA (2000) Pharmacol Rev 52:145–176]. Since then, several new receptors have been discovered, and major advances have been made for the others in many areas, including structural biology, signal transduction mechanisms, biology, and pharmacology. New and diverse roles have been identified in infection, immunity, inflammation, development, cancer, and other areas. The first two drugs acting at chemokine receptors have been approved by the U.S. Food and Drug Administration (FDA), maraviroc targeting CCR5 in human immunodeficiency virus (HIV)/AIDS, and plerixafor targeting CXCR4 for stem cell mobilization for transplantation in cancer, and other candidates are now undergoing pivotal clinical trials for diverse disease indications. In addition, a subfamily of atypical chemokine receptors has emerged that may signal through arrestins instead of G proteins to act as chemokine scavengers, and many microbial and invertebrate G protein-coupled chemokine receptors and soluble chemokine-binding proteins have been described. Here, we review this extended family of chemokine receptors and chemokine-binding proteins at the basic, translational, and clinical levels, including an update on drug development. We also introduce a new nomenclature for atypical chemokine receptors with the stem ACKR (atypical chemokine receptor) approved by the Nomenclature Committee of the International Union of Pharmacology and the Human

  11. Polymorphisms of the low-density lipoprotein receptor gene in Brazilian individuals with heterozygous familial hypercholesterolemia

    Directory of Open Access Journals (Sweden)

    L.A. Salazar

    2000-11-01

    Full Text Available Familial hypercholesterolemia (FH is a metabolic disorder inherited as an autosomal dominant trait characterized by an increased plasma low-density lipoprotein (LDL level. The disease is caused by several different mutations in the LDL receptor gene. Although early identification of individuals carrying the defective gene could be useful in reducing the risk of atherosclerosis and myocardial infarction, the techniques available for determining the number of the functional LDL receptor molecules are difficult to carry out and expensive. Polymorphisms associated with this gene may be used for unequivocal diagnosis of FH in several populations. The aim of our study was to evaluate the genotype distribution and relative allele frequencies of three polymorphisms of the LDL receptor gene, HincII1773 (exon 12, AvaII (exon 13 and PvuII (intron 15, in 50 unrelated Brazilian individuals with a diagnosis of heterozygous FH and in 130 normolipidemic controls. Genomic DNA was extracted from blood leukocytes by a modified salting-out method. The polymorphisms were detected by PCR-RFLP. The FH subjects showed a higher frequency of A+A+ (AvaII, H+H+ (HincII1773 and P1P1 (PvuII homozygous genotypes when compared to the control group (P<0.05. In addition, FH probands presented a high frequency of A+ (0.58, H+ (0.61 and P1 (0.78 alleles when compared to normolipidemic individuals (0.45, 0.45 and 0.64, respectively. The strong association observed between these alleles and FH suggests that AvaII, HincII1773 and PvuII polymorphisms could be useful to monitor the inheritance of FH in Brazilian families.

  12. Receptor Activity-modifying Protein-directed G Protein Signaling Specificity for the Calcitonin Gene-related Peptide Family of Receptors.

    Science.gov (United States)

    Weston, Cathryn; Winfield, Ian; Harris, Matthew; Hodgson, Rose; Shah, Archna; Dowell, Simon J; Mobarec, Juan Carlos; Woodlock, David A; Reynolds, Christopher A; Poyner, David R; Watkins, Harriet A; Ladds, Graham

    2016-10-14

    The calcitonin gene-related peptide (CGRP) family of G protein-coupled receptors (GPCRs) is formed through the association of the calcitonin receptor-like receptor (CLR) and one of three receptor activity-modifying proteins (RAMPs). Binding of one of the three peptide ligands, CGRP, adrenomedullin (AM), and intermedin/adrenomedullin 2 (AM2), is well known to result in a Gα s -mediated increase in cAMP. Here we used modified yeast strains that couple receptor activation to cell growth, via chimeric yeast/Gα subunits, and HEK-293 cells to characterize the effect of different RAMP and ligand combinations on this pathway. We not only demonstrate functional couplings to both Gα s and Gα q but also identify a Gα i component to CLR signaling in both yeast and HEK-293 cells, which is absent in HEK-293S cells. We show that the CGRP family of receptors displays both ligand- and RAMP-dependent signaling bias among the Gα s , Gα i , and Gα q/11 pathways. The results are discussed in the context of RAMP interactions probed through molecular modeling and molecular dynamics simulations of the RAMP-GPCR-G protein complexes. This study further highlights the importance of RAMPs to CLR pharmacology and to bias in general, as well as identifying the importance of choosing an appropriate model system for the study of GPCR pharmacology. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  13. Surface localization of the nuclear receptor CAR in influenza A virus-infected cells

    International Nuclear Information System (INIS)

    Takahashi, Tadanobu; Moriyama, Yusuke; Ikari, Akira; Sugatani, Junko; Suzuki, Takashi; Miwa, Masao

    2008-01-01

    Constitutive active/androstane receptor CAR is a member of the nuclear receptors which regulate transcription of xenobiotic metabolism enzymes. CAR is usually localized in the cytosol and nucleus. Here, we found that CAR was localized at the cell surface of influenza A virus (IAV)-infected cells. Additionally, we demonstrated that expression of a viral envelope glycoprotein, either hemagglutinin (HA) or neuraminidase (NA), but not viral nucleoprotein (NP), was responsible for this localization. This report is the first demonstration of CAR at the surface of tissue culture cells, and suggests that CAR may exert the IAV infection mechanism

  14. Identifying plant cell-surface receptors: combining 'classical' techniques with novel methods.

    Science.gov (United States)

    Uebler, Susanne; Dresselhaus, Thomas

    2014-04-01

    Cell-cell communication during development and reproduction in plants depends largely on a few phytohormones and many diverse classes of polymorphic secreted peptides. The peptide ligands are bound at the cell surface of target cells by their membranous interaction partners representing, in most cases, either receptor-like kinases or ion channels. Although knowledge of both the extracellular ligand and its corresponding receptor(s) is necessary to describe the downstream signalling pathway(s), to date only a few ligand-receptor pairs have been identified. Several methods, such as affinity purification and yeast two-hybrid screens, have been used very successfully to elucidate interactions between soluble proteins, but most of these methods cannot be applied to membranous proteins. Experimental obstacles such as low concentration and poor solubility of membrane receptors, as well as instable transient interactions, often hamper the use of these 'classical' approaches. However, over the last few years, a lot of progress has been made to overcome these problems by combining classical techniques with new methodologies. In the present article, we review the most promising recent methods in identifying cell-surface receptor interactions, with an emphasis on success stories outside the field of plant research.

  15. Characterization of cell-surface receptors for monoclonal-nonspecific suppressor factor (MNSF)

    International Nuclear Information System (INIS)

    Nakamura, M.; Ogawa, H.; Tsunematsu, T.

    1990-01-01

    Monoclonal-nonspecific suppressor factor (MNSF) is a lymphokine derived from murine T cell hybridoma. The target tissues are both LPS-stimulated B cells and Con A-stimulated T cells. Since the action of MNSF may be mediated by its binding to specific cell surface receptors, we characterized the mode of this binding. The purified MNSF was labeled with 125 I, using the Bolton-Hunter reagent. The labeled MNSF bound specifically to a single class of receptor (300 receptors per cell) on mitogen-stimulated murine B cells or T cells with an affinity of 16 pM at 24 degrees C, in the presence of sodium azide. Competitive experiments showed that MNSF bound to the specific receptor and that the binding was not shared with IL2, IFN-gamma, and TNF. Various cell types were surveyed for the capacity to specifically bind 125 I-MNSF. 125 I-MNSF bound to MOPC-31C (a murine plasmacytoma line) and to EL4 (a murine T lymphoma line). The presence of specific binding correlates with the capacity of the cells to respond to MNSF. These data support the view that like other polypeptide hormones, the action of MNSF is mediated by specific cell surface membrane receptor protein. Identification of these receptors will provide insight into the apparently diverse activities of MNSF

  16. Albumin receptor effect may be due to a surface-induced conformational change in albumin

    International Nuclear Information System (INIS)

    Reed, R.G.; Burrington, C.M.

    1989-01-01

    To determine whether equilibrium binding between albumin and hepatocytes involves a cell surface receptor for albumin, we incubated freshly isolated rat hepatocytes with 125 I-albumin and determined the amount of albumin associated with the cells as a function of the total albumin concentration. The resulting two-phase binding curve showed the rat albumin-hepatocyte interaction to consist of a saturable binding interaction with a dissociation constant of 1.1 microM and 2 X 10(6) sites/cell in addition to a weak, nonsaturable binding interaction. However, the saturable binding of albumin to hepatocytes did not appear to result from the presence of an albumin receptor on the cell surface; the interaction was the same for different species of albumin, for chemically modified albumins, and for fragments of albumin representing mutually exclusive domains of the molecule. The saturable binding was, instead, found to involve a subpopulation of albumin with an enhanced affinity for the cell surface. We show that this subpopulation of albumin is generated upon contact with either solid surfaces or cell surfaces and can be transferred from one surface to another. We propose that the two-phase Scatchard binding curve and the ''albumin receptor effect'' reflect two populations of albumin that bind to the cell surface with different affinities rather than one population of albumin that binds to two classes of binding sites

  17. Localization of Estrogen Receptors α and β in the Articular Surface of the Rat Femur

    International Nuclear Information System (INIS)

    Oshima, Yasushi; Matsuda, Ken-ichi; Yoshida, Atsuhiko; Watanabe, Nobuyoshi; Kawata, Mitsuhiro; Kubo, Toshikazu

    2007-01-01

    It has been suggested that the degradation of the articular cartilage and osteoarthritis (OA) are associated with gender and the estrogen hormone. Although many investigators have reported the presence of the estrogen receptors (ERs) α and β in the articular cartilage, the localization of these receptors and the difference in their in vivo expression have not yet been clearly demonstrated. We performed immunofluorescence staining of ERα and ERβ to elucidate the localization of the ERs and to note the effects of gender and the aging process on these receptors. The results revealed that ERα and ERβ were expressed in the articular cartilage and subchondral bone layers of adult rats of both sexes. We also observed the high expression of these receptors in immature rats. In contrast, their expression levels decreased in an ovariectomised model, as a simulation of postmenopause, and in aged female rats. Therefore, this study suggests the direct effects of estrogen and ER expression on articular surface metabolism

  18. A sensitive electrochemiluminescence cytosensor for quantitative evaluation of epidermal growth factor receptor expressed on cell surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Yanjuan; Zhang, Shaolian; Wen, Qingqing; Huang, Hongxing; Yang, Peihui, E-mail: typh@jnu.edu.cn

    2015-06-30

    Highlights: • EGF-cytosensor was used for evaluating EGFR expression level on cell surfaces. • CdSQDs and EGF were coated on magnetic beads (MBs) for ECL-probe. • Good sensitivity was achieved due to the signal amplification of ECL-probe. - Abstract: A sensitive electrochemiluminescence (ECL) strategy for evaluating the epidermal growth factor receptor (EGFR) expression level on cell surfaces was designed by integrating the specific recognition of EGFR expressed on MCF-7 cell surfaces with an epidermal growth factor (EGF)-funtionalized CdS quantum dots (CdSQDs)-capped magnetic bead (MB) probe. The high sensitivity of ECL probe of EGF-funtionalized CdSQD-capped-MB was used for competitive recognition with EGFR expressed on cell surfaces with recombinant EGFR protein. The changes of ECL intensity depended on both the cell number and the expression level of EGFR receptor on cell surfaces. A wide linear response to cells ranging from 80 to 4 × 10{sup 6} cells mL{sup −1} with a detection limit of 40 cells mL{sup −1} was obtained. The EGF-cytosensor was used to evaluate EGFR expression levels on MCF-7 cells, and the average number of EGFR receptor on single MCF-7 cells was 1.35 × 10{sup 5} with the relative standard deviation of 4.3%. This strategy was further used for in-situ and real-time evaluating EGFR receptor expressed on cell surfaces in response to drugs stimulation at different concentration and incubation time. The proposed method provided potential applications in the detection of receptors on cancer cells and anticancer drugs screening.

  19. Surface expression of NMDA receptor changes during memory consolidation in the crab Neohelice granulata

    Science.gov (United States)

    Hepp, Yanil; Salles, Angeles; Carbo-Tano, Martin

    2016-01-01

    The aim of the present study was to analyze the surface expression of the NMDA-like receptors during the consolidation of contextual learning in the crab Neohelice granulata. Memory storage is based on alterations in the strength of synaptic connections between neurons. The glutamatergic synapses undergo various forms of N-methyl-D aspartate receptor (NMDAR)-dependent changes in strength, a process that affects the abundance of other receptors at the synapse and underlies some forms of learning and memory. Here we propose a direct regulation of the NMDAR. Changes in NMDAR's functionality might be induced by the modification of the subunit's expression or cellular trafficking. This trafficking does not only include NMDAR's movement between synaptic and extra-synaptic localizations but also the cycling between intracellular compartments and the plasma membrane, a process called surface expression. Consolidation of contextual learning affects the surface expression of the receptor without affecting its general expression. The surface expression of the GluN1 subunit of the NMDAR is down-regulated immediately after training, up-regulated 3 h after training and returns to naïve and control levels 24 h after training. The changes in NMDAR surface expression observed in the central brain are not seen in the thoracic ganglion. A similar increment in surface expression of GluN1 in the central brain is observed 3 h after administration of the competitive GABAA receptor antagonist, bicuculline. These consolidation changes are part of a plasticity event that first, during the down-regulation, stabilizes the trace and later, at 3-h post-training, changes the threshold for synapse activation. PMID:27421895

  20. Familial risks and estrogen receptor-positive breast cancer in Hong Kong Chinese women.

    Directory of Open Access Journals (Sweden)

    Lap Ah Tse

    Full Text Available The role of family history to the risk of breast cancer was analyzed by incorporating menopausal status in Hong Kong Chinese women, with a particular respect to the estrogen receptor-positive (ER+ type.Seven hundred and forty seven breast cancer incident cases and 781 hospital controls who had completed information on family cancer history in first-degree relatives (nature father, mother, and siblings were recruited. Odds ratio for breast cancer were calculated by unconditional multiple logistic regression, stratified by menopausal status (a surrogate of endogenous female sex hormone level and age and type of relative affected with the disease. Further subgroup analysis by tumor type according to ER status was investigated.Altogether 52 (6.96% breast cancer cases and 23 (2.95% controls was found that the patients' one or more first-degree relatives had a history of breast cancer, showing an adjusted odds ratio (OR of 2.41 (95%CI: 1.45-4.02. An excess risk of breast cancer was restricted to the ER+ tumor (OR = 2.43, 95% CI: 1.38-4.28, with a relatively higher risk associated with an affected mother (OR = 3.97, 95%CI: 1.46-10.79 than an affected sister (OR = 2.06, 95%CI: 1.07-3.97, while the relative risk was more prominent in the subgroup of pre-menopausal women. Compared with the breast cancer overall, the familial risks to the ER+ tumor increased progressively with the number of affected first-degree relatives.This study provides new insights on a relationship between family breast cancer history, menopausal status, and the ER+ breast cancer. A separate risk prediction model for ER+ tumor in Asian population is desired.

  1. Familial risks and estrogen receptor-positive breast cancer in Hong Kong Chinese women.

    Science.gov (United States)

    Tse, Lap Ah; Li, Mengjie; Chan, Wing-cheong; Kwok, Chi-hei; Leung, Siu-lan; Wu, Cherry; Yu, Ignatius Tak-sun; Yu, Wai-cho; Lao, Xiangqian; Wang, Xiaorong; Wong, Carmen Ka-man; Lee, Priscilla Ming-yi; Wang, Feng; Yang, Xiaohong Rose

    2015-01-01

    The role of family history to the risk of breast cancer was analyzed by incorporating menopausal status in Hong Kong Chinese women, with a particular respect to the estrogen receptor-positive (ER+) type. Seven hundred and forty seven breast cancer incident cases and 781 hospital controls who had completed information on family cancer history in first-degree relatives (nature father, mother, and siblings) were recruited. Odds ratio for breast cancer were calculated by unconditional multiple logistic regression, stratified by menopausal status (a surrogate of endogenous female sex hormone level and age) and type of relative affected with the disease. Further subgroup analysis by tumor type according to ER status was investigated. Altogether 52 (6.96%) breast cancer cases and 23 (2.95%) controls was found that the patients' one or more first-degree relatives had a history of breast cancer, showing an adjusted odds ratio (OR) of 2.41 (95%CI: 1.45-4.02). An excess risk of breast cancer was restricted to the ER+ tumor (OR = 2.43, 95% CI: 1.38-4.28), with a relatively higher risk associated with an affected mother (OR = 3.97, 95%CI: 1.46-10.79) than an affected sister (OR = 2.06, 95%CI: 1.07-3.97), while the relative risk was more prominent in the subgroup of pre-menopausal women. Compared with the breast cancer overall, the familial risks to the ER+ tumor increased progressively with the number of affected first-degree relatives. This study provides new insights on a relationship between family breast cancer history, menopausal status, and the ER+ breast cancer. A separate risk prediction model for ER+ tumor in Asian population is desired.

  2. Orphan Nuclear Receptor NR4A1 Binds a Novel Protein Interaction Site on Anti-apoptotic B Cell Lymphoma Gene 2 Family Proteins.

    Science.gov (United States)

    Godoi, Paulo H C; Wilkie-Grantham, Rachel P; Hishiki, Asami; Sano, Renata; Matsuzawa, Yasuko; Yanagi, Hiroko; Munte, Claudia E; Chen, Ya; Yao, Yong; Marassi, Francesca M; Kalbitzer, Hans R; Matsuzawa, Shu-Ichi; Reed, John C

    2016-07-01

    B cell lymphoma gene 2 (Bcl-2) family proteins are key regulators of programmed cell death and important targets for drug discovery. Pro-apoptotic and anti-apoptotic Bcl-2 family proteins reciprocally modulate their activities in large part through protein interactions involving a motif known as BH3 (Bcl-2 homology 3). Nur77 is an orphan member of the nuclear receptor family that lacks a BH3 domain but nevertheless binds certain anti-apoptotic Bcl-2 family proteins (Bcl-2, Bfl-1, and Bcl-B), modulating their effects on apoptosis and autophagy. We used a combination of NMR spectroscopy-based methods, mutagenesis, and functional studies to define the interaction site of a Nur77 peptide on anti-apoptotic Bcl-2 family proteins and reveal a novel interaction surface. Nur77 binds adjacent to the BH3 peptide-binding crevice, suggesting the possibility of cross-talk between these discrete binding sites. Mutagenesis of residues lining the identified interaction site on Bcl-B negated the interaction with Nur77 protein in cells and prevented Nur77-mediated modulation of apoptosis and autophagy. The findings establish a new protein interaction site with the potential to modulate the apoptosis and autophagy mechanisms governed by Bcl-2 family proteins. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  3. Characterization of the formyl peptide chemotactic receptor appearing at the phagocytic cell surface after exposure to phorbol myristate acetate

    International Nuclear Information System (INIS)

    Gardner, J.P.; Melnick, D.A.; Malech, H.L.

    1986-01-01

    The biochemistry and subcellular source of new formyl peptide chemotactic receptor appearing at the human neutrophil and differentiated HL-60 (d-HL-60) cell surface after stimulation with phorbol myristate acetate (PMA) were examined. Formyl peptide receptor was analyzed by affinity labeling with formyl-norleu-leu-phe-norleu- [ 125 I]iodotyr-lys and ethylene glycol bis(succinimidyl succinate) followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and densitometric analysis of autoradiographs. PMA, a specific granule secretagogue, increases affinity labeling of formyl peptide receptors on the neutrophil surface by 100%, and on d-HL-60, which lack specific granule markers, by 20%. Papain treatment markedly reduces surface labeling of formyl peptide receptor in both neutrophils and d-HL-60, and results in the appearance of a lower m.w. membrane-bound receptor fragment. PMA stimulation of papain-treated cells increases uncleaved surface receptor on neutrophils by 400%, and on D-HL-60 by only 45%. This newly appearing receptor is the same apparent m.w. (55,000 to 75,000 for neutrophils; 62,000 to 80,000 for d-HL-60) and yields the same papain cleavage product as receptor on the surface of unstimulated cells. These observations suggest that specific granule membranes contain large amounts of formyl peptide receptor, which is biochemically identical to that found on the cell surface and can be mobilized to the cell surface with appropriate stimulation

  4. Minireview: nuclear receptor coregulators of the p160 family: insights into inflammation and metabolism.

    Science.gov (United States)

    Rollins, David A; Coppo, Maddalena; Rogatsky, Inez

    2015-04-01

    Nuclear receptor coactivators (NCOAs) are multifunctional transcriptional coregulators for a growing number of signal-activated transcription factors. The members of the p160 family (NCOA1/2/3) are increasingly recognized as essential and nonredundant players in a number of physiological processes. In particular, accumulating evidence points to the pivotal roles that these coregulators play in inflammatory and metabolic pathways, both under homeostasis and in disease. Given that chronic inflammation of metabolic tissues ("metainflammation") is a driving force for the widespread epidemic of obesity, insulin resistance, cardiovascular disease, and associated comorbidities, deciphering the role of NCOAs in "normal" vs "pathological" inflammation and in metabolic processes is indeed a subject of extreme biomedical importance. Here, we review the evolving and, at times, contradictory, literature on the pleiotropic functions of NCOA1/2/3 in inflammation and metabolism as related to nuclear receptor actions and beyond. We then briefly discuss the potential utility of NCOAs as predictive markers for disease and/or possible therapeutic targets once a better understanding of their molecular and physiological actions is achieved.

  5. Scratching the surface: Regulation of cell surface receptors in cholesterol metabolism

    NARCIS (Netherlands)

    Nelson, J.K.

    2016-01-01

    Elevated plasma levels of low density lipoprotein cholesterol (LDL) are an established risk factor for the development of atherosclerosis and cardiovascular diseases. The LDL-Receptor is a key determinant in regulating LDL levels in plasma, and current lipid-lowering strategies aim to increase its

  6. Ligand-independent Thrombopoietin Mutant Receptor Requires Cell Surface Localization for Endogenous Activity*

    Science.gov (United States)

    Marty, Caroline; Chaligné, Ronan; Lacout, Catherine; Constantinescu, Stefan N.; Vainchenker, William; Villeval, Jean-Luc

    2009-01-01

    The activating W515L mutation in the thrombopoietin receptor (MPL) has been identified in primary myelofibrosis and essential thrombocythemia. MPL belongs to a subset of the cytokine receptor superfamily that requires the JAK2 kinase for signaling. We examined whether the ligand-independent MPLW515L mutant could signal intracellularly. Addition of the endoplasmic reticulum (ER) retention KDEL sequence to the receptor C terminus efficiently locked MPLW515L within its natural ER/Golgi maturation pathway. In contrast to cells expressing the parental MPLW515L, MPLW515L-KDEL-expressing FDC-P1 cells were unable to grow autonomously and to produce tumors in nude mice. When observed, tumor nodules resulted from in vivo selection of cells leaking the receptor at their surface. JAK2 co-immunoprecipitated with MPLW515L-KDEL but was not phosphorylated. We generated disulfide-bonded MPLW515L homodimers by the S402C substitution, both in the normal and KDEL context. Unlike MPLW515L-KDEL, MPLW515L-S402C-KDEL signaled constitutively and exhibited cell surface localization. These data establish that MPLW515L with appended JAK2 matures through the ER/Golgi system in an inactive conformation and suggest that the MPLW515L/JAK2 complex requires membrane localization for JAK2 phosphorylation, resulting in autonomous receptor signaling. PMID:19261614

  7. Rapid surface accumulation of NMDA receptors increases glutamatergic excitation during status epilepticus.

    Science.gov (United States)

    Naylor, David E; Liu, Hantao; Niquet, Jerome; Wasterlain, Claude G

    2013-06-01

    After 1h of lithium-pilocarpine status epilepticus (SE), immunocytochemical labeling of NMDA receptor NR1 subunits reveals relocation of subunits from the interior to the cell surface of dentate gyrus granule cells and CA3 pyramidal cells. Simultaneously, an increase in NMDA-miniature excitatory postsynaptic currents (mEPSC) as well as an increase in NMDA receptor-mediated tonic currents is observed in hippocampal slices after SE. Mean-variance analysis of NMDA-mEPSCs estimates that the number of functional postsynaptic NMDA receptors per synapse increases 38% during SE, and antagonism by ifenprodil suggests that an increase in the surface representation of NR2B-containing NMDA receptors is responsible for the augmentation of both the phasic and tonic excitatory currents with SE. These results provide a potential mechanism for an enhancement of glutamatergic excitation that maintains SE and may contribute to excitotoxic injury during SE. Therapies that directly antagonize NMDA receptors may be a useful therapeutic strategy during refractory SE. Copyright © 2013 Elsevier Inc. All rights reserved.

  8. Sequence comparisons of odorant receptors among tortricid moths reveal different rates of molecular evolution among family members.

    Directory of Open Access Journals (Sweden)

    Colm Carraher

    Full Text Available In insects, odorant receptors detect volatile cues involved in behaviours such as mate recognition, food location and oviposition. We have investigated the evolution of three odorant receptors from five species within the moth genera Ctenopseustis and Planotrotrix, family Tortricidae, which fall into distinct clades within the odorant receptor multigene family. One receptor is the orthologue of the co-receptor Or83b, now known as Orco (OR2, and encodes the obligate ion channel subunit of the receptor complex. In comparison, the other two receptors, OR1 and OR3, are ligand-binding receptor subunits, activated by volatile compounds produced by plants--methyl salicylate and citral, respectively. Rates of sequence evolution at non-synonymous sites were significantly higher in OR1 compared with OR2 and OR3. Within the dataset OR1 contains 109 variable amino acid positions that are distributed evenly across the entire protein including transmembrane helices, loop regions and termini, while OR2 and OR3 contain 18 and 16 variable sites, respectively. OR2 shows a high level of amino acid conservation as expected due to its essential role in odour detection; however we found unexpected differences in the rate of evolution between two ligand-binding odorant receptors, OR1 and OR3. OR3 shows high sequence conservation suggestive of a conserved role in odour reception, whereas the higher rate of evolution observed in OR1, particularly at non-synonymous sites, may be suggestive of relaxed constraint, perhaps associated with the loss of an ancestral role in sex pheromone reception.

  9. Receptor homodimerization plays a critical role in a novel dominant negative P2RY12 variant identified in a family with severe bleeding.

    Science.gov (United States)

    Mundell, S J; Rabbolini, D; Gabrielli, S; Chen, Q; Aungraheeta, R; Hutchinson, J L; Kilo, T; Mackay, J; Ward, C M; Stevenson, W; Morel-Kopp, M-C

    2018-01-01

    Essentials Three dominant variants for the autosomal recessive bleeding disorder type-8 have been described. To date, there has been no phenotype/genotype correlation explaining their dominant transmission. Proline plays an important role in P2Y12R ligand binding and signaling defects. P2Y12R homodimer formation is critical for the receptor function and signaling. Background Although inherited platelet disorders are still underdiagnosed worldwide, advances in molecular techniques are improving disease diagnosis and patient management. Objective To identify and characterize the mechanism underlying the bleeding phenotype in a Caucasian family with an autosomal dominant P2RY12 variant. Methods Full blood counts, platelet aggregometry, flow cytometry and western blotting were performed before next-generation sequencing (NGS). Detailed molecular analysis of the identified variant of the P2Y12 receptor (P2Y12R) was subsequently performed in mammalian cells overexpressing receptor constructs. Results All three referred individuals had markedly impaired ADP-induced platelet aggregation with primary wave only, despite normal total and surface P2Y12R expression. By NGS, a single P2RY12:c.G794C substitution (p.R265P) was identified in all affected individuals, and this was confirmed by Sanger sequencing. Mammalian cell experiments with the R265P-P2Y12R variant showed normal receptor surface expression versus wild-type (WT) P2Y12R. Agonist-stimulated R265P-P2Y12R function (both signaling and surface receptor loss) was reduced versus WT P2Y12R. Critically, R265P-P2Y12R acted in a dominant negative manner, with agonist-stimulated WT P2Y12R activity being reduced by variant coexpression, suggesting dramatic loss of WT homodimers. Importantly, platelet P2RY12 cDNA cloning and sequencing in two affected individuals also revealed three-fold mutant mRNA overexpression, decreasing even further the likelihood of WT homodimer formation. R265 located within extracellular loop 3 (EL3) is

  10. Morphological Specifications of the Bird Schistosome Cercariae and Surface Carbohydrates as Receptors for Lectins

    Directory of Open Access Journals (Sweden)

    I Moebedi

    2007-04-01

    Full Text Available Background: To determine the morphological specifications of the bird schistosomes cercaria from Lymnaea gedrosiana and to detect the surface carbohydrates as receptors for host lectins in the host-parasite relationship systems such as avian schistosomiasis and human cercarial dermatitis. Methods: One hundred ninety two snails collected from Dezful areas in Khuzestan Province, in the south west of Iran, during 2005-2006 were examined for cercariae using shedding and crushing methods. In addition, surface carbohydrates on the cercariae were detected by lentil (Lens culinaris lectins. Results: From the total number of Lymnaea gedrosiana, which examined for bird schistosomes cercaria, 9(4% snails were found to be infected with furcocercus cercaria of the bird schistosomes (probably Gigantobilharzia sp.. Mannose monosaccharide CH2OH (CHOH4CHO as surface carbohydrate was also detected on the cercariae. Conclusion: Mannose carbohydrate on these cercariae may be used as receptor by lectins.

  11. Quantification of the number of EP3 receptors on a living CHO cell surface by the AFM

    International Nuclear Information System (INIS)

    Kim, Hyonchol; Arakawa, Hideo; Hatae, Noriyuki; Sugimoto, Yukihiko; Matsumoto, Osamu; Osada, Toshiya; Ichikawa, Atsushi; Ikai, Atsushi

    2006-01-01

    The distribution of EP3 receptors on a living cell surface was quantitatively studied by atomic force microscopy (AFM). Green fluorescent protein (GFP) was introduced to the extracellular region of the EP3 receptor on a CHO cell. A microbead was used as a probe to ensure certain contact area, whose surface was coated with anti-GFP antibody. The interactions between the antibodies and GFP molecules on the cell surface were recorded to observe the distribution of the receptors. The result indicated that EP3 receptors were distributed on the CHO cell surface not uniformly but in small patches coincident with immunohistochemical observation. Repeated measurements on the same area of cell surface gave confirmation that it was unlikely that the receptors were extracted from the cell membrane during the experiments. The measurement of single molecular interaction between GFP and the anti-GFP antibody was succeeded on the cell surface using compression-free force spectroscopy. The value of separation work required to break a single molecular pair was estimated to be about 1.5x10 -18 J. The number of EP3 receptor on the CHO cell surface was estimated using this value to be about 1x10 4 under the assumption that the area of the cell surface was about 5000 μm 2 . These results indicated that the number of receptors on a living cell surface could be quantified through the force measurement by the AFM

  12. A model for the biosynthesis and transport of plasma membrane-associated signaling receptors to the cell surface

    Directory of Open Access Journals (Sweden)

    Sorina Claudia Popescu

    2012-04-01

    Full Text Available Intracellular protein transport is emerging as critical in determining the outcome of receptor-activated signal transduction pathways. In plants, relatively little is known about the nature of the molecular components and mechanisms involved in coordinating receptor synthesis and transport to the cell surface. Recent advances in this field indicate that signaling pathways and intracellular transport machinery converge and coordinate to render receptors competent for signaling at their plasma membrane activity sites. The biogenesis and transport to the cell surface of signaling receptors appears to require both general trafficking and receptor-specific factors. Several molecular determinants, residing or associated with compartments of the secretory pathway and known to influence aspects in receptor biogenesis, are discussed and integrated into a predictive cooperative model for the functional expression of signaling receptors at the plasma membrane.

  13. Deletion in the first cysteine-rich repeat of low density lipoprotein receptor impairs its transport but not lipoprotein binding in fibroblasts from a subject with familial hypercholesterolemia

    International Nuclear Information System (INIS)

    Leitersdorf, E.; Hobbs, H.H.; Fourie, A.M.; Jacobs, M.; Van Der Westhuyzen, D.R.; Coetzee, G.A.

    1988-01-01

    The ligand-binding domain of the low density lipoprotein (LDL) receptor is composed of seven cysteine-rich repeats, each ∼ 40 amino acids long. Previous studies showed that if the first repeat of the ligand-binding domain (encoded by exon 2) is deleted, the receptor fails to bind an anti-LDL receptor monoclonal antibody (IgG-C7) but continues to bind LDL with high affinity. Cultured fibroblasts from a Black South African Xhosa patient (TT) with the clinical syndrome of homozygous familial hypercholesterolemia demonstrated high-affinity cell-surface binding of 125 I-labeled LDL but not 125 I-labeled IgG-C7. previous haplotype analysis, using 10 restriction fragment length polymorphic sites, suggested that the patient inherited two identical LDL receptor alleles. The polymerase chain reaction technique was used to selectively amplify exon 2 of the LDL receptor gene from this patient. Sequence analysis of the amplified fragment disclosed a deletion of six base pairs that removes two amino acids, aspartic acid and glycine, from the first cysteine-rich ligand binding repeat. The mutation creates a new Pst I restriction site that can be used to detect the deletion. The existence of this mutant allele confirms that the epitope of IgG-C7 is located in the first cysteine-rich repeat and that this repeat is not necessary for LDL binding. The mutant gene produced a normally sized 120-kilodalton LDL receptor precursor protein that matured to the 160-kilodalton form at less than one-fourth the normal rate

  14. Mutation G805R in the transmembrane domain of the LDL receptor gene causes familial hypercholesterolemia by inducing ectodomain cleavage of the LDL receptor in the endoplasmic reticulum

    Directory of Open Access Journals (Sweden)

    Thea Bismo Strøm

    2014-01-01

    Full Text Available More than 1700 mutations in the low density lipoprotein receptor (LDLR gene have been found to cause familial hypercholesterolemia (FH. These are commonly divided into five classes based upon their effects on the structure and function of the LDLR. However, little is known about the mechanism by which mutations in the transmembrane domain of the LDLR gene cause FH. We have studied how the transmembrane mutation G805R affects the function of the LDLR. Based upon Western blot analyses of transfected HepG2 cells, mutation G805R reduced the amounts of the 120 kDa precursor LDLR in the endoplasmic reticulum. This led to reduced amounts of the mature 160 kDa LDLR at the cell surface. However, significant amounts of a secreted 140 kDa G805R-LDLR ectodomain fragment was observed in the culture media. Treatment of the cells with the metalloproteinase inhibitor batimastat largely restored the amounts of the 120 and 160 kDa forms in cell lysates, and prevented secretion of the 140 kDa ectodomain fragment. Together, these data indicate that a metalloproteinase cleaved the ectodomain of the 120 kDa precursor G805R-LDLR in the endoplasmic reticulum. It was the presence of the polar Arg805 and not the lack of Gly805 which led to ectodomain cleavage. Arg805 also prevented γ-secretase cleavage within the transmembrane domain. It is conceivable that introducing a charged residue within the hydrophobic membrane lipid bilayer, results in less efficient incorporation of the 120 kDa G805R-LDLR in the endoplasmic reticulum membrane and makes it a substrate for metalloproteinase cleavage.

  15. On algebraic cycles on a fibre product of families of K3-surfaces

    International Nuclear Information System (INIS)

    Nikol'skaya, Ol'ga V

    2013-01-01

    We prove the Hodge conjecture and the standard conjecture of Lefschetz type for fibre squares of smooth projective non-isotrivial families of K3-surfaces over a smooth projective curve under the assumption that the rank of the lattice of transcendental cycles on a generic geometric fibre of the family is an odd prime. We prove the Hodge conjecture for a fibre product of two non-isotrivial families of K3-surfaces (possibly with degenerations) under the condition that, for every point of the curve, at least one family has non-singular fibre over this point, and the rank of the lattice of transcendental cycles on a generic geometric fibre of one family is odd and not equal to the corresponding rank for the other.

  16. Activation of Relaxin Family Receptor 1 from different mammalian species by relaxin peptide and small molecule agonist ML290

    Directory of Open Access Journals (Sweden)

    Zaohua eHuang

    2015-08-01

    Full Text Available Relaxin peptide (RLN, which signals through the relaxin family peptide 1 (RXFP1 GPCR receptor, has shown therapeutic effects in an acute heart failure clinical trial. We have identified a small molecule agonist of human RXFP1, ML290; however, it does not activate the mouse receptor. To find a suitable animal model for ML290 testing and to gain mechanistic insights into the interaction of various ligands with RXFP1, we have cloned rhesus macaque, pig, rabbit, and guinea pig RXFP1s and analyzed their activation by RLN and ML290. HEK293T cells expressing macaque or pig RXFP1 responded to relaxin and ML290 treatment as measured by an increase of cAMP production. Guinea pig RXFP1 responded to relaxin but had very low response to ML290 treatment only at highest concentrations used. The rabbit RXFP1 amino acid sequence was the most divergent, with a number of unique substitutions within the ectodomain and the 7-transmembrane domain (7TM. Two splice variants of rabbit RXFP1 derived through alternative splicing of the forth exon were identified. In contrast to the other species, rabbit RXFP1s were activated by ML290, but not with human, pig, mouse, or rabbit relaxins. Using FLAG-tagged constructs, we have shown that both rabbit RXFP1 variants are expressed on the cell surface. No binding of human Eu-labeled relaxin to rabbit RXFP1 was detected, suggesting that in this species RXFP1 might be non-functional. We used chimeric rabbit-human and guinea pig-human constructs to identify regions important for RLN or ML290 receptor activation. Chimeras with the human ectodomain and rabbit 7TM domain were activated by RLN, whereas substitution of part of the guinea pig 7TM domain with the human sequence only partially restored ML290 activation, confirming the allosteric mode of action for the two ligands. Our data demonstrate that macaque and pig models can be used for ML290 testing.

  17. Radiation-induced pulmonary fibrosis: examination of chemokine and chemokine receptor families.

    Science.gov (United States)

    Johnston, Carl J; Williams, Jacqueline P; Okunieff, Paul; Finkelstein, Jacob N

    2002-03-01

    Fibrosis is a common outcome of chronic inflammation or injury. Pulmonary fibrosis may be the result of abnormal repair after an acute inflammatory response. The process of repair initiated by a tissue insult is largely a function of the activation of cells to produce important biological mediators such as cytokines, growth factors and chemokines, which orchestrate most aspects of the inflammatory response. Consequently, altered regulation of the production of inflammatory cell cytokines and chemokines after injury and repair likely contributes to the fibrosis. Our hypothesis is that chronic expression of specific chemokine and chemokine receptors during the fibrotic phase induced by thoracic irradiation may perpetuate the recruitment and activation of lymphocytes and macrophages, which may contribute to the development of fibrosis. Fibrosis-sensitive (C57BL/6) and fibrosis-resistant (C3H/HeJ) mice were irradiated with a single dose of 12.5 Gy to the thorax. Total lung RNA was prepared and hybridized using microarray analysis and RNase protection assays. At 26 weeks postirradiation, messages encoding the chemokines BLC (now known as Scyb13), C10 (now known as Scya6), IP-10 (now known as Scyb10), MCP-1 (now known as Scya2), MCP-3 (now known as Scya7), MIP-1gamma (now known as Scya9), and RANTES (now known as Scya5) and the chemokine receptors Ccr1, Ccr2, Ccr5 and Ccr6 were elevated in fibrosis-sensitive (C57BL/6) mice. In contrast, only the messages encoding SDF-1alpha (now known as Sdf1) and Ccr1 were elevated 26 weeks postirradiation in fibrosis-resistant (C3H/HeJ) mice. Our results point to the CC and CCR family members as the predominant chemokine responders during the development of fibrosis. These studies suggest that monocyte/macrophage and lymphocyte recruitment and activation are key components of radiation-induced fibrosis.

  18. Vitamin A Transport Mechanism of the Multitransmembrane Cell-Surface Receptor STRA6

    Directory of Open Access Journals (Sweden)

    Riki Kawaguchi

    2015-08-01

    Full Text Available Vitamin A has biological functions as diverse as sensing light for vision, regulating stem cell differentiation, maintaining epithelial integrity, promoting immune competency, regulating learning and memory, and acting as a key developmental morphogen. Vitamin A derivatives have also been used in treating human diseases. If vitamin A is considered a drug that everyone needs to take to survive, evolution has come up with a natural drug delivery system that combines sustained release with precise and controlled delivery to the cells or tissues that depend on it. This “drug delivery system” is mediated by plasma retinol binding protein (RBP, the principle and specific vitamin A carrier protein in the blood, and STRA6, the cell-surface receptor for RBP that mediates cellular vitamin A uptake. The mechanism by which the RBP receptor absorbs vitamin A from the blood is distinct from other known cellular uptake mechanisms. This review summarizes recent progress in elucidating the fundamental molecular mechanism mediated by the RBP receptor and multiple newly discovered catalytic activities of this receptor, and compares this transport system with retinoid transport independent of RBP/STRA6. How to target this new type of transmembrane receptor using small molecules in treating diseases is also discussed.

  19. Model for capping of membrane receptors based on boundary surface effects

    Science.gov (United States)

    Gershon, N. D.

    1978-01-01

    Crosslinking of membrane surface receptors may lead to their segregation into patches and then into a single large aggregate at one pole of the cell. This process is called capping. Here, a novel explanation of such a process is presented in which the membrane is viewed as a supersaturated solution of receptors in the lipid bilayer and the adjacent two aqueous layers. Without a crosslinking agent, a patch of receptors that is less than a certain size cannot stay in equilibrium with the solution and thus should dissolve. Patches greater than a certain size are stable and can, in principle, grow by the precipitation of the remaining dissolved receptors from the supersaturated solution. The task of the crosslinking molecules is to form such stable patches. These considerations are based on a qualitative thermodynamic calculation that takes into account the existence of a boundary tension in a patch (in analogy to the surface tension of a droplet). Thermodynamically, these systems should cap spontaneously after the patches have reached a certain size. But, in practice, such a process can be very slow. A suspension of patches may stay practically stable. The ways in which a cell may abolish this metastable equilibrium and thus achieve capping are considered and possible effects of capping inhibitors are discussed. PMID:274724

  20. Fc-receptors and surface immunoglobulins in cells of the hairy cell leukemia

    Energy Technology Data Exchange (ETDEWEB)

    Rieber, E P; Linke, R P; Riethmueller, G [Tuebingen Univ. (Germany, F.R.). Abt. fuer Experimentelle Chirurgie und Immunologie; Heyden, H.W. von; Waller, H D [Tuebingen Univ. (Germany, F.R.). Abt. Innere Medizin 2

    1976-01-01

    Using /sup 125/I-labelled aggregated IgG in a quantitative assay a strong expression of Fc-receptors was found on the leukemic cells of a patient with hairy cell leukemia. The Fc-receptor activity on these cells was much higher than that on monocytes and B-lymphocytes from normal blood. Surface immunoglobulins were detected by radioautography using radioactively labelled (Fab')/sub 2/-fragments of monospecific antibodies directed against immunoglobulin heavy chains. Prior to radioautography the cells were stained for the tartrate resistant acid phosphatase. It is found that all cells containing this enzyme bore delta-chains on their surface. On more than 90% of these cells a simultaneous expression of ..mu..-chains was detected. ..gamma..-chains could only be demonstrated on cells which were negative for the tartrate resistant acid phosphatase; part of these cells, however, were hairy cells by morphological criteria.

  1. Fc-receptors and surface immunoglobulins in cells of the hairy cell leukemia

    International Nuclear Information System (INIS)

    Rieber, E.P.; Linke, R.P.; Riethmueller, G.; Heyden, H.W. von; Waller, H.D.

    1976-01-01

    Using 125 I-labelled aggregated IgG in a quantitative assay a strong expression of Fc-receptors was found on the leukemic cells of a patient with hairy cell leukemia. The Fc-receptor activity on these cells was much higher than that on monocytes and B-lymphocytes from normal blood. Surface immunoglobulins were detected by radioautography using radioactively labelled (Fab') 2 -fragments of monospecific antibodies directed against immunoglobulin heavy chains. Prior to radioautography the cells were stained for the tartrate resistant acid phosphatase. It is found that all cells containing this enzyme bore delta-chains on their surface. On more than 90% of these cells a simultaneous expression of μ-chains was detected. γ-chains could only be demonstrated on cells which were negative for the tartrate resistant acid phosphatase; part of these cells, however, were hairy cells by morphological criteria. (orig.) [de

  2. The macrophage CD163 surface glycoprotein is an erythroblast adhesion receptor

    DEFF Research Database (Denmark)

    Fabriek, Babs O; Polfliet, Machteld M J; Vloet, Rianka P M

    2007-01-01

    Erythropoiesis occurs in erythroblastic islands, where developing erythroblasts closely interact with macrophages. The adhesion molecules that govern macrophage-erythroblast contact have only been partially defined. Our previous work has implicated the rat ED2 antigen, which is highly expressed...... on the surface of macrophages in erythroblastic islands, in erythroblast binding. In particular, the monoclonal antibody ED2 was found to inhibit erythroblast binding to bone marrow macrophages. Here, we identify the ED2 antigen as the rat CD163 surface glycoprotein, a member of the group B scavenger receptor...... that it enhanced erythroid proliferation and/or survival, but did not affect differentiation. These findings identify CD163 on macrophages as an adhesion receptor for erythroblasts in erythroblastic islands, and suggest a regulatory role for CD163 during erythropoiesis....

  3. Parathyroid hormone induces the Nrna family of nuclear orphan receptors in vivo

    International Nuclear Information System (INIS)

    Pirih, Flavia Q.; Aghaloo, Tara L.; Bezouglaia, Olga; Nervina, Jeanne M.; Tetradis, Sotirios

    2005-01-01

    Parathyroid hormone (PTH) has both anabolic and catabolic effects on bone metabolism, although the molecular mechanisms mediating these effects are largely unknown. Among the transcription factors induced by Pth in osteoblasts are the nerve growth factor-inducible factor B (NR4A; NGFI-B) family of orphan nuclear receptors: Nurr1, Nur77, and NOR-1. PTH induces NR4A members through the cAMP-protein kinase A (PKA) pathway in vitro. We report here that PTH rapidly and transiently induced expression of all three NR4A genes in PTH-target tissues in vivo. In calvaria, long bones, and kidneys, NR4A induction was maximal 0.5-1 h after a single intraperitoneal (i.p.) injection of 80 μg/kg PTH. Nur77 demonstrated the highest expression, followed, in order, by Nurr1 and NOR-1. In calvaria and long bone, PTH-induced expression of each NR4A gene was detectable at 10 μg/kg i.p. with maximum induction at 40-80 μg/kg. PTH (3-34) did not induce NR4A mRNA levels in calvaria, long bone, and kidney in vivo, confirming our in vitro results that NR4A genes are induced primarily through the cAMP-PKA pathway. The magnitude of PTH-induced NR4A expression was comparable in vivo and in vitro. However, NR4A mRNA levels peaked and returned to baseline faster in vivo. Both in vivo and in vitro, PTH induced NR4A pre-mRNA levels suggesting that induction of these genes is, at least in part, through activation of mRNA synthesis. The in vivo induction of the NR4A family members by PTH suggests their involvement in, at least some, PTH-induced changes in bone metabolism

  4. Oxygen Modulates Human Decidual Natural Killer Cell Surface Receptor Expression and Interactions with Trophoblasts1

    Science.gov (United States)

    Wallace, Alison E.; Goulwara, Sonu S.; Whitley, Guy S.; Cartwright, Judith E.

    2014-01-01

    Decidual natural killer (dNK) cells have been shown to both promote and inhibit trophoblast behavior important for decidual remodeling in pregnancy and have a distinct phenotype compared to peripheral blood NK cells. We investigated whether different levels of oxygen tension, mimicking the physiological conditions of the decidua in early pregnancy, altered cell surface receptor expression and activity of dNK cells and their interactions with trophoblast. dNK cells were isolated from terminated first-trimester pregnancies and cultured in oxygen tensions of 3%, 10%, and 21% for 24 h. Cell surface receptor expression was examined by flow cytometry, and the effects of secreted factors in conditioned medium (CM) on the trophoblast cell line SGHPL-4 were assessed in vitro. SGHPL-4 cells treated with dNK cell CM incubated in oxygen tensions of 10% were significantly more invasive (P cells treated with dNK cell CM incubated in oxygen tensions of 3% or 21%. After 24 h, a lower percentage of dNK cells expressed CD56 at 21% oxygen (P cells expressed NKG2D at 10% oxygen (P oxygen tensions, with large patient variation. This study demonstrates dNK cell phenotype and secreted factors are modulated by oxygen tension, which induces changes in trophoblast invasion and endovascular-like differentiation. Alterations in dNK cell surface receptor expression and secreted factors at different oxygen tensions may represent regulation of function within the decidua during the first trimester of pregnancy. PMID:25232021

  5. Ligand-specific regulation of the extracellular surface of a G-protein-coupled receptor

    Energy Technology Data Exchange (ETDEWEB)

    Bokoch, Michael P.; Zou, Yaozhong; Rasmussen, Søren G.F.; Liu, Corey W.; Nygaard, Rie; Rosenbaum, Daniel M.; Fung, Juan José; Choi, Hee-Jung; Thian, Foon Sun; Kobilka, Tong Sun; Puglisi, Joseph D.; Weis, William I.; Pardo, Leonardo; Prosser, R. Scott; Mueller, Luciano; Kobilka, Brian K. (Stanford-MED); (Toronto); (BMS); (UAB, Spain)

    2010-01-14

    G-protein-coupled receptors (GPCRs) are seven-transmembrane proteins that mediate most cellular responses to hormones and neurotransmitters. They are the largest group of therapeutic targets for a broad spectrum of diseases. Recent crystal structures of GPCRs have revealed structural conservation extending from the orthosteric ligand-binding site in the transmembrane core to the cytoplasmic G-protein-coupling domains. In contrast, the extracellular surface (ECS) of GPCRs is remarkably diverse and is therefore an ideal target for the discovery of subtype-selective drugs. However, little is known about the functional role of the ECS in receptor activation, or about conformational coupling of this surface to the native ligand-binding pocket. Here we use NMR spectroscopy to investigate ligand-specific conformational changes around a central structural feature in the ECS of the {beta}{sub 2} adrenergic receptor: a salt bridge linking extracellular loops 2 and 3. Small-molecule drugs that bind within the transmembrane core and exhibit different efficacies towards G-protein activation (agonist, neutral antagonist and inverse agonist) also stabilize distinct conformations of the ECS. We thereby demonstrate conformational coupling between the ECS and the orthosteric binding site, showing that drugs targeting this diverse surface could function as allosteric modulators with high subtype selectivity. Moreover, these studies provide a new insight into the dynamic behaviour of GPCRs not addressable by static, inactive-state crystal structures.

  6. A novel mutation in the calcium-sensing receptor gene in an Irish pedigree showing familial hypocalciuric hypercalcemia: a case report.

    LENUS (Irish Health Repository)

    Elamin, Wael F

    2010-01-01

    Familial hypocalciuric hypercalcemia is a rare autosomal dominant disorder characterized by asymptomatic and non-progressive hypercalcemia due to mutations of the calcium-sensing receptor gene. Disorders of calcium metabolism are very common in the elderly, and they can coexist with familial hypocalciuric hypercalcemia in affected families.

  7. Basigin-2 Is a Cell Surface Receptor for Soluble Basigin Ligand*S⃞

    Science.gov (United States)

    Belton, Robert J.; Chen, Li; Mesquita, Fernando S.; Nowak, Romana A.

    2008-01-01

    The metastatic spread of a tumor is dependent upon the ability of the tumor to stimulate surrounding stromal cells to express enzymes required for tissue remodeling. The immunoglobulin superfamily protein basigin (EMMPRIN/CD147) is a cell surface glycoprotein expressed by tumor cells that stimulates matrix metalloproteinase and vascular endothelial growth factor expression in stromal cells. The ability of basigin to stimulate expression of molecules involved in tissue remodeling and angiogenesis makes basigin a potential target for the development of strategies to block metastasis. However, the identity of the cell surface receptor for basigin remains controversial. The goal of this study was to determine the identity of the receptor for basigin. Using a novel recombinant basigin protein (rBSG) corresponding to the extracellular domain of basigin, it was demonstrated that the native, nonglycosylated rBSG protein forms dimers in solution. Furthermore, rBSG binds to the surface of uterine fibroblasts, activates the ERK1/2 signaling pathway, and induces expression of matrix metalloproteinases 1, 2, and 3. Proteins that interact with rBSG were isolated using a biotin label transfer technique and sequenced by matrix-assisted laser desorption ionization tandem mass spectrophotometry. The results demonstrate that rBSG interacts with basigin expressed on the surface of fibroblasts and is subsequently internalized. During internalization, rBSG associates with a novel form of human basigin (basigin-3). It was concluded that cell surface basigin functions as a membrane receptor for soluble basigin and this homophilic interaction is not dependent upon glycosylation of the basigin ligand. PMID:18434307

  8. Single Particle Tracking reveals two distinct environments for CD4 receptors at the surface of living T lymphocytes

    International Nuclear Information System (INIS)

    Mascalchi, Patrice; Lamort, Anne Sophie; Salomé, Laurence; Dumas, Fabrice

    2012-01-01

    Highlights: ► We studied the diffusion of single CD4 receptors on living lymphocytes. ► This study reveals that CD4 receptors have either a random or confined diffusion. ► The dynamics of unconfined CD4 receptors was accelerated by a temperature raise. ► The dynamics of confined CD4 receptors was unchanged by a temperature raise. ► Our results suggest the existence of two different environments for CD4 receptors. -- Abstract: We investigated the lateral diffusion of the HIV receptor CD4 at the surface of T lymphocytes at 20 °C and 37 °C by Single Particle Tracking using Quantum Dots. We found that the receptors presented two major distinct behaviors that were not equally affected by temperature changes. About half of the receptors showed a random diffusion with a diffusion coefficient increasing upon raising the temperature. The other half of the receptors was permanently or transiently confined with unchanged dynamics on raising the temperature. These observations suggest that two distinct subpopulations of CD4 receptors with different environments are present at the surface of living T lymphocytes.

  9. Insight into pattern of codon biasness and nucleotide base usage in serotonin receptor gene family from different mammalian species.

    Science.gov (United States)

    Dass, J Febin Prabhu; Sudandiradoss, C

    2012-07-15

    5-HT (5-Hydroxy-tryptamine) or serotonin receptors are found both in central and peripheral nervous system as well as in non-neuronal tissues. In the animal and human nervous system, serotonin produces various functional effects through a variety of membrane bound receptors. In this study, we focus on 5-HT receptor family from different mammals and examined the factors that account for codon and nucleotide usage variation. A total of 110 homologous coding sequences from 11 different mammalian species were analyzed using relative synonymous codon usage (RSCU), correspondence analysis (COA) and hierarchical cluster analysis together with nucleotide base usage frequency of chemically similar amino acid codons. The mean effective number of codon (ENc) value of 37.06 for 5-HT(6) shows very high codon bias within the family and may be due to high selective translational efficiency. The COA and Spearman's rank correlation reveals that the nucleotide compositional mutation bias as the major factors influencing the codon usage in serotonin receptor genes. The hierarchical cluster analysis suggests that gene function is another dominant factor that affects the codon usage bias, while species is a minor factor. Nucleotide base usage was reported using Goldman, Engelman, Stietz (GES) scale reveals the presence of high uracil (>45%) content at functionally important hydrophobic regions. Our in silico approach will certainly help for further investigations on critical inference on evolution, structure, function and gene expression aspects of 5-HT receptors family which are potential antipsychotic drug targets. Copyright © 2012 Elsevier B.V. All rights reserved.

  10. Unique expression pattern of the three insulin receptor family members in the rat mammary gland

    DEFF Research Database (Denmark)

    Hvid, Henning; Klopfleisch, Robert; Vienberg, Sara Gry

    2011-01-01

    mammary gland. Using laser micro-dissection, quantitative RT-PCR and immunohistochemistry, we examined the expression of IR (insulin receptor), IGF-1R (IGF-1 receptor), IRR (insulin receptor-related receptor), ERα (estrogen receptor alpha), ERβ (estrogen receptor beta) and PR (progesteron receptor......) in young, virgin, female Sprague-Dawley rats and compared to expression in reference organs. The mammary gland displayed the highest expression of IRR and IGF-1R. In contrast, low expression of IR transcripts was observed in the mammary gland tissue with expression of the IR-A isoform being 5-fold higher...... than the expression of the IR-B. By immunohistochemistry, expression of IR and IGF-1R was detected in all mammary gland epithelial cells. Expression of ERα and PR was comparable between mammary gland and ovary, whereas expression of ERβ was lower in mammary gland than in the ovary. Finally, expression...

  11. Molecular cloning of a novel, putative G protein-coupled receptor from sea anemones structurally related to members of the FSH, TSH, LH/CG receptor family from mammals

    DEFF Research Database (Denmark)

    Nothacker, H P; Grimmelikhuijzen, C J

    1993-01-01

    hormone (FSH, TSH, LH/CG) receptor family from mammals, including a very large, extracellular N terminus (18-25% sequence identity) and a 7 transmembrane region (44-48% sequence identity). As with the mammalian glycoprotein hormone receptor genes, the sea anemone receptor gene yields transcripts which can...... be alternatively spliced, thereby yielding a shortened receptor variant only containing the large extracellular (soluble) N terminus. All this is strong evidence that the putative glycoprotein hormone receptor from sea anemones is evolutionarily related to those from mammals. This is the first report showing...

  12. Characterizing Spatial Organization of Cell Surface Receptors in Human Breast Cancer with STORM

    Science.gov (United States)

    Lyall, Evan; Chapman, Matthew R.; Sohn, Lydia L.

    2012-02-01

    Regulation and control of complex biological functions are dependent upon spatial organization of biological structures at many different length scales. For instance Eph receptors and their ephrin ligands bind when opposing cells come into contact during development, resulting in spatial organizational changes on the nanometer scale that lead to changes on the macro scale, in a process known as organ morphogenesis. One technique able to probe this important spatial organization at both the nanometer and micrometer length scales, including at cell-cell junctions, is stochastic optical reconstruction microscopy (STORM). STORM is a technique that localizes individual fluorophores based on the centroids of their point spread functions and then reconstructs a composite image to produce super resolved structure. We have applied STORM to study spatial organization of the cell surface of human breast cancer cells, specifically the organization of tyrosine kinase receptors and chemokine receptors. A better characterization of spatial organization of breast cancer cell surface proteins is necessary to fully understand the tumorigenisis pathways in the most common malignancy in United States women.

  13. Interaction of KSHV with Host Cell Surface Receptors and Cell Entry

    Directory of Open Access Journals (Sweden)

    Mohanan Valiya Veettil

    2014-10-01

    Full Text Available Virus entry is a complex process characterized by a sequence of events. Since the discovery of KSHV in 1994, tremendous progress has been made in our understanding of KSHV entry into its in vitro target cells. KSHV entry is a complex multistep process involving viral envelope glycoproteins and several cell surface molecules that is utilized by KSHV for its attachment and entry. KSHV has a broad cell tropism and the attachment and receptor engagement on target cells have an important role in determining the cell type-specific mode of entry. KSHV utilizes heparan sulfate, integrins and EphrinA2 molecules as receptors which results in the activation of host cell pre-existing signal pathways that facilitate the subsequent cascade of events resulting in the rapid entry of virus particles, trafficking towards the nucleus followed by viral and host gene expression. KSHV enters human fibroblast cells by dynamin dependant clathrin mediated endocytosis and by dynamin independent macropinocytosis in dermal endothelial cells. Once internalized into endosomes, fusion of the viral envelope with the endosomal membranes in an acidification dependent manner results in the release of capsids which subsequently reaches the nuclear pore vicinity leading to the delivery of viral DNA into the nucleus. In this review, we discuss the principal mechanisms that enable KSHV to interact with the host cell surface receptors as well as the mechanisms that are required to modulate cell signaling machinery for a successful entry.

  14. GABAB receptor cell surface export is controlled by an endoplasmic reticulum gatekeeper

    Science.gov (United States)

    Doly, Stéphane; Shirvani, Hamasseh; Gäta, Gabriel; Meye, Frank; Emerit, Michel-Boris; Enslen, Hervé; Achour, Lamia; Pardo-Lopez, Liliana; Kwon, Yang Seung; Armand, Vincent; Gardette, Robert; Giros, Bruno; Gassmann, Martin; Bettler, Bernhard; Mameli, Manuel; Darmon, Michèle; Marullo, Stefano

    2016-01-01

    Summary Endoplasmic reticulum (ER) release and cell surface export of many G protein-coupled receptors (GPCRs), are tightly regulated. For GABAB receptors of GABA, the major mammalian inhibitory neurotransmitter, the ligand-binding GB1 subunit is maintained in the ER by unknown mechanisms in the absence of hetero-dimerization with the GB2 subunit. We report that GB1 retention is regulated by a specific gatekeeper, PRAF2. This ER resident transmembrane protein binds to GB1, preventing its progression in the biosynthetic pathway. GB1 release occurs upon competitive displacement from PRAF2 by GB2. PRAF2 concentration, relative to that of GB1 and GB2, tightly controls cell surface receptor density and controls GABAB function in neurons. Experimental perturbation of PRAF2 levels in vivo caused marked hyperactivity disorders in mice. These data reveal an unanticipated major impact of specific ER gate-keepers on GPCR function and identify PRAF2 as a new molecular target with therapeutic potential for psychiatric and neurological diseases involving GABAB function. PMID:26033241

  15. Modes of Action and Functions of ERECTA-family Receptor-like Kinases in Plant Organ Growth and Development

    Energy Technology Data Exchange (ETDEWEB)

    TORII, Keiko U.

    2012-05-01

    Higher plants constitute the central resource for renewable lignocellulose biomass that can supplement for the world's depleting stores of fossil fuels. As such, understanding the molecular and genetic mechanisms of plant organ growth will provide key knowledge and genetic resources that enables manipulation of plant biomass feedstock for better growth and productivity. The goal of this proposal is to understand how cell proliferation and growth are coordinated during aboveground organ morphogenesis, and how cell-cell signaling mediated by a family of receptor kinases coordinates plant organogenesis. The well-established model plant Arabidopsis thaliana is used for our research to facilitate rapid progress. Specifically, we focus on how ERECTA-family leucine-rich repeat receptor kinases (LRR-RLKs) interact in a synergistic manner to promote organogenesis and pattern formation in Arabidopsis. This project was highly successful, resulted in fourteen publications including nine peer-reviewed original research articles. One provisional US patent has been filed through this DOE funding. We have addressed the critical roles for a family of receptor kinases in coordinating proliferation and differentiation of plants, and we successfully elucidated the downstream targets of this signaling pathway in specifying stomatal patterning.

  16. Detection of the plant parasite Cuscuta reflexa by a tomato cell surface receptor.

    Science.gov (United States)

    Hegenauer, Volker; Fürst, Ursula; Kaiser, Bettina; Smoker, Matthew; Zipfel, Cyril; Felix, Georg; Stahl, Mark; Albert, Markus

    2016-07-29

    Parasitic plants are a constraint on agriculture worldwide. Cuscuta reflexa is a stem holoparasite that infests most dicotyledonous plants. One exception is tomato, which is resistant to C. reflexa We discovered that tomato responds to a small peptide factor occurring in Cuscuta spp. with immune responses typically activated after perception of microbe-associated molecular patterns. We identified the cell surface receptor-like protein CUSCUTA RECEPTOR 1 (CuRe1) as essential for the perception of this parasite-associated molecular pattern. CuRe1 is sufficient to confer responsiveness to the Cuscuta factor and increased resistance to parasitic C. reflexa when heterologously expressed in otherwise susceptible host plants. Our findings reveal that plants recognize parasitic plants in a manner similar to perception of microbial pathogens. Copyright © 2016, American Association for the Advancement of Science.

  17. Ligand-specific regulation of the extracellular surface of a G-protein-coupled receptor

    DEFF Research Database (Denmark)

    Bokoch, Michael P; Zou, Yaozhong; Rasmussen, Søren Gøgsig Faarup

    2010-01-01

    extending from the orthosteric ligand-binding site in the transmembrane core to the cytoplasmic G-protein-coupling domains. In contrast, the extracellular surface (ECS) of GPCRs is remarkably diverse and is therefore an ideal target for the discovery of subtype-selective drugs. However, little is known...... conformational coupling between the ECS and the orthosteric binding site, showing that drugs targeting this diverse surface could function as allosteric modulators with high subtype selectivity. Moreover, these studies provide a new insight into the dynamic behaviour of GPCRs not addressable by static, inactive...... about the functional role of the ECS in receptor activation, or about conformational coupling of this surface to the native ligand-binding pocket. Here we use NMR spectroscopy to investigate ligand-specific conformational changes around a central structural feature in the ECS of the beta(2) adrenergic...

  18. The CRF Family of Neuropeptides and their Receptors - Mediators of the Central Stress Response

    Science.gov (United States)

    Dedic, Nina; Chen, Alon; Deussing, Jan M.

    2018-01-01

    Background: Dysregulated stress neurocircuits, caused by genetic and/or environmental changes, underlie the development of many neuropsychiatric disorders. Corticotropin-releasing factor (CRF) is the major physiological activator of the hypothalamic-pituitary-adrenal (HPA) axis and conse-quently a primary regulator of the mammalian stress response. Together with its three family members, urocortins (UCNs) 1, 2, and 3, CRF integrates the neuroendocrine, autonomic, metabolic and behavioral responses to stress by activating its cognate receptors CRFR1 and CRFR2. Objective: Here we review the past and current state of the CRF/CRFR field, ranging from pharmacologi-cal studies to genetic mouse models and virus-mediated manipulations. Results: Although it is well established that CRF/CRFR1 signaling mediates aversive responses, includ-ing anxiety and depression-like behaviors, a number of recent studies have challenged this viewpoint by revealing anxiolytic and appetitive properties of specific CRF/CRFR1 circuits. In contrast, the UCN/CRFR2 system is less well understood and may possibly also exert divergent functions on physiol-ogy and behavior depending on the brain region, underlying circuit, and/or experienced stress conditions. Conclusion: A plethora of available genetic tools, including conventional and conditional mouse mutants targeting CRF system components, has greatly advanced our understanding about the endogenous mecha-nisms underlying HPA system regulation and CRF/UCN-related neuronal circuits involved in stress-related behaviors. Yet, the detailed pathways and molecular mechanisms by which the CRF/UCN-system translates negative or positive stimuli into the final, integrated biological response are not completely un-derstood. The utilization of future complementary methodologies, such as cell-type specific Cre-driver lines, viral and optogenetic tools will help to further dissect the function of genetically defined CRF/UCN neurocircuits in the context of

  19. Ryanodine receptors, a family of intracellular calcium ion channels, are expressed throughout early vertebrate development

    Directory of Open Access Journals (Sweden)

    Wu Houdini HT

    2011-12-01

    Full Text Available Abstract Background Calcium signals ([Ca2+]i direct many aspects of embryo development but their regulation is not well characterised. Ryanodine receptors (RyRs are a family of intracellular Ca2+ release channels that control the flux of Ca2+ from internal stores into the cytosol. RyRs are primarily known for their role in excitation-contraction coupling in adult striated muscle and ryr gene mutations are implicated in several human diseases. Current evidence suggests that RyRs do not have a major role to play prior to organogenesis but regulate tissue differentiation. Findings The sequences of the five zebrafish ryr genes were confirmed, their evolutionary relationship established and the primary sequences compared to other vertebrates, including humans. RyRs are differentially expressed in slow (ryr1a, fast (ryr3 and both types (ryr1b of developing skeletal muscle. There are two ryr2 genes (ryr2a and ryr2b which are expressed exclusively in developing CNS and cardiac tissue, respectively. In addition, ryr3 and ryr2a mRNA is detectable in the initial stages of development, prior to embryonic axis formation. Conclusions Our work reveals that zebrafish ryr genes are differentially expressed throughout the developing embryo from cleavage onwards. The data suggests that RyR-regulated Ca2+ signals are associated with several aspects of embryonic development, from organogenesis through to the differentiation of the musculoskeletal, cardiovascular and nervous system. These studies will facilitate further work to explore the developmental function of RyRs in each of these tissue types.

  20. Sex bias in copy number variation of olfactory receptor gene family depends on ethnicity

    Directory of Open Access Journals (Sweden)

    Farideh eShadravan

    2013-03-01

    Full Text Available Gender plays a pivotal role in the human genetic identity and is also manifested in many genetic disorders particularly mental retardation. In this study its effect on copy number variation (CNV, known to cause genetic disorders was explored. As the olfactory receptor (OR repertoire comprises the largest human gene family, it was selected for this study, which was carried out within and between three populations, derived from 150 individuals from the 1000 Genome Project. Analysis of 3872 CNVs detected among 791 OR loci, in which 307 loci showed CNV, revealed the following novel findings: Sex bias in CNV was significantly more prevalent in uncommon than common CNV variants of OR pseudogenes, in which the male genome showed more CNVs; and in one-copy number loss compared to complete deletion of OR pseudogenes; both findings implying a more recent evolutionary role for gender. Sex bias in copy number gain was also detected. Another novel finding was that the observed six bias was largely dependent on ethnicity and was in general absent in East Asians. Using a CNV public database for sick children (ISCA the application of these findings for improving clinical molecular diagnostics is discussed by showing an example of sex bias in CNV among kids with autism. Additional clinical relevance is discussed, as the most polymorphic CNV-enriched OR cluster in the human genome, located on chr 15q11.2, is found near the PWS/AS bi-directionally imprinted region associated with two well-known mental retardation syndromes. As olfaction represents the primitive cognition in most mammals, arguably in competition with the development of a larger brain, the extensive retention of OR pseudogenes in females of this study, might point to a parent-of-origin indirect regulatory role for OR pseudogenes in the embryonic development of human brain. Thus any perturbation in the temporal regulation of olfactory system could lead to developmental delay disorders including

  1. Using Force to Probe Single-Molecule Receptor-Cytoskeletal Anchoring Beneath the Surface of a Living Cell

    DEFF Research Database (Denmark)

    Evans, Evan; Kinoshita, Koji

    2007-01-01

    -cytoskeletal unbinding increased exponentially with the level of force, suggesting disruption at a site of single-molecule interaction. Since many important enzymes and signaling molecules are closely associated with a membrane receptor-cytoskeletal linkage, pulling on a receptor could alter interactions among its......The ligation of cell surface receptors often communicates a signal that initiates a cytoplasmic chemical cascade to implement an important cell function. Less well understood is how physical stress applied to a cell surface adhesive bond propagates throughout the cytostructure to catalyze...... or trigger important steps in these chemical processes. Probing the nanoscale impact of pulling on cell surface bonds, we discovered that receptors frequently detach prematurely from the interior cytostructure prior to failure of the exterior adhesive bond [Evans, E., Heinrich, V., Leung, A., and Kinoshita...

  2. Microscopic visualization of metabotropic glutamate receptors on the surface of living cells using bifunctional magnetic resonance imaging probes.

    Science.gov (United States)

    Mishra, Anurag; Mishra, Ritu; Gottschalk, Sven; Pal, Robert; Sim, Neil; Engelmann, Joern; Goldberg, Martin; Parker, David

    2014-02-19

    A series of bimodal metabotropic glutamate-receptor targeted MRI contrast agents has been developed and evaluated, based on established competitive metabotropic Glu receptor subtype 5 (mGluR5) antagonists. In order to directly visualize mGluR5 binding of these agents on the surface of live astrocytes, variations in the core structure were made. A set of gadolinium conjugates containing either a cyanine dye or a fluorescein moiety was accordingly prepared, to allow visualization by optical microscopy in cellulo. In each case, surface receptor binding was compromised and cell internalization observed. Another approach, examining the location of a terbium analogue via sensitized emission, also exhibited nonspecific cell uptake in neuronal cell line models. Finally, biotin derivatives of two lead compounds were prepared, and the specificity of binding to the mGluR5 cell surface receptors was demonstrated with the aid of their fluorescently labeled avidin conjugates, using both total internal reflection fluorescence (TIRF) and confocal microscopy.

  3. Relevance of the NR4A sub-family of nuclear orphan receptors in trophoblastic BeWo cell differentiation.

    Science.gov (United States)

    Malhotra, Sudha Saryu; Gupta, Satish Kumar

    2017-01-01

    Nur-77, a member of the NR4A sub-family of nuclear orphan receptors, is downregulated in the placentae of pre-eclamptic women. Here, we investigate the relevance of Nor-1, Nurr-1 and Nur-77 in trophoblastic cell differentiation. Their transcript levels were found to be significantly upregulated in BeWo cells treated with forskolin. The maximum increase was observed after 2 h, with a second peak in the expression levels after 48 h. The expression of NR4A sub-family members was also found to be upregulated in BeWo cells after treatment with hCG and GnRH. A similar significant increase was observed at the respective protein levels after 2 and 48 h of treatment with forskolin, hCG or GnRH. Silencing Nor-1, Nurr-1 or Nur-77 individually did not show any effect on forskolin-, hCG- and/or GnRH-mediated BeWo cell fusion and/or hCG secretion. After silencing any one member of the NR4A sub-family, an increase in the transcript levels of the other sub-family members was observed, indicating a compensatory effect due to their functional redundancy. Simultaneously silencing all three NR4A sub-family members significantly downregulated forskolin- and hCG-mediated BeWo cell fusion and/or hCG secretion. However, a considerable amount of cell death occurred after forskolin or hCG treatment as compared to the control siRNA-transfected cells. These results suggest that the NR4A sub-family of nuclear orphan receptors has a role in trophoblastic cell differentiation.

  4. Expression analysis of the Toll-like receptor and TIR domain adaptor families of zebrafish.

    NARCIS (Netherlands)

    Meijer, A.H.; Krens, SF Gabby; Rodriguez, IA Medina; He, S; Bitter, W.; Snaar-Jagalska, B Ewa; Spaink, H.P.

    2004-01-01

    The zebrafish genomic sequence database was analysed for the presence of genes encoding members of the Toll-like receptors (TLR) and interleukin receptors (IL-R) and associated adaptor proteins containing a TIR domain. The resulting predictions show the presence of one or more counterparts for the

  5. Cathelicidin LL-37 Affects Surface and Intracellular Toll-Like Receptor Expression in Tissue Mast Cells

    Directory of Open Access Journals (Sweden)

    Justyna Agier

    2018-01-01

    Full Text Available Undoubtedly, mast cells take part in host defense against microorganisms as they are numerous at the portal of infection, they release many proinflammatory and antimicrobial mediators, and they express pattern recognition receptors, such as TLRs. These receptors play a key role in recognition and binding molecules associated with microorganisms and molecules associated with damage. Cathelicidins exhibit direct antimicrobial activities against a broad spectrum of microbes by perturbing their cell membranes. Accumulating evidence suggests a role for these molecules in supporting cell activation. We examined the impact of human cathelicidin LL-37 on tissue mast cell TLR expression and distribution. Depending on context, we show that LL-37 stimulation resulted in minor to major effects on TLR2, TLR3, TLR4, TLR5, TLR7, and TLR9 expression. Confocal microscopy analysis showed that, upon stimulation, TLRs may translocate from the cell interior to the surface and conversely. FPR2 and EGFR inhibitors reduced the increase in expression of selected receptors. We also established that LL-37 acts as a powerful inducer of CCL3 and ROS generation. These results showed that in response to LL-37, mast cells enhance the capability to detect invading pathogens by modulation of TLR expression in what may be involved FPR2 or EGFR molecules.

  6. CD150 is a member of a family of genes that encode glycoproteins on the surface of hematopoietic cells.

    Science.gov (United States)

    Wang, N; Morra, M; Wu, C; Gullo, C; Howie, D; Coyle, T; Engel, P; Terhorst, C

    2001-07-01

    Human CD150 (SLAM) is a glycoprotein expressed on the surface of T, B, natural killer, and dendritic cells. The extracellular domain of CD150 is the receptor for measles virus and CD150 acts as a co-activator on T and B cells. We characterized the mouse and human CD150 genes, each of which comprises seven exons spanning approximately 32 kb. Mouse CD150 mRNA was detected in T cells and in most thymocyte subsets, except CD4-8- cells. Surprisingly, the CD4-8- thymocytes of CD3gammadeltanull mice, but not of Ragnull or severe combined immunodeficiency mice, expressed CD150. Whereas high levels of CD150 were found in Th1 cells, only small amounts were detectable in Th2 cells. CD150 expression was up-regulated upon in vitro activation of mouse T cells by anti-CD3. The complete mouse CD150 gene is highly homologous to its human orthologue in terms of nucleotide sequences and intron/exon organization. The human genomic sequences indicate that all isoforms detected so far have arisen from alternative splicing events. As judged by fluorescence in situ hybridization, mouse CD150 mapped to Chromosome (Chr) 1, band 1H2.2-2.3, and human CD150 was found on Chr 1q22. Human and mouse CD150 share sequence homologies with six other genes, five of which - CD84, CD229 (Ly-9), CD244 (2B4), CD48, and 19A - are localized in a 250-kb segment in close proximity to the human gene. Their location and their sequence similarities strongly suggest that the CD150 family of cell surface receptors arose via successive duplications of a common ancestral gene.

  7. The Cell Surface Estrogen Receptor, G Protein- Coupled Receptor 30 (GPR30, is Markedly Down Regulated During Breast Tumorigenesis

    Directory of Open Access Journals (Sweden)

    Indira Poola

    2008-01-01

    Full Text Available Background: GPR30 is a cell surface estrogen receptor that has been shown to mediate a number of non-genomic rapid effects of estrogen and appear to balance the signaling of estrogen and growth factors. In addition, progestins appear to use GPR30 for their actions. Therefore, GPR30 could play a critical role in hormonal regulation of breast epithelial cell integrity. Deregulation of the events mediated by GPR30 could contribute to tumorigenesis.Methods: To understand the role of GPR30 in the deregulation of estrogen signaling processes during breast carcinogenesis, we have undertaken this study to investigate its expression at mRNA levels in tumor tissues and their matched normal tissues. We compared its expression at mRNA levels by RT quantitative real-time PCR relative to GAPDH in ERα”—positive (n = 54 and ERα”—negative (n = 45 breast cancer tissues to their matched normal tissues.Results: We report here, for the first time, that GPR30 mRNA levels were significantly down-regulated in cancer tissues in comparison with their matched normal tissues (p 0.0001 by two sided paired t-test. The GPR30 expression levels were significantly lower in tumor tissues from patients (n = 29 who had lymph node metastasis in comparison with tumors from patients (n = 53 who were negative for lymph node metastasis (two sample t-test, p 0.02, but no association was found with ERα, PR and other tumor characteristics.Conclusions: Down-regulation of GPR30 could contribute to breast tumorigenesis and lymph node metastasis.

  8. Cytokine-like factor-1, a novel soluble protein, shares homology with members of the cytokine type I receptor family.

    Science.gov (United States)

    Elson, G C; Graber, P; Losberger, C; Herren, S; Gretener, D; Menoud, L N; Wells, T N; Kosco-Vilbois, M H; Gauchat, J F

    1998-08-01

    In this report we describe the identification, cloning, and expression pattern of human cytokine-like factor 1 (hCLF-1) and the identification and cloning of its murine homologue. They were identified from expressed sequence tags using amino acid sequences from conserved regions of the cytokine type I receptor family. Human CLF-1 and murine CLF-1 shared 96% amino acid identity and significant homology with many cytokine type I receptors. CLF-1 is a secreted protein, suggesting that it is either a soluble subunit within a cytokine receptor complex, like the soluble form of the IL-6R alpha-chain, or a subunit of a multimeric cytokine, e.g., IL-12 p40. The highest levels of hCLF-1 mRNA were observed in lymph node, spleen, thymus, appendix, placenta, stomach, bone marrow, and fetal lung, with constitutive expression of CLF-1 mRNA detected in a human kidney fibroblastic cell line. In fibroblast primary cell cultures, CLF-1 mRNA was up-regulated by TNF-alpha, IL-6, and IFN-gamma. Western blot analysis of recombinant forms of hCLF-1 showed that the protein has the tendency to form covalently linked di- and tetramers. These results suggest that CLF-1 is a novel soluble cytokine receptor subunit or part of a novel cytokine complex, possibly playing a regulatory role in the immune system and during fetal development.

  9. Synthesis of an endothelial cell mimicking surface containing thrombomodulin and endothelial protein C receptor

    Science.gov (United States)

    Kador, Karl Erich

    Synthetic materials for use in blood contacting applications have been studied for many years with limited success. One of the main areas of need for these materials is the design of synthetic vascular grafts for use in the hundreds of thousands of patients who have coronary artery bypass grafting, many without suitable veins for autologous grafts. The design of these grafts is constrained by two common modes of failure, the formation of intimal hyperplasia (IH) and thrombosis. IH formation has been previously linked to a mismatching of the mechanical properties of the graft and has been overcome by creating grafts using materials whose compliance mimics that of the native artery. Several techniques and surface modification have been designed to limit thrombosis on the surface of synthetic materials. One which has shown the greatest promise is the immobilization of Thrombomodulin (TM), a protein found on the endothelial cell membrane lining native blood vessels involved in the activation of the anticoagulant Protein C (PC). While TM immobilization has been shown to arrest thrombin formation and limit fibrous formations in in-vitro and in-vivo experiments, it has shown to be transport limiting under arterial flow. On the endothelial cell surface, TM is co-localized with Endothelial Protein C Receptor (EPCR), which increases PC transport onto the cell surface and increases PC activation via TM between 20-100 fold. This dissertation will describe the chemical modification of medical grade polyurethane (PU), whose compliance has been shown to match that of native arteries. This modification will enable the immobilization of two proteins on an enzymatically relevant scale estimated at less than 10 nm. This dissertation will further describe the immobilization of the proteins TM and EPCR, and analyze the ability of a surface co-immobilized with these proteins to activate the anticoagulant PC. Finally, it will compare the ability of this co-immobilized surface to delay

  10. A novel germline mutation in the aryl hydrocarbon receptor-interacting protein (AIP) gene in an Italian family with gigantism.

    Science.gov (United States)

    Urbani, C; Russo, D; Raggi, F; Lombardi, M; Sardella, C; Scattina, I; Lupi, I; Manetti, L; Tomisti, L; Marcocci, C; Martino, E; Bogazzi, F

    2014-10-01

    Acromegaly usually occurs as a sporadic disease, but it may be a part of familial pituitary tumor syndromes in rare cases. Germline mutations in the aryl hydrocarbon receptor-interacting protein (AIP) gene have been associated with a predisposition to familial isolated pituitary adenoma. The aim of the present study was to evaluate the AIP gene in a patient with gigantism and in her relatives. Direct sequencing of AIP gene was performed in fourteen members of the family, spanning among three generations. The index case was an 18-year-old woman with gigantism due to an invasive GH-secreting pituitary adenoma and a concomitant tall-cell variant of papillary thyroid carcinoma. A novel germline mutation in the AIP gene (c.685C>T, p.Q229X) was identified in the proband and in two members of her family, who did not present clinical features of acromegaly or other pituitary disorders. Eleven subjects had no mutation in the AIP gene. Two members of the family with clinical features of acromegaly refused either the genetic or the biochemical evaluation. The Q229X mutation was predicted to generate a truncated AIP protein, lacking the last two tetratricopeptide repeat domains and the final C-terminal α-7 helix. We identified a new AIP germline mutation predicted to produce a truncated AIP protein, lacking its biological properties due to the disruption of the C-terminus binding sites for both the chaperones and the client proteins of AIP.

  11. The Role of TAM Family Receptors in Immune Cell Function: Implications for Cancer Therapy.

    Science.gov (United States)

    Paolino, Magdalena; Penninger, Josef M

    2016-10-21

    The TAM receptor protein tyrosine kinases-Tyro3, Axl, and Mer-are essential regulators of immune homeostasis. Guided by their cognate ligands Growth arrest-specific gene 6 (Gas6) and Protein S (Pros1), these receptors ensure the resolution of inflammation by dampening the activation of innate cells as well as by restoring tissue function through promotion of tissue repair and clearance of apoptotic cells. Their central role as negative immune regulators is highlighted by the fact that deregulation of TAM signaling has been linked to the pathogenesis of autoimmune, inflammatory, and infectious diseases. Importantly, TAM receptors have also been associated with cancer development and progression. In a cancer setting, TAM receptors have a dual regulatory role, controlling the initiation and progression of tumor development and, at the same time, the associated anti-tumor responses of diverse immune cells. Thus, modulation of TAM receptors has emerged as a potential novel strategy for cancer treatment. In this review, we discuss our current understanding of how TAM receptors control immunity, with a particular focus on the regulation of anti-tumor responses and its implications for cancer immunotherapy.

  12. Cell surface estrogen receptor alpha is upregulated during subchronic metabolic stress and inhibits neuronal cell degeneration.

    Directory of Open Access Journals (Sweden)

    Cristiana Barbati

    Full Text Available In addition to the classical nuclear estrogen receptor, the expression of non-nuclear estrogen receptors localized to the cell surface membrane (mER has recently been demonstrated. Estrogen and its receptors have been implicated in the development or progression of numerous neurodegenerative disorders. Furthermore, the pathogenesis of these diseases has been associated with disturbances of two key cellular programs: apoptosis and autophagy. An excess of apoptosis or a defect in autophagy has been implicated in neurodegeneration. The aim of this study was to clarify the role of ER in determining neuronal cell fate and the possible implication of these receptors in regulating either apoptosis or autophagy. The human neuronal cell line SH-SY5Y and mouse neuronal cells in primary culture were thus exposed to chronic minimal peroxide treatment (CMP, a form of subcytotoxic minimal chronic stress previously that mimics multiple aspects of long-term cell stress and represents a limited molecular proxy for neurodegenerative processes. We actually found that either E2 or E2-bovine serum albumin construct (E2BSA, i.e. a non-permeant form of E2 was capable of modulating intracellular cell signals and regulating cell survival and death. In particular, under CMP, the up-regulation of mERα, but not mERβ, was associated with functional signals (ERK phosphorylation and p38 dephosphorylation compatible with autophagic cytoprotection triggering and leading to cell survival. The mERα trafficking appeared to be independent of the microfilament system cytoskeletal network but was seemingly associated with microtubular apparatus network, i.e., to MAP2 molecular chaperone. Importantly, antioxidant treatments, administration of siRNA to ERα, or the presence of antagonist of ERα hindered these events. These results support that the surface expression of mERα plays a pivotal role in determining cell fate, and that ligand-induced activation of mER signalling exerts a

  13. THYROID HORMONE RECEPTOR BETA GENE MUTATION (P453A) IN A TURKISH FAMILY PRODUCING RESISTANCE TO THYROID HORMONE

    Science.gov (United States)

    Bayraktaroglu, Taner; Noel, Janet; Mukaddes, Nahit Motavalli; Refetoff, Samuel

    2018-01-01

    Two members of a Turkish family, a mother and son, had thyroid function tests suggestive of resistance to thyroid hormone (RTH). The clinical presentation was, however, different. The mother (proposita) had palpitation, weakness, tiredness, nervousness, dry mouth and was misdiagnosed as having multinodular toxic goiter which was treated with antithyroid drugs and partial thyroidectomy. Her younger son had attention deficit hyperactivity disorder and primary encopresis, but normal intellectual quotient. Both had elevated serum iodothyronine levels with nonsuppressed thyrotropin. A mutation in one allele of the thyroid hormone receptor beta gene (P453A) was identified, providing a genetic confirmation for the diagnosis of RTH. PMID:18561095

  14. Leptospira surface adhesin (Lsa21) induces Toll like receptor 2 and 4 mediated inflammatory responses in macrophages

    OpenAIRE

    Syed M. Faisal; Vivek P. Varma; M. Subathra; Sarwar Azam; Anil K. Sunkara; Mohd Akif; Mirza. S. Baig; Yung-Fu Chang

    2016-01-01

    Leptospirosis is zoonotic and emerging infectious disease of global importance. Little is understood about Leptospira pathogenesis and host immune response. In the present work we have investigated how Leptospira modulates the host innate immune response mediated by Toll-like receptors (TLRs) via surface exposed proteins. We screened Leptospira outer membrane/surface proteins for their ability to activate/inhibit TLR2/4 signaling in HEK293 cell lines. Of these the 21?kDa Leptospira surface ad...

  15. The relaxin family peptide receptors and their ligands: new developments and paradigms in the evolution from jawless fish to mammals.

    Science.gov (United States)

    Yegorov, Sergey; Bogerd, Jan; Good, Sara V

    2014-12-01

    Relaxin family peptide receptors (Rxfps) and their ligands, relaxin (Rln) and insulin-like (Insl) peptides, are broadly implicated in the regulation of reproductive and neuroendocrine processes in mammals. Most placental mammals harbour genes for four receptors, namely rxfp1, rxfp2, rxfp3 and rxfp4. The number and identity of rxfps in other vertebrates are immensely variable, which is probably attributable to intraspecific variation in reproductive and neuroendocrine regulation. Here, we highlight several interesting, but greatly overlooked, aspects of the rln/insl-rxfp evolutionary history: the ancient origin, recruitment of novel receptors, diverse roles of selection, differential retention and lineage-specific loss of genes over evolutionary time. The tremendous diversity of rln/insl and rxfp genes appears to have arisen from two divergent receptors and one ligand that were duplicated by whole genome duplications (WGD) in early vertebrate evolution, although several genes, notably relaxin in mammals, were also duplicated via small scale duplications. Duplication and loss of genes have varied across lineages: teleosts retained more WGD-derived genes, dominated by those thought to be involved in neuroendocrine regulation (rln3, insl5 and rxfp 3/4 genes), while eutherian mammals witnessed the diversification and rapid evolution of genes involved in reproduction (rln/insl3). Several genes that arose early in evolutionary history were lost in most mammals, but retained in teleosts and, to a lesser extent, in early diverging tetrapods. To elaborate on their evolutionary history, we provide updated phylogenies of the Rxfp1/2 and Rxfp3/4 receptors and their ligands, including new sequences from early diverging vertebrate taxa such as coelacanth, skate, spotted gar, and lamprey. We also summarize the recent progress made towards understanding the functional biology of Rxfps in non-mammalian taxa, providing a new conceptual framework for research on Rxfp signaling across

  16. Estradiol coupling to human monocyte nitric oxide release is dependent on intracellular calcium transients: evidence for an estrogen surface receptor.

    Science.gov (United States)

    Stefano, G B; Prevot, V; Beauvillain, J C; Fimiani, C; Welters, I; Cadet, P; Breton, C; Pestel, J; Salzet, M; Bilfinger, T V

    1999-10-01

    We tested the hypothesis that estrogen acutely stimulates constitutive NO synthase (cNOS) activity in human peripheral monocytes by acting on an estrogen surface receptor. NO release was measured in real time with an amperometric probe. 17beta-estradiol exposure to monocytes stimulated NO release within seconds in a concentration-dependent manner, whereas 17alpha-estradiol had no effect. 17beta-estradiol conjugated to BSA (E2-BSA) also stimulated NO release, suggesting mediation by a membrane surface receptor. Tamoxifen, an estrogen receptor inhibitor, antagonized the action of both 17beta-estradiol and E2-BSA, whereas ICI 182,780, a selective inhibitor of the nuclear estrogen receptor, had no effect. We further showed, using a dual emission microfluorometry in a calcium-free medium, that the 17beta-estradiol-stimulated release of monocyte NO was dependent on the initial stimulation of intracellular calcium transients in a tamoxifen-sensitive process. Leeching out the intracellular calcium stores abolished the effect of 17beta-estradiol on NO release. RT-PCR analysis of RNA obtained from the cells revealed a strong estrogen receptor-alpha amplification signal and a weak beta signal. Taken together, a physiological dose of estrogen acutely stimulates NO release from human monocytes via the activation of an estrogen surface receptor that is coupled to increases in intracellular calcium.

  17. Nuclear receptor 4A (NR4A) family - orphans no more.

    Science.gov (United States)

    Safe, Stephen; Jin, Un-Ho; Morpurgo, Benjamin; Abudayyeh, Ala; Singh, Mandip; Tjalkens, Ronald B

    2016-03-01

    The orphan nuclear receptors NR4A1, NR4A2 and NR4A3 are immediate early genes induced by multiple stressors, and the NR4A receptors play an important role in maintaining cellular homeostasis and disease. There is increasing evidence for the role of these receptors in metabolic, cardiovascular and neurological functions and also in inflammation and inflammatory diseases and in immune functions and cancer. Despite the similarities of NR4A1, NR4A2 and NR4A3 and their interactions with common cis-genomic elements, they exhibit unique activities and cell-/tissue-specific functions. Although endogenous ligands for NR4A receptors have not been identified, there is increasing evidence that structurally-diverse synthetic molecules can directly interact with the ligand binding domain of NR4A1 and act as agonists or antagonists, and ligands for NR4A2 and NR4A3 have also been identified. Since NR4A receptors are key factors in multiple diseases, there are opportunities for the future development of NR4A ligands for clinical applications in treating multiple health problems including metabolic, neurologic and cardiovascular diseases, other inflammatory conditions, and cancer. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. The EGFR family of receptors sensitizes cancer cells towards UV light

    DEFF Research Database (Denmark)

    Petersen, Steffen B.; Neves Petersen, Teresa; Olsen, Birgitte

    2008-01-01

    A combination of bioinformatics, biophysical, advanced laser studies and cell biology lead to the realization that laser-pulsed UV light stops cancer growth and induces apoptosis. We have previously shown that laser-pulsed UV (LP-UV) illumination of two different skin-derived cancer cell lines both...... bridges. The EGF receptor is often overexpressed in cancers and other proliferative skin disorders, it might be possible to significantly reduce the proliferative potential of these cells making them good targets for laser-pulsed UV-light treatment. The discovery that UV light can be used to open...... disulphide bridges in proteins upon illumination of nearby aromatic amino acids was the first step that lead to the hypothesis that UV light could modulate the structure and therefore the function of these key receptor proteins. The observation that membrane receptors (EGFR) contained exactly the motifs...

  19. Surface receptor Toso controls B cell-mediated regulation of T cell immunity.

    Science.gov (United States)

    Yu, Jinbo; Duong, Vu Huy Hoang; Westphal, Katrin; Westphal, Andreas; Suwandi, Abdulhadi; Grassl, Guntram A; Brand, Korbinian; Chan, Andrew C; Föger, Niko; Lee, Kyeong-Hee

    2018-05-01

    The immune system is tightly controlled by regulatory processes that allow for the elimination of invading pathogens, while limiting immunopathological damage to the host. In the present study, we found that conditional deletion of the cell surface receptor Toso on B cells unexpectedly resulted in impaired proinflammatory T cell responses, which led to impaired immune protection in an acute viral infection model and was associated with reduced immunopathological tissue damage in a chronic inflammatory context. Toso exhibited its B cell-inherent immunoregulatory function by negatively controlling the pool of IL-10-competent B1 and B2 B cells, which were characterized by a high degree of self-reactivity and were shown to mediate immunosuppressive activity on inflammatory T cell responses in vivo. Our results indicate that Toso is involved in the differentiation/maintenance of regulatory B cells by fine-tuning B cell receptor activation thresholds. Furthermore, we showed that during influenza A-induced pulmonary inflammation, the application of Toso-specific antibodies selectively induced IL-10-competent B cells at the site of inflammation and resulted in decreased proinflammatory cytokine production by lung T cells. These findings suggest that Toso may serve as a novel therapeutic target to dampen pathogenic T cell responses via the modulation of IL-10-competent regulatory B cells.

  20. Genetic characterization of the chemokine receptor CXCR4 gene in lagomorphs: comparison between the families Ochotonidae and Leporidae.

    Science.gov (United States)

    Abrantes, J; Esteves, P J; Carmo, C R; Müller, A; Thompson, G; van der Loo, W

    2008-04-01

    Chemokines receptors are transmembrane proteins that bind chemokines. Chemokines and their receptors are known to play a crucial role in the immune system and in pathogen entry. There is evidence that myxoma virus, the causative agent of myxomatosis, can use the chemokine receptor CXCR4 to infect cells. This virus causes a benign disease in its natural host, Sylvilagus, but in the European rabbit (Oryctolagus cuniculus) it causes a highly fatal and infectious disease known as myxomatosis. We have characterized the chemokine receptor CXCR4 gene in five genera of the order Lagomorpha, Ochotona (Ochotonidae), and Oryctolagus, Lepus, Bunolagus and Sylvilagus (Leporidae). In lagomorphs, the CXCR4 is highly conserved, with most of the protein diversity found at surface regions. Five amino acid replacements were observed, two in the intracellular loops, one in the transmembrane domain and two in the extracellular loops. Oryctolagus features unique amino acid changes at the intracellular domains, putting this genus apart of all other lagomorphs. Furthermore, in the 37 European rabbits analysed, which included healthy rabbits and rabbits with clinical symptoms of myxomatosis, 14 nucleotide substitutions were obtained but no amino acid differences were observed.

  1. G-Protein-coupled receptors as potential drug candidates in preeclampsia: targeting the relaxin/insulin-like family peptide receptor 1 for treatment and prevention.

    Science.gov (United States)

    Conrad, Kirk P

    2016-09-01

    Important roles for G-protein-coupled receptors (GPCRs) have been identified in the maternal physiological adaptations to pregnancy and in the pathogenesis of preeclampsia. On this basis, GPCRs are potential therapeutic targets for preeclampsia. In this review, vasopressin and apelin are initially considered in this context before the focus on the hormone relaxin and its cognate receptor, the relaxin/insulin-like family peptide receptor 1 (RXFP1). Based on both compelling scientific rationale and a promising safety profile, the relaxin ligand-receptor system is comprehensively evaluated as a potential therapeutic endpoint in preeclampsia. The published literature relating to the topic was searched through January 2016 using PubMed. Relaxin is a peptide hormone secreted by the corpus luteum; it circulates in the luteal phase and during pregnancy. Activation of RXFP1 is vasodilatory; thus, relaxin supplementation is expected to at least partly restore the fundamental vasodilatory changes of normal pregnancy, thereby alleviating maternal organ hypoperfusion, which is a major pathogenic manifestation of severe preeclampsia. Specifically, by exploiting its pleiotropic hemodynamic attributes in preeclampsia, relaxin administration is predicted to (i) reverse robust arterial myogenic constriction; (ii) blunt systemic and renal vasoconstriction in response to activation of the angiotensin II receptor, type 1; (iii) mollify the action of endogenous vasoconstrictors on uterine spiral arteries with failed remodeling and retained smooth muscle; (iv) increase arterial compliance; (v) enhance insulin-mediated glucose disposal by promoting skeletal muscle vasodilation and (vi) mobilize and activate bone marrow-derived angiogenic progenitor cells, thereby repairing injured endothelium and improving maternal vascularity in organs such as breast, uterus, pancreas, skin and fat. By exploiting its pleiotropic molecular attributes in preeclampsia, relaxin supplementation is

  2. A receptor-based biosensor for lipoprotein docking at the endothelial surface and vascular matrix.

    Science.gov (United States)

    Siegel, G; Malmsten, M; Klüssendorf, D; Michel, F

    2001-12-01

    Proteoheparan sulfate can be adsorbed to a methylated silica surface in a monomolecular layer via its transmembrane hydrophobic protein core domain. Due to electrostatic repulsion, its anionic glycosaminoglycan side chains are stretched out into the blood substitute solution, representing a receptor site for specific lipoprotein binding through basic amino acid-rich residues within their apolipoproteins. The binding process was studied by ellipsometric techniques showing that HDL has a high binding affinity to the receptor and a protective effect on interfacial heparan sulfate proteoglycan layers, with respect to LDL and Ca(2+) complexation. LDL was found to deposit strongly at the proteoheparan sulfate, particularly in the presence of Ca(2+), thus creating the complex formation "proteoglycan-low density lipoprotein-calcium". This ternary complex build-up may be interpreted as arteriosclerotic nanoplaque formation on the molecular level responsible for the arteriosclerotic primary lesion. On the other hand, HDL bound to heparan sulfate proteoglycan protected against LDL docking and completely suppressed calcification of the proteoglycan-lipoprotein complex. In addition, HDL and aqueous garlic extract were able to reduce the ternary complex deposition and to disintegrate HS-PG/LDL/Ca(2+) aggregates. Although much remains unclear regarding the mechanism of lipoprotein depositions at proteoglycan-coated surfaces, it seems clear that the use of such systems offers possibilities for investigating lipoprotein deposition at a "nanoscopic" level under close to physiological conditions. In particular, Ca(2+)-promoted LDL deposition and the protective effect of HDL, even at high Ca(2+) and LDL concentrations, agree well with previous clinical observations regarding risk and beneficial factors for early stages of atherosclerosis. Therefore, we believe that the system can be of some use in investigations, e.g. of the interplay between different lipoproteins in arteriosclerotic

  3. Novel nonsense mutation of the endothelin-B receptor gene in a family with Waardenburg-Hirschsprung disease.

    Science.gov (United States)

    Syrris, P; Carter, N D; Patton, M A

    1999-11-05

    Waardenburg syndrome (WS) comprises sensorineural hearing loss, hypopigmentation of skin and hair, and pigmentary disturbances of the irides. Four types of WS have been classified to date; in WS type IV (WS4), patients additionally have colonic aganglionosis (Hirschsprung disease, HSCR). Mutations in the endothelin-3 (EDN3), endothelin-B receptor (EDNRB), and Sox10 genes have been identified as causative for WS type IV. We screened a family with a combined WS-HSCR phenotype for mutations in the EDNRB locus using standard DNA mutation analysis and sequencing techniques. We have identified a novel nonsense mutation at codon 253 (CGA-->TGA, Arg-->STOP). This mutation leads to a premature end of the translation of EDNRB at exon 3, and it is predicted to produce a truncated and nonfunctional endothelin-B receptor. All affected relatives were heterozygous for the Arg(253)-->STOP mutation, whereas it was not observed in over 50 unrelated individuals used as controls. These data confirm the role of EDNRB in the cause of the Waardenburg-Hirschsprung syndrome and demonstrate that in WS-HSCR there is a lack of correlation between phenotype and genotype and a variable expression of disease even within the same family. Copyright 1999 Wiley-Liss, Inc.

  4. Microbial receptor assay for rapid detection and identification of seven families of antimicrobial drugs in milk: collaborative study

    International Nuclear Information System (INIS)

    Charm, S.E.; Chi, R.

    1988-01-01

    A microbial competitive receptor assay for detecting residues of antibiotic families in milk was studied collaboratively by 13 laboratories. In this method, microbial cells added to a milk sample provide specific binding sites for which 14 C or 3 H labeled drug competes with drug resides in the sample. The 14 C or 3 H binding to the specific binding sites is measured in a scintillation counter and compared with a zero standard milk. If the sample is statistically different from the zero standard, it is positive. The assay takes about 15 min. The binding reaction occurs between the receptor site and the drug functional group, so all members of a drug family are detected. In this case, beta-lactams, tetracyclines, macrolides, aminoglycosides, novobiocin, chloramphenicol, and sulfonamides, including p-amino-benzoic acid (PABA) and its other analogs, are detectable. The incidence of false negative determinations among samples is about 1%; the incidence of false positives is about 3%. For negative cases, the relative standard deviations for repeatability ranged from 0 to 5% and for reproducibility from 0 to 6%. For positive cases, relative standard deviations ranged from 0 to 13% for repeatability and from 0 to 14% for reproducibility. The method has been adopted official first action

  5. En route to new blockbuster antihistamines:surveying the offspring of the expanding histamine receptor family

    NARCIS (Netherlands)

    Leurs, R.; Vischer, H.F.; Wijtmans, M.; De Esch, I.J.

    2011-01-01

    With the recognition of two new histamine receptors at the start of the new millennium, the field of histamine research has seen a clear revival. In the last 10 years, many academic and industrial groups have taken up the challenge to target these new members of the aminergic G-protein-coupled

  6. Ionotropic glutamate receptors (iGluRs) of the delta family (GluD1 ...

    African Journals Online (AJOL)

    Muhammad Zahid Khan

    2016-10-20

    Oct 20, 2016 ... GluD1 knockout mice (GluD1 KO) have normal learning in the Morris water maze .... could bind and activate the receptor.5,6 D-Ser and glycine have now been identified as .... English editing of this manuscript. References. 1.

  7. Ionotropic glutamate receptors (iGluRs) of the delta family (GluD1 ...

    African Journals Online (AJOL)

    ... such as Neurexin1. This review presents current knowledge regarding the expression, structure and function of Glu delta receptors (GluD1, GluD2) in brain, focusing on synapse formation, function and dysfunction. Keywords: iGluRs; GluD1; GluD2; Synaptogenesis; Autism spectrum disorder (ASD); Schizophrenia (SCZ) ...

  8. Polymorphisms in the estrogen receptor 1 and vitamin C and matrix metalloproteinase gene families are associated with susceptibility to lymphoma.

    Directory of Open Access Journals (Sweden)

    Christine F Skibola

    Full Text Available BACKGROUND: Non-Hodgkin lymphoma (NHL is the fifth most common cancer in the U.S. and few causes have been identified. Genetic association studies may help identify environmental risk factors and enhance our understanding of disease mechanisms. METHODOLOGY/PRINCIPAL FINDINGS: 768 coding and haplotype tagging SNPs in 146 genes were examined using Illumina GoldenGate technology in a large population-based case-control study of NHL in the San Francisco Bay Area (1,292 cases 1,375 controls are included here. Statistical analyses were restricted to HIV- participants of white non-Hispanic origin. Genes involved in steroidogenesis, immune function, cell signaling, sunlight exposure, xenobiotic metabolism/oxidative stress, energy balance, and uptake and metabolism of cholesterol, folate and vitamin C were investigated. Sixteen SNPs in eight pathways and nine haplotypes were associated with NHL after correction for multiple testing at the adjusted q<0.10 level. Eight SNPs were tested in an independent case-control study of lymphoma in Germany (494 NHL cases and 494 matched controls. Novel associations with common variants in estrogen receptor 1 (ESR1 and in the vitamin C receptor and matrix metalloproteinase gene families were observed. Four ESR1 SNPs were associated with follicular lymphoma (FL in the U.S. study, with rs3020314 remaining associated with reduced risk of FL after multiple testing adjustments [odds ratio (OR = 0.42, 95% confidence interval (CI = 0.23-0.77 and replication in the German study (OR = 0.24, 95% CI = 0.06-0.94. Several SNPs and haplotypes in the matrix metalloproteinase-3 (MMP3 and MMP9 genes and in the vitamin C receptor genes, solute carrier family 23 member 1 (SLC23A1 and SLC23A2, showed associations with NHL risk. CONCLUSIONS/SIGNIFICANCE: Our findings suggest a role for estrogen, vitamin C and matrix metalloproteinases in the pathogenesis of NHL that will require further validation.

  9. Characterization of a family of gamma-ray-induced CHO mutants demonstrates that the ldlA locus is diploid and encodes the low-density lipoprotein receptor

    International Nuclear Information System (INIS)

    Sege, R.D.; Kozarsky, K.F.; Krieger, M.

    1986-01-01

    The ldlA locus is one of four Chinese hamster ovary (CHO) cell loci which are known to be required for the synthesis of functional low-density lipoprotein (LDL) receptors. Previous studies have suggested that the ldlA locus is diploid and encodes the LDL receptor. To confirm this assignment, we have isolated a partial genomic clone of the Chinese hamster LDL receptor gene and used this and other nucleic acid and antibody probes to study a family of ldlA mutants isolated after gamma-irradiation. Our analysis suggests that there are two LDL receptor alleles in wild-type CHO cells. Each of the three mutants isolated after gamma-irradiation had detectable deletions affecting one of the two LDL receptor alleles. One of the mutants also had a disruption of the remaining allele, resulting in the synthesis of an abnormal receptor precursor which was not subject to Golgi-associated posttranslational glycoprotein processing. The correlation of changes in the expression, structure, and function of LDL receptors with deletions in the LDL receptor genes in these mutants directly demonstrated that the ldlA locus in CHO cells is diploid and encodes the LDL receptor. In addition, our analysis suggests that CHO cells in culture may contain a partial LDL receptor pseudogene

  10. Delivery of folates to the cytoplasm of MA104 cells is mediated by a surface membrane receptor that recycles

    International Nuclear Information System (INIS)

    Kamen, B.A.; Wang, M.T.; Streckfuss, A.J.; Peryea, X.; Anderson, R.G.

    1988-01-01

    MA104 cells, as well as several other rapidly dividing tissue culture cells, have a folate-binding protein associated with their cell surface. The protein has the properties of a membrane receptor: (a) 5-methyl[ 3 H]tetrahydrofolic acid binds with high affinity (Kd approximately equal to 3 nM); (b) the protein is an integral membrane protein; (c) it appears to deliver physiological concentrations of 5-methyl[ 3 H]tetrahydrofolic acid to the inside of the cell; (d) binding activity is regulated by the concentration of folate within the cell. To better understand the mechanism of action of this receptor, we have studied the pathway of folate internalization. We present evidence that during internalization: (a) folate binds to the membrane receptor; (b) the ligand-receptor complex moves into the cell; (c) the ligand is released from the receptor in an acidic intracellular compartment and moves into the cytoplasm; and (d) the unoccupied receptor returns to the cell surface

  11. Binding Preferences, Surface Attachment, Diffusivity, and Orientation of a Family 1 Carbohydrate-Binding Module on Cellulose

    Energy Technology Data Exchange (ETDEWEB)

    Nimlos, M. R.; Beckham, G. T.; Matthews, J. F.; Bu, L.; Himmel, M. E.; Crowley, M. F.

    2012-06-08

    Cellulase enzymes often contain carbohydrate-binding modules (CBMs) for binding to cellulose. The mechanisms by which CBMs recognize specific surfaces of cellulose and aid in deconstruction are essential to understand cellulase action. The Family 1 CBM from the Trichoderma reesei Family 7 cellobiohydrolase, Cel7A, is known to selectively bind to hydrophobic surfaces of native cellulose. It is most commonly suggested that three aromatic residues identify the planar binding face of this CBM, but several recent studies have challenged this hypothesis. Here, we use molecular simulation to study the CBM binding orientation and affinity on hydrophilic and hydrophobic cellulose surfaces. Roughly 43 {mu}s of molecular dynamics simulations were conducted, which enables statistically significant observations. We quantify the fractions of the CBMs that detach from crystal surfaces or diffuse to other surfaces, the diffusivity along the hydrophobic surface, and the overall orientation of the CBM on both hydrophobic and hydrophilic faces. The simulations demonstrate that there is a thermodynamic driving force for the Cel7A CBM to bind preferentially to the hydrophobic surface of cellulose relative to hydrophilic surfaces. In addition, the simulations demonstrate that the CBM can diffuse from hydrophilic surfaces to the hydrophobic surface, whereas the reverse transition is not observed. Lastly, our simulations suggest that the flat faces of Family 1 CBMs are the preferred binding surfaces. These results enhance our understanding of how Family 1 CBMs interact with and recognize specific cellulose surfaces and provide insights into the initial events of cellulase adsorption and diffusion on cellulose.

  12. On the Emerging Role of the Taste Receptor Type 1 (T1R Family of Nutrient-Sensors in the Musculoskeletal System

    Directory of Open Access Journals (Sweden)

    Shoichiro Kokabu

    2017-03-01

    Full Text Available The special sense of taste guides and guards food intake and is essential for body maintenance. Salty and sour tastes are sensed via ion channels or gated ion channels while G protein-coupled receptors (GPCRs of the taste receptor type 1 (T1R family sense sweet and umami tastes and GPCRs of the taste receptor type 2 (T2R family sense bitter tastes. T1R and T2R receptors share similar downstream signaling pathways that result in the stimulation of phospholipase-C-β2. The T1R family includes three members that form heterodimeric complexes to recognize either amino acids or sweet molecules such as glucose. Although these functions were originally described in gustatory tissue, T1R family members are expressed in numerous non-gustatory tissues and are now viewed as nutrient sensors that play important roles in monitoring global glucose and amino acid status. Here, we highlight emerging evidence detailing the function of T1R family members in the musculoskeletal system and review these findings in the context of the musculoskeletal diseases sarcopenia and osteoporosis, which are major public health problems among the elderly that affect locomotion, activities of daily living, and quality of life. These studies raise the possibility that T1R family member function may be modulated for therapeutic benefit.

  13. Joint association of nicotinic acetylcholine receptor variants with abdominal obesity in American Indians: the Strong Heart Family Study.

    Science.gov (United States)

    Zhu, Yun; Yang, Jingyun; Yeh, Fawn; Cole, Shelley A; Haack, Karin; Lee, Elisa T; Howard, Barbara V; Zhao, Jinying

    2014-01-01

    Cigarette smoke is a strong risk factor for obesity and cardiovascular disease. The effect of genetic variants involved in nicotine metabolism on obesity or body composition has not been well studied. Though many genetic variants have previously been associated with adiposity or body fat distribution, a single variant usually confers a minimal individual risk. The goal of this study is to evaluate the joint association of multiple variants involved in cigarette smoke or nicotine dependence with obesity-related phenotypes in American Indians. To achieve this goal, we genotyped 61 tagSNPs in seven genes encoding nicotine acetylcholine receptors (nAChRs) in 3,665 American Indians participating in the Strong Heart Family Study. Single SNP association with obesity-related traits was tested using family-based association, adjusting for traditional risk factors including smoking. Joint association of all SNPs in the seven nAChRs genes were examined by gene-family analysis based on weighted truncated product method (TPM). Multiple testing was controlled by false discovery rate (FDR). Results demonstrate that multiple SNPs showed weak individual association with one or more measures of obesity, but none survived correction for multiple testing. However, gene-family analysis revealed significant associations with waist circumference (p = 0.0001) and waist-to-hip ratio (p = 0.0001), but not body mass index (p = 0.20) and percent body fat (p = 0.29), indicating that genetic variants are jointly associated with abdominal, but not general, obesity among American Indians. The observed combined genetic effect is independent of cigarette smoking per se. In conclusion, multiple variants in the nAChR gene family are jointly associated with abdominal obesity in American Indians, independent of general obesity and cigarette smoking per se.

  14. Interaction between tumor cell surface receptor RAGE and proteinase 3 mediates prostate cancer metastasis to bone

    Science.gov (United States)

    Kolonin, Mikhail G.; Sergeeva, Anna; Staquicini, Daniela I.; Smith, Tracey L.; Tarleton, Christy A.; Molldrem, Jeffrey J.; Sidman, Richard L.; Marchiò, Serena; Pasqualini, Renata; Arap, Wadih

    2017-01-01

    Human prostate cancer often metastasizes to bone, but the biological basis for such site-specific tropism remains largely unresolved. Recent work led us to hypothesize that this tropism may reflect pathogenic interactions between RAGE, a cell surface receptor expressed on malignant cells in advanced prostate cancer, and proteinase 3 (PR3), a serine protease present in inflammatory neutrophils and hematopoietic cells within the bone marrow microenvironment. In this study, we establish that RAGE-PR3 interaction mediates homing of prostate cancer cells to the bone marrow. PR3 bound to RAGE on the surface of prostate cancer cells in vitro, inducing tumor cell motility through a non-proteolytic signal transduction cascade involving activation and phosphorylation of ERK1/2 and JNK1. In preclinical models of experimental metastasis, ectopic expression of RAGE on human prostate cancer cells was sufficient to promote bone marrow homing within a short time frame. Our findings demonstrate how RAGE-PR3 interactions between human prostate cancer cells and the bone marrow microenvironment mediate bone metastasis during prostate cancer progression, with potential implications for prognosis and therapeutic intervention. PMID:28428279

  15. Layilin, a cell surface hyaluronan receptor, interacts with merlin and radixin

    International Nuclear Information System (INIS)

    Bono, Petri; Cordero, Etchell; Johnson, Kristen; Borowsky, Mark; Ramesh, Vijaya; Jacks, Tyler; Hynes, Richard O.

    2005-01-01

    Layilin is a widely expressed integral membrane hyaluronan receptor, originally identified as a binding partner of talin located in membrane ruffles. We have identified merlin, the neurofibromatosis type 2 tumor suppressor protein and radixin, as other interactors with the carboxy-terminal domain of layilin. We show that the carboxy-terminal domain of layilin is capable of binding to the amino-terminal domain of radixin. An interdomain interaction between the amino- and the carboxy-terminal domains of radixin inhibits its ability to bind to layilin. In the presence of acidic phospholipids, the interdomain interaction of radixin is inhibited and layilin can bind to full-length radixin. In contrast, layilin binds both full-length and amino-terminal merlin-GST fusion proteins without a requirement for phospholipids. Furthermore, layilin antibody can immunoprecipitate merlin, confirming association in vivo between these two proteins, which also display similar subcellular localizations in ruffling membranes. No interaction was observed between layilin and ezrin or layilin and moesin. These findings expand the known binding partners of layilin to include other members of the talin/band 4.1/ERM (ezrin, radixin, and moesin) family of cytoskeletal-membrane linker molecules. This in turn suggests that layilin may mediate signals from extracellular matrix to the cell cytoskeleton via interaction with different intracellular binding partners and thereby be involved in the modulation of cortical structures in the cell

  16. Quantitation of Fc receptors and surface immunoglobulin is affected by cell isolation procedures using plasmagel and ficoll-hypaque.

    Science.gov (United States)

    Alexander, E L; Titus, J A; Segal, D M

    1978-01-01

    When mononuclear leukocytes are isolated directly from whole human blood using Ficoll-Hypaque or Plasmagel, cytophilic immunoglobulin is detected on cell surfaces. Upon incubation at 37 degrees C, this cell-associated immunoglobulin is shed slowly into the medium. However, when cells are prewashed in phosphate-buffered saline prior to isolation, they appear to be free of cytophilic immunoglobulin. Compared to prewashed cells, populations retaining cytophilic immunoglobulin on their surfaces demonstrate a decreased binding of soluble immune complexes and radiolabelled trimeric rabbit IgG. The data suggest that Ficoll-Hypaque and Plasmagel cause serum IgG to bind with abnormally high affinity to human mononuclear leukocytes, probably via Fc receptors. This artifact of preparation can lead to erroneous estimates of the numbers of cells bearing Fc receptors or intrinsic membrane immunoglobulin within a given population of cells and to an inaccurate assessment of the average number of Fc receptors per cell.

  17. Feeding and the rhodopsin family G-Protein Coupled Receptors (GPCRs in nematodes and arthropods

    Directory of Open Access Journals (Sweden)

    Joao Carlos dos Reis Cardoso

    2012-12-01

    Full Text Available In vertebrates, receptors of the rhodopsin G-protein coupled superfamily (GPCRs play an important role in the regulation of feeding and energy homeostasis and are activated by peptide hormones produced in the brain-gut axis. These peptides regulate appetite and energy expenditure by promoting or inhibiting food intake. Sequence and function homologues of human GPCRs involved in feeding exist in the nematode roundworm, Caenorhabditis elegans (C. elegans and the arthropod fruit fly, Drosophila melanogaster (D. melanogaster, suggesting that the mechanisms that regulate food intake emerged early and have been conserved during metazoan radiation. Nematodes and arthropods are the most diverse and successful animal phyla on Earth. They can survive in a vast diversity of environments and have acquired distinct life styles and feeding strategies. The aim of the present review is to investigate if this diversity has affected the evolution of invertebrate GPCRs. Homologues of the C. elegans and D. melanogaster rhodopsin receptors were characterized in the genome of other nematodes and arthropods and receptor evolution compared. With the exception of bombesin receptors (BBR that are absent from nematodes, a similar gene complement was found. In arthropods, rhodopsin GPCR evolution is characterized by species-specific gene duplications and deletions and in nematodes by gene expansions in species with a free-living stage and gene deletions in representatives of obligate parasitic taxa. Based upon variation in GPCR gene number and potentially divergent functions within phyla we hypothesize that life style and feeding diversity practiced by nematodes and arthropods was one factor that contributed to rhodopsin GPCR gene evolution. Understanding how the regulation of food intake has evolved in invertebrates will contribute to the development of novel drugs to control nematodes and arthropods and the pests and diseases that use them as vectors.

  18. Feeding and the rhodopsin family g-protein coupled receptors in nematodes and arthropods.

    Science.gov (United States)

    Cardoso, João C R; Félix, Rute C; Fonseca, Vera G; Power, Deborah M

    2012-01-01

    In vertebrates, receptors of the rhodopsin G-protein coupled superfamily (GPCRs) play an important role in the regulation of feeding and energy homeostasis and are activated by peptide hormones produced in the brain-gut axis. These peptides regulate appetite and energy expenditure by promoting or inhibiting food intake. Sequence and function homologs of human GPCRs involved in feeding exist in the nematode roundworm, Caenorhabditis elegans (C. elegans), and the arthropod fruit fly, Drosophila melanogaster (D. melanogaster), suggesting that the mechanisms that regulate food intake emerged early and have been conserved during metazoan radiation. Nematodes and arthropods are the most diverse and successful animal phyla on Earth. They can survive in a vast diversity of environments and have acquired distinct life styles and feeding strategies. The aim of the present review is to investigate if this diversity has affected the evolution of invertebrate GPCRs. Homologs of the C. elegans and D. melanogaster rhodopsin receptors were characterized in the genome of other nematodes and arthropods and receptor evolution compared. With the exception of bombesin receptors (BBR) that are absent from nematodes, a similar gene complement was found. In arthropods, rhodopsin GPCR evolution is characterized by species-specific gene duplications and deletions and in nematodes by gene expansions in species with a free-living stage and gene deletions in representatives of obligate parasitic taxa. Based upon variation in GPCR gene number and potentially divergent functions within phyla we hypothesize that life style and feeding diversity practiced by nematodes and arthropods was one factor that contributed to rhodopsin GPCR gene evolution. Understanding how the regulation of food intake has evolved in invertebrates will contribute to the development of novel drugs to control nematodes and arthropods and the pests and diseases that use them as vectors.

  19. Identification and phylogeny of the tomato receptor-like proteins family

    OpenAIRE

    Ermis Yanes-Paz; Gioser María Ramos-Echazábal; Glay Chinea; Yanelis Capdesuñer Ruiz; Ramón Santos Bermúdez

    2017-01-01

    The receptor-like proteins (RLPs) play multiple roles in development and defense. In the current work 75 RLPs were identified in tomato (Solanum lycopersicum L.) using iterative BLAST searches and domain prediction. A phylogenetic tree including all the identified RLPs from tomato and some functionally characterized RLPs from other species was built to identify their putative homologues in tomato. We first tested whether C3-F-based phylogeny was a good indicator of functional relation between...

  20. Multiple functions and essential roles of nuclear receptor coactivators of bHLH-PAS family.

    Science.gov (United States)

    Pecenova, L; Farkas, Robert

    2016-07-01

    Classical non-peptide hormones, such as steroids, retinoids, thyroid hormones, vitamin D3 and their derivatives including prostaglandins, benzoates, oxysterols, and bile acids, are collectively designated as small lipophilic ligands, acting via binding to the nuclear receptors (NRs). The NRs form a large superfamily of transcription factors that participate virtually in every key biological process. They control various aspects of animal development, fertility, gametogenesis, and numerous metabolic pathways, and can be misregulated in many types of cancers. Their enormous functional plasticity, as transcription factors, relates in part to NR-mediated interactions with plethora of coregulatory proteins upon ligand binding to their ligand binding domains (LBD), or following covalent modification. Here, we review some general views of a specific group of NR coregulators, so-called nuclear receptor coactivators (NRCs) or steroid receptor coactivators (SRCs) and highlight some of their unique functions/roles, which are less extensively mentioned and discussed in other reviews. We also try to pinpoint few neglected moments in the cooperative action of SRCs, which may also indicate their variable roles in the hormone-independent signaling pathways.

  1. Differential expression of the P2X7 receptor in ovarian surface epithelium during the oestrous cycle in the mouse.

    Science.gov (United States)

    Vázquez-Cuevas, F G; Cruz-Rico, A; Garay, E; García-Carrancá, A; Pérez-Montiel, D; Juárez, B; Arellano, R O

    2013-01-01

    Purinergic signalling has been proposed as an intraovarian regulatory mechanism. Of the receptors responsible for purinergic transmission, the P2X7 receptor is an ATP-gated cationic channel that displays a broad spectrum of cellular functions ranging from apoptosis to cell proliferation and tumourigenesis. In the present study, we investigated the functional expression of P2X7 receptors in ovarian surface epithelium (OSE). P2X7 protein was detected in the OSE layer of the mouse, both in situ and in primary cultures. In cultures, 2'(3')-O-(4-Benzoylbenzoyl)adenosine-5'-triphosphate (BzATP) activation of P2X7 receptors increased [Ca(2+)]i and induced apoptosis. The functionality of the P2X7 receptor was investigated in situ by intrabursal injection of BzATP on each day of the oestrous cycle and evaluation of apoptosis 24h using the terminal deoxyribonucleotidyl transferase-mediated dUTP-fluorescein nick end-labelling (TUNEL) assay. Maximum effects of BzATP were observed during pro-oestrus, with the effects being blocked by A438079, a specific P2X7 receptor antagonist. Immunofluorescence staining for P2X7 protein revealed more robust expression during pro-oestrus and in OSE regions behind the antral follicles, strongly supporting the notion that the differences in apoptosis can be explained by increased receptor expression, which is regulated during the oestrous cycle. Finally, P2X7 receptor expression was detected in the OSE layer of human ovaries, with receptor expression maintained in human ovaries diagnosed with cancer, as well as in the human ovarian carcinoma SKOV3 cell line.

  2. Ligand receptor dynamics at streptavidin-coated particle surfaces: A flow cytometric and spectrofluorimetric study

    Energy Technology Data Exchange (ETDEWEB)

    Buranda, T. [Univ. of New Mexico School of Medicine, Albuquerque, NM (United States)]|[Univ. of New Mexico, Albuquerque, NM (United States); Jones, G.M. [Univ. of New Mexico School of Medicine, Albuquerque, NM (United States); Nolan, J.P.; Keij, J. [Los Alamos National Labs., NM (United States); Lopez, G.P. [Univ. of New Mexico, Albuquerque, NM (United States); Sklar, L.A. [Univ. of New Mexico School of Medicine, Albuquerque, NM (United States)]|[Los Alamos National Lab., NM (United States)

    1999-04-29

    The authors have studied the binding of 5-((N-(5-(N-(6-(biotinoyl)amino)hexanoyl)amino)pentyl)thioureidyl)fluorescein (fluorescein biotin) to 6.2 {micro}m diameter, streptavidin-coated polystyrene beads using a combination of fluorimetric and flow cytometric methods. They have determined the average number of binding sites per bead, the extent of fluorescein quenching upon binding to the bead, and the association and dissociation kinetics. The authors estimate the site number to be {approx}1 million per bead. The binding of the fluorescein biotin ligand occurs in steps where the insertion of the biotin moiety into one receptor pocket is followed immediately by the capture of the fluorescein moiety by a neighboring binding pocket; fluorescence quenching is a consequence of this secondary binding. At high surface coverage, the dominant mechanism of quenching appears to be via the formation of nonfluorescent nearest-neighbor aggregates. At early times, the binding process is characterized by biphasic association and dissociation kinetics which are remarkably dependent on the initial concentration of the ligand. The rate constant for binding to the first receptor pocket of a streptavidin molecule is {approx}(1.3 {+-} 0.3) {times} 10{sup 7} 1{sup {minus}1} S{sup {minus}1}. The rate of binding of a second biotin may be reduced due to steric interference. The early time dissociative behavior is in sharp contrast to the typical stability associated with this system. The early time dissociative behavior is in sharp contrast to the typical stability associated with this system. The dissociation rate constant is as high as 0.05 s{sup {minus}1} shortly after binding, but decreases by 3 orders of magnitude after 3 h of binding. Potential sources for the time dependence of the dissociation rate constant are discussed.

  3. Clinical Significance of ErbB Receptor Family in Urothelial Carcinoma of the Bladder: A Systematic Review and Meta-Analysis

    Directory of Open Access Journals (Sweden)

    Yuh-Shyan Tsai

    2012-01-01

    Full Text Available The prognostic importance of examining ErbB receptor family expression in human bladder cancer remains uncertain. Using published evidence, we examined the clinical value and the updated results of clinical trials targeting ErbB receptor family members. Twenty-seven articles from 65 references related to ErbB receptor expression assessment in bladder cancer were reviewed. The estimates included the association significance, hazard ratios, and 95% confidence intervals (CIs from actuarial curves and survival analyses. A meta-analysis was done on those reports using univariate log-rank tests or a Cox-regression model. The methods of analysis and study subjects chosen varied widely among studies. The overall risks of disease progression for patients with EGFR or ErbB2 overexpression were 4.5 (95% CI: 2.5–8.4 and 1.1 (95% CI: 0.6–1.9, and the risks of mortality were 3.0 (95% CI: 1.6–5.9 and 1.1 (95% CI: 1.0–1.2, respectively. However, the significance of coexpression patterns of the ErbB receptor family remains controversial. None of six clinical trials yielded convincing results for blockading ErbB receptor signaling in urothelial carcinoma. The results of this analysis suggest that assessing co-expression patterns of the ErbB family may provide better prognostic information for bladder cancer patients.

  4. DNA secondary structures are associated with recombination in major Plasmodium falciparum variable surface antigen gene families

    DEFF Research Database (Denmark)

    Sander, Adam F.; Lavstsen, Thomas; Rask, Thomas Salhøj

    2014-01-01

    falciparum-erythrocyte membrane protein 1 class on the infected erythrocyte surface. Recombination clearly generates var diversity, but the nature and control of the genetic exchanges involved remain unclear. By experimental and bioinformatic identification of recombination events and genome...... of recombination during DNA replication in P. falciparum sexual stages, and that these DSS-regulated genetic exchanges generate functional and diverse P. falciparum adhesion antigens. DSS-induced recombination may represent a common mechanism for optimizing the evolvability of virulence gene families in pathogens....

  5. The neuronal Ca(2+) -binding protein 2 (NECAB2) interacts with the adenosine A(2A) receptor and modulates the cell surface expression and function of the receptor.

    Science.gov (United States)

    Canela, Laia; Luján, Rafael; Lluís, Carme; Burgueño, Javier; Mallol, Josefa; Canela, Enric I; Franco, Rafael; Ciruela, Francisco

    2007-09-01

    Heptaspanning membrane also known as G protein-coupled receptors (GPCR) do interact with a variety of intracellular proteins whose function is regulate receptor traffic and/or signaling. Using a yeast two-hybrid screen, NECAB2, a neuronal calcium binding protein, was identified as a binding partner for the adenosine A(2A) receptor (A(2A)R) interacting with its C-terminal domain. Co-localization, co-immunoprecipitation and pull-down experiments showed a close and specific interaction between A(2A)R and NECAB2 in both transfected HEK-293 cells and also in rat striatum. Immunoelectron microscopy detection of NECAB2 and A(2A)R in the rat striatopallidal structures indicated that both proteins are co-distributed in the same glutamatergic nerve terminals. The interaction of NECAB2 with A(2A)R modulated the cell surface expression, the ligand-dependent internalization and the receptor-mediated activation of the MAPK pathway. Overall, these results show that A(2A)R interacts with NECAB2 in striatal neurones co-expressing the two proteins and that the interaction is relevant for A(2A)R function.

  6. Ionotropic glutamate receptors (iGluRs of the delta family (GluD1 and GluD2 and synaptogenesis

    Directory of Open Access Journals (Sweden)

    Muhammad Zahid Khan

    2017-08-01

    Full Text Available Glutamate delta-1 (GluD1 and glutamate delta-2 (GluD2 form the delta family of ionotropic glutamate receptors (iGluRs and are distinct from other (iGluRs in that they do not exhibit typical agonist-induced ion channel currents. Recent studies have demonstrated a crucial role of the delta receptors in synapse formation by interacting with presynaptic proteins such as Neurexin1. This review presents current knowledge regarding the expression, structure and function of Glu delta receptors (GluD1, GluD2 in brain, focusing on synapse formation, function and dysfunction.

  7. receptores

    Directory of Open Access Journals (Sweden)

    Salete Regina Daronco Benetti

    2006-01-01

    Full Text Available Se trata de un estudio etnográfico, que tuvo lo objetivo de interpretar el sistema de conocimiento y del significado atribuidos a la sangre referente a la transfusión sanguínea por los donadores y receptores de un banco de sangre. Para la colecta de las informaciones se observaron los participantes y la entrevista etnográfica se realizó el análisis de dominio, taxonómicos y temáticos. Los dominios culturales fueron: la sangre es vida: fuente de vida y alimento valioso; creencias religiosas: fuentes simbólicas de apoyos; donación sanguínea: un gesto colaborador que exige cuidarse, gratifica y trae felicidad; donación sanguínea: fuente simbólica de inseguridad; estar enfermo es una condición para realizar transfusión sanguínea; transfusión sanguínea: esperanza de vida; Creencias populares: transfusión sanguínea como riesgo para la salud; donadores de sangre: personas benditas; donar y recibir sangre: como significado de felicidad. Temática: “líquido precioso que origina, sostiene, modifica la vida, provoca miedo e inseguridad”.

  8. Functional evolution of a multigene family: orthologous and paralogous pheromone receptor genes in the turnip moth, Agrotis segetum.

    Directory of Open Access Journals (Sweden)

    Dan-Dan Zhang

    Full Text Available Lepidopteran pheromone receptors (PRs, for which orthologies are evident among closely related species, provide an intriguing example of gene family evolution in terms of how new functions may arise. However, only a limited number of PRs have been functionally characterized so far and thus evolutionary scenarios suffer from elements of speculation. In this study we investigated the turnip moth Agrotis segetum, in which female moths produce a mixture of chemically related pheromone components that elicit specific responses from receptor cells on male antennae. We cloned nine A. segetum PR genes and the Orco gene by degenerate primer based RT-PCR. The nine PR genes, named as AsegOR1 and AsegOR3-10, fall into four distinct orthologous clusters of known lepidopteran PRs, of which one contains six paralogues. The paralogues are under relaxed selective pressure, contrasting with the purifying selection on other clusters. We identified the receptors AsegOR9, AsegOR4 and AsegOR5, specific for the respective homologous pheromone components (Z-5-decenyl, (Z-7-dodecenyl and (Z-9-tetradecenyl acetates, by two-electrode voltage clamp recording from Xenopus laevis oocytes co-expressing Orco and each PR candidate. These receptors occur in three different orthologous clusters. We also found that the six paralogues with high sequence similarity vary dramatically in ligand selectivity and sensitivity. Different from AsegOR9, AsegOR6 showed a relatively large response to the behavioural antagonist (Z-5-decenol, and a small response to (Z-5-decenyl acetate. AsegOR1 was broadly tuned, but most responsive to (Z-5-decenyl acetate, (Z-7-dodecenyl acetate and the behavioural antagonist (Z-8-dodecenyl acetate. AsegOR8 and AsegOR7, which differ from AsegOR6 and AsegOR1 by 7 and 10 aa respectively, showed much lower sensitivities. AsegOR10 showed only small responses to all the tested compounds. These results suggest that new receptors arise through gene duplication, and

  9. Down-regulation of Cell Surface Cyclic AMP Receptors and Desensitization of Cyclic AMP-stimulated Adenylate Cyclase by Cyclic AMP in Dictyostelium discoideum. Kinetics and Concentration Dependence

    NARCIS (Netherlands)

    Haastert, Peter J.M. van

    1987-01-01

    cAMP binds to Dictyostelium discoideum surface receptors and induces a transient activation of adenylate cyclase, which is followed by desensitization. cAMP also induces a loss of detectable surface receptors (down-regulation). Cells were incubated with constant cAMP concentrations, washed free of

  10. The Toll-like receptor gene family is integrated into human DNA damage and p53 networks.

    Directory of Open Access Journals (Sweden)

    Daniel Menendez

    2011-03-01

    Full Text Available In recent years the functions that the p53 tumor suppressor plays in human biology have been greatly extended beyond "guardian of the genome." Our studies of promoter response element sequences targeted by the p53 master regulatory transcription factor suggest a general role for this DNA damage and stress-responsive regulator in the control of human Toll-like receptor (TLR gene expression. The TLR gene family mediates innate immunity to a wide variety of pathogenic threats through recognition of conserved pathogen-associated molecular motifs. Using primary human immune cells, we have examined expression of the entire TLR gene family following exposure to anti-cancer agents that induce the p53 network. Expression of all TLR genes, TLR1 to TLR10, in blood lymphocytes and alveolar macrophages from healthy volunteers can be induced by DNA metabolic stressors. However, there is considerable inter-individual variability. Most of the TLR genes respond to p53 via canonical as well as noncanonical promoter binding sites. Importantly, the integration of the TLR gene family into the p53 network is unique to primates, a recurrent theme raised for other gene families in our previous studies. Furthermore, a polymorphism in a TLR8 response element provides the first human example of a p53 target sequence specifically responsible for endogenous gene induction. These findings-demonstrating that the human innate immune system, including downstream induction of cytokines, can be modulated by DNA metabolic stress-have many implications for health and disease, as well as for understanding the evolution of damage and p53 responsive networks.

  11. Oestrogen receptor beta isoform expression in sporadic colorectal cancer, familial adenomatous polyposis and progressive stages of colorectal cancer

    DEFF Research Database (Denmark)

    Stevanato Filho, Paulo Roberto; Aguiar Júnior, Samuel; Begnami, Maria Dirlei

    2017-01-01

    BACKGROUND: Among the sex hormones, oestrogen may play a role in colorectal cancer, particularly in conjunction with oestrogen receptor-β (ERβ). The expression of ERβ isoform variants and their correlations with familial adenomatous polyposis (FAP) syndrome and sporadic colorectal carcinomas...... was identified in sporadic polyps and in sporadic colorectal cancer as well as in polyps from FAP syndrome patients compared with normal tissues (p expression in polyps (p ..., no differences were observed when sporadic colorectal carcinomas were compared to normal mucosa tissues. These findings suggest an association of the ERβ isoform variants in individuals affected by germline mutations of the APC gene. Progressively decreased expression of ERβ was found in polyps at early stages...

  12. Harnessing Integrative Omics to Facilitate Molecular Imaging of the Human Epidermal Growth Factor Receptor Family for Precision Medicine.

    Science.gov (United States)

    Pool, Martin; de Boer, H Rudolf; Hooge, Marjolijn N Lub-de; van Vugt, Marcel A T M; de Vries, Elisabeth G E

    2017-01-01

    Cancer is a growing problem worldwide. The cause of death in cancer patients is often due to treatment-resistant metastatic disease. Many molecularly targeted anticancer drugs have been developed against 'oncogenic driver' pathways. However, these treatments are usually only effective in properly selected patients. Resistance to molecularly targeted drugs through selective pressure on acquired mutations or molecular rewiring can hinder their effectiveness. This review summarizes how molecular imaging techniques can potentially facilitate the optimal implementation of targeted agents. Using the human epidermal growth factor receptor (HER) family as a model in (pre)clinical studies, we illustrate how molecular imaging may be employed to characterize whole body target expression as well as monitor drug effectiveness and the emergence of tumor resistance. We further discuss how an integrative omics discovery platform could guide the selection of 'effect sensors' - new molecular imaging targets - which are dynamic markers that indicate treatment effectiveness or resistance.

  13. Differential Expression of Claudin Family Proteins in Mouse Ovarian Serous Papillary Epithelial Adenoma in Aging FSH Receptor-Deficient Mutants

    Directory of Open Access Journals (Sweden)

    Jayaprakash Aravindakshan

    2006-12-01

    Full Text Available Ovarian cancer is a deadly disease with long latency. To understand the consequences of loss of folliclestimulating hormone receptor (FSH-R signaling and to explore why the atrophic and anovulatory ovaries of follitropin receptor knockout (FORKO mice develop different types of ovarian tumors, including serous papillary epithelial adenoma later in life, we used mRNA expression profiling to gain a comprehensive view of misregulated genes. Using real-time quantitative reverse transcription-polymerase chain reaction, protein analysis, and cellular localization, we show, for the first time, in vivo evidence that, in the absence of FSH-R signaling, claudin-3, claudin-4, and claudin-11 are selectively upregulated, whereas claudin-1 decreases in ovarian surface epithelium and tumors in comparison to wild type. In vitro experiments using a mouse ovarian surface epithelial cell line derived from wild-type females reveal direct hormonal influence on claudin proteins. Although recent studies suggest that cell junction proteins are differentially expressed in ovarian tumors in women, the etiology of such changes remains unclear. Our results suggest an altered hormonal environment resulting from FSH-R loss as a cause of early changes in tight junction proteins that predispose the ovary to late-onset tumors that occur with aging. More importantly, this study identifies claudin-11 overexpression in mouse ovarian serous cystadenoma.

  14. Peroxisomal proliferator activated receptor-γ deficiency in a Canadian kindred with familial partial lipodystrophy type 3 (FPLD3

    Directory of Open Access Journals (Sweden)

    Cao Henian

    2006-01-01

    Full Text Available Abstract Background Familial partial lipodystrophy (Dunnigan type 3 (FPLD3, Mendelian Inheritance in Man [MIM] 604367 results from heterozygous mutations in PPARG encoding peroxisomal proliferator-activated receptor-γ. Both dominant-negative and haploinsufficiency mechanisms have been suggested for this condition. Methods We present a Canadian FPLD3 kindred with an affected mother who had loss of fat on arms and legs, but no increase in facial, neck, suprascapular or abdominal fat. She had profound insulin resistance, diabetes, severe hypertriglyceridemia and relapsing pancreatitis, while her pre-pubescent daughter had normal fat distribution but elevated plasma triglycerides and C-peptide and depressed high-density lipoprotein cholesterol. Results The mother and daughter were each heterozygous for PPARG nonsense mutation Y355X, whose protein product in vitro was transcriptionally inactive with no dominant-negative activity against the wild-type receptor. In addition the mutant protein appeared to be markedly unstable. Conclusion Taken together with previous studies of human PPARG mutations, these findings suggest that PPAR-γ deficiency due either to haploinsufficiency or to substantial activity loss due to dominant negative interference of the normal allele product's function can each contribute to the FPLD3 phenotype.

  15. Expression profiles of relaxin family peptides and their receptors indicate their influence on spermatogenesis in the domestic cat (Felis catus).

    Science.gov (United States)

    Braun, B C; Müller, K; Jewgenow, K

    2015-07-01

    Disturbed spermatogenesis is a common problem in felines. Studying spermatogenesis in the domestic cat can improve the understanding of the biological background and help to counteract fertility problems in other feline species. Here, we analyzed 3 relaxin family peptides (relaxin, relaxin-3, and INSL3) and their receptors (RXFP1, RXFP2, and RXFP3) as potential spermatogenic factors involving their expression in the testis at different stages of its development. It may be concluded from its stage-dependent expression that relaxin, together with RXFP1, appears to be involved in the first stage of spermatogenesis, whereas relaxin-3 via binding to RXFP3 influences spermiogenesis. Furthermore, correlations were observed between relaxin, relaxin-3, RXFP1, RXFP2 and RXFP3 messenger RNA expression, and the relative numbers of haploid cells in testes. The peptide INSL3 was highly expressed at all testis development stages. Because of the low and stage-independent expression of its receptor RXFP2, an auto- and/or paracrine function of INSL3 in spermatogenesis seems unlikely. In the adult testis, messenger RNA expression of relaxin, RXFP1, and RXFP3 predominantly occurs in the tubular testis compartment, whereas INLS3 is mainly expressed in the interstitium. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. STC1 interference on calcitonin family of receptors signaling during osteoblastogenesis via adenylate cyclase inhibition.

    Science.gov (United States)

    Terra, Silvia R; Cardoso, João Carlos R; Félix, Rute C; Martins, Leo Anderson M; Souza, Diogo Onofre G; Guma, Fatima C R; Canário, Adelino Vicente M; Schein, Vanessa

    2015-03-05

    Stanniocalcin 1 (STC1) and calcitonin gene-related peptide (CGRP) are involved in bone formation/remodeling. Here we investigate the effects of STC1 on functional heterodimer complex CALCRL/RAMP1, expression and activity during osteoblastogenesis. STC1 did not modify CALCRL and ramp1 gene expression during osteoblastogenesis when compared to controls. However, plasma membrane spatial distribution of CALCRL/RAMP1 was modified in 7-day pre-osteoblasts exposed to either CGRP or STC1, and both peptides induced CALCRL and RAMP1 assembly. CGRP, but not STC1 stimulated cAMP accumulation in 7-day osteoblasts and in CALCRL/RAMP1 transfected HEK293 cells. Furthermore, STC1 inhibited forskolin stimulated cAMP accumulation of HEK293 cells, but not in CALCRL/RAMP1 transfected HEK293 cells. However, STC1 inhibited cAMP accumulation in calcitonin receptor (CTR) HEK293 transfected cells stimulated by calcitonin. In conclusion, STC1 signals through inhibitory G-protein modulates CGRP receptor spatial localization during osteoblastogenesis and may function as a regulatory factor interacting with calcitonin peptide members during bone formation. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  17. Identification and phylogeny of the tomato receptor-like proteins family

    Directory of Open Access Journals (Sweden)

    Ermis Yanes-Paz

    2017-03-01

    Full Text Available The receptor-like proteins (RLPs play multiple roles in development and defense. In the current work 75 RLPs were identified in tomato (Solanum lycopersicum L. using iterative BLAST searches and domain prediction. A phylogenetic tree including all the identified RLPs from tomato and some functionally characterized RLPs from other species was built to identify their putative homologues in tomato. We first tested whether C3-F-based phylogeny was a good indicator of functional relation between related proteins of different species. Indeed, the functionally characterized CLAVATA2 (CLV2, the maize ortholog FASCIATED EAR2 (FEA2 and a putative tomato CLV2 described in Uniprot clustered together, which validates the approach. Using this approach Solyc12g042760.1.1 was identified as the putative tomato homologue of TOO MANY MOUTHS (TMM. It was shown that proteins in the same cluster of the phylogenetic tree share functional relations since several clusters of functionally related proteins i.e. the Ve cluster, the Cf cluster, and the Eix clade were formed.   Keywords: phylogeny, receptors, RLP, tomato

  18. Family environment and adult resilience: contributions of positive parenting and the oxytocin receptor gene

    Directory of Open Access Journals (Sweden)

    Bekh Bradley

    2013-09-01

    Full Text Available Background: Abundant research shows that childhood adversity increases the risk for adult psychopathology while research on influences of positive family environment on risk for psychopathology is limited. Similarly, a growing body of research examines genetic and gene by environment predictors of psychopathology, yet such research on predictors of resilience is sparse. Objectives: We examined the role of positive factors in childhood family environment (CFE and the OXTR rs53576 genotype in predicting levels of adult resilient coping and positive affect. We also examined whether the relationship between positive factors in the CFEs and adult resilient coping and positive affect varied across OXTR rs53576 genotype. Methods: We gathered self-report data on childhood environment, trauma history, and adult resilience and positive affect in a sample of 971 African American adults. Results: We found that positive CFE was positively associated with higher levels of resilient coping and positive affect in adulthood after controlling for childhood maltreatment, other trauma, and symptoms of posttraumatic stress disorder. We did not find a direct effect of OXTR 53576 on a combined resilient coping/positive-affect-dependent variable, but we did find an interaction of OXTR rs53576 with family environment. Conclusions: Our data suggest that even in the face of adversity, positive aspects of the family environment may contribute to resilience. These results highlight the importance of considering protective developmental experiences and the interaction of such experiences with genetic variants in risk and resilience research.For the abstract or full text in other languages, please see Supplementary files under Article Tools online

  19. Surface Expression of TGFβ Docking Receptor GARP Promotes Oncogenesis and Immune Tolerance in Breast Cancer.

    Science.gov (United States)

    Metelli, Alessandra; Wu, Bill X; Fugle, Caroline W; Rachidi, Saleh; Sun, Shaoli; Zhang, Yongliang; Wu, Jennifer; Tomlinson, Stephen; Howe, Philip H; Yang, Yi; Garrett-Mayer, Elizabeth; Liu, Bei; Li, Zihai

    2016-12-15

    GARP encoded by the Lrrc32 gene is the cell surface docking receptor for latent TGFβ, which is expressed naturally by platelets and regulatory T cells (Treg). Although Lrrc32 is amplified frequently in breast cancer, the expression and relevant functions of GARP in cancer have not been explored. Here, we report that GARP exerts oncogenic effects, promoting immune tolerance by enriching and activating latent TGFβ in the tumor microenvironment. We found that human breast, lung, and colon cancers expressed GARP aberrantly. In genetic studies in normal mammary gland epithelial and carcinoma cells, GARP expression increased TGFβ bioactivity and promoted malignant transformation in immunodeficient mice. In breast carcinoma-bearing mice that were immunocompetent, GARP overexpression promoted Foxp3 + Treg activity, which in turn contributed to enhancing cancer progression and metastasis. Notably, administration of a GARP-specific mAb limited metastasis in an orthotopic model of human breast cancer. Overall, these results define the oncogenic effects of the GARP-TGFβ axis in the tumor microenvironment and suggest mechanisms that might be exploited for diagnostic and therapeutic purposes. Cancer Res; 76(24); 7106-17. ©2016 AACR. ©2016 American Association for Cancer Research.

  20. Identification and characterization of the murine cell surface receptor for the urokinase-type plasminogen activator

    DEFF Research Database (Denmark)

    Solberg, H; Løber, D; Eriksen, J

    1992-01-01

    -blotting analysis. Binding of mouse u-PA to its receptor showed species specificity in ligand-blotting analysis, since mouse u-PA did not bind to human u-PAR and human u-PA did not bind to mouse u-PAR. The apparent M(r) of mouse u-PAR varied between different mouse cell lines and ranged over M(r) 45......,000-60,000. In four of the cell lines, mouse u-PA bound to two mouse u-PAR variant proteins, whereas in the other two cell lines studied, there was only one mouse u-PA-binding protein. In the monocyte macrophage cell line P388D.1, trypsin-treatment of intact cells could remove only the large mouse u-PAR variant (M...... to the cell surface by glycosylphosphatidylinositol. Purification of the two mouse u-PAR variant proteins by diisopropylfluorophosphate-inactivated mouse u-PA-Sepharose affinity chromatography yielded two silver-stained bands when analysed by SDS/PAGE, corresponding in electrophoretic mobility to those seen...

  1. Distinctive receptor binding properties of the surface glycoprotein of a natural Feline Leukemia Virus isolate with unusual disease spectrum

    Directory of Open Access Journals (Sweden)

    Albritton Lorraine M

    2011-05-01

    Full Text Available Abstract Background Feline leukemia virus (FeLV-945, a member of the FeLV-A subgroup, was previously isolated from a cohort of naturally infected cats. An unusual multicentric lymphoma of non-T-cell origin was observed in natural and experimental infection with FeLV-945. Previous studies implicated the FeLV-945 surface glycoprotein (SU as a determinant of disease outcome by an as yet unknown mechanism. The present studies demonstrate that FeLV-945 SU confers distinctive properties of binding to the cell surface receptor. Results Virions bearing the FeLV-945 Env protein were observed to bind the cell surface receptor with significantly increased efficiency, as was soluble FeLV-945 SU protein, as compared to the corresponding virions or soluble protein from a prototype FeLV-A isolate. SU proteins cloned from other cohort isolates exhibited increased binding efficiency comparable to or greater than FeLV-945 SU. Mutational analysis implicated a domain containing variable region B (VRB to be the major determinant of increased receptor binding, and identified a single residue, valine 186, to be responsible for the effect. Conclusions The FeLV-945 SU protein binds its cell surface receptor, feTHTR1, with significantly greater efficiency than does that of prototype FeLV-A (FeLV-A/61E when present on the surface of virus particles or in soluble form, demonstrating a 2-fold difference in the relative dissociation constant. The results implicate a single residue, valine 186, as the major determinant of increased binding affinity. Computational modeling suggests a molecular mechanism by which residue 186 interacts with the receptor-binding domain through residue glutamine 110 to effect increased binding affinity. Through its increased receptor binding affinity, FeLV-945 SU might function in pathogenesis by increasing the rate of virus entry and spread in vivo, or by facilitating entry into a novel target cell with a low receptor density.

  2. Ligand-independent Thrombopoietin Mutant Receptor Requires Cell Surface Localization for Endogenous Activity*

    OpenAIRE

    Marty, Caroline; Chaligné, Ronan; Lacout, Catherine; Constantinescu, Stefan N.; Vainchenker, William; Villeval, Jean-Luc

    2009-01-01

    The activating W515L mutation in the thrombopoietin receptor (MPL) has been identified in primary myelofibrosis and essential thrombocythemia. MPL belongs to a subset of the cytokine receptor superfamily that requires the JAK2 kinase for signaling. We examined whether the ligand-independent MPLW515L mutant could signal intracellularly. Addition of the endoplasmic reticulum (ER) retention KDEL sequence to the receptor C terminus efficiently locked MPLW515L within its na...

  3. The TAM family receptor tyrosine kinase TYRO3 is a negative regulator of type 2 immunity

    Science.gov (United States)

    Chan, Pamela Y.; Carrera Silva, Eugenio A.; De Kouchkovsky, Dimitri; Joannas, Leonel D.; Hao, Liming; Hu, Donglei; Huntsman, Scott; Eng, Celeste; Licona-Limón, Paula; Weinstein, Jason S.; Herbert, De’Broski R.; Craft, Joseph E.; Flavell, Richard A.; Repetto, Silvia; Correale, Jorge; Burchard, Esteban G.; Torgerson, Dara G.; Ghosh, Sourav; Rothlin, Carla V.

    2016-01-01

    Host responses against metazoan parasites or an array of environmental substances elicit type 2 immunity. Despite its protective function, type 2 immunity also drives allergic diseases. The mechanisms that regulate the magnitude of the type 2 response remain largely unknown. Here, we show that genetic ablation of a receptor tyrosine kinase encoded by Tyro3 in mice or the functional neutralization of its ortholog in human dendritic cells resulted in enhanced type 2 immunity. Furthermore, the TYRO3 agonist PROS1 was induced in T cells by the quintessential type 2 cytokine, interleukin-4. T cell–specific Pros1 knockouts phenocopied the loss of Tyro3. Thus, a PROS1-mediated feedback from adaptive immunity engages a rheostat, TYRO3, on innate immune cells to limit the intensity of type 2 responses. PMID:27034374

  4. Genetic diversity of bitter taste receptor gene family in Sichuan domestic and Tibetan chicken populations.

    Science.gov (United States)

    Su, Yuan; Li, Diyan; Gaur, Uma; Wang, Yan; Wu, Nan; Chen, Binlong; Xu, Zhongxian; Yin, Huadong; Hu, Yaodong; Zhu, Qing

    2016-09-01

    The sense of bitter taste plays a critical role in animals as it can help them to avoid intake of toxic and harmful substances. Previous research had revealed that chicken has only three bitter taste receptor genes (Tas2r1, Tas2r2 and Tas2r7). To better understand the genetic polymorphisms and importance of bitter taste receptor genes (Tas2rs) in chicken, here, we sequenced Tas2rs of 30 Sichuan domestic chickens and 30 Tibetan chickens. Thirteen single-nucleotide polymorphisms (SNPs) including three nonsynonymous mutations (m.359G>C, m.503C>A and m.583A>G) were detected in Tas2r1 (m. is the abbreviation for mutation); three SNPs were detected in Tas2r2, but none of them were missense mutation; eight SNPs were detected in Tas2r7 including six nonsynonymous substitutions (m.178G>A, m.421A>C, m.787C>T, m.832G>T, m.907A>T and m.943G>A). Tajima's D neutral test indicates that there is no population expansion in both populations, and the size of the population is relatively stable. All the three networks indicate that red jungle fowls share haplotypes with domestic chickens. In addition, we found that haplotypes H1 and HE1 were positively associated with high-altitude adaptation, whereas haplotypes H4 and HE4 showed a negative correlation with high-altitude adaptation in Tas2rs. Although, chicken has only three Tas2rs, our results showed that both Sichuan domestic chickens and Tibetan chickens have abundant haplotypes in Tas2rs, especially in Tas2r7, which might help chickens to recognize a wide variety of bitter-tasting compounds.

  5. Structure-guided identification of a family of dual receptor-binding PfEMP1 that is associated with cerebral malaria

    DEFF Research Database (Denmark)

    Lennartz, Frank; Adams, Yvonne; Bengtsson, Anja

    2017-01-01

    Cerebral malaria is a deadly outcome of infection by Plasmodium falciparum, occurring when parasite-infected erythrocytes accumulate in the brain. These erythrocytes display parasite proteins of the PfEMP1 family that bind various endothelial receptors. Despite the importance of cerebral malaria...

  6. Familial partial lipodystrophy phenotype resulting from a single-base mutation in deoxyribonucleic acid-binding domain of peroxisome proliferator-activated receptor-gamma

    NARCIS (Netherlands)

    Monajemi, Houshang; Zhang, Lin; Li, Gang; Jeninga, Ellen H.; Cao, Henian; Maas, Mario; Brouwer, C. B.; Kalkhoven, Eric; Stroes, Erik; Hegele, Robert A.; Leff, Todd

    2007-01-01

    CONTEXT: Familial partial lipodystrophy (FPLD) results from coding sequence mutations either in LMNA, encoding nuclear lamin A/C, or in PPARG, encoding peroxisome proliferator-activated receptor-gamma (PPARgamma). The LMNA form is called FPLD2 (MIM 151660) and the PPARG form is called FPLD3 (MIM

  7. Cbl-family ubiquitin ligases and their recruitment of CIN85 are largely dispensable for epidermal growth factor receptor endocytosis

    Science.gov (United States)

    Ahmad, Gulzar; Mohapatra, Bhopal; Schulte, Nancy A.; Nadeau, Scott; Luan, Haitao; Zutshi, Neha; Tom, Eric; Ortega-Cava, Cesar; Tu, Chun; Sanada, Masashi; Ogawa, Seishi; Toews, Myron L.; Band, Vimla; Band, Hamid

    2014-01-01

    Members of the Casitas B-Lineage Lymphoma (Cbl) family (Cbl, Cbl-b and Cbl-c) of ubiquitin ligases serve as negative regulators of receptor tyrosine kinases (RTKs). An essential role of Cbl-family protein-dependent ubiquitination for efficient ligand-induced lysosomal targeting and degradation is now well-accepted. However, a more proximal role of Cbl and Cbl-b as adapters for CIN85-endophilin recruitment to mediate ligand-induced initial internalization of RTKs is supported by some studies but refuted by others. Overexpression and/or incomplete depletion of Cbl proteins in these studies is likely to have contributed to this dichotomy. To address the role of endogenous Cbl and Cbl-b in the internalization step of RTK endocytic traffic, we established Cbl/Cbl-b double-knockout (DKO) mouse embryonic fibroblasts (MEFs) and demonstrated that these cells lack the expression of both Cbl-family members as well as endophilin A, while they express CIN85. We show that ligand-induced ubiquitination of EGFR, as a prototype RTK, was abolished in DKO MEFs, and EGFR degradation was delayed. These traits were reversed by ectopic human Cbl expression. EGFR endocytosis, assessed using the internalization of 125I-labeled or fluorescent EGF, or of EGFR itself, was largely retained in Cbl/Cbl-b DKO compared to wild type MEFs. EGFR internalization was also largely intact in Cbl/Cbl-b depleted MCF-10A human mammary epithelial cell line. Inducible shRNA-mediated knockdown of CIN85 in wild type or Cbl/Cbl-b DKO MEFs had no impact on EGFR internalization. Our findings, establish that, at physiological expression levels, Cbl, Cbl-b and CIN85 are largely dispensable for EGFR internalization. Our results support the model that Cbl-CIN85-endophilin complex is not required for efficient internalization of EGFR, a prototype RTK. PMID:25449262

  8. A novel thromboxane A2 receptor N42S variant results in reduced surface expression and platelet dysfunction.

    Science.gov (United States)

    Nisar, Shaista P; Lordkipanidzé, Marie; Jones, Matthew L; Dawood, Ban; Murden, Sherina; Cunningham, Margaret R; Mumford, Andrew D; Wilde, Jonathan T; Watson, Steve P; Mundell, Stuart J; Lowe, Gillian C

    2014-05-05

    A small number of thromboxane receptor variants have been described in patients with a bleeding history that result in platelet dysfunction. We have identified a patient with a history of significant bleeding, who expresses a novel heterozygous thromboxane receptor variant that predicts an asparagine to serine substitution (N42S). This asparagine is conserved across all class A GPCRs, suggesting a vital role for receptor structure and function.We investigated the functional consequences of the TP receptor heterozygous N42S substitution by performing platelet function studies on platelet-rich plasma taken from the patient and healthy controls. We investigated the N42S mutation by expressing the wild-type (WT) and mutant receptor in human embryonic kidney (HEK) cells. Aggregation studies showed an ablation of arachidonic acid responses in the patient, whilst there was right-ward shift of the U46619 concentration response curve (CRC). Thromboxane generation was unaffected. Calcium mobilisation studies in cells lines showed a rightward shift of the U46619 CRC in N42S-expressing cells compared to WT. Radioligand binding studies revealed a reduction in BMax in platelets taken from the patient and in N42S-expressing cells, whilst cell studies confirmed poor surface expression. We have identified a novel thromboxane receptor variant, N42S, which results in platelet dysfunction due to reduced surface expression. It is associated with a significant bleeding history in the patient in whom it was identified. This is the first description of a naturally occurring variant that results in the substitution of this highly conserved residue and confirms the importance of this residue for correct GPCR function.

  9. Nuclear receptors of the NR4a family are not required for the development and function of follicular T helper cells.

    Science.gov (United States)

    Ma, Weiwei; Zhao, Ruozhu; Yang, Runqing; Liu, Bo; Chen, Xin; Wu, Longyan; Qi, Hai

    2015-10-01

    Follicular T helper (Tfh) cells promote germinal center (GC) reaction and high-affinity antibody production. The molecular mechanisms that regulate development and function of Tfh cells are not fully understood. Here we report that ligand-independent nuclear receptors of the Nr4a family are highly expressed in Tfh cells. In a well-established adoptive transfer model, enforced expression of Nr4a receptors reduces helper T cell expansion but apparently increased the T cell capacity to promote the GC response. On the other hand, deletion of all Nr4a receptors in T cells did not significantly affect expansion or differentiation of Tfh cells or the development of GC reaction. These findings suggest that Nr4a receptors may promote but are not necessary for Tfh development or function in vivo. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Studies on mRNA expression of the somatostatin receptor family in lung cancer

    International Nuclear Information System (INIS)

    Wang Jing; Deng Jinglan; Wu Shengxi; Qiao Hongqing

    2000-01-01

    Objective: To investigate the characteristics of expression and distribution of 5 subtypes of somatostatin receptors (SSTR1∼5) in lung cancer. Methods: With [α- 35 S]dATP labelled oligonucleotides of the 5 SSTR subtypes as probes, using in situ hybridization, patterns of mRNA expression were detected in lung cancer tissue sections of 21 cases which fell in varied pathologic types. Additionally, Leica Q-500 image analyzing device was employed to semi-quantitatively analyze density of the expression. Results: Patterns of SSTR1∼5 expression in lung cancer were as follows: SSTR2 expression was dominant in small cell lung cancer (SCLC) while in non-small cell lung cancer (NSCLC) such as adenous and squamous, SSTR1 expression was stronger than that of the other 4 subtypes, In density of SSTR1∼5 expression in lung cancer, NSCLC was higher than SCLC (P<0.01). Conclusions: even though patterns and density of expression of SSTR subtypes in the lung cancer showed heterogeneity in different histopathologic types, as in SCLC and in NSCLC. Therefore, it has positive prospects for somatostatin analog-oriented agents to be used in treatment of both types of the lung cancers

  11. Expression of the somatostatin receptor family mRNAs in lung cancer

    International Nuclear Information System (INIS)

    Wang Jing; Wang Liangang; Deng Jinglan; Wu Shengxi

    2000-01-01

    To investigate the characteristics of expression and distribution of 5 subtypes of somatostatin receptors (SSTR1-5) in lung cancer, in situ hybridization was used to examine the expression patterns of SSTR mRNAs in 21 cases of different pathologic types of lung cancer tissues with [α- 35 S]dATP labelled oligonucleotides of the 5 SSTR subtypes as probes. Additionally, Leica Q-500 image analysis processing system was employed for the semi-quantitatively analysis of the hybridization signals. Patterns of SSTR1-5 expression in lung cancer tissues were found as follows. SSTR2 was prominent in small cell lung cancer (SCLC), whereas in non-small cell lung cancer (NSCLC) including the adenous cancer (Ad) and the squamous cancer (Sq), the expression of SSTR1 mRNA was stronger than that of the other 4 types. the expression density of SSTR1-5 in the NSCLC was higher that the SCLC (p < 0.01). The expression patterns and densities of the SSTR subtypes showed heterogeneity in different pathologic types of lung cancer. The expressions of the SSTR mRNAs in both SCLC and NSCLC indicated the positive prospects for somatostatin analog (SSA)-oriented agents in the treatment of both types of the lung cancer

  12. Familial risk for mood disorder and the personality risk factor, neuroticism, interact in their association with frontolimbic serotonin 2A receptor binding

    DEFF Research Database (Denmark)

    Frøkjær, Vibe Gedsø; Vinberg, Maj; Erritzoe, David

    2010-01-01

    Life stress is a robust risk factor for later development of mood disorders, particularly for individuals at familial risk. Likewise, scoring high on the personality trait neuroticism is associated with an increased risk for mood disorders. Neuroticism partly reflects stress vulnerability...... stress reactivity in individuals at high familial risk for mood disorders might enhance the effect of neuroticism in shaping the impact of potential environmental stress and thereby influence serotonergic neurotransmission....... and is positively correlated to frontolimbic serotonin 2A (5-HT(2A)) receptor binding. Here, we investigate whether neuroticism interacts with familial risk in relation to frontolimbic 5-HT(2A) receptor binding. Twenty-one healthy twins with a co-twin history of mood disorder and 16 healthy twins without a co...

  13. The thrombopoietin receptor, c-Mpl, is a selective surface marker for human hematopoietic stem cells

    Directory of Open Access Journals (Sweden)

    Kerr William G

    2006-02-01

    Full Text Available Abstract Background Thrombopoietin (TPO, the primary cytokine regulating megakaryocyte proliferation and differentiation, exerts significant influence on other hematopoietic lineages as well, including erythroid, granulocytic and lymphoid lineages. We previously demonstrated that the receptor for TPO, c-mpl, is expressed by a subset of human adult bone marrow hematopoietic stem/progenitor cells (HSC/PC that are enriched for long-term multilineage repopulating ability in the SCID-hu Bone in vivo model of human hematopoiesis. Methods Here, we employ flow cytometry and an anti-c-mpl monoclonal antibody to comprehensively define the surface expression pattern of c-mpl in four differentiation stages of human CD34+ HSC/PC (I: CD34+38--, II: CD34+38dim, III: CD34+38+, IV: CD34dim38+ for the major sources of human HSC: fetal liver (FL, umbilical cord blood (UCB, adult bone marrow (ABM, and cytokine-mobilized peripheral blood stem cells (mPBSC. We use a surrogate in vivo model of human thymopoiesis, SCID-hu Thy/Liv, to compare the capacity of c-mpl+ vs. c-mpl-- CD34+38--/dim HSC/PC for thymocyte reconstitution. Results For all tissue sources, the percentage of c-mpl+ cells was significantly highest in stage I HSC/PC (FL 72 ± 10%, UCB 67 ± 19%, ABM 82 ± 16%, mPBSC 71 ± 15%, and decreased significantly through stages II, III, and IV ((FL 3 ± 3%, UCB 8 ± 13%, ABM 0.6 ± 0.6%, mPBSC 0.2 ± 0.1% [ANOVA: P I, decreasing through stage IV [ANOVA: P + cells [P = 0.89] or intensity of c-mpl expression [P = 0.21]. Primary Thy/Liv grafts injected with CD34+38--/dimc-mpl+ cells showed slightly higher levels of donor HLA+ thymocyte reconstitution vs. CD34+38--/dimc-mpl---injected grafts and non-injected controls (c-mpl+ vs. c-mpl--: CD2+ 6.8 ± 4.5% vs. 2.8 ± 3.3%, CD4+8-- 54 ± 35% vs. 31 ± 29%, CD4--8+ 29 ± 19% vs. 18 ± 14%. Conclusion These findings support the hypothesis that the TPO receptor, c-mpl, participates in the regulation of primitive human HSC

  14. Neurotrophin responsiveness of sympathetic neurons is regulated by rapid mobilization of the p75 receptor to the cell surface through TrkA activation of Arf6.

    Science.gov (United States)

    Edward Hickman, F; Stanley, Emily M; Carter, Bruce D

    2018-05-22

    The p75 neurotrophin receptor (p75NTR) plays an integral role in patterning the sympathetic nervous system during development. Initially, p75NTR is expressed at low levels as sympathetic axons project toward their targets, which enables neurotrophin-3 (NT3) to activate TrkA receptors and promote growth. Upon reaching nerve growth factor (NGF) producing tissues, p75NTR is up regulated resulting in formation of TrkA-p75 complexes, which are high affinity binding sites selective for NGF, thereby blunting NT3 signaling. The level of p75NTR expressed on the neuron surface is instrumental in regulating trophic factor response; however, the mechanisms by which p75NTR expression is regulated are poorly understood. Here, we demonstrate a rapid, translation independent increase in surface expression of p75NTR in response to NGF in rat sympathetic neurons. p75NTR was mobilized to the neuron surface from GGA3-postitive vesicles through activation of the GTPase Arf6, which was stimulated by NGF, but not NT3 binding to TrkA. Arf6 activation required PI3 kinase activity and was prevented by an inhibitor of the cytohesin family of Arf6 GEFs. Overexpression of a constitutively active Arf6 mutant (Q67L) was sufficient to significantly increase surface expression of p75NTR even in the absence of NGF. Functionally, expression of active Arf6 markedly attenuated the ability of NT3 to promote neuronal survival and neurite outgrowth while the NGF response was unaltered. These data suggest that NGF activation of Arf6 through TrkA is critical for the increase in p75NTR surface expression that enables the switch in neurotrophin responsiveness during development in the sympathetic nervous system. SIGNIFICANCE STATEMENT p75NTR is instrumental in the regulation of neuronal survival and apoptosis during development and is also implicated as a contributor to aberrant neurodegeneration in numerous conditions. Therefore, a better understanding of the mechanisms that mediate p75NTR surface

  15. A single amino acid substitution in the exoplasmic domain of the human growth hormone (GH) receptor confers familial GH resistance (Laron syndrome) with positive GH-binding activity by abolishing receptor homodimerization.

    Science.gov (United States)

    Duquesnoy, P; Sobrier, M L; Duriez, B; Dastot, F; Buchanan, C R; Savage, M O; Preece, M A; Craescu, C T; Blouquit, Y; Goossens, M

    1994-01-01

    Growth hormone (GH) elicits a variety of biological activities mainly mediated by the GH receptor (GHR), a transmembrane protein that, based on in vitro studies, seemed to function as a homodimer. To test this hypothesis directly, we investigated patients displaying the classic features of Laron syndrome (familial GH resistance characterized by severe dwarfism and metabolic dysfunction), except for the presence of normal binding activity of the plasma GH-binding protein, a molecule that derives from the exoplasmic-coding domain of the GHR gene. In two unrelated families, the same GHR mutation was identified, resulting in the substitution of a highly conserved aspartate residue by histidine at position 152 (D152H) of the exoplasmic domain, within the postulated interface sequence involved in homodimerization. The recombinant mutated receptor protein was correctly expressed at the plasma membrane. It displayed subnormal GH-binding activity, a finding in agreement with the X-ray crystal structure data inferring this aspartate residue outside the GH-binding domain. However, mAb-based studies suggested the critical role of aspartate 152 in the proper folding of the interface area. We show that a recombinant soluble form of the mutant receptor is unable to dimerize, the D152H substitution also preventing the formation of heterodimers of wild-type and mutant molecules. These results provide in vivo evidence that monomeric receptors are inactive and that receptor dimerization is involved in the primary signalling of the GH-associated growth-promoting and metabolic actions. Images PMID:8137822

  16. Surface Expression of TGF-β Docking Receptor GARP Promotes Oncogenesis and Immune Tolerance in Breast Cancer

    OpenAIRE

    Metelli, Alessandra; Wu, Bill X; Fugle, Caroline W; Rachidi, Saleh; Sun, Shaoli; Zhang, Yongliang; Wu, Jennifer; Tomlinson, Stephen; Howe, Philip; Yang, Yi; Garrett-Mayer, Elizabeth; Liu, Bei; Li, Zihai

    2016-01-01

    GARP encoded by the Lrrc32 gene is the cell surface docking receptor for latent TGF-β which is expressed naturally by platelets and regulatory T cells. Although Lrrc32 is amplified frequently in breast cancer, the expression and relevant functions of GARP in cancer have not been explored. Here we report that GARP exerts oncogenic effects, promoting immune tolerance by enriching and activating latent TGF-β in the tumor microenvironment. We found that human breast, lung and colon cancers expres...

  17. ErpC, a member of the complement regulator-acquiring family of surface proteins from Borrelia burgdorferi, possesses an architecture previously unseen in this protein family

    International Nuclear Information System (INIS)

    Caesar, Joseph J. E.; Johnson, Steven; Kraiczy, Peter; Lea, Susan M.

    2013-01-01

    The structure of ErpC, a member of the complement regulator-acquiring surface protein family from B. burgdorferi, has been solved, providing insights into the strategies of complement evasion by this zoonotic bacterium and suggesting a common architecture for other members of this protein family. Borrelia burgdorferi is a spirochete responsible for Lyme disease, the most commonly occurring vector-borne disease in Europe and North America. The bacterium utilizes a set of proteins, termed complement regulator-acquiring surface proteins (CRASPs), to aid evasion of the human complement system by recruiting and presenting complement regulator factor H on its surface in a manner that mimics host cells. Presented here is the atomic resolution structure of a member of this protein family, ErpC. The structure provides new insights into the mechanism of recruitment of factor H and other factor H-related proteins by acting as a molecular mimic of host glycosaminoglycans. It also describes the architecture of other CRASP proteins belonging to the OspE/F-related paralogous protein family and suggests that they have evolved to bind specific complement proteins, aiding survival of the bacterium in different hosts

  18. Surface TRAIL decoy receptor-4 expression is correlated with TRAIL resistance in MCF7 breast cancer cells

    International Nuclear Information System (INIS)

    Sanlioglu, Ahter D; Dirice, Ercument; Aydin, Cigdem; Erin, Nuray; Koksoy, Sadi; Sanlioglu, Salih

    2005-01-01

    Tumor Necrosis Factor (TNF)-Related Apoptosis-Inducing Ligand (TRAIL) selectively induces apoptosis in cancer cells but not in normal cells. Despite this promising feature, TRAIL resistance observed in cancer cells seriously challenged the use of TRAIL as a death ligand in gene therapy. The current dispute concerns whether or not TRAIL receptor expression pattern is the primary determinant of TRAIL sensitivity in cancer cells. This study investigates TRAIL receptor expression pattern and its connection to TRAIL resistance in breast cancer cells. In addition, a DcR2 siRNA approach and a complementary gene therapy modality involving IKK inhibition (AdIKKβKA) were also tested to verify if these approaches could sensitize MCF7 breast cancer cells to adenovirus delivery of TRAIL (Ad5hTRAIL). TRAIL sensitivity assays were conducted using Molecular Probe's Live/Dead Cellular Viability/Cytotoxicity Kit following the infection of breast cancer cells with Ad5hTRAIL. The molecular mechanism of TRAIL induced cell death under the setting of IKK inhibition was revealed by Annexin V binding. Novel quantitative Real Time RT-PCR and flow cytometry analysis were performed to disclose TRAIL receptor composition in breast cancer cells. MCF7 but not MDA-MB-231 breast cancer cells displayed strong resistance to adenovirus delivery of TRAIL. Only the combinatorial use of Ad5hTRAIL and AdIKKβKA infection sensitized MCF7 breast cancer cells to TRAIL induced cell death. Moreover, novel quantitative Real Time RT-PCR assays suggested that while the level of TRAIL Decoy Receptor-4 (TRAIL-R4) expression was the highest in MCF7 cells, it was the lowest TRAIL receptor expressed in MDA-MB-231 cells. In addition, conventional flow cytometry analysis demonstrated that TRAIL resistant MCF7 cells exhibited substantial levels of TRAIL-R4 expression but not TRAIL decoy receptor-3 (TRAIL-R3) on surface. On the contrary, TRAIL sensitive MDA-MB-231 cells displayed very low levels of surface TRAIL-R4

  19. The ErbB family and androgen receptor signaling are targets of Celecoxib in prostate cancer.

    Science.gov (United States)

    Brizzolara, Antonella; Benelli, Roberto; Venè, Roberta; Barboro, Paola; Poggi, Alessandro; Tosetti, Francesca; Ferrari, Nicoletta

    2017-08-01

    Inflammation plays a central role in prostate cancer (PCa) development through significant crosstalk between the COX-2-ErbB family receptor network and androgen receptor (AR)-EGFR signaling pathways. The purpose of this work was to determine the ability of the COX-2 inhibitor Celecoxib to modulate the EGFR-AR signaling pathway in androgen-dependent PCa cells and to provide a rationale for its beneficial use in chemopreventive strategies. Functional studies of Celecoxib activity were performed on LNCaP prostate cancer cells. Western blotting, gene expression analysis, dual-luciferase reporter assay and ELISA were applied to assess the Celecoxib mechanisms of action. We found that Celecoxib, through EGF and amphiregulin (AREG) induction, caused EGFR and ErbB2 activation and consequent degradation associated with the inhibition of androgenic signaling. By upregulating the E3 ubiquitin ligase Nrdp1, Celecoxib also efficiently downregulated ErbB3, which is strongly implicated in castration-resistant prostate cancer. Lastly, Celecoxib directly regulated AR transcription and translation independent of ErbB activation by downregulating the RNA binding protein heterogeneous nuclear ribonucleoprotein K (hnRNP K). The simultaneous suppression of ErbB kinases and androgen signaling by Celecoxib represents a novel strategy to interrupt the vicious cycle of AR/ErbB cross-talk with the primary purpose of undermining their resilient signaling in prostate cancer progression. Our data provide important premises for the chemopreventive use of Celecoxib in the clinical management of prostate cancer. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Positive Charges on the Surface of Thaumatin Are Crucial for the Multi-Point Interaction with the Sweet Receptor.

    Science.gov (United States)

    Masuda, Tetsuya; Kigo, Satomi; Mitsumoto, Mayuko; Ohta, Keisuke; Suzuki, Mamoru; Mikami, Bunzo; Kitabatake, Naofumi; Tani, Fumito

    2018-01-01

    Thaumatin, an intensely sweet-tasting protein, elicits sweet taste with a threshold of only 50 nM. Previous studies from our laboratory suggested that the complex model between the T1R2-T1R3 sweet receptor and thaumatin depends critically on the complementarity of electrostatic potentials. In order to further validate this model, we focused on three lysine residues (Lys78, Lys106, and Lys137), which were expected to be part of the interaction sites. Three thaumatin mutants (K78A, K106A, and K137A) were prepared and their threshold values of sweetness were examined. The results showed that the sweetness of K106A was reduced by about three times and those of K78A and K137A were reduced by about five times when compared to wild-type thaumatin. The three-dimensional structures of these mutants were also determined by X-ray crystallographic analyses at atomic resolutions. The overall structures of mutant proteins were similar to that of wild-type but the electrostatic potentials around the mutated sites became more negative. Since the three lysine residues are located in 20-40 Å apart each other on the surface of thaumatin molecule, these results suggest the positive charges on the surface of thaumatin play a crucial role in the interaction with the sweet receptor, and are consistent with a large surface is required for interaction with the sweet receptor, as proposed by the multipoint interaction model named wedge model.

  1. Functional importance of the Ala(116)-Pro(136) region in the calcium-sensing receptor. Constitutive activity and inverse agonism in a family C G-protein-coupled receptor

    DEFF Research Database (Denmark)

    Jensen, Anders A.; Spalding, T A; Burstein, E S

    2000-01-01

    The calcium-sensing receptor (CaR) belongs to family C of the G-protein-coupled receptor superfamily. To date 14 activating mutations in CaR showing increased sensitivity to Ca(2+) have been identified in humans with autosomal dominant hypocalcemia. Four of these activating mutations are found......, suppressed the elevated basal response of the constitutively activated Ca/1a mutants demonstrating inverse agonist activity of CPCCOEt. Taken together, our results demonstrate that the Ala(116)-Pro(136) region is of key importance for the maintenance of the inactive conformation of CaR....

  2. The Transient Receptor Potential (TRP) Channel Family in Colletotrichum graminicola: A Molecular and Physiological Analysis.

    Science.gov (United States)

    Lange, Mario; Weihmann, Fabian; Schliebner, Ivo; Horbach, Ralf; Deising, Holger B; Wirsel, Stefan G R; Peiter, Edgar

    2016-01-01

    Calcium (Ca2+) is a universal second messenger in all higher organisms and centrally involved in the launch of responses to environmental stimuli. Ca2+ signals in the cytosol are initiated by the activation of Ca2+ channels in the plasma membrane and/or in endomembranes. Yeast (Saccharomyces cerevisiae) contains a Ca2+-permeable channel of the TRP family, TRPY1, which is localized in the vacuolar membrane and contributes to cytosolic free Ca2+ ([Ca2+]cyt) elevations, for example in response to osmotic upshock. A TRPY1 homologue in the rice blast fungus is known to be important for growth and pathogenicity. To determine the role of the TRP channel family in the maize pathogen Colletotrichum graminicola, proteins homologous to TRPY1 were searched. This identified not one, but four genes in the C. graminicola genome, which had putative orthologs in other fungi, and which we named CgTRPF1 through 4. The topology of the CgTRPF proteins resembled that of TRPY1, albeit with a variable number of transmembrane (TM) domains additional to the six-TM-domain core and a diverse arrangement of putatively Ca2+-binding acidic motifs. All CgTRPF genes were expressed in axenic culture and throughout the infection of maize. Like TRPY1, all TRPF proteins of C. graminicola were localized intracellularly, albeit three of them were found not in large vacuoles, but co-localized in vesicular structures. Deletion strains for the CgTRPF genes were not altered in processes thought to involve Ca2+ release from internal stores, i.e. spore germination, the utilization of complex carbon sources, and the generation of tip-focussed [Ca2+]cyt spikes. Heterologous expression of CgTRPF1 through 4 in a tryp1Δ yeast mutant revealed that none of the channels mediated the release of Ca2+ in response to osmotic upshock. Accordingly, aequorin-based [Ca2+]cyt measurements of C. graminicola showed that in this fungus, osmotic upshock-triggered [Ca2+]cyt elevations were generated entirely by influx of Ca2

  3. The Transient Receptor Potential (TRP Channel Family in Colletotrichum graminicola: A Molecular and Physiological Analysis.

    Directory of Open Access Journals (Sweden)

    Mario Lange

    Full Text Available Calcium (Ca2+ is a universal second messenger in all higher organisms and centrally involved in the launch of responses to environmental stimuli. Ca2+ signals in the cytosol are initiated by the activation of Ca2+ channels in the plasma membrane and/or in endomembranes. Yeast (Saccharomyces cerevisiae contains a Ca2+-permeable channel of the TRP family, TRPY1, which is localized in the vacuolar membrane and contributes to cytosolic free Ca2+ ([Ca2+]cyt elevations, for example in response to osmotic upshock. A TRPY1 homologue in the rice blast fungus is known to be important for growth and pathogenicity. To determine the role of the TRP channel family in the maize pathogen Colletotrichum graminicola, proteins homologous to TRPY1 were searched. This identified not one, but four genes in the C. graminicola genome, which had putative orthologs in other fungi, and which we named CgTRPF1 through 4. The topology of the CgTRPF proteins resembled that of TRPY1, albeit with a variable number of transmembrane (TM domains additional to the six-TM-domain core and a diverse arrangement of putatively Ca2+-binding acidic motifs. All CgTRPF genes were expressed in axenic culture and throughout the infection of maize. Like TRPY1, all TRPF proteins of C. graminicola were localized intracellularly, albeit three of them were found not in large vacuoles, but co-localized in vesicular structures. Deletion strains for the CgTRPF genes were not altered in processes thought to involve Ca2+ release from internal stores, i.e. spore germination, the utilization of complex carbon sources, and the generation of tip-focussed [Ca2+]cyt spikes. Heterologous expression of CgTRPF1 through 4 in a tryp1Δ yeast mutant revealed that none of the channels mediated the release of Ca2+ in response to osmotic upshock. Accordingly, aequorin-based [Ca2+]cyt measurements of C. graminicola showed that in this fungus, osmotic upshock-triggered [Ca2+]cyt elevations were generated entirely by

  4. A novel mutation of the adrenocorticotropin receptor (ACTH-R) gene in a family with the syndrome of isolated glucocorticoid deficiency, but no ACTH-R abnormalities in two families with the triple A syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Tsigos, C.; Arai, K.; Latronico, A.C. [National Inst. of Child Health and Human Development, Bethesda, MD (United States)]|[Temple Univ. School of Medicine, Philadelphia, PA (United States)]|[Children`s Hospital of New Jersey, Newark, NJ (United States)] [and others

    1995-07-01

    Isolated glucocorticoid deficiency (IGD) is an autosomal recessive disorder characterized by primary adrenocortical insufficiency, usually without mineralocorticoid deficiency. Occasionally, the disorder is associated with alacrima and achalasia of the esophagus (triple A syndrome), suggesting potential heterogeneity in its etiology. Mutations in the ACTH receptor gene have been reported in several families with IGD. We have amplified and directly sequenced the entire intronless ACTH receptor gene in 1 other family with IGD and 2 famlies with triple A syndrome. The proband with IGD was a homozygote for an A {r_arrow}G substitution, changing tyrosine 254 to cysteine in the third extracellular loop of the receptor protein, probably interfering with ligand binding. Both of her parents were heterozygotes for this mutation, which was not detected in 100 normal alleles. No mutations were identified in the entire coding area of the ACTH receptor in the 2 families with triple A syndrome, supporting the idea of a developmental or postreceptor defect in this syndrome. 19 refs., 1 fig.

  5. Homozygous Familial Hypercholesterolemia Patients With Identical Mutations Variably Express the LDLR (Low-Density Lipoprotein Receptor): Implications for the Efficacy of Evolocumab.

    Science.gov (United States)

    Thedrez, Aurélie; Blom, Dirk J; Ramin-Mangata, Stéphane; Blanchard, Valentin; Croyal, Mikaël; Chemello, Kévin; Nativel, Brice; Pichelin, Matthieu; Cariou, Bertrand; Bourane, Steeve; Tang, Lihua; Farnier, Michel; Raal, Frederick J; Lambert, Gilles

    2018-03-01

    Evolocumab, a PCSK9 (proprotein convertase subtilisin kexin type 9)-neutralizing antibody, lowers low-density lipoprotein cholesterol (LDL-C) in homozygous familial hypercholesterolemic (HoFH) patients with reduced LDLR (low-density lipoprotein receptor) function. However, their individual responses are highly variable, even among carriers of identical LDLR genetic defects. We aimed to elucidate why HoFH patients variably respond to PCSK9 inhibition. Lymphocytes were isolated from 22 HoFH patients enrolled in the TAUSSIG trial (Trial Assessing Long Term Use of PCSK9 Inhibition in Subjects With Genetic LDL Disorders). Ten patients were true homozygotes (FH1/FH1) and 5 identical compound heterozygotes (FH1/FH2). Lymphocytes were plated with or without mevastatin, recombinant PCSK9 (rPCSK9), or a PCSK9-neutralizing antibody. Cell surface LDLR expression was analyzed by flow cytometry. All HoFH lymphocytes had reduced cell surface LDLR expression compared with non-FH lymphocytes, for each treatment modality. Lymphocytes from FH1/FH2 patients (LDLR defective/negative) displayed the lowest LDLR expression levels followed by lymphocytes from FH1/FH1 patients (defective/defective). Mevastatin increased, whereas rPCSK9 reduced LDLR expression. The PCSK9-neutralizing antibody restored LDLR expression. Lymphocytes displaying higher LDLR expression levels were those isolated from patients presenting with lowest levels of LDL-C and apolipoprotein B, before and after 24 weeks of evolocumab treatment. These negative correlations remained significant in FH1/FH1 patients and appeared more pronounced when patients with apolipoprotein E3/E3 genotypes were analyzed separately. Significant positive correlations were found between the levels of LDLR expression and the percentage reduction in LDL-C on evolocumab treatment. Residual LDLR expression in HoFH is a major determinant of LDL-C levels and seems to drive their individual response to evolocumab. © 2017 American Heart Association

  6. Sarcocystis neurona merozoites express a family of immunogenic surface antigens that are orthologues of the Toxoplasma gondii surface antigens (SAGs) and SAG-related sequences.

    Science.gov (United States)

    Howe, Daniel K; Gaji, Rajshekhar Y; Mroz-Barrett, Meaghan; Gubbels, Marc-Jan; Striepen, Boris; Stamper, Shelby

    2005-02-01

    Sarcocystis neurona is a member of the Apicomplexa that causes myelitis and encephalitis in horses but normally cycles between the opossum and small mammals. Analysis of an S. neurona expressed sequence tag (EST) database revealed four paralogous proteins that exhibit clear homology to the family of surface antigens (SAGs) and SAG-related sequences of Toxoplasma gondii. The primary peptide sequences of the S. neurona proteins are consistent with the two-domain structure that has been described for the T. gondii SAGs, and each was predicted to have an amino-terminal signal peptide and a carboxyl-terminal glycolipid anchor addition site, suggesting surface localization. All four proteins were confirmed to be membrane associated and displayed on the surface of S. neurona merozoites. Due to their surface localization and homology to T. gondii surface antigens, these S. neurona proteins were designated SnSAG1, SnSAG2, SnSAG3, and SnSAG4. Consistent with their homology, the SnSAGs elicited a robust immune response in infected and immunized animals, and their conserved structure further suggests that the SnSAGs similarly serve as adhesins for attachment to host cells. Whether the S. neurona SAG family is as extensive as the T. gondii SAG family remains unresolved, but it is probable that additional SnSAGs will be revealed as more S. neurona ESTs are generated. The existence of an SnSAG family in S. neurona indicates that expression of multiple related surface antigens is not unique to the ubiquitous organism T. gondii. Instead, the SAG gene family is a common trait that presumably has an essential, conserved function(s).

  7. Sarcocystis neurona Merozoites Express a Family of Immunogenic Surface Antigens That Are Orthologues of the Toxoplasma gondii Surface Antigens (SAGs) and SAG-Related Sequences†

    Science.gov (United States)

    Howe, Daniel K.; Gaji, Rajshekhar Y.; Mroz-Barrett, Meaghan; Gubbels, Marc-Jan; Striepen, Boris; Stamper, Shelby

    2005-01-01

    Sarcocystis neurona is a member of the Apicomplexa that causes myelitis and encephalitis in horses but normally cycles between the opossum and small mammals. Analysis of an S. neurona expressed sequence tag (EST) database revealed four paralogous proteins that exhibit clear homology to the family of surface antigens (SAGs) and SAG-related sequences of Toxoplasma gondii. The primary peptide sequences of the S. neurona proteins are consistent with the two-domain structure that has been described for the T. gondii SAGs, and each was predicted to have an amino-terminal signal peptide and a carboxyl-terminal glycolipid anchor addition site, suggesting surface localization. All four proteins were confirmed to be membrane associated and displayed on the surface of S. neurona merozoites. Due to their surface localization and homology to T. gondii surface antigens, these S. neurona proteins were designated SnSAG1, SnSAG2, SnSAG3, and SnSAG4. Consistent with their homology, the SnSAGs elicited a robust immune response in infected and immunized animals, and their conserved structure further suggests that the SnSAGs similarly serve as adhesins for attachment to host cells. Whether the S. neurona SAG family is as extensive as the T. gondii SAG family remains unresolved, but it is probable that additional SnSAGs will be revealed as more S. neurona ESTs are generated. The existence of an SnSAG family in S. neurona indicates that expression of multiple related surface antigens is not unique to the ubiquitous organism T. gondii. Instead, the SAG gene family is a common trait that presumably has an essential, conserved function(s). PMID:15664946

  8. Blockade of dopamine D1-family receptors attenuates the mania-like hyperactive, risk-preferring, and high motivation behavioral profile of mice with low dopamine transporter levels.

    Science.gov (United States)

    Milienne-Petiot, Morgane; Groenink, Lucianne; Minassian, Arpi; Young, Jared W

    2017-10-01

    Patients with bipolar disorder mania exhibit poor cognition, impulsivity, risk-taking, and goal-directed activity that negatively impact their quality of life. To date, existing treatments for bipolar disorder do not adequately remediate cognitive dysfunction. Reducing dopamine transporter expression recreates many bipolar disorder mania-relevant behaviors (i.e. hyperactivity and risk-taking). The current study investigated whether dopamine D 1 -family receptor blockade would attenuate the risk-taking, hypermotivation, and hyperactivity of dopamine transporter knockdown mice. Dopamine transporter knockdown and wild-type littermate mice were tested in mouse versions of the Iowa Gambling Task (risk-taking), Progressive Ratio Breakpoint Test (effortful motivation), and Behavioral Pattern Monitor (activity). Prior to testing, the mice were treated with the dopamine D 1 -family receptor antagonist SCH 23390 hydrochloride (0.03, 0.1, or 0.3 mg/kg), or vehicle. Dopamine transporter knockdown mice exhibited hyperactivity and hyperexploration, hypermotivation, and risk-taking preference compared with wild-type littermates. SCH 23390 hydrochloride treatment decreased premature responding in dopamine transporter knockdown mice and attenuated their hypermotivation. SCH 23390 hydrochloride flattened the safe/risk preference, while reducing activity and exploratory levels of both genotypes similarly. Dopamine transporter knockdown mice exhibited mania-relevant behavior compared to wild-type mice. Systemic dopamine D 1 -family receptor antagonism attenuated these behaviors in dopamine transporter knockdown, but not all effects were specific to only the knockdown mice. The normalization of behavior via blockade of dopamine D 1 -family receptors supports the hypothesis that D 1 and/or D 5 receptors could contribute to the mania-relevant behaviors of dopamine transporter knockdown mice.

  9. Three cysteine residues of SLC52A1, a receptor for the porcine endogenous retrovirus-A (PERV-A), play a critical role in cell surface expression and infectivity.

    Science.gov (United States)

    Colon-Moran, Winston; Argaw, Takele; Wilson, Carolyn A

    2017-07-01

    Porcine endogenous retrovirus-A (PERV-A), a gammaretrovirus, infects human cells in vitro, thus raising the potential risk of cross-species transmission in xenotransplantation. Two members of the solute carrier family 52 (SLC52A1 and SLC52A2) are PERV-A receptors. Site-directed mutagenesis of the cDNA encoding SLC52A1 identified that only one of two putative glycosylation signals is occupied by glycans. In addition, we showed that glycosylation of SLC52A1 is not necessary for PERV-A receptor function. We also identified that at a minimum, three cysteine residues are sufficient for SLC52A1 cell surface expression. Mutation of cysteine at position 365 and either of the two cysteine residues in the C-terminal tail at positions 442 or 446 reduced SLC52A1 surface expression and PERV-A infection suggesting that these residues may contribute to overall structural stability and receptor function. Understanding interactions between PERV-A and its cellular receptor may provide novel strategies to prevent zoonotic infection in the setting of xenotransplantation. Published by Elsevier Inc.

  10. The Extracellular Surface of the GLP-1 Receptor Is a Molecular Trigger for Biased Agonism.

    Science.gov (United States)

    Wootten, Denise; Reynolds, Christopher A; Smith, Kevin J; Mobarec, Juan C; Koole, Cassandra; Savage, Emilia E; Pabreja, Kavita; Simms, John; Sridhar, Rohan; Furness, Sebastian G B; Liu, Mengjie; Thompson, Philip E; Miller, Laurence J; Christopoulos, Arthur; Sexton, Patrick M

    2016-06-16

    Ligand-directed signal bias offers opportunities for sculpting molecular events, with the promise of better, safer therapeutics. Critical to the exploitation of signal bias is an understanding of the molecular events coupling ligand binding to intracellular signaling. Activation of class B G protein-coupled receptors is driven by interaction of the peptide N terminus with the receptor core. To understand how this drives signaling, we have used advanced analytical methods that enable separation of effects on pathway-specific signaling from those that modify agonist affinity and mapped the functional consequence of receptor modification onto three-dimensional models of a receptor-ligand complex. This yields molecular insights into the initiation of receptor activation and the mechanistic basis for biased agonism. Our data reveal that peptide agonists can engage different elements of the receptor extracellular face to achieve effector coupling and biased signaling providing a foundation for rational design of biased agonists. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  11. Molecular analysis of the androgen-receptor gene in a family with receptor-positive partial androgen insensitivity: an unusual type of intronic mutation

    NARCIS (Netherlands)

    H.T. Brüggenwirth (Hennie); A.L.M. Boehmer (Annemie); S. Ramnarain; M.C. Verleun-Mooijman; D.P.E. Satijn (David); J. Trapman (Jan); J.A. Grootegoed (Anton); A.O. Brinkmann (Albert)

    1997-01-01

    textabstractIn the coding part and the intron-exon boundaries of the androgen-receptor gene of a patient with partial androgen insensitivity, no mutation was found. The androgen receptor of this patient displayed normal ligand-binding parameters and migrated as a

  12. Intermittent hypoxia induces the proliferation of rat vascular smooth muscle cell with the increases in epidermal growth factor family and erbB2 receptor

    Energy Technology Data Exchange (ETDEWEB)

    Kyotani, Yoji, E-mail: cd147@naramed-u.ac.jp [Department of Pharmacology, Nara Medical University School of Medicine, Kashihara 634-8521 (Japan); Department of Pharmacy, Nara Medical University Hospital, Kashihara 634-8522 (Japan); Ota, Hiroyo [Second Department of Internal Medicine, Nara Medical University School of Medicine, Kashihara 634-8522 (Japan); Department of Biochemistry, Nara Medical University School of Medicine, Kashihara 634-8521 (Japan); Itaya-Hironaka, Asako; Yamauchi, Akiyo; Sakuramoto-Tsuchida, Sumiyo [Department of Biochemistry, Nara Medical University School of Medicine, Kashihara 634-8521 (Japan); Zhao, Jing; Ozawa, Kentaro; Nagayama, Kosuke; Ito, Satoyasu [Department of Pharmacology, Nara Medical University School of Medicine, Kashihara 634-8521 (Japan); Takasawa, Shin [Department of Biochemistry, Nara Medical University School of Medicine, Kashihara 634-8521 (Japan); Kimura, Hiroshi [Second Department of Internal Medicine, Nara Medical University School of Medicine, Kashihara 634-8522 (Japan); Uno, Masayuki [Department of Pharmacy, Nara Medical University Hospital, Kashihara 634-8522 (Japan); Yoshizumi, Masanori [Department of Pharmacology, Nara Medical University School of Medicine, Kashihara 634-8521 (Japan)

    2013-11-15

    Obstructive sleep apnea is characterized by intermittent hypoxia (IH), and associated with cardiovascular diseases, such as stroke and heart failure. These cardiovascular diseases have a relation to atherosclerosis marked by the proliferation of vascular smooth muscle cells (VSMCs). In this study, we investigated the influence of IH on cultured rat aortic smooth muscle cell (RASMC). The proliferation of RASMC was significantly increased by IH without changing the level of apoptosis. In order to see what induces RASMC proliferation, we investigated the influence of normoxia (N)-, IH- and sustained hypoxia (SH)-treated cell conditioned media on RASMC proliferation. IH-treated cell conditioned medium significantly increased RASMC proliferation compared with N-treated cell conditioned medium, but SH-treated cell conditioned medium did not. We next investigated the epidermal growth factor (EGF) family as autocrine growth factors. Among the EGF family, we found significant increases in mRNAs for epiregulin (ER), amphiregulin (AR) and neuregulin-1 (NRG1) in IH-treated cells and mature ER in IH-treated cell conditioned medium. We next investigated the changes in erbB family receptors that are receptors for ER, AR and NRG1, and found that erbB2 receptor mRNA and protein expressions were increased by IH, but not by SH. Phosphorylation of erbB2 receptor at Tyr-1248 that mediates intracellular signaling for several physiological effects including cell proliferation was increased by IH, but not by SH. In addition, inhibitor for erbB2 receptor suppressed IH-induced cell proliferation. These results provide the first demonstration that IH induces VSMC proliferation, and suggest that EGF family, such as ER, AR and NRG1, and erbB2 receptor could be involved in the IH-induced VSMC proliferation. - Highlights: ●In vitro system for intermittent hypoxia (IH) and sustained hypoxia (SH). ●IH, but not SH, induces the proliferation of rat vascular smooth muscle cell. ●Epiregulin m

  13. Intermittent hypoxia induces the proliferation of rat vascular smooth muscle cell with the increases in epidermal growth factor family and erbB2 receptor

    International Nuclear Information System (INIS)

    Kyotani, Yoji; Ota, Hiroyo; Itaya-Hironaka, Asako; Yamauchi, Akiyo; Sakuramoto-Tsuchida, Sumiyo; Zhao, Jing; Ozawa, Kentaro; Nagayama, Kosuke; Ito, Satoyasu; Takasawa, Shin; Kimura, Hiroshi; Uno, Masayuki; Yoshizumi, Masanori

    2013-01-01

    Obstructive sleep apnea is characterized by intermittent hypoxia (IH), and associated with cardiovascular diseases, such as stroke and heart failure. These cardiovascular diseases have a relation to atherosclerosis marked by the proliferation of vascular smooth muscle cells (VSMCs). In this study, we investigated the influence of IH on cultured rat aortic smooth muscle cell (RASMC). The proliferation of RASMC was significantly increased by IH without changing the level of apoptosis. In order to see what induces RASMC proliferation, we investigated the influence of normoxia (N)-, IH- and sustained hypoxia (SH)-treated cell conditioned media on RASMC proliferation. IH-treated cell conditioned medium significantly increased RASMC proliferation compared with N-treated cell conditioned medium, but SH-treated cell conditioned medium did not. We next investigated the epidermal growth factor (EGF) family as autocrine growth factors. Among the EGF family, we found significant increases in mRNAs for epiregulin (ER), amphiregulin (AR) and neuregulin-1 (NRG1) in IH-treated cells and mature ER in IH-treated cell conditioned medium. We next investigated the changes in erbB family receptors that are receptors for ER, AR and NRG1, and found that erbB2 receptor mRNA and protein expressions were increased by IH, but not by SH. Phosphorylation of erbB2 receptor at Tyr-1248 that mediates intracellular signaling for several physiological effects including cell proliferation was increased by IH, but not by SH. In addition, inhibitor for erbB2 receptor suppressed IH-induced cell proliferation. These results provide the first demonstration that IH induces VSMC proliferation, and suggest that EGF family, such as ER, AR and NRG1, and erbB2 receptor could be involved in the IH-induced VSMC proliferation. - Highlights: ●In vitro system for intermittent hypoxia (IH) and sustained hypoxia (SH). ●IH, but not SH, induces the proliferation of rat vascular smooth muscle cell. ●Epiregulin m

  14. Genetic Variations in the Human G Protein-coupled Receptor Class C, Group 6, Member A (GPRC6A) Control Cell Surface Expression and Function

    DEFF Research Database (Denmark)

    Jorgensen, Stine; Have, Christian Theil; Underwood, Christina Rye

    2017-01-01

    -expressed murine and goldfish orthologs. The latter orthologs are Gq-coupled and lead to intracellular accumulation of inositol phosphates and calcium release. In the present study we cloned the bonobo chimpanzee GPRC6A receptor, which is 99% identical to the human receptor, and show that it is cell surface...

  15. Oestrogen receptor beta isoform expression in sporadic colorectal cancer, familial adenomatous polyposis and progressive stages of colorectal cancer.

    Science.gov (United States)

    Stevanato Filho, Paulo Roberto; Aguiar Júnior, Samuel; Begnami, Maria Dirlei; Kuasne, Hellen; Spencer, Ranyell Matheus; Nakagawa, Wilson Toshihiko; Bezerra, Tiago Santoro; Kupper, Bruna Catin; Takahashi, Renata Maymi; Barros Filho, Mateus; Rogatto, Silvia Regina; Lopes, Ademar

    2017-11-13

    Among the sex hormones, oestrogen may play a role in colorectal cancer, particularly in conjunction with oestrogen receptor-β (ERβ). The expression of ERβ isoform variants and their correlations with familial adenomatous polyposis (FAP) syndrome and sporadic colorectal carcinomas are poorly described. This study aimed to investigate the expression levels of the ERβ1, ERβ2, ERβ4 and ERβ5 isoform variants using quantitative RT-PCR (921 analyses) in FAP, normal mucosa, adenomatous polyps and sporadic colorectal carcinomas. Decreased expression of ERβ isoforms was identified in sporadic polyps and in sporadic colorectal cancer as well as in polyps from FAP syndrome patients compared with normal tissues (p colorectal carcinomas were compared to normal mucosa tissues. These findings suggest an association of the ERβ isoform variants in individuals affected by germline mutations of the APC gene. Progressively decreased expression of ERβ was found in polyps at early stages of low-grade dysplasia, followed by T1-T2 and T3-T4 tumours (p colorectal cancer, the loss of expression was an independent predictor of recurrence, and ERβ1 and ERβ5 expression levels were associated with better disease-free survival (p = 0.002). These findings may provide a better understanding of oestrogens and their potential preventive and therapeutic effects on sporadic colorectal cancer and cancers associated with FAP syndrome.

  16. CRISPR Correction of a Homozygous Low-Density Lipoprotein Receptor Mutation in Familial Hypercholesterolemia Induced Pluripotent Stem Cells.

    Science.gov (United States)

    Omer, Linda; Hudson, Elizabeth A; Zheng, Shirong; Hoying, James B; Shan, Yuan; Boyd, Nolan L

    2017-11-01

    Familial hypercholesterolemia (FH) is a hereditary disease primarily due to mutations in the low-density lipoprotein receptor (LDLR) that lead to elevated cholesterol and premature development of cardiovascular disease. Homozygous FH patients (HoFH) with two dysfunctional LDLR alleles are not as successfully treated with standard hypercholesterol therapies, and more aggressive therapeutic approaches to control cholesterol levels must be considered. Liver transplant can resolve HoFH, and hepatocyte transplantation has shown promising results in animals and humans. However, demand for donated livers and high-quality hepatocytes overwhelm the supply. Human pluripotent stem cells can differentiate to hepatocyte-like cells (HLCs) with the potential for experimental and clinical use. To be of future clinical use as autologous cells, LDLR genetic mutations in derived FH-HLCs need to be corrected. Genome editing technology clustered-regularly-interspaced-short-palindromic-repeats/CRISPR-associated 9 (CRISPR/Cas9) can repair pathologic genetic mutations in human induced pluripotent stem cells. We used CRISPR/Cas9 genome editing to permanently correct a 3-base pair homozygous deletion in LDLR exon 4 of patient-derived HoFH induced pluripotent stem cells. The genetic correction restored LDLR-mediated endocytosis in FH-HLCs and demonstrates the proof-of-principle that CRISPR-mediated genetic modification can be successfully used to normalize HoFH cholesterol metabolism deficiency at the cellular level.

  17. Vascular endothelial growth factor receptor-1 mediates migration of human colorectal carcinoma cells by activation of Src family kinases

    Science.gov (United States)

    Lesslie, D P; Summy, J M; Parikh, N U; Fan, F; Trevino, J G; Sawyer, T K; Metcalf, C A; Shakespeare, W C; Hicklin, D J; Ellis, L M; Gallick, G E

    2006-01-01

    Vascular endothelial growth factor (VEGF) is the predominant pro-angiogenic cytokine in human malignancy, and its expression correlates with disease recurrence and poor outcomes in patients with colorectal cancer. Recently, expression of vascular endothelial growth factor receptors (VEGFRs) has been observed on tumours of epithelial origin, including those arising in the colon, but the molecular mechanisms governing potential VEGF-driven biologic functioning in these tumours are not well characterised. In this report, we investigated the role of Src family kinases (SFKs) in VEGF-mediated signalling in human colorectal carcinoma (CRC) cell lines. Vascular endothelial growth factor specifically activated SFKs in HT29 and KM12L4 CRC cell lines. Further, VEGF stimulation resulted in enhanced cellular migration, which was effectively blocked by pharmacologic inhibition of VEGFR-1 or Src kinase. Correspondingly, migration studies using siRNA clones with reduced Src expression confirmed the requirement for Src in VEGF-induced migration in these cells. Furthermore, VEGF treatment enhanced VEGFR-1/SFK complex formation and increased tyrosine phosphorylation of focal adhesion kinase, p130 cas and paxillin. Finally, we demonstrate that VEGF-induced migration is not due, at least in part, to VEGF acting as a mitogen. These results suggest that VEGFR-1 promotes migration of tumour cells through a Src-dependent pathway linked to activation of focal adhesion components that regulate this process. PMID:16685275

  18. Early Alterations in Ovarian Surface Epithelial Cells and Induction of Ovarian Epithelial Tumors Triggered by Loss of FSH Receptor

    Directory of Open Access Journals (Sweden)

    Xinlei Chen

    2007-06-01

    Full Text Available Little is known about the behavior of the ovarian surface epithelium (OSE, which plays a central role in ovarian cancer etiology. It has been suggested that incessant ovulation causes OSE changes leading to transformation and that high gonadotropin levels during postmenopause activate OSE receptors, inducing proliferation. We examined the chronology of OSE changes, including tumor appearance, in a mouse model where ovulation never occurs due to deletion of follitropin receptor. Changes in epithelial cells were marked by pan-cytokeratin (CK staining. Histologic changes and CK staining in the OSE increased from postnatal day 2. CK staining was observed inside the ovary by 24 days and increased thereafter in tumor-bearing animals. Ovaries from a third of aged (1 year mutant mice showed CK deep inside, indicating cell migration. These tumors resembled serous papillary adenoma of human ovaries. Weak expression of GATA-4 and elevation of PCNA, cyclooxygenase-1, cyclooxygenase-2, and plateletderived growth factor receptors α and β in mutants indicated differences in cell proliferation, differentiation, and inflammation. Thus, we report that OSE changes occur long before epithelial tumors appear in FORKO mice. Our results suggest that neither incessant ovulation nor follicle-stimulating hormone receptor presence in the OSE is required for inducing ovarian tumors; thus, other mechanisms must contribute to ovarian tumorigenesis.

  19. Engineering of PDMS surfaces for use in microsystems for capture and isolation of complex and biomedically important proteins: epidermal growth factor receptor as a model system.

    Science.gov (United States)

    Lowe, Aaron M; Ozer, Byram H; Wiepz, Gregory J; Bertics, Paul J; Abbott, Nicholas L

    2008-08-01

    Elastomers based on poly(dimethylsiloxane) (PDMS) are promising materials for fabrication of a wide range of microanalytical systems due to their mechanical and optical properties and ease of processing. To date, however, quantitative studies that demonstrate reliable and reproducible methods for attachment of binding groups that capture complex receptor proteins of relevance to biomedical applications of PDMS microsystems have not been reported. Herein we describe methods that lead to the reproducible capture of a transmembrane protein, the human epidermal growth factor (EGF) receptor, onto PDMS surfaces presenting covalently immobilized antibodies for EGF receptor, and subsequent isolation of the captured receptor by mechanical transfer of the receptor onto a chemically functionalized surface of a gold film for detection. This result is particularly significant because the physical properties of transmembrane proteins make this class of proteins a difficult one to analyze. We benchmark the performance of antibodies to the human EGF receptor covalently immobilized on PDMS against the performance of the same antibodies physisorbed to conventional surfaces utilized in ELISA assays through the use of EGF receptor that was (32)P-radiolabeled in its autophosphorylation domain. These results reveal that two pan-reactive antibodies for the EGF receptor (clones H11 and 111.6) and one phosphospecific EGF receptor antibody (clone pY1068) capture the receptor on both PDMS and ELISA plates. When using H11 antibody to capture EGF receptor and subsequent treatment with a stripping buffer (NaOH and sodium dodecylsulfate) to isolate the receptor, the signal-to-background obtained using the PDMS surface was 82 : 1, exceeding the signal-to-background measured on the ELISA plate (<48 : 1). We also characterized the isolation of captured EGF receptor by mechanical contact of the PDMS surface with a chemically functionalized gold film. The efficiency of mechanical transfer of the

  20. Effect of spatial inhomogeneities on the membrane surface on receptor dimerization and signal initiation

    Directory of Open Access Journals (Sweden)

    Romica Kerketta

    2016-08-01

    Full Text Available Important signal transduction pathways originate on the plasma membrane, where microdomains may transiently entrap diffusing receptors. This results in a non-random distribution of receptors even in the resting state, which can be visualized as clusters by high resolution imaging methods. Here, we explore how spatial in-homogeneities in the plasma membrane might influence the dimerization and phosphorylation status of ErbB2 and ErbB3, two receptor tyrosine kinases that preferentially heterodimerize and are often co-expressed in cancer. This theoretical study is based upon spatial stochastic simulations of the two-dimensional membrane landscape, where variables include differential distributions and overlap of transient confinement zones (domains for the two receptor species. The in silico model is parameterized and validated using data from single particle tracking experiments. We report key differences in signaling output based on the degree of overlap between domains and the relative retention of receptors in such domains, expressed as escape probability. Results predict that a high overlap of domains, which favors transient co-confinement of both receptor species, will enhance the rate of hetero-interactions. Where domains do not overlap, simulations confirm expectations that homo-interactions are favored. Since ErbB3 is uniquely dependent on ErbB2 interactions for activation of its catalytic activity, variations in domain overlap or escape probability markedly alter the predicted patterns and time course of ErbB3 and ErbB2 phosphorylation. Taken together, these results implicate membrane domain organization as an important modulator of signal initiation, motivating the design of novel experimental approaches to measure these important parameters across a wider range of receptor systems.

  1. A simple method to assess unsaturated zone time lag in the travel time from ground surface to receptor.

    Science.gov (United States)

    Sousa, Marcelo R; Jones, Jon P; Frind, Emil O; Rudolph, David L

    2013-01-01

    In contaminant travel from ground surface to groundwater receptors, the time taken in travelling through the unsaturated zone is known as the unsaturated zone time lag. Depending on the situation, this time lag may or may not be significant within the context of the overall problem. A method is presented for assessing the importance of the unsaturated zone in the travel time from source to receptor in terms of estimates of both the absolute and the relative advective times. A choice of different techniques for both unsaturated and saturated travel time estimation is provided. This method may be useful for practitioners to decide whether to incorporate unsaturated processes in conceptual and numerical models and can also be used to roughly estimate the total travel time between points near ground surface and a groundwater receptor. This method was applied to a field site located in a glacial aquifer system in Ontario, Canada. Advective travel times were estimated using techniques with different levels of sophistication. The application of the proposed method indicates that the time lag in the unsaturated zone is significant at this field site and should be taken into account. For this case, sophisticated and simplified techniques lead to similar assessments when the same knowledge of the hydraulic conductivity field is assumed. When there is significant uncertainty regarding the hydraulic conductivity, simplified calculations did not lead to a conclusive decision. Copyright © 2012 Elsevier B.V. All rights reserved.

  2. Characterization of a disease-causing Glu119-Lys mutation in the low-density lipoprotein receptor gene in two Danish families with heterozygous familial hypercholesterolemia

    DEFF Research Database (Denmark)

    Jensen, H K; Jensen, T G; Jensen, L G

    1994-01-01

    acid residue 119 in the third repeat of the cysteine-rich ligand binding domain of the mature LDL receptor. Disruption of LDL receptor function by the Glu119-Lys mutation was confirmed by site-directed mutagenesis and expression in COS-7 cells. By Western blotting the mutation was found to affect...

  3. Nanostructured hydroxyapatite surfaces-mediated adsorption alters recognition of BMP receptor IA and bioactivity of bone morphogenetic protein-2.

    Science.gov (United States)

    Huang, Baolin; Yuan, Yuan; Ding, Sai; Li, Jianbo; Ren, Jie; Feng, Bo; Li, Tong; Gu, Yuantong; Liu, Changsheng

    2015-11-01

    Highly efficient loading of bone morphogenetic protein-2 (BMP-2) onto carriers with desirable performance is still a major challenge in the field of bone regeneration. Till now, the nanoscaled surface-induced changes of the structure and bioactivity of BMP-2 remains poorly understood. Here, the effect of nanoscaled surface on the adsorption and bioactivity of BMP-2 was investigated with a series of hydroxyapatite surfaces (HAPs): HAP crystal-coated surface (HAP), HAP crystal-coated polished surface (HAP-Pol), and sintered HAP crystal-coated surface (HAP-Sin). The adsorption dynamics of recombinant human BMP-2 (rhBMP-2) and the accessibility of the binding epitopes of adsorbed rhBMP-2 for BMP receptors (BMPRs) were examined by a quartz crystal microbalance with dissipation. Moreover, the bioactivity of adsorbed rhBMP-2 and the BMP-induced Smad signaling were investigated with C2C12 model cells. A noticeably high mass-uptake of rhBMP-2 and enhanced recognition of BMPR-IA to adsorbed rhBMP-2 were found on the HAP-Pol surface. For the rhBMP-2-adsorbed HAPs, both ALP activity and Smad signaling increased in the order of HAP-Sinuses of rhBMP-2 in clinical applications and arouse broad interests among researchers in the fields of nano-biotechnology, biomaterials and bone tissue engineering. Copyright © 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  4. Cloning and expression of the receptor for human urokinase plasminogen activator, a central molecule in cell surface, plasmin dependent proteolysis

    DEFF Research Database (Denmark)

    Roldan, A.L.; Cubellis, M.V.; Masucci, M.T.

    1990-01-01

    , and therefore the capacity of cells to migrate and invade neighboring tissues. We have isolated a 1.4 kb cDNA clone coding for the entire human uPAR. An oligonucleotide synthesized on the basis of the N-terminal sequence of the purified protein was used to screen a cDNA library made from SV40 transformed human......, a size very close to that of the cloned cDNA. Expression of the uPAR cDNA in mouse cells confirms that the clone is complete and expresses a functional uPA binding protein, located on the cell surface and with properties similar to the human uPAR. Caseinolytic plaque assay, immunofluorescence analysis......The surface receptor for urokinase plasminogen activator (uPAR) has been recognized in recent years as a key molecule in regulating plasminogen mediated extracellular proteolysis. Surface plasminogen activation controls the connections between cells, basement membrane and extracellular matrix...

  5. Characterization and molecular features of the cell surface receptor for human granulocyte-macrophage colony-stimulating factor

    International Nuclear Information System (INIS)

    Chiba, S.; Tojo, A.; Kitamura, T.; Urabe, A.; Miyazono, K.; Takaku, F.

    1990-01-01

    The receptors for human granulocyte-macrophage colony-stimulating factor (GM-CSF) on the surfaces of normal and leukemic myeloid cells were characterized using 125I-labeled bacterially synthesized GM-CSF. The binding was rapid, specific, time dependent, and saturable. Scatchard analysis of the 125I-GM-CSF binding to peripheral blood neutrophils indicated the presence of a single class of binding site (Kd = 99 +/- 21 pM; 2,304 +/- 953 sites/cell). However, for peripheral blood monocytes and two GM-CSF-responsive myeloid cell lines (U-937 and TF-1), the Scatchard plots were biphasic curvilinear, which were best fit by curves derived from two binding site model: one with high affinity (Kd1 = 10-40 pM) and the other with low affinity (Kd2 = 0.9-2.0 nM). For U-937 cells, the number of high-affinity receptors was 1,058 +/- 402 sites/cell and that of low-affinity receptors was estimated to be 10,834 +/- 2,396 sites/cell. Cross-linking studies yielded three major bands with molecular masses of 150 kDa, 115 kDa, and 95 kDa, which were displaced by an excess amount of unlabeled GM-CSF, suggesting 135-kDa, 100-kDa, and 80-kDa species for the individual components of the human GM-CSF receptor. These bands comigrated for different cell types including peripheral blood neutrophils, U-937 cells and TF-1 cells. In experiments using U-937 cells, only the latter two bands appeared to be labeled in a dose-dependent manner in a low-affinity state. These results suggest that the human GM-CSF receptor possibly forms a multichain complex

  6. Short-term exposure to oleandrin enhances responses to IL-8 by increasing cell surface IL-8 receptors

    Science.gov (United States)

    Raviprakash, Nune; Manna, Sunil Kumar

    2014-01-01

    BACKGROUND AND PURPOSE One of the first steps in host defence is the migration of leukocytes. IL-8 and its receptors are a chemokine system essential to such migration. Up-regulation of these receptors would be a viable strategy to treat dysfunctional host defence. Here, we studied the effects of the plant glycoside oleandrin on responses to IL-8 in a human monocytic cell line. EXPERIMENTAL APPROACH U937 cells were incubated with oleandrin (1-200 ng mL−1) for either 1 h (pulse) or for 24 h (non-pulse). Apoptosis; activation of NF-κB, AP-1 and NFAT; calcineurin activity and IL-8 receptors (CXCR1 and CXCR2) were measured using Western blotting, RT-PCR and reporter gene assays. KEY RESULTS Pulse exposure to oleandrin did not induce apoptosis or cytoxicity as observed after non-pulse exposure. Pulse exposure enhanced activation of NF-κB induced by IL-8 but not that induced by TNF-α, IL-1, EGF or LPS. Exposure to other apoptosis-inducing compounds (azadirachtin, resveratrol, thiadiazolidine, or benzofuran) did not enhance activation of NF-κB. Pulse exposure to oleandrin increased expression of IL-8 receptors and chemotaxis, release of enzymes and activation of NF-κB, NFAT and AP-1 along with increased IL-8-mediated calcineurin activation, and wound healing. Pulse exposure increased numbers of cell surface IL-8 receptors. CONCLUSIONS AND IMPLICATIONS Short-term (1 h; pulse) exposure to a toxic glycoside oleandrin, enhanced biological responses to IL-8 in monocytic cells, without cytoxicity. Pulse exposure to oleandrin could provide a viable therapy for those conditions where leukocyte migration is defective. PMID:24172227

  7. Vitamin A transport and the transmembrane pore in the cell-surface receptor for plasma retinol binding protein.

    Directory of Open Access Journals (Sweden)

    Ming Zhong

    Full Text Available Vitamin A and its derivatives (retinoids play diverse and crucial functions from embryogenesis to adulthood and are used as therapeutic agents in human medicine for eye and skin diseases, infections and cancer. Plasma retinol binding protein (RBP is the principal and specific vitamin A carrier in the blood and binds vitamin A at 1:1 ratio. STRA6 is the high-affinity membrane receptor for RBP and mediates cellular vitamin A uptake. STRA6 null mice have severely depleted vitamin A reserves for vision and consequently have vision loss, even under vitamin A sufficient conditions. STRA6 null humans have a wide range of severe pathological phenotypes in many organs including the eye, brain, heart and lung. Known membrane transport mechanisms involve transmembrane pores that regulate the transport of the substrate (e.g., the gating of ion channels. STRA6 represents a new type of membrane receptor. How this receptor interacts with its transport substrate vitamin A and the functions of its nine transmembrane domains are still completely unknown. These questions are critical to understanding the molecular basis of STRA6's activities and its regulation. We employ acute chemical modification to introduce chemical side chains to STRA6 in a site-specific manner. We found that modifications with specific chemicals at specific positions in or near the transmembrane domains of this receptor can almost completely suppress its vitamin A transport activity. These experiments provide the first evidence for the existence of a transmembrane pore, analogous to the pore of ion channels, for this new type of cell-surface receptor.

  8. Lipopolysaccharide-induced expression of cell surface receptors and cell activation of neutrophils and monocytes in whole human blood

    Directory of Open Access Journals (Sweden)

    N.E. Gomes

    2010-09-01

    Full Text Available Lipopolysaccharide (LPS activates neutrophils and monocytes, inducing a wide array of biological activities. LPS rough (R and smooth (S forms signal through Toll-like receptor 4 (TLR4, but differ in their requirement for CD14. Since the R-form LPS can interact with TLR4 independent of CD14 and the differential expression of CD14 on neutrophils and monocytes, we used the S-form LPS from Salmonella abortus equi and the R-form LPS from Salmonella minnesota mutants to evaluate LPS-induced activation of human neutrophils and monocytes in whole blood from healthy volunteers. Expression of cell surface receptors and reactive oxygen species (ROS and nitric oxide (NO generation were measured by flow cytometry in whole blood monocytes and neutrophils. The oxidative burst was quantified by measuring the oxidation of 2',7'-dichlorofluorescein diacetate and the NO production was quantified by measuring the oxidation of 4-amino-5-methylamino-2',7'-difluorofluorescein diacetate. A small increase of TLR4 expression by monocytes was observed after 6 h of LPS stimulation. Monocyte CD14 modulation by LPS was biphasic, with an initial 30% increase followed by a 40% decrease in expression after 6 h of incubation. Expression of CD11b was rapidly up-regulated, doubling after 5 min on monocytes, while down-regulation of CXCR2 was observed on neutrophils, reaching a 50% reduction after 6 h. LPS induced low production of ROS and NO. This study shows a complex LPS-induced cell surface receptor modulation on human monocytes and neutrophils, with up- and down-regulation depending on the receptor. R- and S-form LPS activate human neutrophils similarly, despite the low CD14 expression, if the stimulation occurs in whole blood.

  9. Molecular genetic analysis of the calcium sensing receptor gene in patients clinically suspected to have familial hypocalciuric hypercalcemia: phenotypic variation and mutation spectrum in a Danish population

    DEFF Research Database (Denmark)

    Nissen, Peter H; Christensen, Signe E; Heickendorff, Lene

    2007-01-01

    CONTEXT: The autosomal dominantly inherited condition familial hypocalciuric hypercalcemia (FHH) is characterized by elevated plasma calcium levels, relative or absolute hypocalciuria, and normal to moderately elevated plasma PTH. The condition is difficult to distinguish clinically from primary...... hyperparathyroidism and is caused by inactivating mutations in the calcium sensing receptor (CASR) gene. OBJECTIVE: We sought to define the mutation spectrum of the CASR gene in a Danish FHH population and to establish genotype-phenotype relationships regarding the different mutations. DESIGN AND PARTICIPANTS...

  10. SOCS proteins in regulation of receptor tyrosine kinase signaling

    DEFF Research Database (Denmark)

    Kazi, Julhash U.; Kabir, Nuzhat N.; Flores Morales, Amilcar

    2014-01-01

    Receptor tyrosine kinases (RTKs) are a family of cell surface receptors that play critical roles in signal transduction from extracellular stimuli. Many in this family of kinases are overexpressed or mutated in human malignancies and thus became an attractive drug target for cancer treatment....... The signaling mediated by RTKs must be tightly regulated by interacting proteins including protein-tyrosine phosphatases and ubiquitin ligases. The suppressors of cytokine signaling (SOCS) family proteins are well-known negative regulators of cytokine receptors signaling consisting of eight structurally similar...

  11. CARbodies: Human Antibodies Against Cell Surface Tumor Antigens Selected From Repertoires Displayed on T Cell Chimeric Antigen Receptors

    Directory of Open Access Journals (Sweden)

    Vanesa Alonso-Camino

    2013-01-01

    Full Text Available A human single-chain variable fragment (scFv antibody library was expressed on the surface of human T cells after transduction with lentiviral vectors (LVs. The repertoire was fused to a first-generation T cell receptor ζ (TCRζ-based chimeric antigen receptor (CAR. We used this library to isolate antibodies termed CARbodies that recognize antigens expressed on the tumor cell surface in a proof-of-principle system. After three rounds of activation-selection there was a clear repertoire restriction, with the emergence dominant clones. The CARbodies were purified from bacterial cultures as soluble and active proteins. Furthermore, to validate its potential application for adoptive cell therapy, human T cells were transduced with a LV encoding a second-generation costimulatory CAR (CARv2 bearing the selected CARbodies. Transduced human primary T cells expressed significant levels of the CARbodies-based CARv2 fusion protein on the cell surface, and importantly could be specifically activated, after stimulation with tumor cells. This approach is a promising tool for the generation of antibodies fully adapted to the display format (CAR and the selection context (cell synapse, which could extend the scope of current adoptive cell therapy strategies with CAR-redirected T cells.

  12. Positive Charges on the Surface of Thaumatin Are Crucial for the Multi-Point Interaction with the Sweet Receptor

    Directory of Open Access Journals (Sweden)

    Tetsuya Masuda

    2018-02-01

    Full Text Available Thaumatin, an intensely sweet-tasting protein, elicits sweet taste with a threshold of only 50 nM. Previous studies from our laboratory suggested that the complex model between the T1R2-T1R3 sweet receptor and thaumatin depends critically on the complementarity of electrostatic potentials. In order to further validate this model, we focused on three lysine residues (Lys78, Lys106, and Lys137, which were expected to be part of the interaction sites. Three thaumatin mutants (K78A, K106A, and K137A were prepared and their threshold values of sweetness were examined. The results showed that the sweetness of K106A was reduced by about three times and those of K78A and K137A were reduced by about five times when compared to wild-type thaumatin. The three-dimensional structures of these mutants were also determined by X-ray crystallographic analyses at atomic resolutions. The overall structures of mutant proteins were similar to that of wild-type but the electrostatic potentials around the mutated sites became more negative. Since the three lysine residues are located in 20–40 Å apart each other on the surface of thaumatin molecule, these results suggest the positive charges on the surface of thaumatin play a crucial role in the interaction with the sweet receptor, and are consistent with a large surface is required for interaction with the sweet receptor, as proposed by the multipoint interaction model named wedge model.

  13. Prevention of cold-associated acute inflammation in familial cold autoinflammatory syndrome by interleukin-1 receptor antagonist.

    Science.gov (United States)

    Hoffman, Hal M; Rosengren, Sanna; Boyle, David L; Cho, Jae Y; Nayar, Jyothi; Mueller, James L; Anderson, Justin P; Wanderer, Alan A; Firestein, Gary S

    Familial cold autoinflammatory syndrome (FCAS) is an autosomal dominant disorder characterised by recurrent episodes of rash, arthralgia, and fever after cold exposure. The genetic basis of this disease has been elucidated. Cryopyrin, the protein that is altered in FCAS, is one of the adaptor proteins that activate caspase 1, resulting in release of interleukin 1. An experimental cold challenge protocol was developed to study the acute inflammatory mechanisms occurring after a general cold exposure in FCAS patients and to investigate the effects of pretreatment with an antagonist of interleukin 1 receptor (IL-1Ra). ELISA, real-time PCR, and immunohistochemistry were used to measure cytokine responses. After cold challenge, untreated patients with FCAS developed rash, fever, and arthralgias within 1-4 h. Significant increases in serum concentrations of interleukin 6 and white-blood-cell counts were seen 4-8 h after cold challenge. Serum concentrations of interleukin 1 and cytokine mRNA in peripheral-blood leucocytes were not raised, but amounts of interleukin 1 protein and mRNA were high in affected skin. IL-1Ra administered before cold challenge blocked symptoms and increases in white-blood-cell counts and serum interleukin 6. The ability of IL-1Ra to prevent the clinical features and haematological and biochemical changes in patients with FCAS indicates a central role for interleukin 1beta in this disorder. Involvement of cryopyrin in activation of caspase 1 and NF-kappaB signalling suggests that it might have a role in many chronic inflammatory diseases. These findings support a new therapy for a disorder with no previously known acceptable treatment. They also offer insights into the role of interleukin 1beta in more common inflammatory diseases.

  14. Clinical features and growth hormone receptor gene mutations of patients with Laron syndrome from a Chinese family.

    Science.gov (United States)

    Ying, Yan-Qin; Wei, Hong; Cao, Li-Zhi; Lu, Juan-Juan; Luo, Xiao-Ping

    2007-08-01

    Laron syndrome is an autosomal recessive disorder caused by defects of growth hormone receptor (GHR) gene. It is characterized by severe postnatal growth retardation and characteristic facial features as well as high circulating levels of growth hormone (GH) and low levels of insulin-like growth factor I (IGF-I) and insulin-like growth factor binding protein-3 (IGFBP-3). This report described the clinical features and GHR gene mutations in 2 siblings with Laron syndrome in a Chinese family. Their heights and weights were in the normal range at birth, but the growth was retarded after birth. When they presented to the clinic, the heights of the boy (8 years old) and his sister (11 years old) were 80.0 cm (-8.2 SDS) and 96.6 cm (-6.8 SDS) respectively. They had typical appearance features of Laron syndrome such as short stature and obesity, with protruding forehead, saddle nose, large eyes, sparse and thin silky hair and high-pitched voice. They had higher basal serum GH levels and lower serum levels of IGF-I, IGFBP-3 and growth hormone binding protein (GHBP) than normal controls. The peak serum GH level after colonidine and insulin stimulations in the boy was over 350 ng/mL. After one-year rhGH treatment, the boy's height increased from 80.0 cm to 83.3 cm. The gene mutation analysis revealed that two patients had same homozygous mutation of S65H (TCA -->CCA) in exon 4, which is a novel gene mutation. It was concluded that a definite diagnosis of Laron syndrome can be made based on characteristic appearance features and serum levels of GH, IGF-I, IGFBP-3 and GHBP. The S65H mutation might be the cause of Laron syndrome in the two patients.

  15. The structure and function of the urokinase receptor, a membrane protein governing plasminogen activation on the cell surface

    DEFF Research Database (Denmark)

    Behrendt, N; Rønne, E; Danø, K

    1995-01-01

    PA receptor, uPAR, is a cell-surface protein which plays an important role in the localization and regulation of these processes. In the present article a number of established conclusions concerning the structure and function of uPAR are presented, and in addition various models are discussed which might...... explain additional observations for which the mechanisms involved have not yet been clarified experimentally. uPAR is a highly glycosylated, 3-domain protein, anchored in the plasma membrane by a glycolipid moiety. The domain organization is important for efficient ligand-binding, and the NH2-terminal...

  16. Effect of cardiopulmonary bypass on beta adrenergic receptor-adenylate cyclase system on surfaces of peripheral lymphocytes.

    Science.gov (United States)

    Luo, A; Tian, Y; Jin, S

    2000-01-01

    The experimental results showed that the level of CAMP, the ratio of cAPM to cGMP, IL-2R expression and IL-2 production in vitro in lymphocytes immediate and 2 weeks after cardiopulmonary bypass (CPB) were significantly lower than those before anesthetics in the patients undergoing cardiac surgery with CPB. These findings suggested that CPB could cause serious damage to adrenergic beta receptor-adenylate cyclase system on circulating lymphocytes surfaces, which might be one of the mechanisms resulting in immunosuppression after open heart surgery with CPB.

  17. The kinesin-3 family motor KLP-4 regulates anterograde trafficking of GLR-1 glutamate receptors in the ventral nerve cord of Caenorhabditis elegans.

    Science.gov (United States)

    Monteiro, Michael I; Ahlawat, Shikha; Kowalski, Jennifer R; Malkin, Emily; Koushika, Sandhya P; Juo, Peter

    2012-09-01

    The transport of glutamate receptors from the cell body to synapses is essential during neuronal development and may contribute to the regulation of synaptic strength in the mature nervous system. We previously showed that cyclin-dependent kinase-5 (CDK-5) positively regulates the abundance of GLR-1 glutamate receptors at synapses in the ventral nerve cord (VNC) of Caenorhabditis elegans. Here we identify a kinesin-3 family motor klp-4/KIF13 in a cdk-5 suppressor screen for genes that regulate GLR-1 trafficking. klp-4 mutants have decreased abundance of GLR-1 in the VNC. Genetic analysis of klp-4 and the clathrin adaptin unc-11/AP180 suggests that klp-4 functions before endocytosis in the ventral cord. Time-lapse microscopy indicates that klp-4 mutants exhibit decreased anterograde flux of GLR-1. Genetic analysis of cdk-5 and klp-4 suggests that they function in the same pathway to regulate GLR-1 in the VNC. Interestingly, GLR-1 accumulates in cell bodies of cdk-5 but not klp-4 mutants. However, GLR-1 does accumulate in klp-4-mutant cell bodies if receptor degradation in the multivesicular body/lysosome pathway is blocked. This study identifies kinesin KLP-4 as a novel regulator of anterograde glutamate receptor trafficking and reveals a cellular control mechanism by which receptor cargo is targeted for degradation in the absence of its motor.

  18. Source contribution analysis of surface particulate polycyclic aromatic hydrocarbon concentrations in northeastern Asia by source–receptor relationships

    International Nuclear Information System (INIS)

    Inomata, Yayoi; Kajino, Mizuo; Sato, Keiichi; Ohara, Toshimasa; Kurokawa, Jun-ichi; Ueda, Hiromasa; Tang, Ning; Hayakawa, Kazuichi; Ohizumi, Tsuyoshi; Akimoto, Hajime

    2013-01-01

    We analyzed the source–receptor relationships for particulate polycyclic aromatic hydrocarbon (PAH) concentrations in northeastern Asia using an aerosol chemical transport model. The model successfully simulated the observed concentrations. In Beijing (China) benzo[a]pyren (BaP) concentrations are due to emissions from its own domain. In Noto, Oki and Tsushima (Japan), transboundary transport from northern China (>40°N, 40–60%) and central China (30–40°N, 10–40%) largely influences BaP concentrations from winter to spring, whereas the relative contribution from central China is dominant (90%) in Hedo. In the summer, the contribution from Japanese domestic sources increases (40–80%) at the 4 sites. Contributions from Japan and Russia are additional source of BaP over the northwestern Pacific Ocean in summer. The contribution rates for the concentrations from each domain are different among PAH species depending on their particulate phase oxidation rates. Reaction with O 3 on particulate surfaces may be an important component of the PAH oxidation processes. -- Highlights: •Source–receptor analysis was conducted for investigating PAHs in northeast Asia. •In winter, transboundary transport from China is large contribution in leeward. •Relative contribution from Korea, Japan, and eastern Russia is increased in summer. •This seasonal variation is strongly controlled by the meteorological conditions. •The transport distance is different among PAH species. -- Transboundary transport of PAHs in northeast Asia was investigated by source–receptor analysis

  19. In vivo stem cell tracking with imageable nanoparticles that bind bioorthogonal chemical receptors on the stem cell surface.

    Science.gov (United States)

    Lee, Sangmin; Yoon, Hwa In; Na, Jin Hee; Jeon, Sangmin; Lim, Seungho; Koo, Heebeom; Han, Sang-Soo; Kang, Sun-Woong; Park, Soon-Jung; Moon, Sung-Hwan; Park, Jae Hyung; Cho, Yong Woo; Kim, Byung-Soo; Kim, Sang Kyoon; Lee, Taekwan; Kim, Dongkyu; Lee, Seulki; Pomper, Martin G; Kwon, Ick Chan; Kim, Kwangmeyung

    2017-09-01

    It is urgently necessary to develop reliable non-invasive stem cell imaging technology for tracking the in vivo fate of transplanted stem cells in living subjects. Herein, we developed a simple and well controlled stem cell imaging method through a combination of metabolic glycoengineering and bioorthogonal copper-free click chemistry. Firstly, the exogenous chemical receptors containing azide (-N 3 ) groups were generated on the surfaces of stem cells through metabolic glycoengineering using metabolic precursor, tetra-acetylated N-azidoacetyl-d-mannosamine(Ac 4 ManNAz). Next, bicyclo[6.1.0]nonyne-modified glycol chitosan nanoparticles (BCN-CNPs) were prepared as imageable nanoparticles to deliver different imaging agents. Cy5.5, iron oxide nanoparticles and gold nanoparticles were conjugated or encapsulated to BCN-CNPs for optical, MR and CT imaging, respectively. These imageable nanoparticles bound chemical receptors on the Ac 4 ManNAz-treated stem cell surface specifically via bioorthogonal copper-free click chemistry. Then they were rapidly taken up by the cell membrane turn-over mechanism resulting in higher endocytic capacity compared non-specific uptake of nanoparticles. During in vivo animal test, BCN-CNP-Cy5.5-labeled stem cells could be continuously tracked by non-invasive optical imaging over 15 days. Furthermore, BCN-CNP-IRON- and BCN-CNP-GOLD-labeled stem cells could be efficiently visualized using in vivo MR and CT imaging demonstrating utility of our stem cell labeling method using chemical receptors. These results conclude that our method based on metabolic glycoengineering and bioorthogonal copper-free click chemistry can stably label stem cells with diverse imageable nanoparticles representing great potential as new stem cell imaging technology. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. The retinoid X receptor response element in the human aldehyde dehydrogenase 2 promoter is antagonized by the chicken ovalbumin upstream promoter family of orphan receptors

    NARCIS (Netherlands)

    Pinaire, J; Hasanadka, R; Fang, M; Chou, WY; Stewart, MJ; Kruijer, W; Crabb, D

    2000-01-01

    Two tandem sites in the aldehyde dehydrogenase 2 promoter (designated FP330-5' and FP330-3') that bind members of the nuclear receptor superfamily mere recently identified. Antibodies against apolipoprotein regulatory protein (ARP-1) altered DNA-protein interactions in electrophoretic mobility shift

  1. An ochre mutation in the vitamin D receptor gene causes hereditary 1,25-dihydroxyvitamin D3-resistant rickets in three families

    International Nuclear Information System (INIS)

    Ritchie, H.H.; Hughes, M.R.; Thompson, E.T.; Pike, J.W.; O'Malley, B.W.; Malloy, P.J.; Feldman, D.; Hochberg, Z.

    1989-01-01

    Hereditary 1,25-dihydroxyvitamin D 3 -resistant rickets is a rare autosomal-recessive disease resulting from target-organ resistance to the action of the active hormonal form of vitamin D. Four affected children from three related families with the classical syndrome of hereditary 1,25-dihydroxyvitamin D 3 -resistant rickets and the absence of detectable binding to the vitamin D receptor (VDR) in cultured fibroblasts or lymphoblasts were examined for genetic abnormalities in the VDR gene. Genomic DNA from Epstein-Barr virus-transformed lymphoblasts of eight family members was isolated and amplified by polymerase chain reaction techniques. Amplified fragments containing the eight structural exons encoding the VDR protein were sequenced. The DNA from all affected children exhibited a single C → A base substitution within exon 7 at nucleotide 970. Although the affected children were all homozygotic for the mutation, the four parents tested all exhibited both wild-type and mutant alleles, indicating a heterozygous state. Recreated mutant receptor exhibited no specific 1,25-[ 3 H]dihydroxyvitamin D 3 binding and failed to activate a cotransfected VDR promoter-reporter gene construct. Thus these findings identify an ochre mutation in a human steroid hormone receptor in patients with hereditary 1,25-dihydroxyvitamin D 3 -resistant rickets

  2. An ochre mutation in the vitamin D receptor gene causes hereditary 1,25-dihydroxyvitamin D sub 3 -resistant rickets in three families

    Energy Technology Data Exchange (ETDEWEB)

    Ritchie, H.H.; Hughes, M.R.; Thompson, E.T.; Pike, J.W.; O' Malley, B.W. (Baylor College of Medicine, Houston, TX (USA)); Malloy, P.J.; Feldman, D. (Stanford Univ. School of Medicine, CA (USA)); Hochberg, Z. (Rambam Medical Center, Haifa (Israel))

    1989-12-01

    Hereditary 1,25-dihydroxyvitamin D{sub 3}-resistant rickets is a rare autosomal-recessive disease resulting from target-organ resistance to the action of the active hormonal form of vitamin D. Four affected children from three related families with the classical syndrome of hereditary 1,25-dihydroxyvitamin D{sub 3}-resistant rickets and the absence of detectable binding to the vitamin D receptor (VDR) in cultured fibroblasts or lymphoblasts were examined for genetic abnormalities in the VDR gene. Genomic DNA from Epstein-Barr virus-transformed lymphoblasts of eight family members was isolated and amplified by polymerase chain reaction techniques. Amplified fragments containing the eight structural exons encoding the VDR protein were sequenced. The DNA from all affected children exhibited a single C {yields} A base substitution within exon 7 at nucleotide 970. Although the affected children were all homozygotic for the mutation, the four parents tested all exhibited both wild-type and mutant alleles, indicating a heterozygous state. Recreated mutant receptor exhibited no specific 1,25-({sup 3}H)dihydroxyvitamin D{sub 3} binding and failed to activate a cotransfected VDR promoter-reporter gene construct. Thus these findings identify an ochre mutation in a human steroid hormone receptor in patients with hereditary 1,25-dihydroxyvitamin D{sub 3}-resistant rickets.

  3. A multiscale computational approach to dissect early events in the Erb family receptor mediated activation, differential signaling, and relevance to oncogenic transformations.

    Science.gov (United States)

    Liu, Yingting; Purvis, Jeremy; Shih, Andrew; Weinstein, Joshua; Agrawal, Neeraj; Radhakrishnan, Ravi

    2007-06-01

    We describe a hierarchical multiscale computational approach based on molecular dynamics simulations, free energy-based molecular docking simulations, deterministic network-based kinetic modeling, and hybrid discrete/continuum stochastic dynamics protocols to study the dimer-mediated receptor activation characteristics of the Erb family receptors, specifically the epidermal growth factor receptor (EGFR). Through these modeling approaches, we are able to extend the prior modeling of EGF-mediated signal transduction by considering specific EGFR tyrosine kinase (EGFRTK) docking interactions mediated by differential binding and phosphorylation of different C-terminal peptide tyrosines on the RTK tail. By modeling signal flows through branching pathways of the EGFRTK resolved on a molecular basis, we are able to transcribe the effects of molecular alterations in the receptor (e.g., mutant forms of the receptor) to differing kinetic behavior and downstream signaling response. Our molecular dynamics simulations show that the drug sensitizing mutation (L834R) of EGFR stabilizes the active conformation to make the system constitutively active. Docking simulations show preferential characteristics (for wildtype vs. mutant receptors) in inhibitor binding as well as preferential enhancement of phosphorylation of particular substrate tyrosines over others. We find that in comparison to the wildtype system, the L834R mutant RTK preferentially binds the inhibitor erlotinib, as well as preferentially phosphorylates the substrate tyrosine Y1068 but not Y1173. We predict that these molecular level changes result in preferential activation of the Akt signaling pathway in comparison to the Erk signaling pathway for cells with normal EGFR expression. For cells with EGFR over expression, the mutant over activates both Erk and Akt pathways, in comparison to wildtype. These results are consistent with qualitative experimental measurements reported in the literature. We discuss these

  4. Mycophenolate mofetil modulates adhesion receptors of the beta1 integrin family on tumor cells: impact on tumor recurrence and malignancy

    International Nuclear Information System (INIS)

    Engl, Tobias; Makarević, Jasmina; Relja, Borna; Natsheh, Iyad; Müller, Iris; Beecken, Wolf-Dietrich; Jonas, Dietger; Blaheta, Roman A

    2005-01-01

    Tumor development remains one of the major obstacles following organ transplantation. Immunosuppressive drugs such as cyclosporine and tacrolimus directly contribute to enhanced malignancy, whereas the influence of the novel compound mycophenolate mofetil (MMF) on tumor cell dissemination has not been explored. We therefore investigated the adhesion capacity of colon, pancreas, prostate and kidney carcinoma cell lines to endothelium, as well as their beta1 integrin expression profile before and after MMF treatment. Tumor cell adhesion to endothelial cell monolayers was evaluated in the presence of 0.1 and 1 μM MMF and compared to unstimulated controls. beta1 integrin analysis included alpha1beta1 (CD49a), alpha2beta1 (CD49b), alpha3beta1 (CD49c), alpha4beta1 (CD49d), alpha5beta1 (CD49e), and alpha6beta1 (CD49f) receptors, and was carried out by reverse transcriptase-polymerase chain reaction, confocal microscopy and flow cytometry. Adhesion of the colon carcinoma cell line HT-29 was strongly reduced in the presence of 0.1 μM MMF. This effect was accompanied by down-regulation of alpha3beta1 and alpha6beta1 surface expression and of alpha3beta1 and alpha6beta1 coding mRNA. Adhesion of the prostate tumor cell line DU-145 was blocked dose-dependently by MMF. In contrast to MMF's effects on HT-29 cells, MMF dose-dependently up-regulated alpha1beta1, alpha2beta1, alpha3beta1, and alpha5beta1 on DU-145 tumor cell membranes. We conclude that MMF possesses distinct anti-tumoral properties, particularly in colon and prostate carcinoma cells. Adhesion blockage of HT-29 cells was due to the loss of alpha3beta1 and alpha6beta1 surface expression, which might contribute to a reduced invasive behaviour of this tumor entity. The enhancement of integrin beta1 subtypes observed in DU-145 cells possibly causes re-differentiation towards a low-invasive phenotype

  5. Mycophenolate mofetil modulates adhesion receptors of the beta1 integrin family on tumor cells: impact on tumor recurrence and malignancy

    Directory of Open Access Journals (Sweden)

    Beecken Wolf-Dietrich

    2005-01-01

    Full Text Available Abstract Background Tumor development remains one of the major obstacles following organ transplantation. Immunosuppressive drugs such as cyclosporine and tacrolimus directly contribute to enhanced malignancy, whereas the influence of the novel compound mycophenolate mofetil (MMF on tumor cell dissemination has not been explored. We therefore investigated the adhesion capacity of colon, pancreas, prostate and kidney carcinoma cell lines to endothelium, as well as their beta1 integrin expression profile before and after MMF treatment. Methods Tumor cell adhesion to endothelial cell monolayers was evaluated in the presence of 0.1 and 1 μM MMF and compared to unstimulated controls. beta1 integrin analysis included alpha1beta1 (CD49a, alpha2beta1 (CD49b, alpha3beta1 (CD49c, alpha4beta1 (CD49d, alpha5beta1 (CD49e, and alpha6beta1 (CD49f receptors, and was carried out by reverse transcriptase-polymerase chain reaction, confocal microscopy and flow cytometry. Results Adhesion of the colon carcinoma cell line HT-29 was strongly reduced in the presence of 0.1 μM MMF. This effect was accompanied by down-regulation of alpha3beta1 and alpha6beta1 surface expression and of alpha3beta1 and alpha6beta1 coding mRNA. Adhesion of the prostate tumor cell line DU-145 was blocked dose-dependently by MMF. In contrast to MMF's effects on HT-29 cells, MMF dose-dependently up-regulated alpha1beta1, alpha2beta1, alpha3beta1, and alpha5beta1 on DU-145 tumor cell membranes. Conclusion We conclude that MMF possesses distinct anti-tumoral properties, particularly in colon and prostate carcinoma cells. Adhesion blockage of HT-29 cells was due to the loss of alpha3beta1 and alpha6beta1 surface expression, which might contribute to a reduced invasive behaviour of this tumor entity. The enhancement of integrin beta1 subtypes observed in DU-145 cells possibly causes re-differentiation towards a low-invasive phenotype.

  6. A family of octopamine [corrected] receptors that specifically induce cyclic AMP production or Ca2+ release in Drosophila melanogaster.

    Science.gov (United States)

    Balfanz, Sabine; Strünker, Timo; Frings, Stephan; Baumann, Arnd

    2005-04-01

    In invertebrates, the biogenic-amine octopamine is an important physiological regulator. It controls and modulates neuronal development, circadian rhythm, locomotion, 'fight or flight' responses, as well as learning and memory. Octopamine mediates its effects by activation of different GTP-binding protein (G protein)-coupled receptor types, which induce either cAMP production or Ca(2+) release. Here we describe the functional characterization of two genes from Drosophila melanogaster that encode three octopamine receptors. The first gene (Dmoa1) codes for two polypeptides that are generated by alternative splicing. When heterologously expressed, both receptors cause oscillatory increases of the intracellular Ca(2+) concentration in response to applying nanomolar concentrations of octopamine. The second gene (Dmoa2) codes for a receptor that specifically activates adenylate cyclase and causes a rise of intracellular cAMP with an EC(50) of approximately 3 x 10(-8) m octopamine. Tyramine, the precursor of octopamine biosynthesis, activates all three receptors at > or = 100-fold higher concentrations, whereas dopamine and serotonin are non-effective. Developmental expression of Dmoa genes was assessed by RT-PCR. Overlapping but not identical expression patterns were observed for the individual transcripts. The genes characterized in this report encode unique receptors that display signature properties of native octopamine receptors.

  7. HUMAN NK CELLS: FROM SURFACE RECEPTORS TO THE THERAPY OF LEUKEMIAS AND SOLID TUMORS

    Directory of Open Access Journals (Sweden)

    LORENZO eMORETTA

    2014-03-01

    Full Text Available Natural Killer (NK cells are major effector cells of the innate immunity. The discovery, over two decades ago, of MHC-class I specific NK receptors and subsequently of activating receptors, recognizing ligands expressed by tumor or virus-infected cells, paved the way to our understanding of the mechanisms of selective recognition and killing of tumor cells. Although NK cells can efficiently kill tumor cells of different histotypes in vitro, their activity may be limited in vivo by their inefficient trafficking to tumor lesions and by the inhibition of their function induced by tumor cells themselves and by the tumor microenvironment. On the other hand, the important role of NK cells has been clearly demonstrated in the therapy of high risk leukemias in the haploidentical hematopoietic cell (HSC transplantation setting. NK cells derived from donor HSC kill leukemic cells residual after the conditioning regimen, thus preventing leukemia relapses. In addition, they also kill residual dendritic cells and T lymphocytes, thus preventing both GvHD and graft rejection.

  8. The TAM-family receptor Mer mediates production of HGF through the RhoA-dependent pathway in response to apoptotic cells.

    Science.gov (United States)

    Park, Hyun-Jung; Baen, Ji-Yeon; Lee, Ye-Ji; Choi, Youn-Hee; Kang, Jihee Lee

    2012-08-01

    The TAM receptor protein tyrosine kinases Tyro3, Axl, and Mer play important roles in macrophage function. We investigated the roles of the TAM receptors in mediating the induction of hepatocyte growth factor (HGF) during the interaction of macrophages with apoptotic cells. Mer-specific neutralizing antibody, small interfering RNA (siRNA), and a recombinant Mer protein (Mer/Fc) inhibited HGF mRNA and protein expression, as well as activation of RhoA, Akt, and specific mitogen-activated protein (MAP) kinases in response to apoptotic cells. Inhibition of Axl or Tyro3 with specific antibodies, siRNA, or Fc-fusion proteins did not prevent apoptotic cell-induced HGF mRNA and protein expression and did not inhibit activation of the postreceptor signaling molecules RhoA and certain MAP kinases, including extracellular signal-regulated protein kinase and c-Jun NH(2)-terminal kinase. However, Axl- and Tyro3-specific blockers did inhibit the activation of Akt and p38 MAP kinase in response to apoptotic cells. In addition, none of the TAM receptors mediated the effects of apoptotic cells on transforming growth factor-β or epidermal growth factor mRNA expression. However, they were involved in the induction of vascular endothelial growth factor mRNA expression. Our data provide evidence that when macrophages interact with apoptotic cells, only Mer of the TAM-family receptors is responsible for mediating transcriptional HGF production through a RhoA-dependent pathway.

  9. The miR9863 family regulates distinct Mla alleles in barley to attenuate NLR receptor-triggered disease resistance and cell-death signaling.

    Directory of Open Access Journals (Sweden)

    Jie Liu

    2014-12-01

    Full Text Available Barley (Hordeum vulgare L. Mla alleles encode coiled-coil (CC, nucleotide binding, leucine-rich repeat (NB-LRR receptors that trigger isolate-specific immune responses against the powdery mildew fungus, Blumeria graminis f. sp. hordei (Bgh. How Mla or NB-LRR genes in grass species are regulated at post-transcriptional level is not clear. The microRNA family, miR9863, comprises four members that differentially regulate distinct Mla alleles in barley. We show that miR9863 members guide the cleavage of Mla1 transcripts in barley, and block or reduce the accumulation of MLA1 protein in the heterologous Nicotiana benthamiana expression system. Regulation specificity is determined by variation in a unique single-nucleotide-polymorphism (SNP in mature miR9863 family members and two SNPs in the Mla miR9863-binding site that separates these alleles into three groups. Further, we demonstrate that 22-nt miR9863s trigger the biogenesis of 21-nt phased siRNAs (phasiRNAs and together these sRNAs form a feed-forward regulation network for repressing the expression of group I Mla alleles. Overexpression of miR9863 members specifically attenuates MLA1, but not MLA10-triggered disease resistance and cell-death signaling. We propose a key role of the miR9863 family in dampening immune response signaling triggered by a group of MLA immune receptors in barley.

  10. Evidence for a partial deficiency of the LDL (apo B,E) receptor within a family of rhesus monkeys with a spontaneous hypercholesterolemia

    International Nuclear Information System (INIS)

    Scanu, A.M.; Khalil, A.; Tidore, M.; Kaiser, M.; Pfaffinger, D.; Carey, D.; Dawson, G.

    1987-01-01

    Spontaneous hypercholesterolemia is rare among non-human primates. Through screening of a rhesus monkey colony they have identified a family in which 3 out of its 6 members have a persistent hypercholesterolemia on a cholesterol-free Purina Chow diet and are high responders to a dietary fat challenge. On a basal diet the 3 affected animals also exhibited high plasma levels of LDL and apoB. To shed light on the mechanism of the hypercholesterolemia they have grown in culture fibroblasts from skin biopsies obtained from all members of the rhesus monkey family and 12 control. Binding studies at 4 0 C and ligand blotting experiments using 125 I-LDL of either normolipidemic rhesus monkeys or human subjects have shown that the fibroblasts from the 3 monkeys with a spontaneous hypercholesterolemia have a significant reduction of the number of LDL receptor and to the same extent as fibroblasts derived from subjects with heterozygous FH studied at the same time. The data suggest that the spontaneous elevation of plasma cholesterol observed in the 3 family members is related, at least in part, to a defective uptake of LDL by the LDL receptor pathway

  11. Screening Effect of PEG on Avidin Binding to Liposome Surface Receptors

    DEFF Research Database (Denmark)

    Kaasgaard, Thomas; Mouritsen, Ole G.; Jørgensen, Kent

    2000-01-01

    This study investigates the screening effect of poly(ethylene glycol)-phospholipids (PE-PEG) on the interaction of avidin with PEGylated liposomes containing surface-bound biotin ligands. The influence of grafting density and lipopolymer chain length is examined. A simple fluorescence assay....... Furthermore. it is found that none of the lipopolymers completely prevents avidin from reaching the surface-bound biotin ligands....

  12. Regulation of C. elegans fat uptake and storage by acyl-CoA synthase-3 is dependent on NR5A family nuclear hormone receptor nhr-25

    DEFF Research Database (Denmark)

    Mullaney, Brendan C; Blind, Raymond D; Lemieux, George A

    2010-01-01

    Acyl-CoA synthases are important for lipid synthesis and breakdown, generation of signaling molecules, and lipid modification of proteins, highlighting the challenge of understanding metabolic pathways within intact organisms. From a C. elegans mutagenesis screen, we found that loss of ACS-3...... mutant phenotypes require the nuclear hormone receptor NHR-25, a key regulator of C. elegans molting. Our findings suggest that ACS-3-derived long-chain fatty acyl-CoAs, perhaps incorporated into complex ligands such as phosphoinositides, modulate NHR-25 function, which in turn regulates an endocrine...... program of lipid uptake and synthesis. These results reveal a link between acyl-CoA synthase function and an NR5A family nuclear receptor in C. elegans....

  13. Identification of urocortin III, an additional member of the corticotropin-releasing factor (CRF) family with high affinity for the CRF2 receptor.

    Science.gov (United States)

    Lewis, K; Li, C; Perrin, M H; Blount, A; Kunitake, K; Donaldson, C; Vaughan, J; Reyes, T M; Gulyas, J; Fischer, W; Bilezikjian, L; Rivier, J; Sawchenko, P E; Vale, W W

    2001-06-19

    The corticotropin-releasing factor (CRF) family of neuropeptides includes the mammalian peptides CRF, urocortin, and urocortin II, as well as piscine urotensin I and frog sauvagine. The mammalian peptides signal through two G protein-coupled receptor types to modulate endocrine, autonomic, and behavioral responses to stress, as well as a range of peripheral (cardiovascular, gastrointestinal, and immune) activities. The three previously known ligands are differentially distributed anatomically and have distinct specificities for the two major receptor types. Here we describe the characterization of an additional CRF-related peptide, urocortin III, in the human and mouse. In searching the public human genome databases we found a partial expressed sequence tagged (EST) clone with significant sequence identity to mammalian and fish urocortin-related peptides. By using primers based on the human EST sequence, a full-length human clone was isolated from genomic DNA that encodes a protein that includes a predicted putative 38-aa peptide structurally related to other known family members. With a human probe, we then cloned the mouse ortholog from a genomic library. Human and mouse urocortin III share 90% identity in the 38-aa putative mature peptide. In the peptide coding region, both human and mouse urocortin III are 76% identical to pufferfish urocortin-related peptide and more distantly related to urocortin II, CRF, and urocortin from other mammalian species. Mouse urocortin III mRNA expression is found in areas of the brain including the hypothalamus, amygdala, and brainstem, but is not evident in the cerebellum, pituitary, or cerebral cortex; it is also expressed peripherally in small intestine and skin. Urocortin III is selective for type 2 CRF receptors and thus represents another potential endogenous ligand for these receptors.

  14. Cell surface-bound TIMP3 induces apoptosis in mesenchymal Cal78 cells through ligand-independent activation of death receptor signaling and blockade of survival pathways.

    Directory of Open Access Journals (Sweden)

    Christina Koers-Wunrau

    Full Text Available BACKGROUND: The matrix metalloproteinases (MMPs and their endogenous regulators, the tissue inhibitor of metalloproteinases (TIMPs 1-4 are responsible for the physiological remodeling of the extracellular matrix (ECM. Among all TIMPs, TIMP3 appears to play a unique role since TIMP3 is a secreted protein and, unlike the other TIMP family members, is tightly bound to the ECM. Moreover TIMP3 has been shown to be able to induce apoptotic cell death. As little is known about the underlying mechanisms, we set out to investigate the pro-apoptotic effect of TIMP3 in human mesenchymal cells. METHODOLOGY/PRINCIPAL FINDINGS: Lentiviral overexpression of TIMP3 in mesenchymal cells led to a strong dose-dependent induction of ligand-independent apoptosis as reflected by a five-fold increase in caspase 3 and 7 activity compared to control (pLenti6/V5-GW/lacZ or uninfected cells, whereas exogenous TIMP3 failed to induce apoptosis. Concordantly, increased cleavage of death substrate PARP and the caspases 3 and 7 was observed in TIMP3 overexpressing cultures. Notably, activation of caspase-8 but not caspase-9 was observed in TIMP3-overexpressing cells, indicating a death receptor-dependent mechanism. Moreover, overexpression of TIMP3 led to a further induction of apoptosis after stimulation with TNF-alpha, FasL and TRAIL. Most interestingly, TIMP3-overexpression was associated with a decrease in phosphorylation of cRaf, extracellular signal-regulated protein kinase (Erk1/2, ribosomal S6 kinase (RSK1 and Akt and serum deprivation of TIMP3-overexpressing cells resulted in a distinct enhancement of apoptosis, pointing to an impaired signaling of serum-derived survival factors. Finally, heparinase treatment of heparan sulfate proteoglycans led to the release of TIMP3 from the surface of overexpressing cells and to a significant decrease in apoptosis indicating that the binding of TIMP3 is necessary for apoptosis induction. CONCLUSION: The results demonstrate that

  15. Correlation between familial cancer history and epidermal growth factor receptor mutations in Taiwanese never smokers with non-small cell lung cancer: a case-control study.

    Science.gov (United States)

    Cheng, Po-Chung; Cheng, Yun-Chung

    2015-03-01

    Lung cancer is a leading cause of cancer deaths in the world. Cigarette smoking remains a prominent risk factor, but lung cancer incidence has been increasing in never smokers. Genetic abnormalities including epidermal growth factor receptor (EGFR) mutations predominate in never smoking lung cancer patients. Furthermore, familial aggregations of patients with these mutations reflect heritable susceptibility to lung cancer. The correlation between familial cancer history and EGFR mutations in never smokers with lung cancer requires investigation. This was a retrospective case-control study that evaluated the prevalence of EGFR mutations in lung cancer patients with familial cancer history. Never smokers with lung cancer treated at a hospital in Taiwan between April 2012 and May 2014 were evaluated. Inclusion criteria were never smokers with non-small cell lung cancer (NSCLC). Exclusion criteria involved patients without records of familial cancer history or tumor genotype. This study included 246 never smokers with lung cancer. The study population mainly involved never smoking women with a mean age of 60 years, and the predominant tumor histology was adenocarcinoma. Lung cancer patients with familial cancer history had an increased prevalence of EGFR mutations compared to patients without family history [odds ratio (OR): 5.9; 95% confidence interval (CI): 3.3-10.6; Pnon-pulmonary cancers (OR: 5.0; 95% CI: 2.5-10.0; Pnever smoking lung cancer patients with familial cancer history. Moreover, a sizable proportion of never smoking cancer patients harbored these mutations. These observations have implications for the treatment of lung cancer in never smokers.

  16. An investigation of interactions between hypocretin/orexin signaling and glutamate receptor surface expression in the rat nucleus accumbens under basal conditions and after cocaine exposure.

    Science.gov (United States)

    Plaza-Zabala, Ainhoa; Li, Xuan; Milovanovic, Mike; Loweth, Jessica A; Maldonado, Rafael; Berrendero, Fernando; Wolf, Marina E

    2013-12-17

    Hypocretin peptides are critical for the effects of cocaine on excitatory synaptic strength in the ventral tegmental area (VTA). However, little is known about their role in cocaine-induced synaptic plasticity in the nucleus accumbens (NAc). First, we tested whether hypocretin-1 by itself could acutely modulate glutamate receptor surface expression in the NAc, given that hypocretin-1 in the VTA reproduces cocaine's effects on glutamate transmission. We found no effect of hypocretin-1 infusion on AMPA or NMDA receptor surface expression in the NAc, measured by biotinylation, either 30 min or 3h after the infusion. Second, we were interested in whether changes in hypocretin receptor-2 (Hcrtr-2) expression contribute to cocaine-induced plasticity in the NAc. As a first step towards addressing this question, Hcrtr-2 surface expression was compared in the NAc after withdrawal from extended-access self-administration of saline (control) versus cocaine. We found that surface Hcrtr-2 levels remain unchanged following 14, 25 or 48 days of withdrawal from cocaine, a time period in which high conductance GluA2-lacking AMPA receptors progressively emerge in the NAc. Overall, our results fail to support a role for hypocretins in acute modulation of glutamate receptor levels in the NAc or a role for altered Hcrtr-2 expression in withdrawal-dependent synaptic adaptations in the NAc following cocaine self-administration. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  17. Cell wall trapping of autocrine peptides for human G-protein-coupled receptors on the yeast cell surface.

    Directory of Open Access Journals (Sweden)

    Jun Ishii

    Full Text Available G-protein-coupled receptors (GPCRs regulate a wide variety of physiological processes and are important pharmaceutical targets for drug discovery. Here, we describe a unique concept based on yeast cell-surface display technology to selectively track eligible peptides with agonistic activity for human GPCRs (Cell Wall Trapping of Autocrine Peptides (CWTrAP strategy. In our strategy, individual recombinant yeast cells are able to report autocrine-positive activity for human GPCRs by expressing a candidate peptide fused to an anchoring motif. Following expression and activation, yeast cells trap autocrine peptides onto their cell walls. Because captured peptides are incapable of diffusion, they have no impact on surrounding yeast cells that express the target human GPCR and non-signaling peptides. Therefore, individual yeast cells can assemble the autonomous signaling complex and allow single-cell screening of a yeast population. Our strategy may be applied to identify eligible peptides with agonistic activity for target human GPCRs.

  18. Host-parasite interaction: selective Pv-fam-a family proteins of Plasmodium vivax bind to a restricted number of human erythrocyte receptors.

    Science.gov (United States)

    Zeeshan, Mohammad; Tyagi, Rupesh Kumar; Tyagi, Kriti; Alam, Mohd Shoeb; Sharma, Yagya Dutta

    2015-04-01

    Plasmodium vivax synthesizes the largest number of 36 tryptophan-rich proteins belonging to the Pv-fam-a family. These parasite proteins need to be characterized for their biological function because tryptophan-rich proteins from other Plasmodium species have been proposed as vaccine candidates. Recombinant P. vivax tryptophan-rich antigens (PvTRAgs) were used to determine their erythrocyte-binding activity by a cell-based enzyme-linked immunosorbent assay, flow cytometry, and a rosetting assay. Only 4 (PvTRAg26.3, PvTRAg34, PvTRAg36, and PvTRAg36.6) of 21 PvTRAgs bind to host erythrocytes. The cross-competition data indicated that PvTRAg36 and PvTRAg34 share their erythrocyte receptors with previously described proteins PvTRAg38 and PvTRAg33.5, respectively. On the other hand, PvTRAg26.3 and PvTRAg36.6 cross-compete with each other and not with any other PvTRAg, indicating that these 2 proteins bind to the same but yet another set of erythrocyte receptor(s). Together, 10 of 36 PvTRAgs possess erythrocyte-binding activity in which each protein recognizes >1 erythrocyte receptor. Further, each erythrocyte receptor is shared by >1 PvTRAg. This redundancy may be useful for the parasite to invade red blood cells and cause disease pathogenesis, and it can be exploited to develop therapeutics against P. vivax malaria. © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  19. Nuclear receptor 5A (NR5A) family regulates 5-aminolevulinic acid synthase 1 (ALAS1) gene expression in steroidogenic cells.

    Science.gov (United States)

    Ju, Yunfeng; Mizutani, Tetsuya; Imamichi, Yoshitaka; Yazawa, Takashi; Matsumura, Takehiro; Kawabe, Shinya; Kanno, Masafumi; Umezawa, Akihiro; Kangawa, Kenji; Miyamoto, Kaoru

    2012-11-01

    5-Aminolevulinic acid synthase 1 (ALAS1) is a rate-limiting enzyme for heme biosynthesis in mammals. Heme is essential for the catalytic activities of P450 enzymes including steroid metabolic enzymes. Nuclear receptor 5A (NR5A) family proteins, steroidogenic factor-1 (SF-1), and liver receptor homolog-1 (LRH-1) play pivotal roles in regulation of steroidogenic enzymes. Recently, we showed that expression of SF-1/LRH-1 induces differentiation of mesenchymal stem cells into steroidogenic cells. In this study, genome-wide analysis revealed that ALAS1 was a novel SF-1-target gene in differentiated mesenchymal stem cells. Chromatin immunoprecipitation and reporter assays revealed that SF-1/LRH-1 up-regulated ALAS1 gene transcription in steroidogenic cells via binding to a 3.5-kb upstream region of ALAS1. The ALAS1 gene was up-regulated by overexpression of SF-1/LRH-1 in steroidogenic cells and down-regulated by knockdown of SF-1 in these cells. Peroxisome proliferator-activated receptor-γ coactivator-1α, a coactivator of nuclear receptors, also strongly coactivated expression of NR5A-target genes. Reporter analysis revealed that peroxisome proliferator-activated receptor-γ coactivator-1α strongly augmented ALAS1 gene transcription caused by SF-1 binding to the 3.5-kb upstream region. Finally knockdown of ALAS1 resulted in reduced progesterone production by steroidogenic cells. These results indicate that ALAS1 is a novel NR5A-target gene and participates in steroid hormone production.

  20. Aryl hydrocarbon receptor (AhR) inducers and estrogen receptor (ER) activities in surface sediments of Three Gorges Reservoir, China evaluated with in vitro cell bioassays

    NARCIS (Netherlands)

    Wang, J.; Bovee, T.F.H.; Bi, Y.; Bernhöft, S.; Schramm, K.W.

    2014-01-01

    Two types of biological tests were employed for monitoring the toxicological profile of sediment cores in the Three Gorges Reservoir (TGR), China. In the present study, sediments collected in June 2010 from TGR were analyzed for estrogen receptor (ER)- and aryl hydrocarbon receptor (AhR)-mediated

  1. Sequence and expression pattern of a novel human orphan G-protein-coupled receptor, GPRC5B, a family C receptor with a short amino-terminal domain

    DEFF Research Database (Denmark)

    Bräuner-Osborne, Hans; Krogsgaard-Larsen, P

    2000-01-01

    Query of GenBank with the amino acid sequence of human metabotropic glutamate receptor subtype 2 (mGluR2) identified a predicted gene product of unknown function on BAC clone CIT987SK-A-69G12 (located on chromosome band 16p12) as a homologous protein. The transcript, entitled GPRC5B, was cloned f...... from an expressed sequence tag clone that contained the entire open reading frame of the transcript encoding a protein of 395 amino acids. Analysis of the protein sequence reveal that GPRC5B contains a signal peptide and seven transmembrane alpha-helices, which is a hallmark of G...

  2. A previously unidentified deletion in G protein-coupled receptor 143 causing X-linked congenital nystagmus in a Chinese family

    Directory of Open Access Journals (Sweden)

    Jing Liu

    2016-01-01

    Full Text Available Background: Congenital nystagmus (CN is characterized by conjugated, spontaneous, and involuntary ocular oscillations. It is an inherited disease and the most common inheritance pattern is X-linked CN. In this study, our aim is to identify the disease-causing mutation in a large sixth-generation Chinese family with X-linked CN. Methods: It has been reported that mutations in four-point-one, ezrin, radixin, moesin domain-containing 7 gene (FRMD7 and G protein-coupled receptor 143 gene (GPR143 account for the majority patients of X-linked nystagmus. We collected 8 ml blood samples from members of a large sixth-generation pedigree with X-linked CN and 100 normal controls. FRMD7 and GPR143 were scanned by polymerase chain reaction (PCR-based DNA sequencing assays, and multiplex PCR assays were applied to detect deletions. Results: We identified a previously unreported deletion covering 7 exons in GPR143 in a Chinese family. The heterozygous deletion from exon 3 to exon 9 of GPR143 was detected in all affected males in the family, while it was not detected in other unaffected relatives or 100 normal controls. Conclusions: This is the first report of molecular characterization in GPR143 gene in the CN family. Our results expand the spectrum of GPR143 mutations causing CN and further confirm the role of GPR143 in the pathogenesis of CN.

  3. Oxytocin receptor gene (OXTR) variant rs1042778 moderates the influence of family environment on changes in perceived social support over time.

    Science.gov (United States)

    Dobewall, Henrik; Hakulinen, Christian; Keltikangas-Järvinen, Liisa; Pulkki-Råback, Laura; Seppälä, Ilkka; Lehtimäki, Terho; Raitakari, Olli T; Hintsanen, Mirka

    2018-08-01

    Lack of social support is an established risk factor across health outcomes, making it important to examine its family environmental and genetic determinants. In a 27-year follow-up of the Young Finns Study (N = 2341), we examined with a latent growth curve model whether genes involved in the oxytocin signaling pathway-namely, oxytocin receptor gene (OXTR) variants rs1042778, rs2254298, and rs53576-moderate the effect of early-life social experiences on perceived social support across the life span. Mothers reported the emotional warmth and acceptance towards their children at baseline when the participants were from 3 to 18 years old (1980). Perceived family support and support from friends and peripheral sources were assessed in five follow-ups 18 years apart (1989-2007). Maternal emotional warmth and acceptance predicted the initial level of perceived social support across subscales, while the rate of change in family support was affected by the family environment only if participants carried the T-allele of OXTR rs1042778. This gene-environment interaction was not found for the rate of change in support from friends and peripheral sources and we also did not find associations between latent growth in perceived social support and OXTR variants rs53576 and rs2254298. Selective attrition in perceived social support, maternal emotional warmth and acceptance, gender, and SES. Family environment was assessed by a non-standardized measure. OXTR rs1042778 polymorphism seems to contribute to changes in perceived family support in that way that some individuals (T-allele carriers) 'recover', to some extent, from the effects of early-life social experiences, whereas others (G/G genotype carriers) do not. Copyright © 2018 Elsevier B.V. All rights reserved.

  4. A cleavable signal peptide enhances cell surface delivery and heterodimerization of Cerulean-tagged angiotensin II AT1 and bradykinin B2 receptor

    Energy Technology Data Exchange (ETDEWEB)

    Quitterer, Ursula, E-mail: ursula.quitterer@pharma.ethz.ch [Molecular Pharmacology Unit, Swiss Federal Institute of Technology and University of Zurich, Zurich (Switzerland); Pohl, Armin; Langer, Andreas; Koller, Samuel; AbdAlla, Said [Molecular Pharmacology Unit, Swiss Federal Institute of Technology and University of Zurich, Zurich (Switzerland)

    2011-06-10

    Highlights: {yields} A new FRET-based method detects AT1/B2 receptor heterodimerization. {yields} First time application of AT1-Cerulean as a FRET donor. {yields} Method relies on signal peptide-enhanced cell surface delivery of AT1-Cerulean. {yields} A high FRET efficiency revealed efficient heterodimerization of AT1/B2R proteins. {yields} AT1/B2R heterodimers were functionally coupled to desensitization mechanisms. -- Abstract: Heterodimerization of the angiotensin II AT1 receptor with the receptor for the vasodepressor bradykinin, B2R, is known to sensitize the AT1-stimulated response of hypertensive individuals in vivo. To analyze features of that prototypic receptor heterodimer in vitro, we established a new method that uses fluorescence resonance energy transfer (FRET) and applies for the first time AT1-Cerulean as a FRET donor. The Cerulean variant of the green fluorescent protein as donor fluorophore was fused to the C-terminus of AT1, and the enhanced yellow fluorescent protein (EYFP) as acceptor fluorophore was fused to B2R. In contrast to AT1-EGFP, the AT1-Cerulean fusion protein was retained intracellularly. To facilitate cell surface delivery of AT1-Cerulean, a cleavable signal sequence was fused to the receptor's amino terminus. The plasma membrane-localized AT1-Cerulean resembled the native AT1 receptor regarding ligand binding and receptor activation. A high FRET efficiency of 24.7% between membrane-localized AT1-Cerulean and B2R-EYFP was observed with intact, non-stimulated cells. Confocal FRET microscopy further revealed that the AT1/B2 receptor heterodimer was functionally coupled to receptor desensitization mechanisms because activation of the AT1-Cerulean/B2R-EYFP heterodimer with a single agonist triggered the co-internalization of AT1/B2R. Receptor co-internalization was sensitive to inhibition of G protein-coupled receptor kinases, GRKs, as evidenced by a GRK-specific peptide inhibitor. In agreement with efficient AT1/B2R

  5. A cleavable signal peptide enhances cell surface delivery and heterodimerization of Cerulean-tagged angiotensin II AT1 and bradykinin B2 receptor

    International Nuclear Information System (INIS)

    Quitterer, Ursula; Pohl, Armin; Langer, Andreas; Koller, Samuel; AbdAlla, Said

    2011-01-01

    Highlights: → A new FRET-based method detects AT1/B2 receptor heterodimerization. → First time application of AT1-Cerulean as a FRET donor. → Method relies on signal peptide-enhanced cell surface delivery of AT1-Cerulean. → A high FRET efficiency revealed efficient heterodimerization of AT1/B2R proteins. → AT1/B2R heterodimers were functionally coupled to desensitization mechanisms. -- Abstract: Heterodimerization of the angiotensin II AT1 receptor with the receptor for the vasodepressor bradykinin, B2R, is known to sensitize the AT1-stimulated response of hypertensive individuals in vivo. To analyze features of that prototypic receptor heterodimer in vitro, we established a new method that uses fluorescence resonance energy transfer (FRET) and applies for the first time AT1-Cerulean as a FRET donor. The Cerulean variant of the green fluorescent protein as donor fluorophore was fused to the C-terminus of AT1, and the enhanced yellow fluorescent protein (EYFP) as acceptor fluorophore was fused to B2R. In contrast to AT1-EGFP, the AT1-Cerulean fusion protein was retained intracellularly. To facilitate cell surface delivery of AT1-Cerulean, a cleavable signal sequence was fused to the receptor's amino terminus. The plasma membrane-localized AT1-Cerulean resembled the native AT1 receptor regarding ligand binding and receptor activation. A high FRET efficiency of 24.7% between membrane-localized AT1-Cerulean and B2R-EYFP was observed with intact, non-stimulated cells. Confocal FRET microscopy further revealed that the AT1/B2 receptor heterodimer was functionally coupled to receptor desensitization mechanisms because activation of the AT1-Cerulean/B2R-EYFP heterodimer with a single agonist triggered the co-internalization of AT1/B2R. Receptor co-internalization was sensitive to inhibition of G protein-coupled receptor kinases, GRKs, as evidenced by a GRK-specific peptide inhibitor. In agreement with efficient AT1/B2R heterodimerization, confocal FRET imaging of

  6. Identification of a point mutation in growth factor repeat C of the low density lipoprotein-receptor gene in a patient with homozygous familial hypercholesterolemia

    International Nuclear Information System (INIS)

    Soutar, A.K.; Knight, B.L.; Patel, D.D.

    1989-01-01

    The coding region of the low density lipoprotein (LDL)-receptor gene from a patient (MM) with homozygous familial hypercholesterolemia (FH) has been sequenced from six overlapping 500-base-pair amplified fragments of the cDNA from cultured skin fibroblasts. Two separate single nucleotide base changes from the normal sequence were detected. The first involved substitution of guanine for adenine in the third position of the codon for amino acid residue Cys-27 and did not affect the protein sequence. The second mutation was substitution of thymine for cytosine in the DNA for the codon for amino acid residue 664, changing the codon from CCG (proline) to CTG (leucine) and introducing a new site for the restriction enzyme PstI. MM is a true homozygote with two identical genes, and the mutation cosegregated with clinically diagnosed FH in his family in which first cousin marriages occurred frequently. LDL receptors in MM's skin fibroblasts bind less LDL than normal and with reduced affinity. Thus this naturally occurring single point mutation affects both intracellular transport of the protein and ligand binding and occurs in growth factor-like repeat C, a region that has not previously been found to influence LDL binding

  7. ARF6 Activated by the LHCG Receptor through the Cytohesin Family of Guanine Nucleotide Exchange Factors Mediates the Receptor Internalization and Signaling*

    Science.gov (United States)

    Kanamarlapudi, Venkateswarlu; Thompson, Aiysha; Kelly, Eamonn; López Bernal, Andrés

    2012-01-01

    The luteinizing hormone chorionic gonadotropin receptor (LHCGR) is a Gs-coupled GPCR that is essential for the maturation and function of the ovary and testis. LHCGR is internalized following its activation, which regulates the biological responsiveness of the receptor. Previous studies indicated that ADP-ribosylation factor (ARF)6 and its GTP-exchange factor (GEF) cytohesin 2 regulate LHCGR internalization in follicular membranes. However, the mechanisms by which ARF6 and cytohesin 2 regulate LHCGR internalization remain incompletely understood. Here we investigated the role of the ARF6 signaling pathway in the internalization of heterologously expressed human LHCGR (HLHCGR) in intact cells using a combination of pharmacological inhibitors, siRNA and the expression of mutant proteins. We found that human CG (HCG)-induced HLHCGR internalization, cAMP accumulation and ARF6 activation were inhibited by Gallein (βγ inhibitor), Wortmannin (PI 3-kinase inhibitor), SecinH3 (cytohesin ARF GEF inhibitor), QS11 (an ARF GAP inhibitor), an ARF6 inhibitory peptide and ARF6 siRNA. However, Dynasore (dynamin inhibitor), the dominant negative mutants of NM23-H1 (dynamin activator) and clathrin, and PBP10 (PtdIns 4,5-P2-binding peptide) inhibited agonist-induced HLHCGR and cAMP accumulation but not ARF6 activation. These results indicate that heterotrimeric G-protein, phosphatidylinositol (PI) 3-kinase (PI3K), cytohesin ARF GEF and ARF GAP function upstream of ARF6 whereas dynamin and clathrin act downstream of ARF6 in the regulation of HCG-induced HLHCGR internalization and signaling. In conclusion, we have identified the components and molecular details of the ARF6 signaling pathway required for agonist-induced HLHCGR internalization. PMID:22523074

  8. The Prader-Willi syndrome proteins MAGEL2 and necdin regulate leptin receptor cell surface abundance through ubiquitination pathways.

    Science.gov (United States)

    Wijesuriya, Tishani Methsala; De Ceuninck, Leentje; Masschaele, Delphine; Sanderson, Matthea R; Carias, Karin Vanessa; Tavernier, Jan; Wevrick, Rachel

    2017-11-01

    In Prader-Willi syndrome (PWS), obesity is caused by the disruption of appetite-controlling pathways in the brain. Two PWS candidate genes encode MAGEL2 and necdin, related melanoma antigen proteins that assemble into ubiquitination complexes. Mice lacking Magel2 are obese and lack leptin sensitivity in hypothalamic pro-opiomelanocortin neurons, suggesting dysregulation of leptin receptor (LepR) activity. Hypothalamus from Magel2-null mice had less LepR and altered levels of ubiquitin pathway proteins that regulate LepR processing (Rnf41, Usp8, and Stam1). MAGEL2 increased the cell surface abundance of LepR and decreased their degradation. LepR interacts with necdin, which interacts with MAGEL2, which complexes with RNF41 and USP8. Mutations in the MAGE homology domain of MAGEL2 suppress RNF41 stabilization and prevent the MAGEL2-mediated increase of cell surface LepR. Thus, MAGEL2 and necdin together control LepR sorting and degradation through a dynamic ubiquitin-dependent pathway. Loss of MAGEL2 and necdin may uncouple LepR from ubiquitination pathways, providing a cellular mechanism for obesity in PWS. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  9. Molecular characterisation of two novel maize LRR receptor-like kinases, which belong to the SERK gene family

    NARCIS (Netherlands)

    Baudino, S.; Hansen, S.; Brettschneider, R.; Hecht, V.F.G.; Dresselhaus, T.; Lörz, H.; Dumas, C.; Rogowsky, P.M.

    2001-01-01

    Genes encoding two novel members of the leucine-rich repeat receptor-like kinase (LRR-RLK) superfamily have been isolated from maize (Zea mays L.). These genes have been named ZmSERK1 and ZmSERK2 since features such as a putative leucine zipper (ZIP) and five leucine rich repeats in the

  10. The Medicago truncatula lysine motif-receptor-like kinase gene family includes NFP and new nodule-expressed genes

    NARCIS (Netherlands)

    Arrighi, J.F.; Barre, A.; Amor, Ben B.; Bersoult, A.; Campos Soriano, L.; Mirabella, R.; Carvalho-Niebel, de F.; Journet, E.P.; Ghérardi, M.; Huguet, T.; Geurts, R.; Dénarié, J.; Rougé, P.; Gough, C.

    2006-01-01

    Rhizobial Nod factors are key symbiotic signals responsible for starting the nodulation process in host legume plants. Of the six Medicago truncatula genes controlling a Nod factor signaling pathway, Nod Factor Perception (NFP) was reported as a candidate Nod factor receptor gene. Here, we provide

  11. Neuropeptide Y family receptors traffic via the Bardet-Biedl syndrome pathway to signal in neuronal primary cilia.

    Science.gov (United States)

    Loktev, Alexander V; Jackson, Peter K

    2013-12-12

    Human monogenic obesity syndromes, including Bardet-Biedl syndrome (BBS), implicate neuronal primary cilia in regulation of energy homeostasis. Cilia in hypothalamic neurons have been hypothesized to sense and regulate systemic energy status, but the molecular mechanism of this signaling remains unknown. Here, we report a comprehensive localization screen of 42 G-protein-coupled receptors (GPCR) revealing seven ciliary GPCRs, including the neuropeptide Y (NPY) receptors NPY2R and NPY5R. We show that mice modeling BBS disease or obese tubby mice fail to localize NPY2R to cilia in the hypothalamus and that BBS mutant mice fail to activate c-fos or decrease food intake in response to the NPY2R ligand PYY3-36. We find that cells with ciliary NPY2R show augmented PYY3-36-dependent cAMP signaling. Our data demonstrate that ciliary targeting of NPY receptors is important for controlling energy balance in mammals, revealing a physiologically defined ligand-receptor pathway signaling within neuronal cilia. Copyright © 2013 The Authors. Published by Elsevier Inc. All rights reserved.

  12. Polysiloxane surface modified with bipyrazolic tripodal receptor for quantitative lead adsorption

    Energy Technology Data Exchange (ETDEWEB)

    Radi, Smaail, E-mail: radi_smaail@yahoo.fr [Laboratoire de Chimie Organique, Macromoleculaire et Produits Naturels, Equipe de Chimie Bio-organique et Macromoleculaire, Unite Associee au CNRST URAC 25, Departement de Chimie, Faculte des Sciences, Universite Med I, BP 524, 60 000 Oujda (Morocco); Tighadouini, Said; Toubi, Yahya [Laboratoire de Chimie Organique, Macromoleculaire et Produits Naturels, Equipe de Chimie Bio-organique et Macromoleculaire, Unite Associee au CNRST URAC 25, Departement de Chimie, Faculte des Sciences, Universite Med I, BP 524, 60 000 Oujda (Morocco); Bacquet, Maryse [Universite des Sciences et Technologies de Lille, UMET: Unite Materiaux et Transformations UMR8207, Equipe Ingenierie des Systemes Polymeres, Batiment C6 salle 119-59655 Villeneuve d' Ascq (France)

    2011-01-15

    A new silica gel compound modified N,N-bis(3,5-dimethylpyrazol-1-ylmethyl) amine (SiN{sub 2}Pz) was synthesized and characterized by elemental analysis, FT-IR, {sup 13}C NMR of the solid state, nitrogen adsorption-desorption isotherm, BET surface area and BJH pore sizes. The new surface exhibits good chemical and thermal stability determined by thermogravimetry curves (TGA). The effect of pH and stirring time on the adsorption of Pb(II) were studied. The process of metal retention was followed by batch method and the optimum pH value for the quantitative adsorption of this toxic metal ion was 7. At this pH value, the new functionalized polysiloxane presents further improvements and shows higher affinity (123 mg of Pb{sup 2+}/g of silica) for the effective adsorption of Pb(II) compared to others described sorbents. The extracted amounts of Pb(II) were determined by atomic absorption measurements.

  13. On Algebraic Cycles on Fibre Products of Non-isotrivial Families of Regular Surfaces with Geometric Genus 1

    Directory of Open Access Journals (Sweden)

    O. V. Nikol’skaya

    2016-01-01

    Full Text Available Let       be a projective family of surfaces (possibly with degenerations over a smooth projective curve  . Assume that the discriminant loci       are disjoint,          for any smooth fibre     and the period map associated with the variation of Hodge structures         (where             is a smooth part of the morphism    , is non-constant. If for generic geometric fibres

  14. Comparative genomic analysis reveals independent expansion of a lineage-specific gene family in vertebrates: The class II cytokine receptors and their ligands in mammals and fish

    Directory of Open Access Journals (Sweden)

    Mogensen Knud

    2003-07-01

    Full Text Available Abstract Background The high degree of sequence conservation between coding regions in fish and mammals can be exploited to identify genes in mammalian genomes by comparison with the sequence of similar genes in fish. Conversely, experimentally characterized mammalian genes may be used to annotate fish genomes. However, gene families that escape this principle include the rapidly diverging cytokines that regulate the immune system, and their receptors. A classic example is the class II helical cytokines (HCII including type I, type II and lambda interferons, IL10 related cytokines (IL10, IL19, IL20, IL22, IL24 and IL26 and their receptors (HCRII. Despite the report of a near complete pufferfish (Takifugu rubripes genome sequence, these genes remain undescribed in fish. Results We have used an original strategy based both on conserved amino acid sequence and gene structure to identify HCII and HCRII in the genome of another pufferfish, Tetraodon nigroviridis that is amenable to laboratory experiments. The 15 genes that were identified are highly divergent and include a single interferon molecule, three IL10 related cytokines and their potential receptors together with two Tissue Factor (TF. Some of these genes form tandem clusters on the Tetraodon genome. Their expression pattern was determined in different tissues. Most importantly, Tetraodon interferon was identified and we show that the recombinant protein can induce antiviral MX gene expression in Tetraodon primary kidney cells. Similar results were obtained in Zebrafish which has 7 MX genes. Conclusion We propose a scheme for the evolution of HCII and their receptors during the radiation of bony vertebrates and suggest that the diversification that played an important role in the fine-tuning of the ancestral mechanism for host defense against infections probably followed different pathways in amniotes and fish.

  15. A Genotypic Analysis of Five P. aeruginosa Strains after Biofilm Infection by Phages Targeting Different Cell Surface Receptors

    Directory of Open Access Journals (Sweden)

    Diana P. Pires

    2017-06-01

    Full Text Available Antibiotic resistance constitutes one of the most serious threats to the global public health and urgently requires new and effective solutions. Bacteriophages are bacterial viruses increasingly recognized as being good alternatives to traditional antibiotic therapies. In this study, the efficacy of phages, targeting different cell receptors, against Pseudomonas aeruginosa PAO1 biofilm and planktonic cell cultures was evaluated over the course of 48 h. Although significant reductions in the number of viable cells were achieved for both cases, the high level of adaptability of the bacteria in response to the selective pressure caused by phage treatment resulted in the emergence of phage-resistant variants. To further investigate the genetic makeup of phage-resistant variants isolated from biofilm infection experiments, some of these bacteria were selected for phenotypic and genotypic characterization. Whole genome sequencing was performed on five phage-resistant variants and all of them carried mutations affecting the galU gene as well as one of pil genes. The sequencing analysis further revealed that three of the P. aeruginosa PAO1 variants carry large deletions (>200 kbp in their genomes. Complementation of the galU mutants with wild-type galU in trans restored LPS expression on the bacterial cell surface of these bacterial strains and rendered the complemented strains to be sensitive to phages. This provides unequivocal evidence that inactivation of galU function was associated with resistance to the phages that uses LPS as primary receptors. Overall, this work demonstrates that P. aeruginosa biofilms can survive phage attack and develop phage-resistant variants exhibiting defective LPS production and loss of type IV pili that are well adapted to the biofilm mode of growth.

  16. Genome-wide characterization, evolution, and expression analysis of the leucine-rich repeat receptor-like protein kinase (LRR-RLK) gene family in Rosaceae genomes.

    Science.gov (United States)

    Sun, Jiangmei; Li, Leiting; Wang, Peng; Zhang, Shaoling; Wu, Juyou

    2017-10-10

    Leucine-rich repeat receptor-like protein kinase (LRR-RLK) is the largest gene family of receptor-like protein kinases (RLKs) and actively participates in regulating the growth, development, signal transduction, immunity, and stress responses of plants. However, the patterns of LRR-RLK gene family evolution in the five main Rosaceae species for which genome sequences are available have not yet been reported. In this study, we performed a comprehensive analysis of LRR-RLK genes for five Rosaceae species: Fragaria vesca (strawberry), Malus domestica (apple), Pyrus bretschneideri (Chinese white pear), Prunus mume (mei), and Prunus persica (peach), which contained 201, 244, 427, 267, and 258 LRR-RLK genes, respectively. All LRR-RLK genes were further grouped into 23 subfamilies based on the hidden Markov models approach. RLK-Pelle_LRR-XII-1, RLK-Pelle_LRR-XI-1, and RLK-Pelle_LRR-III were the three largest subfamilies. Synteny analysis indicated that there were 236 tandem duplicated genes in the five Rosaceae species, among which subfamilies XII-1 (82 genes) and XI-1 (80 genes) comprised 68.6%. Our results indicate that tandem duplication made a large contribution to the expansion of the subfamilies. The gene expression, tissue-specific expression, and subcellular localization data revealed that LRR-RLK genes were differentially expressed in various organs and tissues, and the largest subfamily XI-1 was highly expressed in all five Rosaceae species, suggesting that LRR-RLKs play important roles in each stage of plant growth and development. Taken together, our results provide an overview of the LRR-RLK family in Rosaceae genomes and the basis for further functional studies.

  17. Familial Isolated Pituitary Adenomas (FIPA) and the Pituitary Adenoma Predisposition due to Mutations in the Aryl Hydrocarbon Receptor Interacting Protein (AIP) Gene

    Science.gov (United States)

    Aaltonen, Lauri A.; Daly, Adrian F.

    2013-01-01

    Pituitary adenomas are one of the most frequent intracranial tumors and occur with a prevalence of approximately 1:1000 in the developed world. Pituitary adenomas have a serious disease burden, and their management involves neurosurgery, biological therapies, and radiotherapy. Early diagnosis of pituitary tumors while they are smaller may help increase cure rates. Few genetic predictors of pituitary adenoma development exist. Recent years have seen two separate, complimentary advances in inherited pituitary tumor research. The clinical condition of familial isolated pituitary adenomas (FIPA) has been described, which encompasses the familial occurrence of isolated pituitary adenomas outside of the setting of syndromic conditions like multiple endocrine neoplasia type 1 and Carney complex. FIPA families comprise approximately 2% of pituitary adenomas and represent a clinical entity with homogeneous or heterogeneous pituitary adenoma types occurring within the same kindred. The aryl hydrocarbon receptor interacting protein (AIP) gene has been identified as causing a pituitary adenoma predisposition of variable penetrance that accounts for 20% of FIPA families. Germline AIP mutations have been shown to associate with the occurrence of large pituitary adenomas that occur at a young age, predominantly in children/adolescents and young adults. AIP mutations are usually associated with somatotropinomas, but prolactinomas, nonfunctioning pituitary adenomas, Cushing disease, and other infrequent clinical adenoma types can also occur. Gigantism is a particular feature of AIP mutations and occurs in more than one third of affected somatotropinoma patients. Study of pituitary adenoma patients with AIP mutations has demonstrated that these cases raise clinical challenges to successful treatment. Extensive research on the biology of AIP and new advances in mouse Aip knockout models demonstrate multiple pathways by which AIP may contribute to tumorigenesis. This review assesses

  18. Two novel mutations in exon 3 and 4 of low density lipoprotein (LDL) receptor gene in patients with heterozygous familial hypercholesterolemia

    International Nuclear Information System (INIS)

    Khan, S.P.

    2011-01-01

    Objective: To determine the common mutation of low density lipoprotein receptor in hypercholesterolemia patients requiring screening for heterozygous familial hypercholesterolemia (HeFH) in Karachi. Study Design: Case-series. Place and Duration of Study: Dr. Ziauddin Hospital Laboratory and Dr. Rubina Ghani's Pathological and Molecular Laboratories, Karachi, for the PCR bench work from June 2008 to October 2009. Methodology: All the patients selected for this study were from Dr. Ziauddin Hospital and National Institute of Cardiovascular Diseases. All the patients having high total cholesterol and LDL-cholesterol were included in this study with premature coronary artery diseases or a family history of hypercholesterolemia. Exclusion criteria included Diabetes mellitus, hypertension, renal disease, hypothyroidism and steroid therapy. After lipid profile with overnight fasting, DNA was extracted from whole blood collected in EDTA (ethylenediamine tetra acetic acid) tube and multiplex PCR (polymerase chain reaction) using forward and reverse primers of exons 3, 4, 9 and 14 of base pairs 162, 431, 550 and 496 respectively. Results: Out of total of 120 hypercholesterolemia cases, 42 patients were classical cases of HeFH (heterozygous familial hypercholesterolemia) with xanthomas, xanthelasmas and LDL-C > 160 mg/dl. The total cholesterol (260 +- 57 mg/dL) and LDL-C (192 +- 39 mg/dL ) of cases was significantly high as compared to, controls having total cholesterol (184 9 +- 27 mg/dL) and LDL-C (105 +- 22 mg/dL), p > 0.001. Two novel point mutations were noted in exon 3 and exon 4. The other 78 cases were probable with raised LDL-C (low density lipoprotein cholesterol) and family history of premature coronary heart diseases. Conclusion: The frequency of HeFH was 35% classical and 65% probable cases out of total 120 hypercholesterolemia patients from two tertiary care hospitals in Karachi. The point mutation on exon 3 and exon 4 of LDLR gene was the most common. PCR is

  19. Enhanced Growth Inhibition of Osteosarcoma by Cytotoxic Polymerized Liposomal Nanoparticles Targeting the Alcam Cell Surface Receptor

    Directory of Open Access Journals (Sweden)

    Noah Federman

    2012-01-01

    Full Text Available Osteosarcoma is the most common primary malignancy of bone in children, adolescents, and adults. Despite extensive surgery and adjuvant aggressive high-dose systemic chemotherapy with potentially severe bystander side effects, cure is attainable in about 70% of patients with localized disease and only 20%–30% of those patients with metastatic disease. Targeted therapies clearly are warranted in improving our treatment of this adolescent killer. However, a lack of osteosarcoma-associated/specific markers has hindered development of targeted therapeutics. We describe a novel osteosarcoma-associated cell surface antigen, ALCAM. We, then, create an engineered anti-ALCAM-hybrid polymerized liposomal nanoparticle immunoconjugate (α-AL-HPLN to specifically target osteosarcoma cells and deliver a cytotoxic chemotherapeutic agent, doxorubicin. We have demonstrated that α-AL-HPLNs have significantly enhanced cytotoxicity over untargeted HPLNs and over a conventional liposomal doxorubicin formulation. In this way, α-AL-HPLNs are a promising new strategy to specifically deliver cytotoxic agents in osteosarcoma.

  20. Karyopherin alpha7 (KPNA7), a divergent member of the importin alpha family of nuclear import receptors.

    Science.gov (United States)

    Kelley, Joshua B; Talley, Ashley M; Spencer, Adam; Gioeli, Daniel; Paschal, Bryce M

    2010-08-11

    Classical nuclear localization signal (NLS) dependent nuclear import is carried out by a heterodimer of importin alpha and importin beta. NLS cargo is recognized by importin alpha, which is bound by importin beta. Importin beta mediates translocation of the complex through the central channel of the nuclear pore, and upon reaching the nucleus, RanGTP binding to importin beta triggers disassembly of the complex. To date, six importin alpha family members, encoded by separate genes, have been described in humans. We sequenced and characterized a seventh member of the importin alpha family of transport factors, karyopherin alpha 7 (KPNA7), which is most closely related to KPNA2. The domain of KPNA7 that binds Importin beta (IBB) is divergent, and shows stronger binding to importin beta than the IBB domains from of other importin alpha family members. With regard to NLS recognition, KPNA7 binds to the retinoblastoma (RB) NLS to a similar degree as KPNA2, but it fails to bind the SV40-NLS and the human nucleoplasmin (NPM) NLS. KPNA7 shows a predominantly nuclear distribution under steady state conditions, which contrasts with KPNA2 which is primarily cytoplasmic. KPNA7 is a novel importin alpha family member in humans that belongs to the importin alpha2 subfamily. KPNA7 shows different subcellular localization and NLS binding characteristics compared to other members of the importin alpha family. These properties suggest that KPNA7 could be specialized for interactions with select NLS-containing proteins, potentially impacting developmental regulation.

  1. Circadian clock gene aryl hydrocarbon receptor nuclear translocator-like polymorphisms are associated with seasonal affective disorder: An Indian family study.

    Science.gov (United States)

    Rajendran, Bhagya; Janakarajan, Veeramahali Natarajan

    2016-01-01

    Polymorphisms in aryl hydrocarbon receptor nuclear translocator-like (ARNTL) gene, the key component of circadian clock manifests circadian rhythm abnormalities. As seasonal affective disorder (SAD) is associated with disrupted circadian rhythms, the main objective of this study was to screen an Indian family with SAD for ARNTL gene polymorphisms. In this study, 30 members of close-knit family with SAD, 30 age- and sex-matched controls of the same caste with no prior history of psychiatric illness and 30 age- and sex-matched controls belonging to 17 different castes with no prior history of psychiatric illness were genotyped for five different single nucleotide polymorphisms (SNPs) in ARNTL gene by TaqMan allele-specific genotyping assay. Statistical significance was assessed by more powerful quasi-likelihood score test-XM. Most of the family members carried the risk alleles and we observed a highly significant SNP rs2279287 (A/G) in ARNTL gene with an allelic frequency of 0.75. Polymorphisms in ARNTL gene disrupt circadian rhythms causing SAD and genetic predisposition becomes more deleterious in the presence of adverse environment.

  2. Activation of liver X receptor suppresses the production of the IL-12 family of cytokines by blocking nuclear translocation of NF-κBp50.

    Science.gov (United States)

    Canavan, Mary; McCarthy, Ciara; Larbi, Nadia Ben; Dowling, Jennifer K; Collins, Laura; O'Sullivan, Finbarr; Hurley, Grainne; Murphy, Carola; Quinlan, Aoife; Moloney, Gerry; Darby, Trevor; MacSharry, John; Kagechika, Hiroyuki; Moynagh, Paul; Melgar, Silvia; Loscher, Christine E

    2014-10-01

    There is now convincing evidence that liver X receptor (LXR) is an important modulator of the inflammatory response; however, its mechanism of action remains unclear. This study aimed to examine the effect of LXR on the IL-12 family of cytokines and examined the mechanism by which LXR exerted this effect. We first demonstrated that activation of murine-derived dendritic cells (DC) with a specific agonist to LXR enhanced expression of LXR following activation with LPS, suggesting a role in inflammation. Furthermore, we showed LXR expression to be increased in vivo in dextrane sulphate sodium-induced colitis. LXR activation also suppressed production of IL-12p40, IL-12p70, IL-27 and IL-23 in murine-derived DC following stimulation with LPS, and specifically targeted the p35, p40 and EBI3 subunits of the IL-12 cytokine family, which are under the control of the NF-κB subunit p50 (NF-κBp50). Finally, we demonstrated that LXR can associate with NF-κBp50 in DC and that LXR activation prevents translocation of the p50 subunit into the nucleus. In summary, our study indicates that LXR can specifically suppress the IL-12 family of cytokines though its association with NF-κBp50 and highlights its potential as a therapeutic target for chronic inflammatory diseases. © The Author(s) 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  3. Regulation of plant vascular stem cells by endodermis-derived EPFL-family peptide hormones and phloem-expressed ERECTA-family receptor kinases.

    Science.gov (United States)

    Uchida, Naoyuki; Tasaka, Masao

    2013-12-01

    Plant vasculatures are complex tissues consisting of (pro)cambium, phloem, and xylem. The (pro)cambium serves as vascular stem cells that produce all vascular cells. The Arabidopsis ERECTA (ER) receptor kinase is known to regulate the architecture of inflorescence stems. It was recently reported that the er mutation enhances a vascular phenotype induced by a mutation of TDR/PXY, which plays a significant role in procambial proliferation, suggesting that ER participates in vascular development. However, detailed molecular mechanisms of the ER-dependent vascular regulation are largely unknown. Here, this work found that ER and its paralogue, ER-LIKE1, were redundantly involved in procambial development of inflorescence stems. Interestingly, their activity in the phloem was sufficient for vascular regulation. Furthermore, two endodermis-derived peptide hormones, EPFL4 and EPFL6, were redundantly involved in such regulation. It has been previously reported that EPFL4 and EPFL6 act as ligands of phloem-expressed ER for stem elongation. Therefore, these findings indicate that cell-cell communication between the endodermis and the phloem plays an important role in procambial development as well as stem elongation. Interestingly, similar EPFL-ER modules control two distinct developmental events by slightly changing their components: the EPFL4/6-ER module for stem elongation and the EPFL4/6-ER/ERL1 module for vascular development.

  4. Nonredundant roles of Src-family kinases and Syk in the initiation of B-cell antigen receptor signaling

    Czech Academy of Sciences Publication Activity Database

    Štěpánek, Ondřej; Dráber, Peter; Drobek, Aleš; Hořejší, Václav; Brdička, Tomáš

    2013-01-01

    Roč. 190, č. 4 (2013), s. 1807-1818 ISSN 0022-1767 R&D Projects: GA ČR(CZ) GBP302/12/G101; GA ČR GAP302/12/1712 Institutional support: RVO:68378050 Keywords : BCR signaling * Src family kinases * Syk Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 5.362, year: 2013

  5. Regulation of Src family kinases involved in T cell receptor signaling by protein-tyrosine phosphatase CD148

    Czech Academy of Sciences Publication Activity Database

    Štěpánek, Ondřej; Kalina, T.; Dráber, Peter; Skopcová, Tereza; Svojgr, K.; Angelisová, Pavla; Hořejší, Václav; Weiss, A.; Brdička, Tomáš

    2011-01-01

    Roč. 286, č. 25 (2011), s. 22101-22112 ISSN 0021-9258 R&D Projects: GA MŠk 2B06064; GA MŠk 1M0506 Institutional research plan: CEZ:AV0Z50520514 Keywords : CD148 * tyrosine phosphatase * Src family kinases Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.773, year: 2011

  6. Surface Expression of TGF-β Docking Receptor GARP Promotes Oncogenesis and Immune Tolerance in Breast Cancer

    Science.gov (United States)

    Metelli, Alessandra; Wu, Bill X; Fugle, Caroline W; Rachidi, Saleh; Sun, Shaoli; Zhang, Yongliang; Wu, Jennifer; Tomlinson, Stephen; Howe, Philip; Yang, Yi; Garrett-Mayer, Elizabeth; Liu, Bei; Li, Zihai

    2016-01-01

    GARP encoded by the Lrrc32 gene is the cell surface docking receptor for latent TGF-β which is expressed naturally by platelets and regulatory T cells. Although Lrrc32 is amplified frequently in breast cancer, the expression and relevant functions of GARP in cancer have not been explored. Here we report that GARP exerts oncogenic effects, promoting immune tolerance by enriching and activating latent TGF-β in the tumor microenvironment. We found that human breast, lung and colon cancers expressed GARP aberrantly. In genetic studies in normal mammary gland epithelial and carcinoma cells, GARP expression increased TGF-β bioactivity and promoted malignant transformation in immune deficient mice. In breast carcinoma-bearing mice that were immune competent, GARP overexpression promoted Foxp3+ regulatory T cell activity, which in turn contributed to enhancing cancer progression and metastasis. Notably, administration of a panel of GARP-specific monoclonal antibodies limited metastasis in an orthotopic model of human breast cancer. Overall, these results define the oncogenic effects of the GARP-TGF-β axis in the tumor microenvironment and suggest mechanisms that might be exploited for diagnostic and therapeutic purposes. PMID:27913437

  7. Chronic zinc exposure decreases the surface expression of NR2A-containing NMDA receptors in cultured hippocampal neurons.

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    Jia Zhu

    Full Text Available Zinc distributes widely in the central nervous system, especially in the hippocampus, amygdala and cortex. The dynamic balance of zinc is critical for neuronal functions. Zinc modulates the activity of N-methyl-D-aspartate receptors (NMDARs through the direct inhibition and various intracellular signaling pathways. Abnormal NMDAR activities have been implicated in the aetiology of many brain diseases. Sustained zinc accumulation in the extracellular fluid is known to link to pathological conditions. However, the mechanism linking this chronic zinc exposure and NMDAR dysfunction is poorly understood.We reported that chronic zinc exposure reduced the numbers of NR1 and NR2A clusters in cultured hippocampal pyramidal neurons. Whole-cell and synaptic NR2A-mediated currents also decreased. By contrast, zinc did not affect NR2B, suggesting that chronic zinc exposure specifically influences NR2A-containg NMDARs. Surface biotinylation indicated that zinc exposure attenuated the membrane expression of NR1 and NR2A, which might arise from to the dissociation of the NR2A-PSD-95-Src complex.Chronic zinc exposure perturbs the interaction of NR2A to PSD-95 and causes the disorder of NMDARs in hippocampal neurons, suggesting a novel action of zinc distinct from its acute effects on NMDAR activity.

  8. Aryl hydrocarbon receptor expression is associated with a family history of upper gastrointestinal tract cancer in a high-risk population exposed to aromatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Roth, M.J.; Wei, W.Q.; Baer, J.; Abnet, C.C.; Wang, G.Q.; Sternberg, L.R.; Warner, A.C.; Johnson, L.L.; Lu, N.; Giffen, C.A.; Dawsey, S.M.; Qiao, Y.L.; Cherry, J. [NCI, Bethesda, MD (United States)

    2009-09-15

    Polycyclic aromatic hydrocarbon (PAH) exposure is a risk factor for esophageal squamous cell carcinoma, and PAHs are ligands of the aryl hydrocarbon receptor (AhR). This study measured the expression of AhR and related genes in frozen esophageal cell samples from patients exposed to different levels of indoor air pollution, who did or did not have high-grade squamous dysplasia and who did or did not have a family history of upper gastrointestinal tract (UGI) cancer. 147 samples were evaluated, including 23 (16%) from patients with high-grade dysplasia and 48 (33%) from patients without dysplasia who heated their homes with coal, without a chimney (a 'high' indoor air pollution group), and 27 (18%) from patients with high-grade dysplasia and 49 (33%) from patients without dysplasia who did not heat their homes at all (a 'low' indoor air pollution group). Sixty-four (44%) had a family history of UGI cancer. RNA was extracted and quantitative PCR analysis was done. AhR gene expression was detectable in 85 (58%) of the samples and was >9-fold higher in those with a family history of UGI cancer (median expression (interquartile range), -1,964 (-18,000, -610) versus -18,000 (-18,000, -1036); P = 0.02, Wilcoxon rank-sum test). Heating status, dysplasia category, age, gender, and smoking were not associated with AhR expression (linear regression; all P values {ge} 0.1). AhR expression was higher in patients with a family history of UGI cancer. Such individuals may be more susceptible to the deleterious effects of PAH exposure, including PAH-induced cancer.

  9. The transient receptor potential, TRP4, cation channel is a novel member of the family of calmodulin binding proteins.

    OpenAIRE

    Trost, C; Bergs, C; Himmerkus, N; Flockerzi, V

    2001-01-01

    The mammalian gene products, transient receptor potential (trp)1 to trp7, are related to the Drosophila TRP and TRP-like ion channels, and are candidate proteins underlying agonist-activated Ca(2+)-permeable ion channels. Recently, the TRP4 protein has been shown to be part of native store-operated Ca(2+)-permeable channels. These channels, most likely, are composed of other proteins in addition to TRP4. In the present paper we report the direct interaction of TRP4 and calmodulin (CaM) by: (1...

  10. PpiA, a surface PPIase of the cyclophilin family in Lactococcus lactis.

    Directory of Open Access Journals (Sweden)

    Nicolas Trémillon

    Full Text Available BACKGROUND: Protein folding in the envelope is a crucial limiting step of protein export and secretion. In order to better understand this process in Lactococcus lactis, a lactic acid bacterium, genes encoding putative exported folding factors like Peptidyl Prolyl Isomerases (PPIases were searched for in lactococcal genomes. RESULTS: In L. lactis, a new putative membrane PPIase of the cyclophilin subfamily, PpiA, was identified and characterized. ppiA gene was found to be constitutively expressed under normal and stress (heat shock, H(2O(2 conditions. Under normal conditions, PpiA protein was synthesized and released from intact cells by an exogenously added protease, showing that it was exposed at the cell surface. No obvious phenotype could be associated to a ppiA mutant strain under several laboratory conditions including stress conditions, except a very low sensitivity to H(2O(2. Induction of a ppiA copy provided in trans had no effect i on the thermosensitivity of an mutant strain deficient for the lactococcal surface protease HtrA and ii on the secretion and stability on four exported proteins (a highly degraded hybrid protein and three heterologous secreted proteins in an otherwise wild-type strain background. However, a recombinant soluble form of PpiA that had been produced and secreted in L. lactis and purified from a culture supernatant displayed both PPIase and chaperone activities. CONCLUSIONS: Although L. lactis PpiA, a protein produced and exposed at the cell surface under normal conditions, displayed a very moderate role in vivo, it was found, as a recombinant soluble form, to be endowed with folding activities in vitro.

  11. Functional expression of P2X family receptors in macrophages is affected by microenvironment in mouse T cell acute lymphoblastic leukemia

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Shayan; Feng, Wenli; Yang, Xiao; Yang, Wanzhu; Ru, Yongxin; Liao, Jinfeng; Wang, Lina; Lin, Yongmin; Ren, Qian [State Key Laboratory of Experimental Hematology, Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin 300020 (China); Zheng, Guoguang, E-mail: zhengggtjchn@aliyun.com [State Key Laboratory of Experimental Hematology, Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin 300020 (China); Center for Stem Cell Medicine, Chinese Academy of Medical Sciences, Beijing 100730 (China)

    2014-04-18

    Highlights: • We study the impact of leukemic microenvironment on P2X family receptors in Mφs. • Bone marrow and spleen Mφs are studied in Notch1-induced mouse leukemia model. • Increased expression of P2X7R is found in Mφs during the development of leukemia. • Elevated P2X7R-mediated calcium response is found in Mφs at late stage of leukemia. • More apoptotic Mφs are found in bone marrow and spleen at late stage of leukemia. - Abstract: Nucleotides are important players in intercellular signaling communication network. P2X family receptors (P2XRs) are ATP-gated plasma membrane ion channels with diverse biological functions. Macrophages are important components in the microenvironment of hematopoiesis participating in both physiological and pathological processes. However, the role of P2XRs in macrophages in leukemia has not been established. Here we investigated expression pattern and functions of P2XRs in macrophages from bone marrow (BM) and spleen of Notch1-induced T-ALL mice. Real-time PCR showed that P2XRs except P2X5R were expressed in BM and spleen macrophages. Furthermore, with the development of leukemia, the expression of P2X7R increased in both BM and spleen macrophages whereas expression of P2X1R increased in spleen macrophages. Live cell imaging recoding the Ca{sup 2+} response demonstrated that P2X7R expressed in macrophages was functional. TUNEL and electron microscopy analysis found that apoptotic macrophages were frequently observed in BM and spleen at late stage of leukemia, which was partly contributed by the activation of overexpressed P2X7R. Our results suggested that the intercellular communication mediated by nucleotides might orchestrate in the pathological process of leukemia and could be a potential target for the treatment of leukemia.

  12. Functional expression of P2X family receptors in macrophages is affected by microenvironment in mouse T cell acute lymphoblastic leukemia

    International Nuclear Information System (INIS)

    Chen, Shayan; Feng, Wenli; Yang, Xiao; Yang, Wanzhu; Ru, Yongxin; Liao, Jinfeng; Wang, Lina; Lin, Yongmin; Ren, Qian; Zheng, Guoguang

    2014-01-01

    Highlights: • We study the impact of leukemic microenvironment on P2X family receptors in Mφs. • Bone marrow and spleen Mφs are studied in Notch1-induced mouse leukemia model. • Increased expression of P2X7R is found in Mφs during the development of leukemia. • Elevated P2X7R-mediated calcium response is found in Mφs at late stage of leukemia. • More apoptotic Mφs are found in bone marrow and spleen at late stage of leukemia. - Abstract: Nucleotides are important players in intercellular signaling communication network. P2X family receptors (P2XRs) are ATP-gated plasma membrane ion channels with diverse biological functions. Macrophages are important components in the microenvironment of hematopoiesis participating in both physiological and pathological processes. However, the role of P2XRs in macrophages in leukemia has not been established. Here we investigated expression pattern and functions of P2XRs in macrophages from bone marrow (BM) and spleen of Notch1-induced T-ALL mice. Real-time PCR showed that P2XRs except P2X5R were expressed in BM and spleen macrophages. Furthermore, with the development of leukemia, the expression of P2X7R increased in both BM and spleen macrophages whereas expression of P2X1R increased in spleen macrophages. Live cell imaging recoding the Ca 2+ response demonstrated that P2X7R expressed in macrophages was functional. TUNEL and electron microscopy analysis found that apoptotic macrophages were frequently observed in BM and spleen at late stage of leukemia, which was partly contributed by the activation of overexpressed P2X7R. Our results suggested that the intercellular communication mediated by nucleotides might orchestrate in the pathological process of leukemia and could be a potential target for the treatment of leukemia

  13. Cell cycle-dependent expression of Dub3, Nanog and the p160 family of nuclear receptor coactivators (NCoAs in mouse embryonic stem cells.

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    Siem van der Laan

    Full Text Available Pluripotency of embryonic stem cells (ESC is tightly regulated by a network of transcription factors among which the estrogen-related receptor β (Esrrb. Esrrb contributes to the relaxation of the G1 to S-phase (G1/S checkpoint in mouse ESCs by transcriptional control of the deubiquitylase Dub3 gene, contributing to Cdc25A persistence after DNA damage. We show that in mESCs, Dub3 gene expression is cell cycle regulated and is maximal prior G1/S transition. In addition, following UV-induced DNA damage in G1, Dub3 expression markedly increases in S-phase also suggesting a role in checkpoint recovery. Unexpectedly, we also observed cell cycle-regulation of Nanog expression, and not Oct4, reaching high levels prior to G1/S transition, finely mirroring Cyclin E1 fluctuations. Curiously, while Esrrb showed only limited cell-cycle oscillations, transcript levels of the p160 family of nuclear receptor coactivators (NCoAs displayed strong cell cycle-dependent fluctuations. Since NCoAs function in concert with Esrrb in transcriptional activation, we focussed on NCoA1 whose levels specifically increase prior onset of Dub3 transcription. Using a reporter assay, we show that NCoA1 potentiates Esrrb-mediated transcription of Dub3 and we present evidence of protein interaction between the SRC1 splice variant NCoA1 and Esrrb. Finally, we show a differential developmental regulation of all members of the p160 family during neural conversion of mESCs. These findings suggest that in mouse ESCs, changes in the relative concentration of a coactivator at a given cell cycle phase, may contribute to modulation of the transcriptional activity of the core transcription factors of the pluripotent network and be implicated in cell fate decisions upon onset of differentiation.

  14. Cell cycle-dependent expression of Dub3, Nanog and the p160 family of nuclear receptor coactivators (NCoAs) in mouse embryonic stem cells.

    Science.gov (United States)

    van der Laan, Siem; Golfetto, Eleonora; Vanacker, Jean-Marc; Maiorano, Domenico

    2014-01-01

    Pluripotency of embryonic stem cells (ESC) is tightly regulated by a network of transcription factors among which the estrogen-related receptor β (Esrrb). Esrrb contributes to the relaxation of the G1 to S-phase (G1/S) checkpoint in mouse ESCs by transcriptional control of the deubiquitylase Dub3 gene, contributing to Cdc25A persistence after DNA damage. We show that in mESCs, Dub3 gene expression is cell cycle regulated and is maximal prior G1/S transition. In addition, following UV-induced DNA damage in G1, Dub3 expression markedly increases in S-phase also suggesting a role in checkpoint recovery. Unexpectedly, we also observed cell cycle-regulation of Nanog expression, and not Oct4, reaching high levels prior to G1/S transition, finely mirroring Cyclin E1 fluctuations. Curiously, while Esrrb showed only limited cell-cycle oscillations, transcript levels of the p160 family of nuclear receptor coactivators (NCoAs) displayed strong cell cycle-dependent fluctuations. Since NCoAs function in concert with Esrrb in transcriptional activation, we focussed on NCoA1 whose levels specifically increase prior onset of Dub3 transcription. Using a reporter assay, we show that NCoA1 potentiates Esrrb-mediated transcription of Dub3 and we present evidence of protein interaction between the SRC1 splice variant NCoA1 and Esrrb. Finally, we show a differential developmental regulation of all members of the p160 family during neural conversion of mESCs. These findings suggest that in mouse ESCs, changes in the relative concentration of a coactivator at a given cell cycle phase, may contribute to modulation of the transcriptional activity of the core transcription factors of the pluripotent network and be implicated in cell fate decisions upon onset of differentiation.

  15. Single Nucleotide Polymorphisms in Taste Receptor Genes Are Associated with Snacking Patterns of Preschool-Aged Children in the Guelph Family Health Study: A Pilot Study

    Directory of Open Access Journals (Sweden)

    Elie Chamoun

    2018-01-01

    Full Text Available Snacking is an integral component of eating habits in young children that is often overlooked in nutrition research. While snacking is a substantial source of calories in preschoolers’ diets, there is limited knowledge about the factors that drive snacking patterns. The genetics of taste may help to better understand the snacking patterns of children. The rs1761667 single nucleotide polymorphism (SNP in the CD36 gene has been linked to fat taste sensitivity, the rs35874116 SNP in the TAS1R2 gene has been related to sweet taste preference, and the rs713598 SNP in the TAS2R38 gene has been associated with aversion to bitter, green leafy vegetables. This study seeks to determine the cross-sectional associations between three taste receptor SNPs and snacking patterns among preschoolers in the Guelph Family Health Study. Preschoolers’ snack quality, quantity, and frequency were assessed using three-day food records and saliva was collected for SNP genotyping (n = 47. Children with the TT genotype in TAS1R2 consumed snacks with significantly more calories from sugar, and these snacks were consumed mostly in the evening. Total energy density of snacks was highest in the CC and CG genotypes compared to the GG genotype in TAS2R38, and also greater in the AA genotype in CD36 compared to G allele carriers, however this difference was not individually attributable to energy from fat, carbohydrates, sugar, or protein. Genetic variation in taste receptors may influence snacking patterns of preschoolers.

  16. Effects of serotonin on expression of the LDL receptor family member LR11 and 7-ketocholesterol-induced apoptosis in human vascular smooth muscle cells

    Energy Technology Data Exchange (ETDEWEB)

    Nagayama, Daiji; Ishihara, Noriko [Center of Diabetes, Endocrinology and Metabolism, Toho University, Sakura Medical Center, 564-1, Shimoshizu, Sakura-City, Chiba 285-8741 (Japan); Bujo, Hideaki [Department of Clinical Laboratory Medicine, Toho University, Sakura Medical Center, 564-1, Shimoshizu, Sakura-City, Chiba 285-8741 (Japan); Shirai, Kohji [Department of Vascular Function, Toho University, Sakura Medical Center, 564-1, Shimoshizu, Sakura-City, Chiba 285-8741 (Japan); Tatsuno, Ichiro, E-mail: ichiro.tatsuno@med.toho-u.ac.jp [Center of Diabetes, Endocrinology and Metabolism, Toho University, Sakura Medical Center, 564-1, Shimoshizu, Sakura-City, Chiba 285-8741 (Japan)

    2014-04-18

    Highlights: • The dedifferentiation of VSMCs in arterial intima is involved in atherosclerosis. • 5-HT showed proliferative effect on VSMCs which was abolished by sarpogrelate. • 5-HT enhanced expression of LR11 mRNA in VSMCs which was abolished by sarpogrelate. • 5-HT suppressed 7KCHO-induced apoptosis of VSMCs via caspase-3/7-dependent pathway. • The mechanisms explain the 5-HT-induced remodeling of arterial structure. - Abstract: Serotonin (5-HT) is a known mitogen for vascular smooth muscle cells (VSMCs). The dedifferentiation and proliferation/apoptosis of VSMCs in the arterial intima represent one of the atherosclerotic changes. LR11, a member of low-density lipoprotein receptor family, may contribute to the proliferation of VSMCs in neointimal hyperplasia. We conducted an in vitro study to investigate whether 5-HT is involved in LR11 expression in human VSMCs and apoptosis of VSMCs induced by 7-ketocholesterol (7KCHO), an oxysterol that destabilizes plaque. 5-HT enhanced the proliferation of VSMCs, and this effect was abolished by sarpogrelate, a selective 5-HT2A receptor antagonist. Sarpogrelate also inhibited the 5-HT-enhanced LR11 mRNA expression in VSMCs. Furthermore, 5-HT suppressed the 7KCHO-induced apoptosis of VSMCs via caspase-3/7-dependent pathway. These findings provide new insights on the changes in the differentiation stage of VSMCs mediated by 5-HT.

  17. Bulk and surface band structure of the new family of semiconductors BiTeX (X=I, Br, Cl)

    International Nuclear Information System (INIS)

    Moreschini, L.; Autès, G.; Crepaldi, A.; Moser, S.; Johannsen, J.C.; Kim, K.S.; Berger, H.; Bugnon, Ph.; Magrez, A.; Denlinger, J.; Rotenberg, E.; Bostwick, A.; Yazyev, O.V.

    2015-01-01

    Highlights: • We provide an ARPES comparison between the three tellurohalides BiTeX (X = I, Br, Cl). • They present a similar band structure with namely spin-split bulk and surface states. • They offer, except for BiTeCl, the possibility of ambipolar conduction. • They can be easily doped. • From the data appeared so far, BiTeBr may be the most appealing for applications. - Abstract: We present an overview of the new family of semiconductors BiTeX (X = I, Br, Cl) from the perspective of angle resolved photoemission spectroscopy. The strong band bending occurring at the surface potentially endows them with a large flexibility, as they are capable of hosting both hole and electron conduction, and can be modified by inclusion or adsorption of foreign atoms. In addition, their trigonal crystal structure lacks a center of symmetry and allows for both bulk and surface spin-split bands at the Fermi level. We elucidate analogies and differences among the three materials, also in the light of recent theoretical and experimental work

  18. Galectin-3 Induces Clustering of CD147 and Integrin-β1 Transmembrane Glycoprotein Receptors on the RPE Cell Surface

    Science.gov (United States)

    Priglinger, Claudia S.; Szober, Christoph M.; Priglinger, Siegfried G.; Merl, Juliane; Euler, Kerstin N.; Kernt, Marcus; Gondi, Gabor; Behler, Jennifer; Geerlof, Arie; Kampik, Anselm; Ueffing, Marius; Hauck, Stefanie M.

    2013-01-01

    Proliferative vitreoretinopathy (PVR) is a blinding disease frequently occurring after retinal detachment surgery. Adhesion, migration and matrix remodeling of dedifferentiated retinal pigment epithelial (RPE) cells characterize the onset of the disease. Treatment options are still restrained and identification of factors responsible for the abnormal behavior of the RPE cells will facilitate the development of novel therapeutics. Galectin-3, a carbohydrate-binding protein, was previously found to inhibit attachment and spreading of retinal pigment epithelial cells, and thus bares the potential to counteract PVR-associated cellular events. However, the identities of the corresponding cell surface glycoprotein receptor proteins on RPE cells are not known. Here we characterize RPE-specific Gal-3 containing glycoprotein complexes using a proteomic approach. Integrin-β1, integrin-α3 and CD147/EMMPRIN, a transmembrane glycoprotein implicated in regulating matrix metalloproteinase induction, were identified as potential Gal-3 interactors on RPE cell surfaces. In reciprocal immunoprecipitation experiments we confirmed that Gal-3 associated with CD147 and integrin-β1, but not with integrin-α3. Additionally, association of Gal-3 with CD147 and integrin-β1 was observed in co-localization analyses, while integrin-α3 only partially co-localized with Gal-3. Blocking of CD147 and integrin-β1 on RPE cell surfaces inhibited binding of Gal-3, whereas blocking of integrin-α3 failed to do so, suggesting that integrin-α3 is rather an indirect interactor. Importantly, Gal-3 binding promoted pronounced clustering and co-localization of CD147 and integrin-β1, with only partial association of integrin-α3. Finally, we show that RPE derived CD147 and integrin-β1, but not integrin-α3, carry predominantly β-1,6-N-actyl-D-glucosamine-branched glycans, which are high-affinity ligands for Gal-3. We conclude from these data that extracellular Gal-3 triggers clustering of CD147 and

  19. Galectin-3 induces clustering of CD147 and integrin-β1 transmembrane glycoprotein receptors on the RPE cell surface.

    Directory of Open Access Journals (Sweden)

    Claudia S Priglinger

    Full Text Available Proliferative vitreoretinopathy (PVR is a blinding disease frequently occurring after retinal detachment surgery. Adhesion, migration and matrix remodeling of dedifferentiated retinal pigment epithelial (RPE cells characterize the onset of the disease. Treatment options are still restrained and identification of factors responsible for the abnormal behavior of the RPE cells will facilitate the development of novel therapeutics. Galectin-3, a carbohydrate-binding protein, was previously found to inhibit attachment and spreading of retinal pigment epithelial cells, and thus bares the potential to counteract PVR-associated cellular events. However, the identities of the corresponding cell surface glycoprotein receptor proteins on RPE cells are not known. Here we characterize RPE-specific Gal-3 containing glycoprotein complexes using a proteomic approach. Integrin-β1, integrin-α3 and CD147/EMMPRIN, a transmembrane glycoprotein implicated in regulating matrix metalloproteinase induction, were identified as potential Gal-3 interactors on RPE cell surfaces. In reciprocal immunoprecipitation experiments we confirmed that Gal-3 associated with CD147 and integrin-β1, but not with integrin-α3. Additionally, association of Gal-3 with CD147 and integrin-β1 was observed in co-localization analyses, while integrin-α3 only partially co-localized with Gal-3. Blocking of CD147 and integrin-β1 on RPE cell surfaces inhibited binding of Gal-3, whereas blocking of integrin-α3 failed to do so, suggesting that integrin-α3 is rather an indirect interactor. Importantly, Gal-3 binding promoted pronounced clustering and co-localization of CD147 and integrin-β1, with only partial association of integrin-α3. Finally, we show that RPE derived CD147 and integrin-β1, but not integrin-α3, carry predominantly β-1,6-N-actyl-D-glucosamine-branched glycans, which are high-affinity ligands for Gal-3. We conclude from these data that extracellular Gal-3 triggers

  20. Transmembrane and ubiquitin-like domain-containing protein 1 (Tmub1/HOPS facilitates surface expression of GluR2-containing AMPA receptors.

    Directory of Open Access Journals (Sweden)

    Hyunjeong Yang

    Full Text Available Some ubiquitin-like (UBL domain-containing proteins are known to play roles in receptor trafficking. Alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptors (AMPARs undergo constitutive cycling between the intracellular compartment and the cell surface in the central nervous system. However, the function of UBL domain-containing proteins in the recycling of the AMPARs to the synaptic surface has not yet been reported.Here, we report that the Transmembrane and ubiquitin-like domain-containing 1 (Tmub1 protein, formerly known as the Hepatocyte Odd Protein Shuttling (HOPS protein, which is abundantly expressed in the brain and which exists in a synaptosomal membrane fraction, facilitates the recycling of the AMPAR subunit GluR2 to the cell surface. Neurons transfected with Tmub1/HOPS-RNAi plasmids showed a significant reduction in the AMPAR current as compared to their control neurons. Consistently, the synaptic surface expression of GluR2, but not of GluR1, was significantly decreased in the neurons transfected with the Tmub1/HOPS-RNAi and increased in the neurons overexpressing EGFP-Tmub1/HOPS. The altered surface expression of GluR2 was speculated to be due to the altered surface-recycling of the internalized GluR2 in our recycling assay. Eventually, we found that GluR2 and glutamate receptor interacting protein (GRIP were coimmunoprecipitated by the anti-Tmub1/HOPS antibody from the mouse brain. Taken together, these observations show that the Tmub1/HOPS plays a role in regulating basal synaptic transmission; it contributes to maintain the synaptic surface number of the GluR2-containing AMPARs by facilitating the recycling of GluR2 to the plasma membrane.

  1. α-Helical element at the hormone-binding surface of the insulin receptor functions as a signaling element to activate its tyrosine kinase.

    Science.gov (United States)

    Whittaker, Jonathan; Whittaker, Linda J; Roberts, Charles T; Phillips, Nelson B; Ismail-Beigi, Faramarz; Lawrence, Michael C; Weiss, Michael A

    2012-07-10

    The primary hormone-binding surface of the insulin receptor spans one face of the N-terminal β-helix of the α-subunit (the L1 domain) and an α-helix in its C-terminal segment (αCT). Crystallographic analysis of the free ectodomain has defined a contiguous dimer-related motif in which the αCT α-helix packs against L1 β-strands 2 and 3. To relate structure to function, we exploited expanded genetic-code technology to insert photo-activatable probes at key sites in L1 and αCT. The pattern of αCT-mediated photo-cross-linking within the free and bound receptor is in accord with the crystal structure and prior mutagenesis. Surprisingly, L1 photo-probes in β-strands 2 and 3, predicted to be shielded by αCT, efficiently cross-link to insulin. Furthermore, anomalous mutations were identified on neighboring surfaces of αCT and insulin that impair hormone-dependent activation of the intracellular receptor tyrosine kinase (contained within the transmembrane β-subunit) disproportionately to their effects on insulin binding. Taken together, these results suggest that αCT, in addition to its hormone-recognition role, provides a signaling element in the mechanism of receptor activation.

  2. Human IgG1 Responses to Surface Localised Schistosoma mansoni Ly6 Family Members Drop following Praziquantel Treatment.

    Directory of Open Access Journals (Sweden)

    Iain W Chalmers

    Full Text Available The heptalaminate-covered, syncytial tegument is an important anatomical adaptation that enables schistosome parasites to maintain long-term, intravascular residence in definitive hosts. Investigation of the proteins present in this surface layer and the immune responses elicited by them during infection is crucial to our understanding of host/parasite interactions. Recent studies have revealed a number of novel tegumental surface proteins including three (SmCD59a, SmCD59b and Sm29 containing uPAR/Ly6 domains (renamed SmLy6A SmLy6B and SmLy6D in this study. While vaccination with SmLy6A (SmCD59a and SmLy6D (Sm29 induces protective immunity in experimental models, human immunoglobulin responses to representative SmLy6 family members have yet to be thoroughly explored.Using a PSI-BLAST-based search, we present a comprehensive reanalysis of the Schistosoma mansoni Ly6 family (SmLy6A-K. Our examination extends the number of members to eleven (including three novel proteins and provides strong evidence that the previously identified vaccine candidate Sm29 (renamed SmLy6D is a unique double uPAR/Ly6 domain-containing representative. Presence of canonical cysteine residues, signal peptides and GPI-anchor sites strongly suggest that all SmLy6 proteins are cell surface-bound. To provide evidence that SmLy6 members are immunogenic in human populations, we report IgG1 (as well as IgG4 and IgE responses against two surface-bound representatives (SmLy6A and SmLy6B within a cohort of S. mansoni-infected Ugandan males before and after praziquantel treatment. While pre-treatment IgG1 prevalence for SmLy6A and SmLy6B differs amongst the studied population (7.4% and 25.3% of the cohort, respectively, these values are both higher than IgG1 prevalence (2.7% for a sub-surface tegumental antigen, SmTAL1. Further, post-treatment IgG1 levels against surface-associated SmLy6A and SmLy6B significantly drop (p = 0.020 and p < 0.001, respectively when compared to rising Ig

  3. Family and population-based studies of variation within the ghrelin receptor locus in relation to measures of obesity

    DEFF Research Database (Denmark)

    Gjesing, Anette P.; Larsen, Lesli Hingstrup; Torekov, Signe Sørensen

    2010-01-01

    -carriers (mean BMI: 28+/-5 kg/m(2)) (p>0.05) could be shown. CONCLUSIONS/SIGNIFICANCE: In a population-based study sample of 15,854 Danes no association between GHSR genotypes and measures of obesity and overweight was found. Also, analyses of GHSR haplotypes lack consistent associations with obesity related......BACKGROUND: The growth hormone secretagogue receptor (GHSR) is mediating hunger sensation when stimulated by its natural ligand ghrelin. In the present study, we tested the hypothesis that common and rare variation in the GHSR locus are related to increased prevalence of obesity and overweight...... among Whites. METHODOLOGY/PRINCIPAL FINDINGS: In a population-based study sample of 15,854 unrelated, middle-aged Danes, seven variants were genotyped to capture common variation in an 11 kbp region including GHSR. These were investigated for their individual and haplotypic association with obesity...

  4. Expression of AmGR10 of the Gustatory Receptor Family in Honey Bee Is Correlated with Nursing Behavior.

    Science.gov (United States)

    Paerhati, Yisilahaiti; Ishiguro, Shinichi; Ueda-Matsuo, Risa; Yang, Ping; Yamashita, Tetsuro; Ito, Kikukatsu; Maekawa, Hideaki; Tani, Hiroko; Suzuki, Koichi

    2015-01-01

    We investigated the association between the expression of a gene encoding gustatory receptor (G10) and division of labor in the honey bee, Apis mellifera. Among 10 GR genes encoding proteins 15% ~ 99% amino acid identity in the honey bee, we found that AmGR10 with 99% identity is involved in nursing or brood care. Expression of AmGR10 was restricted to organs of the hypopharyngeal gland, brain, and ovary in the nurse bee phase. Members of an extended nursing caste under natural conditions continued to express this gene. RNAi knockdown of AmGR10 accelerated the transition to foraging. Our findings demonstrate that this one gene has profound effects on the division of labor associated with the development and physiology of honeybee society.

  5. Receptor protein tyrosine phosphatase alpha activates Src-family kinases and controls integrin-mediated responses in fibroblasts

    DEFF Research Database (Denmark)

    Su, J; Muranjan, M; Sap, J

    1999-01-01

    of tyrosine kinases, the activity of which is tightly controlled by inhibitory phosphorylation of a carboxyterminal tyrosine residue (Tyr527 in chicken c-Src); this phosphorylation induces the kinases to form an inactive conformation. Whereas the identity of such inhibitory Tyr527 kinases has been well...... established, no corresponding phosphatases have been identified that, under physiological conditions, function as positive regulators of c-Src and Fyn in fibroblasts. RESULTS: Receptor protein tyrosine phosphatase alpha (RPTPalpha) was inactivated by homologous recombination. Fibroblasts derived from...... these RPTPalpha-/- mice had impaired tyrosine kinase activity of both c-Src and Fyn, and this was accompanied by a concomitant increase in c-Src Tyr527 phosphorylation. RPTPalpha-/- fibroblasts also showed a reduction in the rate of spreading on fibronectin substrates, a trait that is a phenocopy of the effect...

  6. ngs (notochord granular surface) gene encodes a novel type of intermediate filament family protein essential for notochord maintenance in zebrafish.

    Science.gov (United States)

    Tong, Xiangjun; Xia, Zhidan; Zu, Yao; Telfer, Helena; Hu, Jing; Yu, Jingyi; Liu, Huan; Zhang, Quan; Sodmergen; Lin, Shuo; Zhang, Bo

    2013-01-25

    The notochord is an important organ involved in embryonic patterning and locomotion. In zebrafish, the mature notochord consists of a single stack of fully differentiated, large vacuolated cells called chordocytes, surrounded by a single layer of less differentiated notochordal epithelial cells called chordoblasts. Through genetic analysis of zebrafish lines carrying pseudo-typed retroviral insertions, a mutant exhibiting a defective notochord with a granular appearance was isolated, and the corresponding gene was identified as ngs (notochord granular surface), which was specifically expressed in the notochord. In the mutants, the notochord started to degenerate from 32 hours post-fertilization, and the chordocytes were then gradually replaced by smaller cells derived from chordoblasts. The granular notochord phenotype was alleviated by anesthetizing the mutant embryos with tricaine to prevent muscle contraction and locomotion. Phylogenetic analysis showed that ngs encodes a new type of intermediate filament (IF) family protein, which we named chordostatin based on its function. Under the transmission electron microcopy, bundles of 10-nm-thick IF-like filaments were enriched in the chordocytes of wild-type zebrafish embryos, whereas the chordocytes in ngs mutants lacked IF-like structures. Furthermore, chordostatin-enhanced GFP (EGFP) fusion protein assembled into a filamentous network specifically in chordocytes. Taken together, our work demonstrates that ngs encodes a novel type of IF protein and functions to maintain notochord integrity for larval development and locomotion. Our work sheds light on the mechanisms of notochord structural maintenance, as well as the evolution and biological function of IF family proteins.

  7. The dopamine receptor D4 gene and familial loading interact with perceived parenting in predicting externalizing behavior problems in early adolescence: the TRacking Adolescents' Individual Lives Survey (TRAILS).

    Science.gov (United States)

    Marsman, Rianne; Oldehinkel, Albertine J; Ormel, Johan; Buitelaar, Jan K

    2013-08-30

    Although externalizing behavior problems show in general a high stability over time, the course of externalizing behavior problems may vary from individual to individual. Our main goal was to investigate the predictive role of parenting on externalizing behavior problems. In addition, we investigated the potential moderating role of gender and genetic risk (operationalized as familial loading of externalizing behavior problems (FLE), and presence or absence of the dopamine receptor D4 (DRD4) 7-repeat and 4-repeat allele, respectively). Perceived parenting (rejection, emotional warmth, and overprotection) and FLE were assessed in a population-based sample of 1768 10- to 12-year-old adolescents. Externalizing behavior problems were assessed at the same age and 212 years later by parent report (CBCL) and self-report (YSR). DNA was extracted from blood samples. Parental emotional warmth predicted lower, and parental overprotection and rejection predicted higher levels of externalizing behavior problems. Whereas none of the parenting factors interacted with gender and the DRD4 7-repeat allele, we did find interaction effects with FLE and the DRD4 4-repeat allele. That is, the predictive effect of parental rejection was only observed in adolescents from low FLE families and the predictive effect of parental overprotection was stronger in adolescents not carrying the DRD4 4-repeat allele. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  8. The Role of Quinine-Responsive Taste Receptor Family 2 in Airway Immune Defense and Chronic Rhinosinusitis

    Directory of Open Access Journals (Sweden)

    Alan D. Workman

    2018-03-01

    Full Text Available BackgroundBitter (T2R and sweet (T1R taste receptors in the airway are important in innate immune defense, and variations in taste receptor functionality in one T2R (T2R38 correlate with disease status and disease severity in chronic rhinosinusitis (CRS. Quinine is a bitter compound that is an agonist for several T2Rs also expressed on sinonasal cells, but not for T2R38. Because of this property, quinine may stimulate innate immune defense mechanisms in the airway, and functional differences in quinine perception may be reflective of disease status in CRS.MethodsDemographic and taste intensity data were collected prospectively from CRS patients and non-CRS control subjects. Sinonasal tissue from patients undergoing rhinologic surgery was also collected and grown at an air–liquid interface (ALI. Nitric oxide (NO production and dynamic regulation of ciliary beat frequency in response to quinine stimulation were assessed in vitro.ResultsQuinine reliably increased ciliary beat frequency and NO production in ALI cultures in a manner consistent with T2R activation (p < 0.01. Quinine taste intensity rating was performed in 328 CRS patients and 287 control subjects demonstrating that CRS with nasal polyps (CRSwNP patients rated quinine as significantly less intense than did control subjects.ConclusionQuinine stimulates airway innate immune defenses by increasing ciliary beat frequency and stimulating NO production in a manner fitting with T2R activation. Patient variability in quinine sensitivity is observed in taste intensity ratings, and gustatory quinine “insensitivity” is associated with CRSwNP status. Thus, taste tests for quinine may be a biomarker for CRSwNP, and topical quinine has therapeutic potential as a stimulant of innate defenses.

  9. Novel role of cold/menthol-sensitive transient receptor potential melastatine family member 8 (TRPM8) in the activation of store-operated channels in LNCaP human prostate cancer epithelial cells.

    NARCIS (Netherlands)

    Thebault, S.C.; Lemonnier, L.; Bidaux, G.; Flourakis, M.; Bavencoffe, A.; Gordienko, D.; Roudbaraki, M.; Delcourt, P.; Panchin, Y.; Shuba, Y.; Skryma, R.; Prevarskaya, N.

    2005-01-01

    Recent cloning of a cold/menthol-sensitive TRPM8 channel (transient receptor potential melastatine family member 8) from rodent sensory neurons has provided the molecular basis for the cold sensation. Surprisingly, the human orthologue of rodent TRPM8 also appears to be strongly expressed in the

  10. Cloning and characterization of R-PTP-kappa, a new member of the receptor protein tyrosine phosphatase family with a proteolytically cleaved cellular adhesion molecule-like extracellular region

    DEFF Research Database (Denmark)

    Jiang, Y P; Wang, H; D'Eustachio, P

    1993-01-01

    We describe a new member of the receptor protein tyrosine phosphatase family, R-PTP-kappa, cDNA cloning predicts that R-PTP-kappa is synthesized from a precursor protein of 1,457 amino acids. Its intracellular domain displays the classical tandemly repeated protein tyrosine phosphatase homology, ...

  11. Lactobacillus reuteri Surface Mucus Adhesins Upregulate Inflammatory Responses Through Interactions With Innate C-Type Lectin Receptors.

    Science.gov (United States)

    Bene, Krisztián P; Kavanaugh, Devon W; Leclaire, Charlotte; Gunning, Allan P; MacKenzie, Donald A; Wittmann, Alexandra; Young, Ian D; Kawasaki, Norihito; Rajnavolgyi, Eva; Juge, Nathalie

    2017-01-01

    The vertebrate gut symbiont Lactobacillus reuteri exhibits strain-specific adhesion and health-promoting properties. Here, we investigated the role of the mucus adhesins, CmbA and MUB, upon interaction of L. reuteri ATCC PTA 6475 and ATCC 53608 strains with human monocyte-derived dendritic cells (moDCs). We showed that mucus adhesins increased the capacity of L. reuteri strains to interact with moDCs and promoted phagocytosis. Our data also indicated that mucus adhesins mediate anti- and pro-inflammatory effects by the induction of interleukin-10 (IL-10), tumor necrosis factor alpha (TNF-α), IL-1β, IL-6, and IL-12 cytokines. L. reuteri ATCC PTA 6475 and ATCC 53608 were exclusively able to induce moDC-mediated Th1 and Th17 immune responses. We further showed that purified MUB activates moDCs and induces Th1 polarized immune responses associated with increased IFNγ production. MUB appeared to mediate these effects via binding to C-type lectin receptors (CLRs), as shown using cell reporter assays. Blocking moDCs with antibodies against DC-specific intercellular adhesion molecule 3-grabbing non-integrin (DC-SIGN) or Dectin-2 did not affect the uptake of the MUB-expressing strain, but reduced the production of TNF-α and IL-6 by moDCs significantly, in line with the Th1 polarizing capacity of moDCs. The direct interaction between MUB and CLRs was further confirmed by atomic force spectroscopy. Taken together these data suggest that mucus adhesins expressed at the cell surface of L. reuteri strains may exert immunoregulatory effects in the gut through modulating the Th1-promoting capacity of DCs upon interaction with C-type lectins.

  12. Lack of concordance and linkage disequilibrium among brothers for androgenetic alopecia and CAG/GGC haplotypes of the androgen receptor gene in Mexican families.

    Science.gov (United States)

    Arteaga-Vázquez, Jazmín; López-Hernández, María A; Svyryd, Yevgeniya; Mutchinick, Osvaldo M

    2015-12-01

    Androgenetic alopecia (AGA) or common baldness is the most prevalent form of hair loss in males. Familial predisposition has been recognized, and heritability estimated in monozygotic twins suggests an important genetic predisposition. Several studies indicate that the numbers of CAG/GGC repeats in exon 1 of the androgen receptor gene (AR) maybe associated with AGA susceptibility. To investigate a possible correlation between AR CAG/GGC haplotypes and the presence or not of alopecia in sibships with two or more brothers among them at least one of them has AGA. Thirty-two trios including an alopecic man, one brother alopecic or not, and their mother were enrolled. Sanger sequencing of the exon 1 of the AR gene was conducted to ascertain the number of CAG/GGC repeats in each individual. Heterozygous mother for the CAG/GGC haplotypes was an inclusion criterion to analyze the segregation haplotype patterns in the family. Concordance for the number of repeats and AGA among brothers was evaluated using kappa coefficient and the probability of association in the presence of genetic linkage between CAG and GGC repeats and AGA estimated by means of the family-based association test (FBAT). The median for the CAG and GGC repeats in the AR is similar to that reported in other populations. The CAG/GGC haplotypes were less polymorphic than that reported in other studies, especially due to the GGC number of repeats found. Kappa coefficient resulted in a concordance of 37.3% (IC 95%, 5.0-69.0%) for the AGA phenotype and identical CAG/GGC haplotypes. There was no evidence of linkage disequilibrium. Our results do not confirm a possible correlation or linkage disequilibrium between the CAG/GGC haplotypes of the AR gene and androgenetic alopecia in Mexican brothers. © 2015 Wiley Periodicals, Inc.

  13. Urocortin II: A member of the corticotropin-releasing factor (CRF) neuropeptide family that is selectively bound by type 2 CRF receptors

    Science.gov (United States)

    Reyes, T. M.; Lewis, K.; Perrin, M. H.; Kunitake, K. S.; Vaughan, J.; Arias, C. A.; Hogenesch, J. B.; Gulyas, J.; Rivier, J.; Vale, W. W.; Sawchenko, P. E.

    2001-01-01

    Here we describe the cloning and initial characterization of a previously unidentified CRF-related neuropeptide, urocortin II (Ucn II). Searches of the public human genome database identified a region with significant sequence homology to the CRF neuropeptide family. By using homologous primers deduced from the human sequence, a mouse cDNA was isolated from whole brain poly(A)+ RNA that encodes a predicted 38-aa peptide, structurally related to the other known mammalian family members, CRF and Ucn. Ucn II binds selectively to the type 2 CRF receptor (CRF-R2), with no appreciable activity on CRF-R1. Transcripts encoding Ucn II are expressed in discrete regions of the rodent central nervous system, including stress-related cell groups in the hypothalamus (paraventricular and arcuate nuclei) and brainstem (locus coeruleus). Central administration of 1–10 μg of peptide elicits activational responses (Fos induction) preferentially within a core circuitry subserving autonomic and neuroendocrine regulation, but whose overall pattern does not broadly mimic the CRF-R2 distribution. Behaviorally, central Ucn II attenuates nighttime feeding, with a time course distinct from that seen in response to CRF. In contrast to CRF, however, central Ucn II failed to increase gross motor activity. These findings identify Ucn II as a new member of the CRF family of neuropeptides, which is expressed centrally and binds selectively to CRF-R2. Initial functional studies are consistent with Ucn II involvement in central autonomic and appetitive control, but not in generalized behavioral activation. PMID:11226328

  14. Cooperative ethylene receptor signaling

    OpenAIRE

    Liu, Qian; Wen, Chi-Kuang

    2012-01-01

    The gaseous plant hormone ethylene is perceived by a family of five ethylene receptor members in the dicotyledonous model plant Arabidopsis. Genetic and biochemical studies suggest that the ethylene response is suppressed by ethylene receptor complexes, but the biochemical nature of the receptor signal is unknown. Without appropriate biochemical measures to trace the ethylene receptor signal and quantify the signal strength, the biological significance of the modulation of ethylene responses ...

  15. Activation of protein kinase A and clustering of cell surface receptors by N-methyl-N'-nitro-N-nitrosoguanidine are independent of genomic DNA damage

    Energy Technology Data Exchange (ETDEWEB)

    Wang Zheng; Wang Guliang; Yang Jun; Guo Lei; Yu Yingnian

    2003-07-25

    Alkylating agent N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) induces cellular stress leading to chromosomal aberrations, mutations and cell death. Previous reports from our laboratory have shown that low concentration of MNNG induces untargeted mutation (UTM), which occurs on intact DNA in mammalian cells through changes in gene expression profile. It also causes the activation of cAMP-protein kinase A (PKA) and up-regulation of POL-{beta}, which is demonstrated to play a role in DNA repair system. In order to find out the possible initial signal involved in UTM, we try to investigate whether the activation of PKA-CREB signal pathway is closely related to DNA damage. Our data shows that the treatment of low concentration MNNG (0.2 {mu}M) activates PKA-CREB pathway in a comparable level both in a nuclear and enucleated cell system. And similar to the cell response caused by UV, the clustering of cell surface receptors of epidermal growth factor (EGF) and tumor necrosis factor {alpha} (TNF{alpha}) was also observed in cells exposed to MNNG. It was further demonstrated that the clustering of the surface receptors is independent of the genomic DNA damage, as this phenomenon was also observed in enucleated cells. These observations indicate that the initiation of signal cascades induced by low concentration of MNNG might be associated with its interaction with cell surface receptors and/or direct activation of related signal proteins but not its DNA damaging property.

  16. Panel of monoclonal antibodies to sperm surface proteins as a tool for monitoring localization and identification of sperm-zona pellucida receptors

    Czech Academy of Sciences Publication Activity Database

    Zigo, Michal; Dorosh, Andriy; Pohlová, Alžběta; Jonáková, Věra; Šulc, Miroslav; Maňásková-Postlerová, Pavla

    March, č. 359 (2015), s. 895-908 ISSN 0302-766X R&D Projects: GA ČR(CZ) GA14-05547S; GA MŠk(CZ) ED1.1.00/02.0109; GA ČR(CZ) GAP503/12/1834 Institutional research plan: CEZ:AV0Z50520701 Institutional support: RVO:86652036 ; RVO:61388971 Keywords : zona pellucida-binding receptors * monoclonal antibodies against sperm surface proteins * sperm surface proteins * RAB-2A * lactahedrin P47 Subject RIV: CE - Biochemistry Impact factor: 2.948, year: 2015

  17. ERECTA-family receptor kinase genes redundantly prevent premature progression of secondary growth in the Arabidopsis hypocotyl.

    Science.gov (United States)

    Ikematsu, Shuka; Tasaka, Masao; Torii, Keiko U; Uchida, Naoyuki

    2017-03-01

    Secondary growth is driven by continuous cell proliferation and differentiation of the cambium that acts as vascular stem cells, producing xylem and phloem to expand vascular tissues laterally. During secondary growth of hypocotyls in Arabidopsis thaliana, the xylem undergoes a drastic phase transition from a parenchyma-producing phase to a fiber-producing phase at the appropriate time. However, it remains to be fully elucidated how progression of secondary growth is properly controlled. We focused on phenotypes of hypocotyl vasculatures caused by double mutation in ERECTA (ER) and ER-LIKE1 (ERL1) receptor-kinase genes to elucidate their roles in secondary growth. ER and ERL1 redundantly suppressed excessive radial growth of the hypocotyl vasculature during secondary growth. ER and ERL1 also prevented premature initiation of the fiber differentiation process mediated by the NAC SECONDARY WALL THICKENING PROMOTING FACTORs in the hypocotyl xylem. Upon floral transition, the hypocotyl xylem gained a competency to respond to GA in a BREVIPEDICELLUS-dependent manner, which was a prerequisite for fiber differentiation. However, even after the floral transition, ER and ERL1 prevented precocious initiation of the GA-mediated fiber formation. Collectively, our findings reveal that ER and ERL1 redundantly prevent premature progression of sequential events in secondary growth. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

  18. Identification of a Novel Androgen Receptor Mutation in a Family With Multiple Components Compatible With the Testicular Dysgenesis Syndrome

    DEFF Research Database (Denmark)

    Lottrup, Grete; Jørgensen, Anne; Nielsen, John E.

    2013-01-01

    showed features consistent with insufficient testis development and TDS.Conclusion: The presence of all hallmarks of TDS, including germ cell cancer, in a family with a novel AR mutation causing a partial decrease in AR function is in line with the concept that reduced androgen signaling may contribute......, cryptorchidism, hypospadias, and testicular cancer, caused by a novel AR mutation.Objective: The aim of this study was to describe the phenotype of the affected males, characterize functionally the novel AR mutation, and discuss the significance of partial androgen insufficiency in the pathogenesis of TDS...... analysis of the mutation in a gene-reporter assay showed a 50% reduction in AR-induced transcriptional activity. The affected males had elevated LH and T in accordance with decreased AR signaling. The histology and immunohistochemical profile of the testis tissue from the 2 patients with testicular cancer...

  19. Plasma membrane cholesterol level and agonist-induced internalization of δ-opioid receptors; colocalization study with intracellular membrane markers of Rab family.

    Science.gov (United States)

    Brejchova, Jana; Vosahlikova, Miroslava; Roubalova, Lenka; Parenti, Marco; Mauri, Mario; Chernyavskiy, Oleksandr; Svoboda, Petr

    2016-08-01

    Decrease of cholesterol level in plasma membrane of living HEK293 cells transiently expressing FLAG-δ-OR by β-cyclodextrin (β-CDX) resulted in a slight internalization of δ-OR. Massive internalization of δ-OR induced by specific agonist DADLE was diminished in cholesterol-depleted cells. These results suggest that agonist-induced internalization of δ-OR, which has been traditionally attributed exclusively to clathrin-mediated pathway, proceeds at least partially via membrane domains. Identification of internalized pools of FLAG-δ-OR by colocalization studies with proteins of Rab family indicated the decreased presence of receptors in early endosomes (Rab5), late endosomes and lysosomes (Rab7) and fast recycling vesicles (Rab4). Slow type of recycling (Rab11) was unchanged by cholesterol depletion. As expected, agonist-induced internalization of oxytocin receptors was totally suppressed in β-CDX-treated cells. Determination of average fluorescence lifetime of TMA-DPH, the polar derivative of hydrophobic membrane probe diphenylhexatriene, in live cells by FLIM indicated a significant alteration of the overall PM structure which may be interpreted as an increased "water-accessible space" within PM area. Data obtained by studies of HEK293 cells transiently expressing FLAG-δ-OR by "antibody feeding" method were extended by analysis of the effect of cholesterol depletion on distribution of FLAG-δ-OR in sucrose density gradients prepared from HEK293 cells stably expressing FLAG-δ-OR. Major part of FLAG-δ-OR was co-localized with plasma membrane marker Na,K-ATPase and β-CDX treatment resulted in shift of PM fragments containing both FLAG-δ-OR and Na,K-ATPase to higher density. Thus, the decrease in content of the major lipid constituent of PM resulted in increased density of resulting PM fragments.

  20. Genome-wide characterization of Toll-like receptor gene family in common carp (Cyprinus carpio) and their involvement in host immune response to Aeromonas hydrophila infection.

    Science.gov (United States)

    Gong, Yiwen; Feng, Shuaisheng; Li, Shangqi; Zhang, Yan; Zhao, Zixia; Hu, Mou; Xu, Peng; Jiang, Yanliang

    2017-12-01

    The Toll-like receptor (TLR) gene family is a class of conserved pattern recognition receptors, which play an essential role in innate immunity providing efficient defense against invading microbial pathogens. Although TLRs have been extensively characterized in both invertebrates and vertebrates, a comprehensive analysis of TLRs in common carp is lacking. In the present study, we have conducted the first genome-wide systematic analysis of common carp (Cyprinus carpio) TLR genes. A set of 27 common carp TLR genes were identified and characterized. Sequence similarity analysis, functional domain prediction and phylogenetic analysis supported their annotation and orthologies. By examining the gene copy number of TLR genes across several vertebrates, gene duplications and losses were observed. The expression patterns of TLR genes were examined during early developmental stages and in various healthy tissues, and the results showed that TLR genes were ubiquitously expressed, indicating a likely role in maintaining homeostasis. Moreover, the differential expression of TLRs was examined after Aeromons hydrophila infection, and showed that most TLR genes were induced, with diverse patterns. TLR1, TLR4-2, TLR4-3, TLR22-2, TLR22-3 were significantly up-regulated at minimum one timepoint, whereas TLR2-1, TLR4-1, TLR7-1 and TLR7-2 were significantly down-regulated. Our results suggested that TLR genes play critical roles in the common carp immune response. Collectively, our findings provide fundamental genomic resources for future studies on fish disease management and disease-resistance selective breeding strategy development. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. The 10 sea urchin receptor for egg jelly proteins (SpREJ are members of the polycystic kidney disease-1 (PKD1 family

    Directory of Open Access Journals (Sweden)

    Miyata Shinji

    2007-07-01

    Full Text Available Abstract Background Mutations in the human polycystic kidney disease-1 (hPKD1 gene result in ~85% of cases of autosomal dominant polycystic kidney disease, the most frequent human monogenic disease. PKD1 proteins are large multidomain proteins involved in a variety of signal transduction mechanisms. Obtaining more information about members of the PKD1 family will help to clarify their functions. Humans have five hPKD1 proteins, whereas sea urchins have 10. The PKD1 proteins of the sea urchin, Strongylocentrotus purpuratus, are referred to as the Receptor for Egg Jelly, or SpREJ proteins. The SpREJ proteins form a subfamily within the PKD1 family. They frequently contain C-type lectin domains, PKD repeats, a REJ domain, a GPS domain, a PLAT/LH2 domain, 1–11 transmembrane segments and a C-terminal coiled-coil domain. Results The 10 full-length SpREJ cDNA sequences were determined. The secondary structures of their deduced proteins were predicted and compared to the five human hPKD1 proteins. The genomic structures of the 10 SpREJs show low similarity to each other. All 10 SpREJs are transcribed in either embryos or adult tissues. SpREJs show distinct patterns of expression during embryogenesis. Adult tissues show tissue-specific patterns of SpREJ expression. Conclusion Possession of a REJ domain of about 600 residues defines this family. Except for SpREJ1 and 3, that are thought to be associated with the sperm acrosome reaction, the functions of the other SpREJ proteins remain unknown. The sea urchin genome is one-fourth the size of the human genome, but sea urchins have 10 SpREJ proteins, whereas humans have five. Determination of the tissue specific function of each of these proteins will be of interest to those studying echinoderm development. Sea urchins are basal deuterostomes, the line of evolution leading to the vertebrates. The study of individual PKD1 proteins will increase our knowledge of the importance of this gene family.

  2. ngs (Notochord Granular Surface) Gene Encodes a Novel Type of Intermediate Filament Family Protein Essential for Notochord Maintenance in Zebrafish*

    Science.gov (United States)

    Tong, Xiangjun; Xia, Zhidan; Zu, Yao; Telfer, Helena; Hu, Jing; Yu, Jingyi; Liu, Huan; Zhang, Quan; Sodmergen; Lin, Shuo; Zhang, Bo

    2013-01-01

    The notochord is an important organ involved in embryonic patterning and locomotion. In zebrafish, the mature notochord consists of a single stack of fully differentiated, large vacuolated cells called chordocytes, surrounded by a single layer of less differentiated notochordal epithelial cells called chordoblasts. Through genetic analysis of zebrafish lines carrying pseudo-typed retroviral insertions, a mutant exhibiting a defective notochord with a granular appearance was isolated, and the corresponding gene was identified as ngs (notochord granular surface), which was specifically expressed in the notochord. In the mutants, the notochord started to degenerate from 32 hours post-fertilization, and the chordocytes were then gradually replaced by smaller cells derived from chordoblasts. The granular notochord phenotype was alleviated by anesthetizing the mutant embryos with tricaine to prevent muscle contraction and locomotion. Phylogenetic analysis showed that ngs encodes a new type of intermediate filament (IF) family protein, which we named chordostatin based on its function. Under the transmission electron microcopy, bundles of 10-nm-thick IF-like filaments were enriched in the chordocytes of wild-type zebrafish embryos, whereas the chordocytes in ngs mutants lacked IF-like structures. Furthermore, chordostatin-enhanced GFP (EGFP) fusion protein assembled into a filamentous network specifically in chordocytes. Taken together, our work demonstrates that ngs encodes a novel type of IF protein and functions to maintain notochord integrity for larval development and locomotion. Our work sheds light on the mechanisms of notochord structural maintenance, as well as the evolution and biological function of IF family proteins. PMID:23132861

  3. A novel mutation in the endothelin B receptor gene in a moroccan family with shah-waardenburg syndrome.

    Science.gov (United States)

    Doubaj, Yassamine; Pingault, Véronique; Elalaoui, Siham C; Ratbi, Ilham; Azouz, Mohamed; Zerhouni, Hicham; Ettayebi, Fouad; Sefiani, Abdelaziz

    2015-02-01

    Waardenburg syndrome (WS) is a neurocristopathy disorder combining sensorineural deafness and pigmentary abnormalities. The presence of additional signs defines the 4 subtypes. WS type IV, also called Shah-Waardenburg syndrome (SWS), is characterized by the association with congenital aganglionic megacolon (Hirschsprung disease). To date, 3 causative genes have been related to this congenital disorder. Mutations in the EDNRB and EDN3 genes are responsible for the autosomal recessive form of SWS, whereas SOX10 mutations are inherited in an autosomal dominant manner. We report here the case of a 3-month-old Morrocan girl with WS type IV, born to consanguineous parents. The patient had 3 cousins who died in infancy with the same symptoms. Molecular analysis by Sanger sequencing revealed the presence of a novel homozygous missense mutation c.1133A>G (p.Asn378Ser) in the EDNRB gene. The proband's parents as well as the parents of the deceased cousins are heterozygous carriers of this likely pathogenic mutation. This molecular diagnosis allows us to provide genetic counseling to the family and eventually propose prenatal diagnosis to prevent recurrence of the disease in subsequent pregnancies.

  4. The Virtual Family-development of surface-based anatomical models of two adults and two children for dosimetric simulations

    Energy Technology Data Exchange (ETDEWEB)

    Christ, Andreas; Honegger, Katharina; Zefferer, Marcel; Neufeld, Esra; Oberle, Michael; Szczerba, Dominik; Kuster, Niels [Foundation for Research on Information Technologies in Society (IT' IS), Zeughausstr. 43, 8004 Zuerich (Switzerland); Kainz, Wolfgang; Guag, Joshua W [US Food and Drug Administration (FDA), Center for Devices and Radiological Health (CDRH), Silver Spring, MD 20993 (United States); Hahn, Eckhart G; Rascher, Wolfgang; Janka, Rolf; Bautz, Werner [Universitaetsklinikum Erlangen, Friedrich-Alexander Universitaet Erlangen-Nuernberg, 91054 Erlangen (Germany); Chen, Ji; Shen, Jianxiang [Department of Electrical and Computer Engineering, The University of Houston, Houston, TX 77204 (United States); Kiefer, Berthold; Schmitt, Peter; Hollenbach, Hans-Peter [Siemens Healthcare, MR-Application Development, 91052 Erlangen (Germany); Kam, Anthony [Department of Imaging, Johns Hopkins Bayview Medical Center, Baltimore, MD 21224 (United States)], E-mail: christ@itis.ethz.ch

    2010-01-21

    The objective of this study was to develop anatomically correct whole body human models of an adult male (34 years old), an adult female (26 years old) and two children (an 11-year-old girl and a six-year-old boy) for the optimized evaluation of electromagnetic exposure. These four models are referred to as the Virtual Family. They are based on high resolution magnetic resonance (MR) images of healthy volunteers. More than 80 different tissue types were distinguished during the segmentation. To improve the accuracy and the effectiveness of the segmentation, a novel semi-automated tool was used to analyze and segment the data. All tissues and organs were reconstructed as three-dimensional (3D) unstructured triangulated surface objects, yielding high precision images of individual features of the body. This greatly enhances the meshing flexibility and the accuracy with respect to thin tissue layers and small organs in comparison with the traditional voxel-based representation of anatomical models. Conformal computational techniques were also applied. The techniques and tools developed in this study can be used to more effectively develop future models and further improve the accuracy of the models for various applications. For research purposes, the four models are provided for free to the scientific community. (note)

  5. The Virtual Family-development of surface-based anatomical models of two adults and two children for dosimetric simulations

    International Nuclear Information System (INIS)

    Christ, Andreas; Honegger, Katharina; Zefferer, Marcel; Neufeld, Esra; Oberle, Michael; Szczerba, Dominik; Kuster, Niels; Kainz, Wolfgang; Guag, Joshua W; Hahn, Eckhart G; Rascher, Wolfgang; Janka, Rolf; Bautz, Werner; Chen, Ji; Shen, Jianxiang; Kiefer, Berthold; Schmitt, Peter; Hollenbach, Hans-Peter; Kam, Anthony

    2010-01-01

    The objective of this study was to develop anatomically correct whole body human models of an adult male (34 years old), an adult female (26 years old) and two children (an 11-year-old girl and a six-year-old boy) for the optimized evaluation of electromagnetic exposure. These four models are referred to as the Virtual Family. They are based on high resolution magnetic resonance (MR) images of healthy volunteers. More than 80 different tissue types were distinguished during the segmentation. To improve the accuracy and the effectiveness of the segmentation, a novel semi-automated tool was used to analyze and segment the data. All tissues and organs were reconstructed as three-dimensional (3D) unstructured triangulated surface objects, yielding high precision images of individual features of the body. This greatly enhances the meshing flexibility and the accuracy with respect to thin tissue layers and small organs in comparison with the traditional voxel-based representation of anatomical models. Conformal computational techniques were also applied. The techniques and tools developed in this study can be used to more effectively develop future models and further improve the accuracy of the models for various applications. For research purposes, the four models are provided for free to the scientific community. (note)

  6. Effect of angiotensin II type I receptor A1166C polymorphism on benazepril action in hypertensive patients: a family-based association test study.

    Science.gov (United States)

    Zhang, Ning; Cui, Huadong; Yang, Lili

    2012-10-01

    Few studies have examined the effect of the angiotensin II type I receptor (AT1R) A1166C polymorphism on the antihypertensive effect of the angiotensin-converting-enzyme inhibitor benazepril in patients with hypertension, and no such studies have performed analysis using the Family-Based Association Test (FBAT), The aim of our study was to examine the association between AT1R A1166C gene polymorphism and the antihypertensive effect of benazepril using the FBAT. A total of 864 patients (aged, 26-62 years) with essential hypertension were identified in an epidemiological survey and enrolled in this study. Blood pressure (BP) was measured before and after 16 days of treatment with benazepril (10 mg/day). The association between the A1166C gene polymorphism and the antihypertensive effect of benazepril was assessed by FBAT. The frequencies of alleles A and C were 95.1% and 4.9%, respectively. FBAT analysis revealed that the C allele was significantly associated with high baseline diastolic BP (Z = 2.041, p = 0.041), decreased systolic BP after treatment (Z = 2.549, p = 0.011), and decreased diastolic BP after treatment (Z = 2.320, p = 0.020). Our results, determined using the FBAT, are the first evidence that the AT1R A1166C polymorphism may increase the antihypertensive effect of benazepril in patients with hypertension.

  7. Increased expression of endosomal members of toll-like receptor family abrogates wound healing in patients with type 2 diabetes mellitus.

    Science.gov (United States)

    Singh, Kanhaiya; Agrawal, Neeraj K; Gupta, Sanjeev K; Mohan, Gyanendra; Chaturvedi, Sunanda; Singh, Kiran

    2016-10-01

    The inflammatory phase of wound healing cascade is an important determinant of the fate of the wound. Acute inflammation is necessary to initiate proper wound healing, while chronic inflammation abrogates wound healing. Different endosomal members of toll-like receptor (TLR) family initiate inflammatory signalling via a range of different inflammatory mediators such as interferons, internal tissue damaged-associated molecular patterns (DAMPs) and hyperactive effector T cells. Sustained signalling of TLR9 and TLR7 contributes to chronic inflammation by activating the plasmacytoid dendritic cells. Diabetic wounds are also characterised by sustained inflammatory phase. The objective of this study was to analyse the differential expression of endosomal TLRs in human diabetic wounds compared with control wounds. We analysed the differential expression of TLR7 and TLR9 both at transcriptional and translational levels in wounds of 84 patients with type 2 diabetes mellitus (T2DM) and 6 control subjects without diabetes using quantitative real-time polymerase chain reaction (RT-PCR), western blot and immunohistochemistry. TLR7 and TLR9 were significantly up-regulated in wounds of the patients with T2DM compared with the controls and were dependent on the infection status of the diabetic wounds, and wounds with microbial infection exhibited lower expression levels of endosomal TLRs. Altered endosomal TLR expression in T2DM subjects might be associated with wound healing impairment. © 2015 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

  8. Identification of an estrogen receptor α non covalent ubiquitin-binding surface: role in 17β-estradiol-induced transcriptional activity.

    Science.gov (United States)

    Pesiri, Valeria; La Rosa, Piergiorgio; Stano, Pasquale; Acconcia, Filippo

    2013-06-15

    Ubiquitin (Ub)-binding domains (UBDs) located in Ub receptors decode the ubiquitination signal by non-covalently engaging the Ub modification on their binding partners and transduce the Ub signalling through Ub-based molecular interactions. In this way, inducible protein ubiquitination regulates diverse biological processes. The estrogen receptor alpha (ERα) is a ligand-activated transcription factor that mediates the pleiotropic effects of the sex hormone 17β-estradiol (E2). Fine regulation of E2 pleiotropic actions depends on E2-dependent ERα association with a plethora of binding partners and/or on the E2 modulation of receptor ubiquitination. Indeed, E2-induced ERα polyubiquitination triggers receptor degradation and transcriptional activity, and E2-dependent reduction in ERα monoubiquitination is crucial for E2 signalling. Monoubiquitinated proteins often contain UBDs, but whether non-covalent Ub-ERα binding could occur and play a role in E2-ERα signalling is unknown. Here, we report an Ub-binding surface within the ERα ligand binding domain that directs in vitro the receptor interaction with both ubiquitinated proteins and recombinant Ub chains. Mutational analysis reveals that ERα residues leucine 429 and alanine 430 are involved in Ub binding. Moreover, impairment of ERα association to ubiquitinated species strongly affects E2-induced ERα transcriptional activity. Considering the importance of UBDs in the Ub-based signalling network and the central role of different ERα binding partners in the modulation of E2-dependent effects, our discoveries provide novel insights into ERα activity that could also be relevant for ERα-dependent diseases.

  9. Nonconserved tryptophan 38 of the cell surface receptor for subgroup J avian leukosis virus discriminates sensitive from resistant avian species

    Czech Academy of Sciences Publication Activity Database

    Kučerová, Dana; Plachý, Jiří; Reinišová, Markéta; Šenigl, Filip; Trejbalová, Kateřina; Geryk, Josef; Hejnar, Jiří

    2013-01-01

    Roč. 87, č. 15 (2013), s. 8399-8407 ISSN 0022-538X R&D Projects: GA ČR GAP502/10/1651 Institutional support: RVO:68378050 Keywords : avian leukosis virus * ALV-J * NHE1 * host resistance * receptor Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.648, year: 2013

  10. ALTERED EXPRESSION OF SURFACE RECEPTORS AT EA.HY926 ENDOTHELIAL CELL LINE INDUCED WITH PLACENTAL SECRETORY FACTORS

    Directory of Open Access Journals (Sweden)

    O. I. Stepanova

    2012-01-01

    Full Text Available Abstract. Placental cell populations produce a great variety of angiogenic factors and cytokines than control angiogenesis in placenta. Functional regulation of endothelial cells proceeds via modulation of endothelial cell receptors for endogenous angiogenic and apoptotic signals. Endothelial phenotype alteration during normal pregnancy and in cases of preclampsia is not well understood. The goal of this investigation was to evaluate altered expression of angiogenic and cytokine receptors at EA.hy926 endothelial cells under the influence of placental tissue supernatants. Normal placental tissue supernatants from 1st and 3rd trimesters, and pre-eclamptic placental tissue supernatants (3rd trimester stimulated angiogenic and cytokine receptors expression by the cultured endothelial cells, as compared with their background expression. Tissue supernatants from placental samples of 3rd trimester caused a decreased expression of angiogenic and cytokine receptors by endothelial cells, thus reflecting maturation of placental vascular system at these terms. Supernatants from preeclamptic placental tissue induced an increase of CD119 expression, in comparison with normal placental supernatants from the 3rd trimester. This finding suggests that IFNγ may be a factor of endothelial activation in pre-eclampsia. The study was supported by grants ГК №02.740.11.0711, НШ-3594.2010.7., and МД-150.2011.7.

  11. Human cytomegalovirus chemokine receptor US28 induces migration of cells on a CX3CL1-presenting surface

    DEFF Research Database (Denmark)

    Hjortø, Gertrud M; Kiilerich-Pedersen, Katrine; Selmeczi, David

    2013-01-01

    Human cytomegalovirus (HCMV)-encoded G protein-coupled-receptor US28 is believed to participate in virus dissemination through modulation of cell migration and immune evasion. US28 binds different CC chemokines and the CX3C chemokine CX3CL1. Membrane-anchored CX3CL1 is expressed by immune-activat...

  12. Propranolol decreases retention of fear memory by modulating the stability of surface glutamate receptor GluA1 subunits in the lateral amygdala.

    Science.gov (United States)

    Zhou, Jun; Luo, Yi; Zhang, Jie-Ting; Li, Ming-Xing; Wang, Can-Ming; Guan, Xin-Lei; Wu, Peng-Fei; Hu, Zhuang-Li; Jin, You; Ni, Lan; Wang, Fang; Chen, Jian-Guo

    2015-11-01

    Posttraumatic stress disorder (PTSD) is a mental disorder with enhanced retention of fear memory and has profound impact on quality of life for millions of people worldwide. The β-adrenoceptor antagonist propranolol has been used in preclinical and clinical studies for the treatment of PTSD, but the mechanisms underlying its potential efficacy on fear memory retention remain to be elucidated. We investigated the action of propranolol on the retention of conditioned fear memory, the surface expression of glutamate receptor GluA1 subunits of AMPA receptors and synaptic adaptation in the lateral amygdala (LA) of rats. Propranolol attenuated reactivation-induced strengthening of fear retention while reducing enhanced surface expression of GluA1 subunits and restoring the impaired long-term depression in LA. These effects of propranolol were mediated by antagonizing reactivation-induced enhancement of adrenergic signalling, which activates PKA and calcium/calmodulin-dependent protein kinase II and then regulates the trafficking of AMPA receptors via phosphorylation of GluA1 subunits at the C-terminus. Both i.p. injection and intra-amygdala infusion of propranolol attenuated reactivation-induced enhancement of fear retention. Reactivation strengthens fear retention by increasing the level of noradrenaline and promotes the surface expression of GluA1 subunits and the excitatory synaptic transmission in LA. These findings uncover one mechanism underlying the efficiency of propranolol on retention of fear memories and suggest that β-adrenoceptor antagonists, which act centrally, may be more suitable for the treatment of PTSD. © 2015 The British Pharmacological Society.

  13. Nanoscale organization of {beta}{sub 2}-adrenergic receptor-Venus fusion protein domains on the surface of mammalian cells

    Energy Technology Data Exchange (ETDEWEB)

    Vobornik, Dusan; Rouleau, Yanouchka; Haley, Jennifer [Steacie Institute for Molecular Sciences, National Research Council Canada, Ottawa, ON, Canada K1A 0R6 (Canada); Bani-Yaghoub, Mahmud [Institute for Biological Sciences, National Research Council Canada, Ottawa, ON, Canada K1A 0R6 (Canada); Taylor, Rod [Steacie Institute for Molecular Sciences, National Research Council Canada, Ottawa, ON, Canada K1A 0R6 (Canada); Johnston, Linda J., E-mail: Linda.Johnston@nrc-cnrc.gc.ca [Steacie Institute for Molecular Sciences, National Research Council Canada, Ottawa, ON, Canada K1A 0R6 (Canada); Pezacki, John Paul, E-mail: John.Pezacki@nrc-cnrc.gc.ca [Steacie Institute for Molecular Sciences, National Research Council Canada, Ottawa, ON, Canada K1A 0R6 (Canada)

    2009-04-24

    Adrenergic receptors are a key component of nanoscale multiprotein complexes that are responsible for controlling the beat rate in a mammalian heart. We demonstrate the ability of near-field scanning optical microscopy (NSOM) to visualize {beta}{sub 2}-adrenergic receptors ({beta}{sub 2}AR) fused to the GFP analogue Venus at the nanoscale on HEK293 cells. The expression of the {beta}{sub 2}AR-Venus fusion protein was tightly controlled using a tetracycline-induced promoter. Both the size and density of the observed nanoscale domains are dependent on the level of induction and thus the level of protein expression. At concentrations between 100 and 700 ng/ml of inducer doxycycline, the size of domains containing the {beta}{sub 2}AR-Venus fusion protein appears to remain roughly constant, but the number of domains per cell increase. At 700 ng/ml doxycycline the functional receptors are organized into domains with an average diameter of 150 nm with a density similar to that observed for the native protein on primary murine cells. By contrast, larger micron-sized domains of {beta}{sub 2}AR are observed in the membrane of the HEK293 cells that stably overexpress {beta}{sub 2}AR-GFP and {beta}{sub 2}AR-eYFP. We conclude that precise chemical control of gene expression is highly advantageous for the use {beta}{sub 2}AR-Venus fusion proteins as models for {beta}{sub 2}AR function. These observations are critical for designing future cell models and assays based on {beta}{sub 2}AR, since the receptor biology is consistent with a relatively low density of nanoscale receptor domains.

  14. Dynamic determination of kinetic parameters for the interaction between polypeptide hormones and cell-surface receptors in the perfused rat liver by the multiple-indicator dilution method

    International Nuclear Information System (INIS)

    Sato, H.; Sugiyama, Y.; Sawada, Y.; Iga, T.; Sakamoto, S.; Fuwa, T.; Hanano, M.

    1988-01-01

    Hepatic elimination of epidermal growth factor (EGF) via receptor-mediated endocytosis was studied by a multiple-indicator dilution method in the isolated perfused rat liver, in which cell polarity and spatial organization are maintained. In this method EGF was given with inulin, an extracellular reference, as a bolus into the portal vein, and dilution curves of both compounds in the hepatic vein effluent were analyzed. Analysis of the dilution curve for EGF, compared with that for somatostatin, which showed no specific binding to isolated liver plasma membranes, resulted as follows: (i) both extraction ratio and distribution volume of 125 I-labeled EGF decreased as the injected amount of unlabeled EGF increased; (ii) the ratio plot of the dilution curve for EGF exhibited an upward straight line initially for a short period of time, whereas the ratio plot of somatostatin gradually decreased. The multiple-indicator dilution method was used for other peptides also. Insulin and glucagon, known to have hepatocyte receptors, behaved similarly to EGF in shape of their ratio plots. The kinetic parameters calculated by this analysis were comparable with reported values obtained by in vitro direct binding measurements at equilibrium using liver homogenates. They conclude that the multiple-indicator dilution method is a good tool for analyzing the dynamics of peptide hormones-cell-surface receptor interaction under a condition in which spatial architecture of the liver is maintained

  15. Dopamine receptors - physiological understanding to therapeutic intervention potential

    NARCIS (Netherlands)

    Emilien, G; Maloteaux, JM; Hoogenberg, K; Cragg, S

    1999-01-01

    There are two families of dopamine (DA) receptors, called D(1) and D(2), respectively. The D(1) family consists of D(1)- and D(5)-receptor subtypes and the D(2) family consists of D(2)-, D(3)-, and D(4)-receptor subtypes. The amino acid sequences of these receptors show that they all belong to a

  16. Dopamine receptors - physiological understanding to therapeutic intervention potential

    NARCIS (Netherlands)

    Emilien, G; Maloteaux, JM; Hoogenberg, K; Cragg, S

    There are two families of dopamine (DA) receptors, called D(1) and D(2), respectively. The D(1) family consists of D(1)- and D(5)-receptor subtypes and the D(2) family consists of D(2)-, D(3)-, and D(4)-receptor subtypes. The amino acid sequences of these receptors show that they all belong to a

  17. Beta2-adrenergic receptor homodimers: Role of transmembrane domain 1 and helix 8 in dimerization and cell surface expression.

    Science.gov (United States)

    Parmar, Vikas K; Grinde, Ellinor; Mazurkiewicz, Joseph E; Herrick-Davis, Katharine

    2017-09-01

    Even though there are hundreds of reports in the published literature supporting the hypothesis that G protein-coupled receptors (GPCR) form and function as dimers this remains a highly controversial area of research and mechanisms governing homodimer formation are poorly understood. Crystal structures revealing homodimers have been reported for many different GPCR. For adrenergic receptors, a potential dimer interface involving transmembrane domain 1 (TMD1) and helix 8 (H8) was identified in crystal structures of the beta 1 -adrenergic (β 1 -AR) and β 2 -AR. The purpose of this study was to investigate a potential role for TMD1 and H8 in dimerization and plasma membrane expression of functional β 2 -AR. Charged residues at the base of TMD1 and in the distal portion of H8 were replaced, singly and in combination, with non-polar residues or residues of opposite charge. Wild type and mutant β 2 -AR, tagged with YFP and expressed in HEK293 cells, were evaluated for plasma membrane expression and function. Homodimer formation was evaluated using bioluminescence resonance energy transfer, bimolecular fluorescence complementation, and fluorescence correlation spectroscopy. Amino acid substitutions at the base of TMD1 and in the distal portion of H8 disrupted homodimer formation and caused receptors to be retained in the endoplasmic reticulum. Mutations in the proximal region of H8 did not disrupt dimerization but did interfere with plasma membrane expression. This study provides biophysical evidence linking a potential TMD1/H8 interface with ER export and the expression of functional β 2 -AR on the plasma membrane. This article is part of a Special Issue entitled: Interactions between membrane receptors in cellular membranes edited by Kalina Hristova. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Different Use of Cell Surface Glycosaminoglycans As Adherence Receptors to Corneal Cells by Gram Positive and Gram Negative Pathogens

    Science.gov (United States)

    García, Beatriz; Merayo-Lloves, Jesús; Rodríguez, David; Alcalde, Ignacio; García-Suárez, Olivia; Alfonso, José F.; Baamonde, Begoña; Fernández-Vega, Andrés; Vazquez, Fernando; Quirós, Luis M.

    2016-01-01

    The epithelium of the cornea is continuously exposed to pathogens, and adhesion to epithelial cells is regarded as an essential first step in bacterial pathogenesis. In this article, the involvement of glycosaminoglycans in the adhesion of various pathogenic bacteria to corneal epithelial cells is analyzed. All microorganisms use glycosaminoglycans as receptors, but arranged in different patterns depending on the Gram-type of the bacterium. The heparan sulfate chains of syndecans are the main receptors, though other molecular species also seem to be involved, particularly in Gram-negative bacteria. Adherence is inhibited differentially by peptides, including heparin binding sequences, indicating the participation of various groups of Gram-positive, and -negative adhesins. The length of the saccharides produces a major effect, and low molecular weight chains inhibit the binding of Gram-negative microorganisms but increase the adherence of Gram-positives. Pathogen adhesion appears to occur preferentially through sulfated domains, and is very dependent on N- and 6-O-sulfation of the glucosamine residue and, to a lesser extent, 2-O sulfation of uronic acid. These data show the differential use of corneal receptors, which could facilitate the development of new anti-infective strategies. PMID:27965938

  19. Cytokine and surface receptor diversity of NK cells in resistant C3H/HeN and susceptible BALB/c mice with chronic Pseudomonas aeruginosa lung infection

    DEFF Research Database (Denmark)

    Calum, Henrik; Moser, Claus; Jensen, Peter Østrup

    2003-01-01

    The purpose of the present study was to investigate whether NK cells from resistant C3H/HeN mice and susceptible BALB/c mice showed different release of cytokines and expression of surface molecules during chronic P. aeruginosa lung infection using alginate-embedded P. aeruginosa mimicking...... expression of the LFA-1 and Fc receptors on NK cells. At day 2, IFN-gamma levels increased in C3H/HeN mice but decreased in BALB/c mice. The GM-CSF levels increased only in the C3H/HeN mice at day 1 and 2. Surface expression of LFA-1 on the NK cells was higher in C3H/HeN mice at day 1 and 2. In contrast...

  20. A critical role of nucleus accumbens dopamine D1-family receptors in renewal of alcohol seeking after punishment-imposed abstinence.

    Science.gov (United States)

    Marchant, Nathan J; Kaganovsky, Konstantin

    2015-06-01

    In humans, places or contexts previously associated with alcohol use often provoke relapse during abstinence. This phenomenon is modeled in laboratory animals using the ABA renewal procedure, in which extinction training in context (B) suppresses alcohol seeking, and renewal of this seeking occurs when the animal returns to the original training context (A). However, extinction training does not adequately capture the motivation for abstinence in human alcoholics who typically self-initiate abstinence in response to the negative consequences of excessive use. We recently developed a procedure to study renewal in laboratory rats after abstinence imposed by negative consequences (footshock punishment). The mechanisms of renewal of punished alcohol seeking are largely unknown. Here, we used the D1-family receptor antagonist SCH 23390 to examine the role of nucleus accumbens (NAc) shell and core dopamine in renewal of alcohol seeking after punishment-imposed abstinence. We trained alcohol-preferring "P rats" to self-administer 20% alcohol in Context A and subsequently suppressed alcohol taking via response-contingent footshock punishment in Context B. We tested the effects of systemic, NAc shell, or NAc core injections of SCH 23390 on renewal of alcohol seeking after punishment-imposed abstinence. We found that both systemic and NAc shell and core injections of SCH 23390 decreased renewal of punished alcohol seeking. Our results demonstrate a critical role of NAc dopamine in renewal of alcohol seeking after punishment-imposed abstinence. We discuss these results in reference to the brain mechanisms of renewal of alcohol seeking after extinction versus punishment. (c) 2015 APA, all rights reserved).

  1. The expression of ferritin, lactoferrin, transferrin receptor and solute carrier family 11A1 in the host response to BCG-vaccination and Mycobacterium tuberculosis challenge.

    Science.gov (United States)

    Thom, R E; Elmore, M J; Williams, A; Andrews, S C; Drobniewski, F; Marsh, P D; Tree, J A

    2012-05-02

    Iron is an essential cofactor for both mycobacterial growth during infection and for a successful protective immune response by the host. The immune response partly depends on the regulation of iron by the host, including the tight control of expression of the iron-storage protein, ferritin. BCG vaccination can protect against disease following Mycobacterium tuberculosis infection, but the mechanisms of protection remain unclear. To further explore these mechanisms, splenocytes from BCG-vaccinated guinea pigs were stimulated ex vivo with purified protein derivative from M. tuberculosis and a significant down-regulation of ferritin light- and heavy-chain was measured by reverse-transcription quantitative-PCR (P≤0.05 and ≤0.01, respectively). The mechanisms of this down-regulation were shown to involve TNFα and nitric oxide. A more in depth analysis of the mRNA expression profiles, including genes involved in iron metabolism, was performed using a guinea pig specific immunological microarray following ex vivo infection with M. tuberculosis of splenocytes from BCG-vaccinated and naïve guinea pigs. M. tuberculosis infection induced a pro-inflammatory response in splenocytes from both groups, resulting in down-regulation of ferritin (P≤0.05). In addition, lactoferrin (P≤0.002), transferrin receptor (P≤0.05) and solute carrier family 11A1 (P≤0.05), were only significantly down-regulated after infection of the splenocytes from BCG-vaccinated animals. The results show that expression of iron-metabolism genes is tightly regulated as part of the host response to M. tuberculosis infection and that BCG-vaccination enhances the ability of the host to mount an iron-restriction response which may in turn help to combat invasion by mycobacteria. Copyright © 2012 Elsevier Ltd. All rights reserved.

  2. Allelic sequence variations in the hypervariable region of a T-cell receptor β chain: Correlation with restriction fragment length polymorphism in human families and populations

    International Nuclear Information System (INIS)

    Robinson, M.A.

    1989-01-01

    Direct sequence analysis of the human T-cell antigen receptor (TCR) V β1 variable gene identified a single base-pair allelic variation (C/G) located within the coding region. This change results in substitution of a histidine (CAC) for a glutamine (CAG) at position 48 of the TCR β chain, a position predicted to be in the TCR antigen binding site. The V β1 polymorphism was found by DNA sequence analysis of V β1 genes from seven unrelated individuals; V β1 genes were amplified by the polymerase chain reaction, the amplified fragments were cloned into M13 phage vectors, and sequences were determined. To determined the inheritance patterns of the V β1 substitution and to test correlation with V β1 restriction fragment length polymorphism detected with Pvu II and Taq I, allele-specific oligonucleotides were constructed and used to characterize amplified DNA samples. Seventy unrelated individuals and six families were tested for both restriction fragment length polymorphism and for the V β1 substitution. The correlation was also tested using amplified, size-selected, Pvu II- and Taq I-digested DNA samples from heterozygotes. Pvu II allele 1 (61/70) and Taq I allele 1 (66/70) were found to be correlated with the substitution giving rise to a histidine at position 48. Because there are exceptions to the correlation, the use of specific probes to characterize allelic forms of TCR variable genes will provide important tools for studies of basic TCR genetics and disease associations

  3. GPR158, an orphan member of G protein-coupled receptor Family C: glucocorticoid-stimulated expression and novel nuclear role.

    Science.gov (United States)

    Patel, Nitin; Itakura, Tatsuo; Gonzalez, Jose M; Schwartz, Stephen G; Fini, M Elizabeth

    2013-01-01

    Members of the large G protein-coupled receptor (GPCR) clan are implicated in many physiological and disease processes, making them important therapeutic drug targets. In the present study, we follow up on results of a pilot study suggesting a functional relationship between glucocorticoid (GC)-induced ocular hypertension and GPR158, one of three orphan members of the GPCR Family C. GC treatment increases levels of GPR158 mRNA and protein through transcriptional mechanisms, in cultured trabecular meshwork (TBM) cells derived from the eye's aqueous outflow pathway. Like treatment with GCs, transient overexpression of GPR158 stimulates cell proliferation, while siRNA knockdown of endogenous GPR158 has the opposite effect. Both endogenous and overexpressed GPR158 show an unusual subcellular localization pattern, being found almost entirely in the nucleus. However, when cells are treated with inhibitors of clathrin-mediated endocytosis, GPR158 is shifted to the plasma membrane. Mutation of a bipartite nuclear localization signal (NLS) in the 8(th) helix also shifts GPR158 out of the nucleus, but in this case the protein is found in vesicles localized in the cytoplasm. These results suggest that newly synthesized GPR158 first traffics to the plasma membrane, where it rapidly undergoes endocytosis and translocation to the nucleus. Significantly, mutation of the NLS abrogates GPR158-mediated enhancement of cell proliferation, indicating a functional requirement for nuclear localization. GPR158 overexpression upregulates levels of the cell cycle regulator cyclin D1, but mutation of the NLS reverses this. Overexpression of GPR158 enhances the barrier function of a TBM cell monolayer, which is associated with an increase in the levels of tight junction proteins ZO-1 and occludin, similar to reported studies on GC treatment. Regulated paracellular permeability controls aqueous outflow facility in vivo. Since GCs stimulate GPR158 expression, the result is consistent with a

  4. The herpes virus Fc receptor gE-gI mediates antibody bipolar bridging to clear viral antigens from the cell surface.

    Directory of Open Access Journals (Sweden)

    Blaise Ndjamen

    2014-03-01

    Full Text Available The Herpes Simplex Virus 1 (HSV-1 glycoprotein gE-gI is a transmembrane Fc receptor found on the surface of infected cells and virions that binds human immunoglobulin G (hIgG. gE-gI can also participate in antibody bipolar bridging (ABB, a process by which the antigen-binding fragments (Fabs of the IgG bind a viral antigen while the Fc binds to gE-gI. IgG Fc binds gE-gI at basic, but not acidic, pH, suggesting that IgG bound at extracellular pH by cell surface gE-gI would dissociate and be degraded in acidic endosomes/lysosomes if endocytosed. The fate of viral antigens associated with gE-gI-bound IgG had been unknown: they could remain at the cell surface or be endocytosed with IgG. Here, we developed an in vitro model system for ABB and investigated the trafficking of ABB complexes using 4-D confocal fluorescence imaging of ABB complexes with transferrin or epidermal growth factor, well-characterized intracellular trafficking markers. Our data showed that cells expressing gE-gI and the viral antigen HSV-1 gD endocytosed anti-gD IgG and gD in a gE-gI-dependent process, resulting in lysosomal localization. These results suggest that gE-gI can mediate clearance of infected cell surfaces of anti-viral host IgG and viral antigens to evade IgG-mediated responses, representing a general mechanism for viral Fc receptors in immune evasion and viral pathogenesis.

  5. Chemokine receptors CCR6 and CXCR3 are necessary for CD4(+) T cell mediated ocular surface disease in experimental dry eye disease.

    Science.gov (United States)

    Coursey, Terry G; Gandhi, Niral B; Volpe, Eugene A; Pflugfelder, Stephen C; de Paiva, Cintia S

    2013-01-01

    CD4(+) T cells are essential to pathogenesis of ocular surface disease in dry eye. Two subtypes of CD4(+) T cells, Th1 and Th17 cells, function concurrently in dry eye to mediate disease. This occurs in spite of the cross-regulation of IFN-γ and IL-17A, the prototypical cytokines Th1 and Th17 cells, respectively. Essential to an effective immune response are chemokines that direct and summon lymphocytes to specific tissues. T cell trafficking has been extensively studied in other models, but this is the first study to examine the role of chemokine receptors in ocular immune responses. Here, we demonstrate that the chemokine receptors, CCR6 and CXCR3, which are expressed on Th17 and Th1 cells, respectively, are required for the pathogenesis of dry eye disease, as CCR6KO and CXCR3KO mice do not develop disease under desiccating stress. CD4(+) T cells from CCR6KO and CXCR3KO mice exposed to desiccating stress (DS) do not migrate to the ocular surface, but remain in the superficial cervical lymph nodes. In agreement with this, CD4(+) T cells from CCR6 and CXCR3 deficient donors exposed to DS, when adoptively transferred to T cell deficient recipients manifest minimal signs of dry eye disease, including significantly less T cell infiltration, goblet cell loss, and expression of inflammatory cytokine and matrix metalloproteinase expression compared to wild-type donors. These findings highlight the important interaction of chemokine receptors on T cells and chemokine ligand expression on epithelial cells of the cornea and conjunctiva in dry eye pathogenesis and reveal potential new therapeutic targets for dry eye disease.

  6. Chemokine Receptors CCR6 and CXCR3 Are Necessary for CD4+ T Cell Mediated Ocular Surface Disease in Experimental Dry Eye Disease

    Science.gov (United States)

    Coursey, Terry G.; Gandhi, Niral B.; Volpe, Eugene A.; Pflugfelder, Stephen C.; de Paiva, Cintia S.

    2013-01-01

    CD4+ T cells are essential to pathogenesis of ocular surface disease in dry eye. Two subtypes of CD4+ T cells, Th1 and Th17 cells, function concurrently in dry eye to mediate disease. This occurs in spite of the cross-regulation of IFN-γ and IL-17A, the prototypical cytokines Th1 and Th17 cells, respectively. Essential to an effective immune response are chemokines that direct and summon lymphocytes to specific tissues. T cell trafficking has been extensively studied in other models, but this is the first study to examine the role of chemokine receptors in ocular immune responses. Here, we demonstrate that the chemokine receptors, CCR6 and CXCR3, which are expressed on Th17 and Th1 cells, respectively, are required for the pathogenesis of dry eye disease, as CCR6KO and CXCR3KO mice do not develop disease under desiccating stress. CD4+ T cells from CCR6KO and CXCR3KO mice exposed to desiccating stress (DS) do not migrate to the ocular surface, but remain in the superficial cervical lymph nodes. In agreement with this, CD4+ T cells from CCR6 and CXCR3 deficient donors exposed to DS, when adoptively transferred to T cell deficient recipients manifest minimal signs of dry eye disease, including significantly less T cell infiltration, goblet cell loss, and expression of inflammatory cytokine and matrix metalloproteinase expression compared to wild-type donors. These findings highlight the important interaction of chemokine receptors on T cells and chemokine ligand expression on epithelial cells of the cornea and conjunctiva in dry eye pathogenesis and reveal potential new therapeutic targets for dry eye disease. PMID:24223818

  7. Facilitated receptor-recognition and enhanced bioactivity of bone morphogenetic protein-2 on magnesium-substituted hydroxyapatite surface

    Science.gov (United States)

    Huang, Baolin; Yuan, Yuan; Li, Tong; Ding, Sai; Zhang, Wenjing; Gu, Yuantong; Liu, Changsheng

    2016-01-01

    Biomaterial surface functionalized with bone morphogenetic protein-2 (BMP-2) is a promising approach to fabricating successful orthopedic implants/scaffolds. However, the bioactivity of BMP-2 on material surfaces is still far from satisfactory and the mechanism of related protein-surface interaction remains elusive. Based on the most widely used bone-implants/scaffolds material, hydroxyapatite (HAP), we developed a matrix of magnesium-substituted HAP (Mg-HAP, 2.2 at% substitution) to address these issues. Further, we investigated the adsorption dynamics, BMPRs-recruitment, and bioactivity of recombinant human BMP-2 (rhBMP-2) on the HAP and Mg-HAP surfaces. To elucidate the mechanism, molecular dynamic simulations were performed to calculate the preferred orientations, conformation changes, and cysteine-knot stabilities of adsorbed BMP-2 molecules. The results showed that rhBMP-2 on the Mg-HAP surface exhibited greater bioactivity, evidenced by more facilitated BMPRs-recognition and higher ALP activity than on the HAP surface. Moreover, molecular simulations indicated that BMP-2 favoured distinct side-on orientations on the HAP and Mg-HAP surfaces. Intriguingly, BMP-2 on the Mg-HAP surface largely preserved the active protein structure evidenced by more stable cysteine-knots than on the HAP surface. These findings explicitly clarify the mechanism of BMP-2-HAP/Mg-HAP interactions and highlight the promising application of Mg-HAP/BMP-2 matrixes in bone regeneration implants/scaffolds. PMID:27075233

  8. The methyltransferase NSD3 has chromatin-binding motifs, PHD5-C5HCH, that are distinct from other NSD (nuclear receptor SET domain) family members in their histone H3 recognition.

    Science.gov (United States)

    He, Chao; Li, Fudong; Zhang, Jiahai; Wu, Jihui; Shi, Yunyu

    2013-02-15

    The NSD (nuclear receptor SET domain-containing) family members, consisting of NSD1, NSD2 (MMSET/WHSC1), and NSD3 (WHSC1L1), are SET domain-containing methyltransferases and aberrant expression of each member has been implicated in multiple diseases. They have specific mono- and dimethylase activities for H3K36, whereas play nonredundant roles during development. Aside from the well characterized catalytic SET domain, NSD proteins have multiple potential chromatin-binding motifs that are clinically relevant, including the fifth plant homeodomain (PHD5) and the adjacent Cys-His-rich domain (C5HCH) located at the C terminus. Herein, we report the crystal structures of the PHD5-C5HCH module of NSD3, in the free state and in complex with H3(1-7) (H3 residues 1-7), H3(1-15) (H3 residues 1-15), and H3(1-15)K9me3 (H3 residues 1-15 with trimethylation on K9) peptides. These structures reveal that the PHD5 and C5HCH domains fold into a novel integrated PHD-PHD-like structural module with H3 peptide bound only on the surface of PHD5 and provide the molecular basis for the recognition of unmodified H3K4 and trimethylated H3K9 by NSD3 PHD5. Structural studies and binding assays show that differences exist in histone binding specificity of the PHD5 domain between three members of the NSD family. For NSD2, the PHD5-C5HCH:H3 N terminus interaction is largely conserved, although with a stronger preference for unmethylated H3K9 (H3K9me0) than trimethylated H3K9 (H3K9me3), and NSD1 PHD5-C5HCH does not bind to H3 peptides. Our results shed light on how NSD proteins that mediate H3K36 methylation are localized to specific genomic sites and provide implications for the mechanism of functional diversity of NSD proteins.

  9. Six host range variants of the xenotropic/polytropic gammaretroviruses define determinants for entry in the XPR1 cell surface receptor

    Directory of Open Access Journals (Sweden)

    Kozak Christine A

    2009-10-01

    Full Text Available Abstract Background The evolutionary interactions between retroviruses and their receptors result in adaptive selection of restriction variants that can allow natural populations to evade retrovirus infection. The mouse xenotropic/polytropic (X/PMV gammaretroviruses rely on the XPR1 cell surface receptor for entry into host cells, and polymorphic variants of this receptor have been identified in different rodent species. Results We screened a panel of X/PMVs for infectivity on rodent cells carrying 6 different XPR1 receptor variants. The X/PMVs included 5 well-characterized laboratory and wild mouse virus isolates as well as a novel cytopathic XMV-related virus, termed Cz524, isolated from an Eastern European wild mouse-derived strain, and XMRV, a xenotropic-like virus isolated from human prostate cancer. The 7 viruses define 6 distinct tropisms. Cz524 and another wild mouse isolate, CasE#1, have unique species tropisms. Among the PMVs, one Friend isolate is restricted by rat cells. Among the XMVs, two isolates, XMRV and AKR6, differ from other XMVs in their PMV-like restriction in hamster cells. We generated a set of Xpr1 mutants and chimeras, and identified critical amino acids in two extracellular loops (ECLs that mediate entry of these different viruses, including 3 residues in ECL3 that are involved in PMV entry (E500, T507, and V508 and can also influence infectivity by AKR6 and Cz524. Conclusion We used a set of natural variants and mutants of Xpr1 to define 6 distinct host range variants among naturally occurring X/PMVs (2 XMV variants, 2 PMVs, 2 different wild mouse variants. We identified critical amino acids in XPR1 that mediate entry of these viruses. These gammaretroviruses and their XPR1 receptor are thus highly functionally polymorphic, a consequence of the evolutionary pressures that favor both host resistance and virus escape mutants. This variation accounts for multiple naturally occurring virus resistance phenotypes and

  10. Families of null surfaces in the Minkowski tri dimensional space-time and its associated differential equations

    International Nuclear Information System (INIS)

    Silva O, G.; Garcia G, P.

    2004-01-01

    In this work we describe the procedure to obtain all the family of third order ordinary differential equations connected by a contact transformation such that in their spaces of solutions is defined a conformal three dimensional Minkowski metric. (Author)

  11. Complete structure of the cell surface polysaccharide of Streptococcus oralis ATCC 10557: A receptor for lectin-mediated interbacterial adherence

    International Nuclear Information System (INIS)

    Abeygunawardana, C.; Bush, C.A.; Cisar, J.O.

    1991-01-01

    Lectin-carbohydrate binding is known to play an important role in a number of different cell-cell interactions including those between certain species of oral streptococci and actinomyces that colonize teeth. The cell wall polysaccharides of Streptococcus oralis ATCC 10557, S. oralis 34, and Streptococcus mitis J22, although not identical antigenically, each function as a receptor molecule for the galactose and N-acetylgalactosamine reactive fimbrial lectins of Actinomyces viscosus and Actinomyces naeslundii. Carbohydrate analysis of the receptor polysaccharide isolated from S. oralis ATCC 10557 shows galactose (3 mol), glucose (1 mol), GalNAc (1 mol), and rhamnose (1 mol). 1 H NMR spectra of the polysaccharide show that is partially O-acetylated. Analysis of the 1 H NMR spectrum of the de-O-acetylated polysaccharide shows that it is composed of repeating subunits containing six monosaccharides and that the subunits are joined by a phosphodiester linkage. The 1 H and 13 C NMR spectra were completely assigned by two-dimensional homonuclear correlation methods and by 1 H-detected heteronuclear multiple-quantum correlation ( 1 H[ 13 C]HMQC). The complete 1 H and 13 C assignment of the native polysaccharide was carried out by the same techniques augmented by a 13 C-coupled hybrid HMQC-COSY method, which is shown to be especially useful for carbohydrates in which strong coupling and overlapping peaks in the 1 H spectrum pose difficulties

  12. Impaired peroxisome proliferator-activated receptor γ function through mutation of a conserved salt bridge (R425C) in familial partial lipodystrophy

    NARCIS (Netherlands)

    Jeninga, E.H.; van Beekum, P.O; van Dijk, A.D.J.; Hamers, N.; Bonvin, A.M.J.J.; Berger, R.; Kalkhoven, E.

    2007-01-01

    The nuclear receptor peroxisome proliferator-activated receptor (PPAR) γ plays a key role in the regulation of glucose and lipid metabolism in adipocytes by regulating their differentiation, maintenance, and function. A heterozygous mutation in the PPARG gene, which changes an arginine residue at

  13. A PRACTICAL APPROACH TO THE DETECTION OF ANDROGEN RECEPTOR GENE-MUTATIONS AND PEDIGREE ANALYSIS IN FAMILIES WITH X-LINKED ANDROGEN INSENSITIVITY

    NARCIS (Netherlands)

    RISSTALPERS, C; HOOGENBOEZEM, T; SLEDDENS, HFBM; VERLEUNMOOIJMAN, MCT; DEGENHART, HJ; DROP, SLS; HALLEY, DJJ; Oosterwijk, Jan; HODGINS, MB; TRAPMAN, J; BRINKMANN, AO

    Androgen insensitivity syndrome (AIS) is an X-linked disorder in which defects in the androgen receptor gene have prevented the normal development of both internal and external male structures in 46,XY individuals. This survey reports the analysis of 11 AIS subjects. The androgen receptor gene of

  14. A practical approach to the detection of androgen receptor gene mutations and pedigree analysis in families with x-linked androgen insensitivity

    NARCIS (Netherlands)

    Ris-Stalpers, C.; Hoogenboezem, T.; Sleddens, H. F.; Verleun-Mooijman, M. C.; Degenhart, H. J.; Drop, S. L.; Halley, D. J.; Oosterwijk, J. C.; Hodgins, M. B.; Trapman, J.

    1994-01-01

    Androgen insensitivity syndrome (AIS) is an X-linked disorder in which defects in the androgen receptor gene have prevented the normal development of both internal and external male structures in 46,XY individuals. This survey reports the analysis of 11 AIS subjects. The androgen receptor gene of

  15. Effects of the Sazetidine-a Family of Compounds on the Body Temperature in Wildtype, Nicotinic Receptor B2(-/-) and a7(-/-) Mice

    Science.gov (United States)

    Nicotine elicits hypothermic responses in rodents. This effect appears to be related to nicotinic receptor desensitization because sazetidine-A, an a4B2 nicotinic receptor desensitizing agent, produces marked hypothermia and potentiates nicotine-induced hypothermia in mice. To de...

  16. Congruence and Incongruence in Adolescents' and Parents' Perceptions of the Family: Using Response Surface Analysis to Examine Links with Adolescents' Psychological Adjustment.

    Science.gov (United States)

    Human, Lauren J; Dirks, Melanie A; DeLongis, Anita; Chen, Edith

    2016-10-01

    Parents and adolescents often hold discrepant views about the family environment and these discrepancies may in turn influence adolescents' psychological adjustment. The current study examined how adolescent-parent perceptions of family routines and chaos, and their congruence and incongruence, relate to adolescents' self-reported psychological adjustment (depressive symptoms and perceived stress), both concurrently (N dyads = 261; 53 % female) and 2 years later (N dyads = 118; 50 % female). Using polynomial regression and response surface analysis, results indicated that adolescents' perceptions of the family environment were a stronger predictor of adolescents' adjustment than parents' perceptions (76 % mothers), concurrently and over time. However, both congruence and incongruence in adolescent-parent perceptions were also related to adolescents' adjustment. Specifically, congruently negative adolescent-parent perceptions were associated with worse concurrent adolescent adjustment. Further, incongruence defined by more negativity in adolescents' versus parents' perceptions was associated with worse adolescent psychological adjustment, concurrently and over time. In sum, in addition to the strong links between adolescents' perceptions of the family and their own psychological adjustment, examining how congruent and incongruent adolescents' perceptions are with parents' perceptions may shed additional light on how the family environment relates to adolescent adjustment.

  17. An integrated model for assessing the risk of TCE groundwater contamination to human receptors and surface water ecosystems

    DEFF Research Database (Denmark)

    McKnight, Ursula S.; Funder, S.G.; Rasmussen, J.J.

    2010-01-01

    The practical implementation of the European Water Framework Directive has resulted in an increased focus on the hyporheic zone. In this paper, an integrated model was developed for evaluating the impact of point sources in groundwater on human health and surface water ecosystems....... This was accomplished by coupling the system dynamics-based decision support system CARO-PLUS to the aquatic ecosystem model AQUATOX using an analytical volatilization model for the stream. The model was applied to a case study where a TCE contaminated groundwater plume is discharging to a stream. The TCE source...... will not be depleted for many decades, however measured and predicted TCE concentrations in surface water were found to be below human health risk management targets. Volatilization rapidly attenuates TCE concentrations in surface water. Thus, only a 300 m stream reach fails to meet surface water quality criteria...

  18. G protein-coupled receptor mutations and human genetic disease.

    Science.gov (United States)

    Thompson, Miles D; Hendy, Geoffrey N; Percy, Maire E; Bichet, Daniel G; Cole, David E C

    2014-01-01

    Genetic variations in G protein-coupled receptor genes (GPCRs) disrupt GPCR function in a wide variety of human genetic diseases. In vitro strategies and animal models have been used to identify the molecular pathologies underlying naturally occurring GPCR mutations. Inactive, overactive, or constitutively active receptors have been identified that result in pathology. These receptor variants may alter ligand binding, G protein coupling, receptor desensitization and receptor recycling. Receptor systems discussed include rhodopsin, thyrotropin, parathyroid hormone, melanocortin, follicle-stimulating hormone (FSH), luteinizing hormone, gonadotropin-releasing hormone (GNRHR), adrenocorticotropic hormone, vasopressin, endothelin-β, purinergic, and the G protein associated with asthma (GPRA or neuropeptide S receptor 1 (NPSR1)). The role of activating and inactivating calcium-sensing receptor (CaSR) mutations is discussed in detail with respect to familial hypocalciuric hypercalcemia (FHH) and autosomal dominant hypocalemia (ADH). The CASR mutations have been associated with epilepsy. Diseases caused by the genetic disruption of GPCR functions are discussed in the context of their potential to be selectively targeted by drugs that rescue altered receptors. Examples of drugs developed as a result of targeting GPCRs mutated in disease include: calcimimetics and calcilytics, therapeutics targeting melanocortin receptors in obesity, interventions that alter GNRHR loss from the cell surface in idiopathic hypogonadotropic hypogonadism and novel drugs that might rescue the P2RY12 receptor congenital bleeding phenotype. De-orphanization projects have identified novel disease-associated receptors, such as NPSR1 and GPR35. The identification of variants in these receptors provides genetic reagents useful in drug screens. Discussion of the variety of GPCRs that are disrupted in monogenic Mendelian disorders provides the basis for examining the significance of common

  19. Neurobeachin regulates neurotransmitter receptor trafficking to synapses

    NARCIS (Netherlands)

    Nair, R.; Lauks, J.; Jung, S; Cooke, N.E.; de Wit, H.; Brose, N.; Kilimann, M.W.; Verhage, M.; Rhee, J.

    2013-01-01

    The surface density of neurotransmitter receptors at synapses is a key determinant of synaptic efficacy. Synaptic receptor accumulation is regulated by the transport, postsynaptic anchoring, and turnover of receptors, involving multiple trafficking, sorting, motor, and scaffold proteins. We found

  20. A Novel Mechanism of Androgen Receptor Action

    National Research Council Canada - National Science Library

    Roberts, Jr, Charles T

    2006-01-01

    .... Specifically, the authors had determined that the androgen receptor controls the expression of the cell-surface receptor for the hormone IGF-1 at the level of translation of the IGF-1 receptor mRNA...

  1. A Missense Mutation in Epsilon-subunit of Acetylcholine Receptor Causing Autosomal Dominant Slow-channel Congenital Myasthenic Syndrome in a Chinese Family

    Directory of Open Access Journals (Sweden)

    Jia-Ze Tan

    2016-01-01

    Conclusions: We reported a SCCMS family of Chinese origin. In the family, classical clinical phenotype with phenotypic variability among different members was found. Genetic testing could help diagnose this rare disease.

  2. Internalization of G-protein-coupled receptors: Implication in receptor function, physiology and diseases.

    Science.gov (United States)

    Calebiro, Davide; Godbole, Amod

    2018-04-01

    G protein-coupled receptors (GPCRs) are the largest family of membrane receptors and mediate the effects of numerous hormones and neurotransmitters. The nearly 1000 GPCRs encoded by the human genome regulate virtually all physiological functions and are implicated in the pathogenesis of prevalent human diseases such as thyroid disorders, hypertension or Parkinson's disease. As a result, 30-50% of all currently prescribed drugs are targeting these receptors. Once activated, GPCRs induce signals at the cell surface. This is often followed by internalization, a process that results in the transfer of receptors from the plasma membrane to membranes of the endosomal compartment. Internalization was initially thought to be mainly implicated in signal desensitization, a mechanism of adaptation to prolonged receptor stimulation. However, several unexpected functions have subsequently emerged. Most notably, accumulating evidence indicates that internalization can induce prolonged receptor signaling on intracellular membranes, which is apparently required for at least some biological effects of hormones like TSH, LH and adrenaline. These findings reveal an even stronger connection between receptor internalization and signaling than previously thought. Whereas new studies are just beginning to reveal an important physiological role for GPCR signaling after internalization and ways to exploit it for therapeutic purposes, future investigations will be required to explore its involvement in human disease. Copyright © 2018 Elsevier Ltd. All rights reserved.

  3. Differential effect on TCR:CD3 stimulation of a 90-kD glycoprotein (gp90/Mac-2BP), a member of the scavenger receptor cysteine-rich domain protein family

    DEFF Research Database (Denmark)

    Silvestri, B; Calderazzo, F; Coppola, V

    1998-01-01

    We studied the effects of a 90-kD glycoprotein (gp90/Mac-2BP) belonging to the scavenger receptor family, present in normal serum and at increased levels in inflammatory disease and cancer patients, on some T cell function parameters. Whereas the lymphocyte proliferative response to non-specific ......We studied the effects of a 90-kD glycoprotein (gp90/Mac-2BP) belonging to the scavenger receptor family, present in normal serum and at increased levels in inflammatory disease and cancer patients, on some T cell function parameters. Whereas the lymphocyte proliferative response to non......-specific mitogens such as phytohaemagglutinin (PHA) and concanavalin A (Con A), but not pokeweed mitogen (PWM), was strongly reduced, probably due to the lectin-binding properties of gp90/Mac-2BP, the response to T cell receptor (TCR) agonists such as superantigens and allogeneic cells was potentiated. When...... lymphocytes were stimulated with different anti-TCR:CD3 MoAbs, both in soluble and solid-phase form, gp90/Mac-2BP was able to down-regulate the proliferative response to anti-CD3 MoAb, whereas the response to anti-TCR alphabeta MoAb was enhanced. A similar differential effect was observed when a MoAb against...

  4. Glucocorticoid-induced TNF receptor family related protein ligand [GITR-L] is requisite for optimal functioning of regulatory CD4+ T cells.

    Directory of Open Access Journals (Sweden)

    Gongxian eLiao

    2014-02-01

    Full Text Available Glucocorticoid-Induced Tumor necrosis factor Receptor family-related protein (GITR, TNFRSF18, CD357 is constitutively expressed on regulatory T cells (Tregs and is inducible on effector T cells (Teffs. In this report, we examine the role of GITR-Ligand (GITR-L, which is expressed by antigen presenting cells, on the development and expansion of Tregs. We found that GITR-L is dispensable for the development of naturally occurring FoxP3+ Treg cells in the thymus. However, the expansion of Treg in GITR-L-/- mice is impaired after injection of the dendritic cells (DCs inducing factor Flt3 ligand. Furthermore, DCs from the liver of GITR-L-/- mice were less efficient in inducing proliferation of antigen-specific Treg cells in vitro than the same cells from WT littermates. Upon gene transfer of ovalbumin into hepatocytes of GITR-L-/- FoxP3(GFP reporter mice using adeno-associated virus (AAV8-OVA the number of antigen-specific Treg in liver and spleen is reduced. The reduced number of Tregs resulted in an increase in the number of ovalbumin specific CD8+ T effector cells. This is highly significant because proliferation of antigen specific CD8+ cells itself is dependent on the presence of GITR-L, as shown by in vitro experiments and by adoptive transfers into GITR-L-/-Rag-/- and Rag-/- mice that had received AAV8-OVA. Surprisingly, administering αCD3 significantly reduced the numbers of FoxP3+ Treg cells in the liver and spleen of GITR-L-/- but not WT mice. Because soluble Fc-GITR-L partially rescues αCD3 induced in vitro depletion of the CD103+ subset of FoxP3+CD4+ Treg cells, we conclude that expression of GITR-L by antigen presenting cells is requisite for optimal Treg-mediated regulation of immune responses including those in response during gene transfer.

  5. Role of ErbB receptors in cancer cell migration and invasion

    Directory of Open Access Journals (Sweden)

    Aline eAppert-Collin

    2015-11-01

    Full Text Available Growth factors mediate their diverse biologic responses (regulation of cellular proliferation, differentiation, migration and survival by binding to and activating cell-surface receptors with intrinsic protein kinase activity named Receptor Tyrosine Kinases (RTKs. About 60 RTKs have been identified and can be classified into more than 16 different receptor families. Their activity is normally tightly controlled and regulated. Overexpression of RTK proteins or functional alterations caused by mutations in the corresponding genes or abnormal stimulation by autocrine growth factor loops contribute to constitutive RTK signaling, resulting in alterations in the physiological activities of cells. The ErbB receptor family of RTKs comprises four distinct receptors: the EGFR (also known as ErbB1/HER1, ErbB2 (neu, HER2, ErbB3 (HER3 and ErbB4 (HER4. ErbB family members are often overexpressed, amplified, or mutated in many forms of cancer, making them important therapeutic targets. EGFR has been found to be amplified in gliomas and non-small-cell lung carcinoma while ErbB2 amplifications are seen in breast, ovarian, bladder, non-small-cell lung carcinoma, as well as several other tumor types. Several data have shown that ErbB receptor family and its downstream pathway regulate epithelial-mesenchymal transition, migration, and tumor invasion by modulating extracellular matrix components. Recent findings indicate that extracellular matrix components such as matrikines bind specifically to EGF receptor and promote cell invasion. In this review, we will present an in-depth overview of the structure, mechanisms, cell signaling, and functions of ErbB family receptors in cell adhesion and migration. Furthermore, we will describe in a last part the new strategies developed in anti-cancer therapy to inhibit ErbB family receptor activation.

  6. A Val85Met Mutation in Melanocortin-1 Receptor Is Associated with Reductions in Eumelanic Pigmentation and Cell Surface Expression in Domestic Rock Pigeons (Columba livia)

    Science.gov (United States)

    Guernsey, Michael W.; Ritscher, Lars; Miller, Matthew A.; Smith, Daniel A.; Schöneberg, Torsten; Shapiro, Michael D.

    2013-01-01

    Variation in the melanocortin-1 receptor (Mc1r) is associated with pigmentation diversity in wild and domesticated populations of vertebrates, including several species of birds. Among domestic bird species, pigmentation variation in the rock pigeon ( Columba livia ) is particularly diverse. To determine the potential contribution of Mc1r variants to pigment diversity in pigeons, we sequenced Mc1r in a wide range of pigeon breeds and identified several single nucleotide polymorphisms, including a variant that codes for an amino acid substitution (Val85Met). In contrast to the association between Val85Met and eumelanism in other avian species, this change was associated with pheomelanism in pigeons. In vitro cAMP accumulation and protein expression assays revealed that Val85Met leads to decreased receptor function and reduced cell surface expression of the mutant protein. The reduced in vitro function is consistent with the observed association with reduced eumelanic pigmentation. Comparative genetic and cellular studies provide important insights about the range of mechanisms underlying diversity among vertebrates, including different phenotypic associations with similar mutations in different species. PMID:23977400

  7. Residues essential for Panton-Valentine leukocidin S component binding to its cell receptor suggest both plasticity and adaptability in its interaction surface.

    Directory of Open Access Journals (Sweden)

    Benoit-Joseph Laventie

    Full Text Available Panton-Valentine leukocidin (PVL, a bicomponent staphylococcal leukotoxin, is involved in the poor prognosis of necrotizing pneumonia. The present study aimed to elucidate the binding mechanism of PVL and in particular its cell-binding domain. The class S component of PVL, LukS-PV, is known to ensure cell targeting and exhibits the highest affinity for the neutrophil membrane (Kd∼10(-10 M compared to the class F component of PVL, LukF-PV (Kd∼10(-9 M. Alanine scanning mutagenesis was used to identify the residues involved in LukS-PV binding to the neutrophil surface. Nineteen single alanine mutations were performed in the rim domain previously described as implicated in cell membrane interactions. Positions were chosen in order to replace polar or exposed charged residues and according to conservation between leukotoxin class S components. Characterization studies enabled to identify a cluster of residues essential for LukS-PV binding, localized on two loops of the rim domain. The mutations R73A, Y184A, T244A, H245A and Y250A led to dramatically reduced binding affinities for both human leukocytes and undifferentiated U937 cells expressing the C5a receptor. The three-dimensional structure of five of the mutants was determined using X-ray crystallography. Structure analysis identified residues Y184 and Y250 as crucial in providing structural flexibility in the receptor-binding domain of LukS-PV.

  8. Cytokine and surface receptor diversity of NK cells in resistant C3H/HeN and susceptible BALB/c mice with chronic Pseudomonas aeruginosa lung infection

    DEFF Research Database (Denmark)

    Calum, Henrik; Moser, Claus; Jensen, Peter Østrup

    2003-01-01

    The purpose of the present study was to investigate whether NK cells from resistant C3H/HeN mice and susceptible BALB/c mice showed different release of cytokines and expression of surface molecules during chronic P. aeruginosa lung infection using alginate-embedded P. aeruginosa mimicking...... the infection in cystic fibrosis. Lung cell suspensions were depleted of lymphocytes by magnetic cell sorting. The concentrations of IFN-gamma, IL-1beta and GM-CSF were estimated by ELISA at day 1 and 2 after infection. Non-infected mice were used as controls. Flow cytometry was used to estimate the surface...... expression of the LFA-1 and Fc receptors on NK cells. At day 2, IFN-gamma levels increased in C3H/HeN mice but decreased in BALB/c mice. The GM-CSF levels increased only in the C3H/HeN mice at day 1 and 2. Surface expression of LFA-1 on the NK cells was higher in C3H/HeN mice at day 1 and 2. In contrast...

  9. Clinical experience in the screening and management of a large kindred with familial isolated pituitary adenoma due to an aryl hydrocarbon receptor interacting protein (AIP) mutation.

    Science.gov (United States)

    Williams, Fred; Hunter, Steven; Bradley, Lisa; Chahal, Harvinder S; Storr, Helen L; Akker, Scott A; Kumar, Ajith V; Orme, Stephen M; Evanson, Jane; Abid, Noina; Morrison, Patrick J; Korbonits, Márta; Atkinson, A Brew

    2014-04-01

    Germline AIP mutations usually cause young-onset acromegaly with low penetrance in a subset of familial isolated pituitary adenoma families. We describe our experience with a large family with R304* AIP mutation and discuss some of the diagnostic dilemmas and management issues. The aim of the study was to identify and screen mutation carriers in the family. Forty-three family members participated in the study. The study was performed in university hospitals. We conducted genetic and endocrine screening of family members. We identified 18 carriers of the R304* mutation, three family members with an AIP-variant A299V, and two family members who harbored both changes. One of the two index cases presented with gigantism and pituitary apoplexy, the other presented with young-onset acromegaly, and both had surgery and radiotherapy. After genetic and clinical screening of the family, two R304* carriers were diagnosed with acromegaly. They underwent transsphenoidal surgery after a short period of somatostatin analog treatment. One of these two patients is in remission; the other achieved successful pregnancy despite suboptimal control of acromegaly. One of the A299V carrier family members was previously diagnosed with a microprolactinoma; we consider this case to be a phenocopy. Height of the unaffected R304* carrier family members is not different compared to noncarrier relatives. Families with AIP mutations present particular problems such as the occurrence of large invasive tumors, poor response to medical treatment, difficulties with fertility and management of pregnancy, and the finding of AIP sequence variants of unknown significance. Because disease mostly develops at a younger age and penetrance is low, the timing and duration of the follow-up of carriers without overt disease requires further study. The psychological and financial impact of prolonged clinical screening must be considered. Excellent relationships between the family, endocrinologists, and

  10. An integrated model for assessing the risk of TCE groundwater contamination to human receptors and surface water ecosystems

    DEFF Research Database (Denmark)

    McKnight, Ursula S.; Funder, S.G.; Rasmussen, J.J.

    2010-01-01

    The practical implementation of the European Water Framework Directive has resulted in an increased focus on the hyporheic zone. In this paper, an integrated model was developed for evaluating the impact of point sources in groundwater on human health and surface water ecosystems. This was accomp...

  11. Apoplastic Venom Allergen-like Proteins of Cyst Nematodes Modulate the Activation of Basal Plant Innate Immunity by Cell Surface Receptors

    Science.gov (United States)

    Lozano-Torres, Jose L.; Wilbers, Ruud H. P.; Warmerdam, Sonja; Finkers-Tomczak, Anna; Diaz-Granados, Amalia; van Schaik, Casper C.; Helder, Johannes; Bakker, Jaap; Goverse, Aska; Schots, Arjen; Smant, Geert

    2014-01-01

    Despite causing considerable damage to host tissue during the onset of parasitism, nematodes establish remarkably persistent infections in both animals and plants. It is thought that an elaborate repertoire of effector proteins in nematode secretions suppresses damage-triggered immune responses of the host. However, the nature and mode of action of most immunomodulatory compounds in nematode secretions are not well understood. Here, we show that venom allergen-like proteins of plant-parasitic nematodes selectively suppress host immunity mediated by surface-localized immune receptors. Venom allergen-like proteins are uniquely conserved in secretions of all animal- and plant-parasitic nematodes studied to date, but their role during the onset of parasitism has thus far remained elusive. Knocking-down the expression of the venom allergen-like protein Gr-VAP1 severely hampered the infectivity of the potato cyst nematode Globodera rostochiensis. By contrast, heterologous expression of Gr-VAP1 and two other venom allergen-like proteins from the beet cyst nematode Heterodera schachtii in plants resulted in the loss of basal immunity to multiple unrelated pathogens. The modulation of basal immunity by ectopic venom allergen-like proteins in Arabidopsis thaliana involved extracellular protease-based host defenses and non-photochemical quenching in chloroplasts. Non-photochemical quenching regulates the initiation of the defense-related programmed cell death, the onset of which was commonly suppressed by venom allergen-like proteins from G. rostochiensis, H. schachtii, and the root-knot nematode Meloidogyne incognita. Surprisingly, these venom allergen-like proteins only affected the programmed cell death mediated by surface-localized immune receptors. Furthermore, the delivery of venom allergen-like proteins into host tissue coincides with the enzymatic breakdown of plant cell walls by migratory nematodes. We, therefore, conclude that parasitic nematodes most likely utilize

  12. Apoplastic venom allergen-like proteins of cyst nematodes modulate the activation of basal plant innate immunity by cell surface receptors.

    Science.gov (United States)

    Lozano-Torres, Jose L; Wilbers, Ruud H P; Warmerdam, Sonja; Finkers-Tomczak, Anna; Diaz-Granados, Amalia; van Schaik, Casper C; Helder, Johannes; Bakker, Jaap; Goverse, Aska; Schots, Arjen; Smant, Geert

    2014-12-01

    Despite causing considerable damage to host tissue during the onset of parasitism, nematodes establish remarkably persistent infections in both animals and plants. It is thought that an elaborate repertoire of effector proteins in nematode secretions suppresses damage-triggered immune responses of the host. However, the nature and mode of action of most immunomodulatory compounds in nematode secretions are not well understood. Here, we show that venom allergen-like proteins of plant-parasitic nematodes selectively suppress host immunity mediated by surface-localized immune receptors. Venom allergen-like proteins are uniquely conserved in secretions of all animal- and plant-parasitic nematodes studied to date, but their role during the onset of parasitism has thus far remained elusive. Knocking-down the expression of the venom allergen-like protein Gr-VAP1 severely hampered the infectivity of the potato cyst nematode Globodera rostochiensis. By contrast, heterologous expression of Gr-VAP1 and two other venom allergen-like proteins from the beet cyst nematode Heterodera schachtii in plants resulted in the loss of basal immunity to multiple unrelated pathogens. The modulation of basal immunity by ectopic venom allergen-like proteins in Arabidopsis thaliana involved extracellular protease-based host defenses and non-photochemical quenching in chloroplasts. Non-photochemical quenching regulates the initiation of the defense-related programmed cell death, the onset of which was commonly suppressed by venom allergen-like proteins from G. rostochiensis, H. schachtii, and the root-knot nematode Meloidogyne incognita. Surprisingly, these venom allergen-like proteins only affected the programmed cell death mediated by surface-localized immune receptors. Furthermore, the delivery of venom allergen-like proteins into host tissue coincides with the enzymatic breakdown of plant cell walls by migratory nematodes. We, therefore, conclude that parasitic nematodes most likely utilize

  13. Apoplastic venom allergen-like proteins of cyst nematodes modulate the activation of basal plant innate immunity by cell surface receptors.

    Directory of Open Access Journals (Sweden)

    Jose L Lozano-Torres

    2014-12-01

    Full Text Available Despite causing considerable damage to host tissue during the onset of parasitism, nematodes establish remarkably persistent infections in both animals and plants. It is thought that an elaborate repertoire of effector proteins in nematode secretions suppresses damage-triggered immune responses of the host. However, the nature and mode of action of most immunomodulatory compounds in nematode secretions are not well understood. Here, we show that venom allergen-like proteins of plant-parasitic nematodes selectively suppress host immunity mediated by surface-localized immune receptors. Venom allergen-like proteins are uniquely conserved in secretions of all animal- and plant-parasitic nematodes studied to date, but their role during the onset of parasitism has thus far remained elusive. Knocking-down the expression of the venom allergen-like protein Gr-VAP1 severely hampered the infectivity of the potato cyst nematode Globodera rostochiensis. By contrast, heterologous expression of Gr-VAP1 and two other venom allergen-like proteins from the beet cyst nematode Heterodera schachtii in plants resulted in the loss of basal immunity to multiple unrelated pathogens. The modulation of basal immunity by ectopic venom allergen-like proteins in Arabidopsis thaliana involved extracellular protease-based host defenses and non-photochemical quenching in chloroplasts. Non-photochemical quenching regulates the initiation of the defense-related programmed cell death, the onset of which was commonly suppressed by venom allergen-like proteins from G. rostochiensis, H. schachtii, and the root-knot nematode Meloidogyne incognita. Surprisingly, these venom allergen-like proteins only affected the programmed cell death mediated by surface-localized immune receptors. Furthermore, the delivery of venom allergen-like proteins into host tissue coincides with the enzymatic breakdown of plant cell walls by migratory nematodes. We, therefore, conclude that parasitic nematodes

  14. Integrated molecular targeting of IGF1R and HER2 surface receptors and destruction of breast cancer cells using single wall carbon nanotubes

    International Nuclear Information System (INIS)

    Shao Ning; Lu Shaoxin; Wickstrom, Eric; Panchapakesan, Balaji

    2007-01-01

    Molecular targeting and photodynamic therapy have shown great potential for selective cancer therapy. We hypothesized that monoclonal antibodies that are specific to the IGF1 receptor and HER2 cell surface antigens could be bound to single wall carbon nanotubes (SWCNT) in order to concentrate SWCNT on breast cancer cells for specific near-infrared phototherapy. SWCNT functionalized with HER2 and IGF1R specific antibodies showed selective attachment to breast cancer cells compared to SWCNT functionalized with non-specific antibodies. After the complexes were attached to specific cancer cells, SWCNT were excited by ∼808 nm infrared photons at ∼800 mW cm -2 for 3 min. Viability after phototherapy was determined by Trypan blue exclusion. Cells incubated with SWCNT/non-specific antibody hybrids were still alive after photo-thermal treatment due to the lack of SWNT binding to the cell membrane. All cancerous cells treated with IGF1R and HER2 specific antibody/SWCNT hybrids and receiving infrared photons showed cell death after the laser excitation. Quantitative analysis demonstrated that all the cells treated with SWCNT/IGF1R and HER2 specific antibody complex were completely destroyed, while more than 80% of the cells with SWCNT/non-specific antibody hybrids remained alive. Following multi-component targeting of IGF1R and HER2 surface receptors, integrated photo-thermal therapy in breast cancer cells led to the complete destruction of cancer cells. Functionalizing SWCNT with antibodies in combination with their intrinsic optical properties can therefore lead to a new class of molecular delivery and cancer therapeutic systems

  15. Physical and functional interactions between SH2 and SH3 domains of the Src family protein tyrosine kinase p59fyn

    NARCIS (Netherlands)

    Panchamoorthy, G.; Fukazawa, T.; Stolz, L.; Payne, G.; Reedquist, K.; Shoelson, S.; Songyang, Z.; Cantley, L.; Walsh, C.; Band, H.

    1994-01-01

    The Src family protein tyrosine kinases participate in signalling through cell surface receptors that lack intrinsic tyrosine kinase domains. All nine members of this family possess adjacent Src homology (SH2 and SH3) domains, both of which are essential for repression of the enzymatic activity. The

  16. [GPCRs heterodimerization: a new way towards the discovery of function for the orphan receptors?].

    Science.gov (United States)

    Levoye, Angélique; Jockers, Ralf

    2007-01-01

    G protein-coupled receptors (GPCRs), also called seven transmembrane domain (7TM) proteins, represent the largest family of cell surface receptors. GPCRs control a variety of physiological processes, are involved in multiple diseases and are major drug targets. Despite a vast effort of academic and industrial research, more than one hundred receptors remain orphans. These orphan GPCRs offer a great potential for drug discovery, as almost 60% of currently prescribed drugs target GPCRs. Deorphenization strategies have concentrated mainly on the identification of the natural ligands of these proteins. Recent advances have shown that orphan GPCRs, similar to orphan nuclear receptors, can regulate the function of non-orphan receptors by heterodimerization. These findings not only help to better understand the extraordinary diversity of GPCRs, but also open new perspectives for the identification of the function of these orphan receptors that hold great therapeutic potential.

  17. Cloning of human tumor necrosis factor (TNF) receptor cDNA and expression of recombinant soluble TNF-binding protein

    International Nuclear Information System (INIS)

    Gray, P.W.; Barrett, K.; Chantry, D.; Turner, M.; Feldmann, M.

    1990-01-01

    The cDNA for one of the receptors for human tumor necrosis factor (TNF) has been isolated. This cDNA encodes a protein of 455 amino acids that is divided into an extracellular domain of 171 residues and a cytoplasmic domain of 221 residues. The extracellular domain has been engineered for expression in mammalian cells, and this recombinant derivative binds TNFα with high affinity and inhibits its cytotoxic activity in vitro. The TNF receptor exhibits similarity with a family of cell surface proteins that includes the nerve growth factor receptor, the human B-cell surface antigen CD40, and the rat T-cell surface antigen OX40. The TNF receptor contains four cysteine-rich subdomains in the extracellular portion. Mammalian cells transfected with the entire TNF receptor cDNA bind radiolabeled TNFα with an affinity of 2.5 x 10 -9 M. This binding can be competitively inhibited with unlabeled TNFα or lymphotoxin (TNFβ)

  18. GPR81, a Cell-Surface Receptor for Lactate, Regulates Intestinal Homeostasis and Protects Mice from Experimental Colitis.

    Science.gov (United States)

    Ranganathan, Punithavathi; Shanmugam, Arulkumaran; Swafford, Daniel; Suryawanshi, Amol; Bhattacharjee, Pushpak; Hussein, Mohamed S; Koni, Pandelakis A; Prasad, Puttur D; Kurago, Zoya B; Thangaraju, Muthusamy; Ganapathy, Vadivel; Manicassamy, Santhakumar

    2018-03-01

    At mucosal sites such as the intestine, the immune system launches robust immunity against invading pathogens while maintaining a state of tolerance to commensal flora and ingested food Ags. The molecular mechanisms underlying this phenomenon remain poorly understood. In this study, we report that signaling by GPR81, a receptor for lactate, in colonic dendritic cells and macrophages plays an important role in suppressing colonic inflammation and restoring colonic homeostasis. Genetic deletion of GPR81 in mice led to increased Th1/Th17 cell differentiation and reduced regulatory T cell differentiation, resulting in enhanced susceptibility to colonic inflammation. This was due to increased production of proinflammatory cytokines (IL-6, IL-1β, and TNF-α) and decreased expression of immune regulatory factors (IL-10, retinoic acid, and IDO) by intestinal APCs lacking GPR81. Consistent with these findings, pharmacological activation of GPR81 decreased inflammatory cytokine expression and ameliorated colonic inflammation. Taken together, these findings identify a new and important role for the GPR81 signaling pathway in regulating immune tolerance and colonic inflammation. Thus, manipulation of the GPR81 pathway could provide novel opportunities for enhancing regulatory responses and treating colonic inflammation. Copyright © 2018 by The American Association of Immunologists, Inc.

  19. Insulin receptors

    International Nuclear Information System (INIS)

    Kahn, C.R.; Harrison, L.C.

    1988-01-01

    This book contains the proceedings on insulin receptors. Part A: Methods for the study of structure and function. Topics covered include: Method for purification and labeling of insulin receptors, the insulin receptor kinase, and insulin receptors on special tissues

  20. Receptor activity modifying proteins (RAMPs) interact with the VPAC1 receptor: evidence for differential RAMP modulation of multiple signalling pathways

    International Nuclear Information System (INIS)

    Christopoulos, G.; Morfis, M.; Sexton, P.M.; Christopoulos, A.; Laburthe, M.; Couvineau, A.

    2001-01-01

    Full text: Receptor activity modifying proteins (RAMP) constitute a family of three accessory proteins that affect the expression and/or phenotype of the calcitonin receptor (CTR) or CTR-like receptor (CRLR). In this study we screened a range of class II G protein-coupled receptors (PTH1, PTH2, GHRH, VPAC1, VPAC2 receptors) for possible RAMP interactions by measurement of receptor-induced translocation of c-myc tagged RAMP1 or HA tagged RAMP3. Of these, only the VPAC1 receptor caused significant translocation of c-myc-RAMP1 or HA-RAMP3 to the cell surface. Co-transfection of VPAC1 and RAMPs did not alter 125 I-VIP binding and specificity. VPAC1 receptor function was subsequently analyzed through parallel determinations of cAMP accumulation and phosphoinositide (PI) hydrolysis in the presence and absence of each of the three RAMPs. In contrast to CTR-RAMP interaction, where there was an increase in cAMP Pharmacologisand a decrease in PI hydrolysis, VPAC1-RAMP interaction was characterized by a specific increase in agonist-mediated PI hydrolysis when co-transfected with RAMP2. This change was due to an enhancement of Emax with no change in EC 50 value for VIP. No significant change in cAMP accumulation was observed. This is the first demonstration of an interaction of RAMPs with a G protein-coupled receptor outside the CTR family and may suggest a more generalized role for RAMPs in modulating G protein-coupled receptor signaling. Copyright (2001) Australasian Society of Clinical and Experimental Pharmacologists and Toxicologists

  1. C,N-bipyrazole receptor grafted onto a porous silica surface as a novel adsorbent based polymer hybrid.

    Science.gov (United States)

    Radi, Smaail; Attayibat, Ahmed; El-Massaoudi, Mohamed; Bacquet, Maryse; Jodeh, Shehdeh; Warad, Ismail; Al-Showiman, Salim S; Mabkhot, Yahia N

    2015-10-01

    A simple heterogeneous synthesis of pure adsorbent based polymer hybrid made by condensing a functionalized C,N-bipyrazole with a 3-glycidoxypropyl-trimethoxysilane silylant agent, previously anchored on a silica surface was developed. The formed material (SG2P) was characterized through elemental analysis, FT-IR spectroscopy, (13)C NMR of solid state, scanning electron microscope (SEM), and was studied and evaluated by determination of the surface area using the BET equation, the adsorption and desorption capability using the isotherm of nitrogen and B.J.H. pore sizes. The new material exhibits good thermal stability determined by thermogravimetry curves and good chemical stability was examined in various acidic and buffer solutions (pH 1-7). The binding and adsorption abilities of SG2P were investigated for Hg(2+), Cd(2+), Pb(2+), Zn(2+), K(+), Na(+) and Li(+) cations and compared to the results of classical liquid-liquid extraction with the unbound C,N-bipyrazole compound. The grafting at the surface of silica does not affect complexing properties of the ligand and the SG2P exhibits a high selectivity toward Hg(2+) ion with no complexation being observed towards zinc and alkali metals. The extracted and the complexing cation percentages were determined by atomic absorption measurements. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Characterization, cell-surface expression and ligand-binding properties of different truncated N-terminal extracellular domains of the ionotropic glutamate receptor subunit GluR1.

    Science.gov (United States)

    McIlhinney, R A; Molnár, E

    1996-04-01

    To identify the location of the first transmembrane segment of the GluR1 glutamate receptor subunit artificial stop codons have been introduced into the N-terminal domain at amino acid positions 442, 510, and 563, namely just before and spanning the proposed first two transmembrane regions. The resultant truncated N-terminal fragments of GluR1, termed NT1, NT2, and NT3 respectively were expressed in Cos-7 cells and their cellular distribution and cell-surface expression analysed using an N-terminal antibody to GluR1. All of the fragments were fully glycosylated and were found to be associated with cell membranes but none was secreted. Differential extraction of the cell membranes indicated that both NT1 and NT2 behave as peripheral membrane proteins. In contrast NT3, like the full subunit, has integral membrane protein properties. Furthermore only NT3 is expressed at the cell surface as determined by immunofluorescence and cell-surface biotinylation. Protease protection assays indicated that only NT3 had a cytoplasmic tail. Binding studies using the selective ligand [(3)H]alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate ([(3)H]AMPA) demonstrated that NT3 does not bind ligand. Together these results indicate that the first transmembrane domain of the GluR1 subunit lies between residues 509 and 562, that the N-terminal domain alone cannot form a functional ligand-binding site and that this domain can be targeted to the cell surface provided that it has a transmembrane-spanning region.

  3. Stimulation of the innate immune system of carp: role of Toll-like receptors

    NARCIS (Netherlands)

    Pietretti, D.

    2013-01-01

    Toll-like receptors (TLRs), named after the Toll gene identified in fruit flies, are a family of evolutionary conserved proteins that play a key role in the innate immune system. TLRs are found inside or on the surface of immune cells of virtually all-living animals and recognize integral parts

  4. Saddle-like topological surface states on the T T'X family of compounds (T , T' = Transition metal, X =Si , Ge)

    Science.gov (United States)

    Singh, Bahadur; Zhou, Xiaoting; Lin, Hsin; Bansil, Arun

    2018-02-01

    Topological nodal-line semimetals are exotic conductors that host symmetry-protected conducting nodal lines in their bulk electronic spectrum and nontrivial drumhead states on the surface. Based on first-principles calculations and an effective model analysis, we identify the presence of topological nodal-line semimetal states in the low crystalline symmetric T T'X family of compounds (T ,T' = transition metal, X = Si or Ge) in the absence of spin-orbit coupling (SOC). Taking ZrPtGe as an exemplar system, we show that owing to small lattice symmetry this material harbors a single nodal line on the ky=0 plane with large energy dispersion and unique drumhead surface state with a saddlelike energy dispersion. When the SOC is included, the nodal line gaps out and the system transitions to a strong topological insulator state with Z2=(1 ;000 ) . The topological surface state evolves from the drumhead surface state via the sharing of its saddlelike energy dispersion within the bulk energy gap. These features differ remarkably from those of the currently known topological surface states in topological insulators such as Bi2Se3 with Dirac-cone-like energy dispersions.

  5. The Role of Hydrophobicity and Surface Receptors at Hyphae of Lyophyllum sp. Strain Karsten in the Interaction with Burkholderia terrae BS001 – Implications for Interactions in Soil

    Science.gov (United States)

    Vila, Taissa; Nazir, Rashid; Rozental, Sonia; dos Santos, Giulia M. P.; Calixto, Renata O. R.; Barreto-Bergter, Eliana; Wick, Lukas Y.; van Elsas, Jan Dirk

    2016-01-01

    The soil bacterium Burkholderia terrae strain BS001 can interact with varying soil fungi, using mechanisms that range from the utilization of carbon/energy sources such as glycerol to the ability to reach novel territories in soil via co-migration with growing fungal mycelia. Here, we investigate the intrinsic properties of the B. terrae BS001 interaction with the basidiomycetous soil fungus Lyophyllum sp. strain Karsten. In some experiments, the ascomycetous Trichoderma asperellum 302 was also used. The hyphae of Lyophyllum sp. strain Karsten were largely hydrophilic on water-containing media versus hydrophobic when aerial, as evidenced by contact angle analyses (CA). Co-migration of B. terrae strain BS001 cells with the hyphae of the two fungi occurred preferentially along the - presumably hydrophilic - soil-dwelling hyphae, whereas aerial hyphae did not allow efficient migration, due to reduced thickness of their surrounding mucous films. Moreover, the cell numbers over the length of the hyphae in soil showed an uneven distribution, i.e., the CFU numbers increased from minima at the inoculation point to maximal numbers in the middle of the extended hyphae, then decreasing toward the terminal side. Microscopic analyses of the strain BS001 associations with the Lyophyllum sp. strain Karsten hyphae in the microcosms confirmed the presence of B. terrae BS001 cells on the mucous matter that was present at the hyphal surfaces of the fungi used. Cell agglomerates were found to accumulate at defined sites on the hyphal surfaces, which were coined ‘fungal-interactive’ hot spots. Evidence was further obtained for the contention that receptors for a physical bacterium-fungus interaction occur at the Lyophyllum sp. strain Karsten hyphal surface, in which the specific glycosphingolipid ceramide monohexoside (CMH) plays an important role. Thus, bacterial adherence may be mediated by heterogeneously distributed fungal-specific receptors, implying the CMH moieties. This

  6. Role of Site-Specific N-Glycans Expressed on GluA2 in the Regulation of Cell Surface Expression of AMPA-Type Glutamate Receptors.

    Directory of Open Access Journals (Sweden)

    Yusuke Takeuchi

    Full Text Available The AMPA-type glutamate receptor (AMPAR, which is a tetrameric complex composed of four subunits (GluA1-4 with several combinations, mediates the majority of rapid excitatory synaptic transmissions in the nervous system. Cell surface expression levels of AMPAR modulate synaptic plasticity, which is considered one of the molecular bases for learning and memory formation. To date, a unique trisaccharide (HSO3-3GlcAβ1-3Galβ1-4GlcNAc, human natural killer-1 (HNK-1 carbohydrate, was found expressed specifically on N-linked glycans of GluA2 and regulated the cell surface expression of AMPAR and the spine maturation process. However, evidence that the HNK-1 epitope on N-glycans of GluA2 directly affects these phenomena is lacking. Moreover, it is thought that other N-glycans on GluA2 also have potential roles in the regulation of AMPAR functions. In the present study, using a series of mutants lacking potential N-glycosylation sites (N256, N370, N406, and N413 within GluA2, we demonstrated that the mutant lacking the N-glycan at N370 strongly suppressed the intracellular trafficking of GluA2 from the endoplasmic reticulum (ER in HEK293 cells. Cell surface expression of GluA1, which is a major subunit of AMPAR in neurons, was also suppressed by co-expression of the GluA2 N370S mutant. The N370S mutant and wild-type GluA2 were co-immunoprecipitated with GluA1, suggesting that N370S was properly associated with GluA1. Moreover, we found that N413 was the main potential site of the HNK-1 epitope that promoted the interaction of GluA2 with N-cadherin, resulting in enhanced cell surface expression of GluA2. The HNK-1 epitope on N-glycan at the N413 of GluA2 was also involved in the cell surface expression of GluA1. Thus, our data suggested that site-specific N-glycans on GluA2 regulate the intracellular trafficking and cell surface expression of AMPAR.

  7. Manipulation of Very Few Receptor Discriminator Residues Greatly Enhances Receptor Specificity of Non-visual Arrestins*

    Science.gov (United States)

    Gimenez, Luis E.; Vishnivetskiy, Sergey A.; Baameur, Faiza; Gurevich, Vsevolod V.

    2012-01-01

    Based on the identification of residues that determine receptor selectivity of arrestins and the analysis of the evolution in the arrestin family, we introduced 10 mutations of “receptor discriminator” residues in arrestin-3. The recruitment of these mutants to M2 muscarinic (M2R), D1 (D1R) and D2 (D2R) dopamine, and β2-adrenergic receptors (β2AR) was assessed using bioluminescence resonance energy transfer-based assays in cells. Seven of 10 mutations differentially affected arrestin-3 binding to individual receptors. D260K and Q262P reduced the binding to β2AR, much more than to other receptors. The combination D260K/Q262P virtually eliminated β2AR binding while preserving the interactions with M2R, D1R, and D2R. Conversely, Y239T enhanced arrestin-3 binding to β2AR and reduced the binding to M2R, D1R, and D2R, whereas Q256Y selectively reduced recruitment to D2R. The Y239T/Q256Y combination virtually eliminated the binding to D2R and reduced the binding to β2AR and M2R, yielding a mutant with high selectivity for D1R. Eleven of 12 mutations significantly changed the binding to light-activated phosphorhodopsin. Thus, manipulation of key residues on the receptor-binding surface modifies receptor preference, enabling the construction of non-visual arrestins specific for particular receptor subtypes. These findings pave the way to the construction of signaling-biased arrestins targeting the receptor of choice for research or therapeutic purposes. PMID:22787152

  8. Manipulation of very few receptor discriminator residues greatly enhances receptor specificity of non-visual arrestins.

    Science.gov (United States)

    Gimenez, Luis E; Vishnivetskiy, Sergey A; Baameur, Faiza; Gurevich, Vsevolod V

    2012-08-24

    Based on the identification of residues that determine receptor selectivity of arrestins and the analysis of the evolution in the arrestin family, we introduced 10 mutations of "receptor discriminator" residues in arrestin-3. The recruitment of these mutants to M2 muscarinic (M2R), D1 (D1R) and D2 (D2R) dopamine, and β(2)-adrenergic receptors (β(2)AR) was assessed using bioluminescence resonance energy transfer-based assays in cells. Seven of 10 mutations differentially affected arrestin-3 binding to individual receptors. D260K and Q262P reduced the binding to β(2)AR, much more than to other receptors. The combination D260K/Q262P virtually eliminated β(2)AR binding while preserving the interactions with M2R, D1R, and D2R. Conversely, Y239T enhanced arrestin-3 binding to β(2)AR and reduced the binding to M2R, D1R, and D2R, whereas Q256Y selectively reduced recruitment to D2R. The Y239T/Q256Y combination virtually eliminated the binding to D2R and reduced the binding to β(2)AR and M2R, yielding a mutant with high selectivity for D1R. Eleven of 12 mutations significantly changed the binding to light-activated phosphorhodopsin. Thus, manipulation of key residues on the receptor-binding surface modifies receptor preference, enabling the construction of non-visual arrestins specific for particular receptor subtypes. These findings pave the way to the construction of signaling-biased arrestins targeting the receptor of choice for research or therapeutic purposes.

  9. Energetics and Structure Prediction of the Network of Homo- and Hetero-Oligomers Formed by the Transmembrane Domains of the ErbReceptor Family of Proteins

    Science.gov (United States)

    2006-06-01

    amino acid residue motif, Small-x-x-Large-G/A, consist- ing of a small residue (Gly, Ala , Ser, Thr, or Pro) in the zero position, a large aliphatic...residue ( Ala , Val, Leu, or Ile) in position 3, followed by Gly or Ala in position four.15 This motif was identified in a large number of receptor tyrosine...M. A., Codony-Servat, J., Albanell, J., Rojo, F., Arribas , J. & Baselga, J. (2001). Trastuzumab (her- ceptin), a humanized anti-Her2 receptor

  10. No evidence for a major gene effect of the dopamine D{sub 4} receptor gene in the susceptibility to Gilles de la Tourette Syndrome in five Canadian families

    Energy Technology Data Exchange (ETDEWEB)

    Barr, C.L.; Wigg, K.G.; Tsui, Lap-Chee [Univ. of Toronto, Ontario (Canada)] [and others

    1996-05-31

    Gilles de la Tourette Syndrome (TS) is a neuropsychiatric disorder characterized by both motor and vocal tics affecting approximately 1/10,000 females and 1/2000 males. Because of the success of neuroleptics and other agents interacting with the dopaminergic system in the suppression of tics, a defect in the dopamine system has been hypothesized in the etiology of TS. In this paper we test the hypothesis that the dopamine D{sub 4} receptor (DRD44) is linked to the genetic susceptibility to TS in five families. We tested three polymorphisms in the DRD4 gene and a polymorphism in the closely linked locus, tyrosine hydroxylase (TH). We found no evidence for linkage of DRD4 or TH to TS using an autosomal dominant model with reduced penetrance or using non-parametric methods. The presence of a mutation that results in a truncated non-functional D{sub 4} receptor protein was also tested for, but was not observed in these families. 36 refs., 1 tab.

  11. Responses to microbial challenges by SLAMF receptors

    Directory of Open Access Journals (Sweden)

    Boaz Job Van Driel

    2016-01-01

    Full Text Available The SLAMF Family (SLAMF of cell surface glycoproteins is comprised of nine glycoproteins and whilst SLAMF1, 3, 5, 6, 7, 8, 9 are self-ligand receptors, SLAMF2 and SLAMF4 interact with each other. Their interactions induce signal transduction networks in trans, thereby shaping immune cell-cell communications. Collectively, these receptors modulate a wide range of functions, such as myeloid cell and lymphocyte development and, T and B cell responses to microbes and parasites. In addition, several SLAMF receptors serve as microbial sensors, which either positively or negatively modulate the function of macrophages, dendritic cells, neutrophils and NK cells in response to microbial challenges. The SLAMF receptor-microbe interactions contribute both to intracellular microbicidal activity as well as to migration of phagocytes to the site of inflammation. In this review, we describe the current knowledge on how the SLAMF receptors and their specific adapters SAP and EAT-2 regulate innate and adaptive immune responses to microbes.

  12. Decreased surface expression of the δ subunit of the GABAA receptor contributes to reduced tonic inhibition in dentate granule cells in a mouse model of fragile X syndrome.

    Science.gov (United States)

    Zhang, Nianhui; Peng, Zechun; Tong, Xiaoping; Lindemeyer, A Kerstin; Cetina, Yliana; Huang, Christine S; Olsen, Richard W; Otis, Thomas S; Houser, Carolyn R

    2017-11-01

    While numerous changes in the GABA system have been identified in models of Fragile X Syndrome (FXS), alterations in subunits of the GABA A receptors (GABA A Rs) that mediate tonic inhibition are particularly intriguing. Considering the key role of tonic inhibition in controlling neuronal excitability, reduced tonic inhibition could contribute to FXS-associated disorders such as hyperactivity, hypersensitivity, and increased seizure susceptibility. The current study has focused on the expression and function of the δ subunit of the GABA A R, a major subunit involved in tonic inhibition, in granule cells of the dentate gyrus in the Fmr1 knockout (KO) mouse model of FXS. Electrophysiological studies of dentate granule cells revealed a marked, nearly four-fold, decrease in tonic inhibition in the Fmr1 KO mice, as well as reduced effects of two δ subunit-preferring pharmacological agents, THIP and DS2, supporting the suggestion that δ subunit-containing GABA A Rs are compromised in the Fmr1 KO mice. Immunohistochemistry demonstrated a small but statistically significant decrease in δ subunit labeling in the molecular layer of the dentate gyrus in Fmr1 KO mice compared to wildtype (WT) littermates. The discrepancy between the large deficits in GABA-mediated tonic inhibition in granule cells in the Fmr1 KO mice and only modest reductions in immunolabeling of the δ subunit led to studies of surface expression of the δ subunit. Cross-linking experiments followed by Western blot analysis demonstrated a small, non-significant decrease in total δ subunit protein in the hippocampus of Fmr1 KO mice, but a four-fold decrease in surface expression of the δ subunit in these mice. No significant changes were observed in total or surface expression of the α4 subunit protein, a major partner of the δ subunit in the forebrain. Postembedding immunogold labeling for the δ subunit demonstrated a large, three-fold, decrease in the number of symmetric synapses with

  13. Analysis of surface binding sites (SBSs) in carbohydrate active enzymes with focus on glycoside hydrolase families 13 and 77

    DEFF Research Database (Denmark)

    Cockburn, Darrell; Wilkens, Casper; Ruzanski, Christian

    2014-01-01

    Surface binding sites (SBSs) interact with carbohydrates outside of the enzyme active site. They are frequently situated on catalytic domains and are distinct from carbohydrate binding modules (CBMs). SBSs are found in a variety of enzymes and often seen in crystal structures. Notably about half ...

  14. Plasma membrane cholesterol level and agonist-induced internalization of delta-opioid receptors; colocalization study with intracellular membrane markers of Rab family\

    Czech Academy of Sciences Publication Activity Database

    Brejchová, Jana; Vošahlíková, Miroslava; Roubalová, Lenka; Parenti, M.; Mauri, M.; Chernyavskiy, Oleksandr; Svoboda, Petr

    2016-01-01

    Roč. 48, č. 4 (2016), s. 375-396 ISSN 0145-479X R&D Projects: GA ČR(CZ) GAP207/12/0919 Institutional support: RVO:67985823 Keywords : cholesterol * plasma membrane * delta-opioid receptor * internalization * Rab proteins Subject RIV: CE - Biochemistry Impact factor: 2.576, year: 2016

  15. The E3 Ubiquitin Ligase IDOL Induces the Degradation of the Low Density Lipoprotein Receptor Family Members VLDLR and ApoER2

    NARCIS (Netherlands)

    Hong, Cynthia; Duit, Sarah; Jalonen, Pilvi; Out, Ruud; Scheer, Lilith; Sorrentino, Vincenzo; Boyadjian, Rima; Rodenburg, Kees C. W.; Foley, Edan; Korhonen, Laura; Lindholm, Dan; Nimpf, Johannes; van Berkel, Theo J. C.; Tontonoz, Peter; Zelcer, Noam

    2010-01-01

    We have previously identified the E3-ubiquitin ligase Inducible Degrader of the LDLR (Idol)1 as a post-translational modulator of LDLR levels. Idol is a direct target for regulation by Liver X Receptors (LXRs) and its expression is responsive to cellular sterol status independent of the

  16. Serotonin Transporter (5-HTT) and gamma-Aminobutyric Acid Receptor Subunit beta3 (GABRB3) Gene Polymorphisms are not Associated with Autism in the IMGSA Families

    DEFF Research Database (Denmark)

    Maestrini, E.; Lai, C.; Marlow, A.

    1999-01-01

    Previous studies have suggested that the serotonin transporter (5-HTT) gene and the gamma-aminobutyric acid receptor subunit beta3 (GABRB3) gene, or other genes in the 15q11-q13 region, are possibly involved in susceptibility to autism. To test this hypothesis we performed an association study on...

  17. Molecular Characterization and Differential Expression of an Olfactory Receptor Gene Family in the White-Backed Planthopper Sogatella furcifera Based on Transcriptome Analysis.

    Directory of Open Access Journals (Sweden)

    Ming He

    Full Text Available The white-backed planthopper, Sogatella furcifera, a notorious rice pest in Asia, employs host plant volatiles as cues for host location. In insects, odor detection is mediated by two types of olfactory receptors: odorant receptors (ORs and ionotropic receptors (IRs. In this study, we identified 63 SfurORs and 14 SfurIRs in S. furcifera based on sequences obtained from the head transcriptome and bioinformatics analysis. The motif-pattern of 130 hemiptera ORs indicated an apparent differentiation in this order. Phylogenetic trees of the ORs and IRs were constructed using neighbor-joining estimates. Most of the ORs had orthologous genes, but a specific OR clade was identified in S. furcifera, which suggests that these ORs may have specific olfactory functions in this species. Our results provide a basis for further investigations of how S. furcifera coordinates its olfactory receptor genes with its plant hosts, thereby providing a foundation for novel pest management approaches based on these genes.

  18. Association Analysis of Arg16Gly Polymorphism of the Beta2-adreneric Receptor Gene in Offspring from Hypertensive and Normotensive Families

    Czech Academy of Sciences Publication Activity Database

    Jindra, A.; Horký, K.; Peleška, Jan; Jáchymová, M.; Bultas, J.; Umnerová, V.; Heller, S.; Hlubocká, Z.

    2002-01-01

    Roč. 11, č. 4 (2002), s. 213-217 ISSN 0803-7051 R&D Projects: GA MZd NA5615 Keywords : Arg16Gly polymorphism of the beta2-adrenergic receptor gene * normotensive offspring * essential hypertension Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 1.344, year: 2002

  19. A common W556S mutation in the LDL receptor gene of Danish patients with familial hypercholesterolemia encodes a transport-defective protein

    DEFF Research Database (Denmark)

    Jensen, H K; Holst, H; Jensen, L G

    1997-01-01

    -Trp-Thr-Asp in the epidermal growth factor homology region, was studied in transfected COS-7 cells expressing normal and mutant LDL receptor cDNAs. Results obtained by immunofluorescence flow cytometry and confocal microscopy, as well as by immunoprecipitation, were compatible with complete retention of the mutant protein...

  20. Detection of Serum Lysophosphatidic Acids Using Affinity Binding and Surface Enhanced Laser Desorption/Ionization (SELDI) Time of Flight Mass Spectrometry

    Science.gov (United States)

    2005-04-01

    sensitivity to cisplatin (the most effective drug in ovarian cancer), and increases production and activity of multiple growth factors, proteases and...clinical grade assay. The detection approach of cocrystalizing LPA and Zn is an improvement of the approach proposed here and will be implemented in our...surface receptors for lysophospholipids belong to the G protein coupled receptor family. As over 40% of all drugs in current use target this family of

  1. The interleukin-4 receptor: signal transduction by a hematopoietin receptor.

    Science.gov (United States)

    Keegan, A D; Pierce, J H

    1994-02-01

    Over the last several years, the receptors for numerous cytokines have been molecularly characterized. Analysis of their amino acid sequences shows that some of these receptors bear certain motifs in their extracellular domains that define a family of receptors called the Hematopoietin receptor superfamily. Significant advances in characterizing the structure, function, and mechanisms of signal transduction have been made for several members of this family. The purpose of this review is to discuss the recent advances made for one of the family members, the interleukin (IL) 4 receptor. Other receptor systems have recently been reviewed elsewhere. The IL-4 receptor consists of, at the minimum, the cloned 140 kDa IL-4-binding chain with the potential for associating with other chains. The IL-4 receptor transduces its signal by activating a tyrosine kinase that phosphorylates cellular substrates, including the receptor itself, and the 170 kDa substrate called 4PS. Phosphorylated 4PS interacts with the SH2 domain of the enzyme PI-3'-kinase and increases its enzymatic activity. These early events in the IL-4 receptor initiated signaling pathway may trigger a series of signals that will ultimately lead to an IL-4 specific biologic outcome.

  2. The N-terminal region of the dopamine D2 receptor, a rhodopsin-like GPCR, regulates correct integration into the plasma membrane and endocytic routes

    Science.gov (United States)

    Cho, DI; Min, C; Jung, KS; Cheong, SY; Zheng, M; Cheong, SJ; Oak, MH; Cheong, JH; Lee, BK; Kim, KM

    2012-01-01

    BACKGROUND AND PURPOSE Functional roles of the N-terminal region of rhodopsin-like GPCR family remain unclear. Using dopamine D2 and D3 receptors as a model system, we probed the roles of the N-terminal region in the signalling, intracellular trafficking of receptor proteins, and explored the critical factors that determine the functionality of the N-terminal region. EXPERIMENTAL APPROACH The N-terminal region of the D2 receptor was gradually shortened or switched with that of the D3 receptor or a non-specific sequence (FLAG), or potential N-terminal glycosylation sites were mutated. Effects of these manipulations on surface expression, internalization, post-endocytic behaviours and signalling were determined. KEY RESULTS Shortening the N-terminal region of the D2 receptor enhanced receptor internalization and impaired surface expression and signalling; ligand binding, desensitization and down-regulation were not affected but their association with a particular microdomain, caveolae, was disrupted. Replacement of critical residues within the N-terminal region with the FLAG epitope failed to restore surface expression but partially restored the altered internalization and signalling. When the N-terminal regions were switched between D2 and D3 receptors, cell surface expression pattern of each receptor was switched. Mutations of potential N-terminal glycosylation sites inhibited surface expression but enhanced internalization of D2 receptors. CONCLUSIONS AND IMPLICATIONS Shortening of N-terminus or mutation of glycosylation sites located within the N-terminus enhanced receptor internalization but impaired the surface expression of D2 receptors. The N-terminal region of the D2 receptor, in a sequence-specific manner, controls the receptor's conformation and integration into the plasma membrane, which determine its subcellular localization, intracellular trafficking and signalling properties. PMID:22117524

  3. Presence of Epstein-Barr virus-infected B lymphocytes with thyrotropin receptor antibodies on their surface in Graves' disease patients and in healthy individuals.

    Science.gov (United States)

    Nagata, Keiko; Higaki, Katsumi; Nakayama, Yuji; Miyauchi, Hiromi; Kiritani, Yui; Kanai, Kyosuke; Matsushita, Michiko; Iwasaki, Takeshi; Sugihara, Hirotsugu; Kuwamoto, Satoshi; Kato, Masako; Murakami, Ichiro; Nanba, Eiji; Kimura, Hiroshi; Hayashi, Kazuhiko

    2014-05-01

    Graves' disease is an autoimmune hyperthyroidism caused by thyrotropin receptor antibodies (TRAbs). Because Epstein-Barr virus (EBV) persists in B cells and is occasionally reactivated, we hypothesized that EBV contributes to TRAbs production in Graves' disease patients by stimulating the TRAbs-producing B cells. In order for EBV to stimulate antibody-producing cells, EBV must be present in those cells but that have not yet been observed. We examined whether EBV-infected (EBV(+)) B cells with TRAbs on their surface (TRAbs(+)) as membrane immunoglobulin were present in peripheral blood of Graves' disease patients. We analyzed cultured or non-cultured peripheral blood mononuclear cells (PBMCs) from 13 patients and 11 healthy controls by flow-cytometry and confocal laser microscopy, and confirmed all cultured PBMCs from 8 patients really had TRAbs(+) EBV(+) double positive cells. We unexpectedly detected TRAbs(+) cells in all healthy controls, and TRAbs(+) EBV(+) double positive cells in all cultured PBMC from eight healthy controls. The frequency of TRAbs(+) cells in cultured PBMCs was significantly higher in patients than in controls (p = 0.021). In this study, we indicated the presence of EBV-infected B lymphocytes with TRAbs on their surface, a possible player of the production of excessive TRAbs, the causative autoantibody for Graves' disease. This is a basic evidence for our hypothesis that EBV contributes to TRAbs production in Graves' disease patients. Our results further suggest that healthy controls have the potential for TRAbs production. This gives us an important insight into the pathogenesis of Graves' disease.

  4. Combination of Hypomorphic Mutations of the Drosophila Homologues of Aryl Hydrocarbon Receptor and Nucleosome Assembly Protein Family Genes Disrupts Morphogenesis, Memory and Detoxification

    OpenAIRE

    Kuzin, Boris A.; Nikitina, Ekaterina A.; Cherezov, Roman O.; Vorontsova, Julia E.; Slezinger, Mikhail S.; Zatsepina, Olga G.; Simonova, Olga B.; Enikolopov, Grigori N.; Savvateeva-Popova, Elena V.

    2014-01-01

    Aryl hydrocarbon receptor is essential for biological responses to endogenous and exogenous toxins in mammals. Its Drosophila homolog spineless plays an important role in fly morphogenesis. We have previously shown that during morphogenesis spineless genetically interacts with CG5017 gene, which encodes a nucleosome assembly factor and may affect cognitive function of the fly. We now demonstrate synergistic interactions of spineless and CG5017 in pathways controlling oxidative stress response...

  5. The Role of Rab Proteins in Neuronal Cells and in the Trafficking of Neurotrophin Receptors

    Directory of Open Access Journals (Sweden)

    Cecilia Bucci

    2014-10-01

    Full Text Available Neurotrophins are a family of proteins that are important for neuronal development, neuronal survival and neuronal functions. Neurotrophins exert their role by binding to their receptors, the Trk family of receptor tyrosine kinases (TrkA, TrkB, and TrkC and p75NTR, a member of the tumor necrosis factor (TNF receptor superfamily. Binding of neurotrophins to receptors triggers a complex series of signal transduction events, which are able to induce neuronal differentiation but are also responsible for neuronal maintenance and neuronal functions. Rab proteins are small GTPases localized to the cytosolic surface of specific intracellular compartments and are involved in controlling vesicular transport. Rab proteins, acting as master regulators of the membrane trafficking network, play a central role in both trafficking and signaling pathways of neurotrophin receptors. Axonal transport represents the Achilles' heel of neurons, due to the long-range distance that molecules, organelles and, in particular, neurotrophin-receptor complexes have to cover. Indeed, alterations of axonal transport and, specifically, of axonal trafficking of neurotrophin receptors are responsible for several human neurodegenerative diseases, such as Huntington’s disease, Alzheimer’s disease, amyotrophic lateral sclerosis and some forms of Charcot-Marie-Tooth disease. In this review, we will discuss the link between Rab proteins and neurotrophin receptor trafficking and their influence on downstream signaling pathways.

  6. The Role of Rab Proteins in Neuronal Cells and in the Trafficking of Neurotrophin Receptors

    Science.gov (United States)

    Bucci, Cecilia; Alifano, Pietro; Cogli, Laura

    2014-01-01

    Neurotrophins are a family of proteins that are important for neuronal development, neuronal survival and neuronal functions. Neurotrophins exert their role by binding to their receptors, the Trk family of receptor tyrosine kinases (TrkA, TrkB, and TrkC) and p75NTR, a member of the tumor necrosis factor (TNF) receptor superfamily. Binding of neurotrophins to receptors triggers a complex series of signal transduction events, which are able to induce neuronal differentiation but are also responsible for neuronal maintenance and neuronal functions. Rab proteins are small GTPases localized to the cytosolic surface of specific intracellular compartments and are involved in controlling vesicular transport. Rab proteins, acting as master regulators of the membrane trafficking network, play a central role in both trafficking and signaling pathways of neurotrophin receptors. Axonal transport represents the Achilles' heel of neurons, due to the long-range distance that molecules, organelles and, in particular, neurotrophin-receptor complexes have to cover. Indeed, alterations of axonal transport and, specifically, of axonal trafficking of neurotrophin receptors are responsible for several human neurodegenerative diseases, such as Huntington’s disease, Alzheimer’s disease, amyotrophic lateral sclerosis and some forms of Charcot-Marie-Tooth disease. In this review, we will discuss the link between Rab proteins and neurotrophin receptor trafficking and their influence on downstream signaling pathways. PMID:25295627

  7. ABA signaling in guard cells entails a dynamic protein-protein interaction relay from the PYL-RCAR family receptors to ion channels.

    Science.gov (United States)

    Lee, Sung Chul; Lim, Chae Woo; Lan, Wenzhi; He, Kai; Luan, Sheng

    2013-03-01

    Plant hormone abscisic acid (ABA) serves as an integrator of environmental stresses such as drought to trigger stomatal closure by regulating specific ion channels in guard cells. We previously reported that SLAC1, an outward anion channel required for stomatal closure, was regulated via reversible protein phosphorylation events involving ABA signaling components, including protein phosphatase 2C members and a SnRK2-type kinase (OST1). In this study, we reconstituted the ABA signaling pathway as a protein-protein interaction relay from the PYL/RCAR-type receptors, to the PP2C-SnRK2 phosphatase-kinase pairs, to the ion channel SLAC1. The ABA receptors interacted with and inhibited PP2C phosphatase activity against the SnRK2-type kinase, releasing active SnRK2 kinase to phosphorylate, and activate the SLAC1 channel, leading to reduced guard cell turgor and stomatal closure. Both yeast two-hybrid and bimolecular fluorescence complementation assays were used to verify the interactions among the components in the pathway. These biochemical assays demonstrated activity modifications of phosphatases and kinases by their interaction partners. The SLAC1 channel activity was used as an endpoint readout for the strength of the signaling pathway, depending on the presence of different combinations of signaling components. Further study using transgenic plants overexpressing one of the ABA receptors demonstrated that changing the relative level of interacting partners would change ABA sensitivity.

  8. Molecular Characterization of a Novel Family of Trypanosoma cruzi Surface Membrane Proteins (TcSMP) Involved in Mammalian Host Cell Invasion.

    Science.gov (United States)

    Martins, Nadini Oliveira; Souza, Renata Torres de; Cordero, Esteban Mauricio; Maldonado, Danielle Cortez; Cortez, Cristian; Marini, Marjorie Mendes; Ferreira, Eden Ramalho; Bayer-Santos, Ethel; Almeida, Igor Correia de; Yoshida, Nobuko; Silveira, José Franco da

    2015-11-01

    The surface coat of Trypanosoma cruzi is predominantly composed of glycosylphosphatidylinositol-anchored proteins, which have been extensively characterized. However, very little is known about less abundant surface proteins and their role in host-parasite interactions. Here, we described a novel family of T. cruzi surface membrane proteins (TcSMP), which are conserved among different T. cruzi lineages and have orthologs in other Trypanosoma species. TcSMP genes are densely clustered within the genome, suggesting that they could have originated by tandem gene duplication. Several lines of evidence indicate that TcSMP is a membrane-spanning protein located at the cellular surface and is released into the extracellular milieu. TcSMP exhibited the key elements typical of surface proteins (N-terminal signal peptide or signal anchor) and a C-terminal hydrophobic sequence predicted to be a trans-membrane domain. Immunofluorescence of live parasites showed that anti-TcSMP antibodies clearly labeled the surface of all T. cruzi developmental forms. TcSMP peptides previously found in a membrane-enriched fraction were identified by proteomic analysis in membrane vesicles as well as in soluble forms in the T. cruzi secretome. TcSMP proteins were also located intracellularly likely associated with membrane-bound structures. We demonstrated that TcSMP proteins were capable of inhibiting metacyclic trypomastigote entry into host cells. TcSMP bound to mammalian cells and triggered Ca2+ signaling and lysosome exocytosis, events that are required for parasitophorous vacuole biogenesis. The effects of TcSMP were of lower magnitude compared to gp82, the major adhesion protein of metacyclic trypomastigotes, suggesting that TcSMP may play an auxiliary role in host cell invasion. We hypothesized that the productive interaction of T. cruzi with host cells that effectively results in internalization may depend on diverse adhesion molecules. In the metacyclic forms, the signaling induced by

  9. Adrenocorticotropic Hormone (ACTH) Responses Require Actions of the Melanocortin-2 Receptor Accessory Protein on the Extracellular Surface of the Plasma Membrane.

    Science.gov (United States)

    Malik, Sundeep; Dolan, Terrance M; Maben, Zachary J; Hinkle, Patricia M

    2015-11-13

    The melanocortin-2 (MC2) receptor is a G protein-coupled receptor that mediates responses to ACTH. The MC2 receptor acts in concert with the MC2 receptor accessory protein (MRAP) that is absolutely required for ACTH binding and signaling. MRAP has a single transmembrane domain and forms a highly unusual antiparallel homodimer that is stably associated with MC2 receptors at the plasma membrane. Despite the physiological importance of the interaction between the MC2 receptor and MRAP, there is little understanding of how the accessory protein works. The dual topology of MRAP has made it impossible to determine whether highly conserved and necessary regions of MRAP are required on the intracellular or extracellular face of the plasma membrane. The strategy used here was to fix the orientation of two antiparallel MRAP molecules and then introduce inactivating mutations on one side of the membrane or the other. This was achieved by engineering proteins containing tandem copies of MRAP fused to the amino terminus of the MC2 receptor. The data firmly establish that only the extracellular amino terminus (Nout) copy of MRAP, oriented with critical segments on the extracellular side of the membrane, is essential. The transmembrane domain of MRAP is also required in only the Nout orientation. Finally, activity of MRAP-MRAP-MC2-receptor fusion proteins with inactivating mutations in either MRAP or the receptor was rescued by co-expression of free wild-type MRAP or free wild-type receptor. These results show that the basic MRAP-MRAP-receptor signaling unit forms higher order complexes and that these multimers signal. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  10. On the geometry of a smooth model of a fibre product of families of K3 surfaces

    International Nuclear Information System (INIS)

    Nikol'skaya, O V

    2014-01-01

    The Hodge conjecture on algebraic cycles is proved for a smooth projective model X of a fibre product X 1 × C X 2 of nonisotrivial 1-parameter families of K3 surfaces (possibly with degeneracies) X k →C (k=1,2) over a smooth projective curve C under the assumption that, for generic geometric fibres X 1s and X 2s , the ring End Hg(X 1s ) NS Q (X 1s ) ⊥ is an imaginary quadratic field, rankNS(X 1s )≠18, and End Hg(X 2s ) NS Q (X 2s ) ⊥ is a totally real field or else rankNS(X 1s )

  11. McWRI1, a transcription factor of the AP2/SHEN family, regulates the biosynthesis of the cuticular waxes on the apple fruit surface under low temperature

    Science.gov (United States)

    Ji, Qianlong; Zhang, Kezhong; Yang, Mingfeng

    2017-01-01

    Cuticular waxes of plant and organ surfaces play an important role in protecting plants from biotic and abiotic stress and extending the freshness, storage time and shelf life in the post-harvest agricultural products. WRI1, a transcription factor of AP2/SHEN families, had been found to trigger the related genes taking part in the biosynthesis of seed oil in many plants. But whether WRI1 is involved in the biosynthesis of the cuticular waxes on the Malus fruits surface has been unclear. We investigated the changes of wax composition and structure, the related genes and WRI1 expression on Malus asiatica Nakai and sieversii fruits with the low temperature treatments, found that low temperature induced the up-regulated expression of McWRI1, which promoted gene expression of McKCS, McLACs and McWAX in very-long-chain fatty acid biosynthesis pathway, resulting in the accumulation of alkanes component and alteration of wax structure on the fruit surface. Corresponding results were verified in McWRI1 silenced by VIGS, and WRI1 silenced down-regulated the related genes on two kinds of fruits, it caused the diversity alteration in content of some alkanes, fatty acid and ester component in two kinds of fruits. We further conducted Y1H assay to find that McWRI1 transcription factor activated the promoter of McKCS, McLAC and McWAX to regulate their expression. These results demonstrated that McWRI1 is involved in regulating the genes related synthesis of very long chain fatty acid on surface of apple fruits in storage process, providing a highlight for improvement of the modified atmosphere storage of apple fruits. PMID:29073205

  12. Two novel partial deletions of LDL-receptor gene in Italian patients with familial hypercholesterolemia (FH Siracusa and FH Reggio Emilia).

    Science.gov (United States)

    Garuti, R; Lelli, N; Barozzini, M; Tiozzo, R; Ghisellini, M; Simone, M L; Li Volti, S; Garozzo, R; Mollica, F; Vergoni, W; Bertolini, S; Calandra, S

    1996-03-01

    In the present study we report two novel partial deletions of the LDL-R gene. The first (FH Siracusa), found in an FH-heterozygote, consists of a 20 kb deletion spanning from the 5' flanking region to the intron 2 of the LDL-receptor gene. The elimination of the promoter and the first two exons prevents the transcription of the deleted allele, as shown by Northern blot analysis of LDL-R mRNA isolated from the proband's fibroblasts. The second deletion (FH Reggio Emilia), which eliminates 11 nucleotides of exon 10, was also found in an FH heterozygote. The characterization of this deletion was made possible by a combination of techniques such as single strand conformation polymorphism (SSCP) analysis, direct sequence of exon 10 and cloning of the normal and deleted exon 10 from the proband's DNA. The 11 nt deletion occurs in a region of exon 10 which contains three triplets (CTG) and two four-nucleotides (CTGG) direct repeats. This structural feature might render this region more susceptible to a slipped mispairing during DNA duplication. Since this deletion causes a shift of the BamHI site at the 5' end of exon 10, a method has been devised for its rapid screening which is based on the PCR amplification of exon 10 followed by BamHI digestion. FH Reggio Emilia deletion produces a shift in the reading frame downstream from Lys458, leading to a sequence of 51 novel amino acids before the occurrence of a premature stop codon (truncated receptor). However, since RT-PCR failed to demonstrate the presence of the mutant LDL-R mRNA in proband fibroblasts, it is likely that the amount of truncated receptor produced in these cells is negligible.

  13. A family of uranyl-aromatic dicarboxylate (pht-, ipa-, tpa-) framework hybrid materials: photoluminescence, surface photovoltage and dye adsorption.

    Science.gov (United States)

    Gao, Xue; Wang, Che; Shi, Zhong-Feng; Song, Jian; Bai, Feng-Ying; Wang, Ji-Xiao; Xing, Yong-Heng

    2015-07-07

    Four uranyl complexes [(UO2)(pht)H2O]·H2O (pht = phthalic acid) (1), (UO2)2(Hipa)4(H2O)2 (Hipa = isophthalic acid) (2), (UO2)(tpa)(DMF)2 (tpa = terephthalic acid) (3) and (UO2)(box)2 (box = benzoic acid) (4) were synthesized by the reaction of UO2(CH3COO)2·2H2O as the metal source and phthalic acid, isophthalic acid, terephthalic acid or benzoic acid as the ligand. They were characterized by elemental analyses, IR, UV-Vis, XRD, single crystal X-ray diffraction analysis and thermal gravimetric analysis. The structural analysis reveals that complex 1 exhibits a one-dimensional chain structure constructed by the building unit [(UO2)2(pht)4(H2O)2] and further extends the chain into a 2D supramolecular architecture by hydrogen bonding interactions. Complex 2 is a discrete [(UO2)2(Hipa)4(H2O)2] structure, and by the hydrogen bonding interaction, forms a 3D supramolecular structure. In complexes 3 and 4, adjacent uranyl polyhedra form a 1D chain through bridging terephthalic acid and benzoic acid, respectively. In order to extend their functional properties, their photoluminescence, surface photovoltage and dye adsorption properties have been studied.

  14. The DLGAP family

    DEFF Research Database (Denmark)

    Rasmussen, Andreas H; Rasmussen, Hanne B; Silahtaroglu, Asli

    2017-01-01

    downstream signalling in the neuron. The postsynaptic density, a highly specialized matrix, which is attached to the postsynaptic membrane, controls this downstream signalling. The postsynaptic density also resets the synapse after each synaptic firing. It is composed of numerous proteins including a family...... in the postsynapse, the DLGAP family seems to play a vital role in synaptic scaling by regulating the turnover of both ionotropic and metabotropic glutamate receptors in response to synaptic activity. DLGAP family has been directly linked to a variety of psychological and neurological disorders. In this review we...... focus on the direct and indirect role of DLGAP family on schizophrenia as well as other brain diseases....

  15. HR38, an ortholog of NR4A family nuclear receptors, mediates 20-hydroxyecdysone regulation of carbohydrate metabolism during mosquito reproduction.

    Science.gov (United States)

    Dong, Dujuan; Zhang, Yang; Smykal, Vlastimil; Ling, Lin; Raikhel, Alexander S

    2018-05-01

    The Aedes aegypti mosquito is the principal vector for many dangerous human viral diseases. Carbohydrate metabolism (CM) is essential for supplying the energy necessary for host seeking, blood digestion and rapid egg development of this vector insect. The steroid hormone 20-hydroxyecdysone (20E) and the ecdysone receptor (EcR) are important regulators of CM, coordinating it with female reproductive events. We report here that the NR4A nuclear receptor AHR38 plays a critical role in mediating these actions of 20E and EcR. AHR38 RNA interference (RNAi) depletion in female mosquitoes blocked the transcriptional activation of CM genes encoding phosphoglucomutase (PGM) and trehalose-6-phophate synthase (TPS); it caused an increase of glycogen accumulation and a decrease of the circulating sugar trehalose. This treatment also resulted in a dramatic reduction in fecundity. Considering that these phenotypes resulting from AHR38 RNAi depletion are similar to those of EcR RNAi, we investigated a possible connection between these transcription factors in CM regulation. EcR RNAi inhibits the AHR38 gene expression. Moreover, the 20E-induced EcR complex directly activates AHR38 by binding to the ecdysone response element (EcRE) in the upstream regulatory region of this gene. The present work has implicated AHR38 in the 20E-mediated control of CM and provided new insight into mechanisms of 20E regulation of metabolism during female mosquito reproduction. © 2018 Published by Elsevier Ltd.

  16. Crystallization and preliminary X-ray diffraction analysis of two extracytoplasmic solute receptors of the DctP family from Bordetella pertussis

    International Nuclear Information System (INIS)

    Rucktooa, Prakash; Huvent, Isabelle; Antoine, Rudy; Lecher, Sophie; Jacob-Dubuisson, Françoise; Villeret, Vincent; Bompard, Coralie

    2006-01-01

    Sample preparation, crystallization and preliminary X-ray analysis are reported for two B. pertussis extracytoplasmic solute receptors. DctP6 and DctP7 are two Bordetella pertussis proteins which belong to the extracytoplasmic solute receptors (ESR) superfamily. ESRs are involved in the transport of substrates from the periplasm to the cytosol of Gram-negative bacteria. DctP6 and DctP7 have been crystallized and diffraction data were collected using a synchrotron-radiation source. DctP6 crystallized in space group P4 1 2 1 2, with unit-cell parameters a = 108.39, b = 108.39, c = 63.09 Å, while selenomethionyl-derivatized DctP7 crystallized in space group P2 1 2 1 2 1 , with unit-cell parameters a = 64.87, b = 149.83, c = 170.65 Å. The three-dimensional structure of DctP7 will be determined by single-wavelength anomalous diffraction, while the DctP6 structure will be solved by molecular-replacement methods

  17. Crystallization and preliminary X-ray diffraction analysis of two extracytoplasmic solute receptors of the DctP family from Bordetella pertussis

    Energy Technology Data Exchange (ETDEWEB)

    Rucktooa, Prakash; Huvent, Isabelle [UMR8161 CNRS Institut de Biologie de Lille, Laboratoire de Cristallographie Macromoléculaire, 1 Rue du Professeur Calmette, BP 447, 59021 Lille CEDEX (France); IFR 142, Institut Pasteur de Lille, 1 Rue du Professeur Calmette, BP 245, 59021 Lille CEDEX (France); Antoine, Rudy; Lecher, Sophie; Jacob-Dubuisson, Françoise, E-mail: francoise.jacob@ibl.fr [IFR 142, Institut Pasteur de Lille, 1 Rue du Professeur Calmette, BP 245, 59021 Lille CEDEX (France); INSERM-U629, Lille (France); Institut Pasteur de Lille, 1 Rue du Professeur Calmette, BP 245, 59021 Lille CEDEX (France); Villeret, Vincent, E-mail: francoise.jacob@ibl.fr; Bompard, Coralie [UMR8161 CNRS Institut de Biologie de Lille, Laboratoire de Cristallographie Macromoléculaire, 1 Rue du Professeur Calmette, BP 447, 59021 Lille CEDEX (France); IFR 142, Institut Pasteur de Lille, 1 Rue du Professeur Calmette, BP 245, 59021 Lille CEDEX (France)

    2006-10-01

    Sample preparation, crystallization and preliminary X-ray analysis are reported for two B. pertussis extracytoplasmic solute receptors. DctP6 and DctP7 are two Bordetella pertussis proteins which belong to the extracytoplasmic solute receptors (ESR) superfamily. ESRs are involved in the transport of substrates from the periplasm to the cytosol of Gram-negative bacteria. DctP6 and DctP7 have been crystallized and diffraction data were collected using a synchrotron-radiation source. DctP6 crystallized in space group P4{sub 1}2{sub 1}2, with unit-cell parameters a = 108.39, b = 108.39, c = 63.09 Å, while selenomethionyl-derivatized DctP7 crystallized in space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 64.87, b = 149.83, c = 170.65 Å. The three-dimensional structure of DctP7 will be determined by single-wavelength anomalous diffraction, while the DctP6 structure will be solved by molecular-replacement methods.

  18. Transient receptor potential channels in essential hypertension

    DEFF Research Database (Denmark)

    Liu, Daoyan; Scholze, Alexandra; Zhu, Zhiming

    2006-01-01

    The role of nonselective cation channels of the transient receptor potential channel (TRPC) family in essential hypertension has not yet been investigated.......The role of nonselective cation channels of the transient receptor potential channel (TRPC) family in essential hypertension has not yet been investigated....

  19. Over, and Underexpression of Endothelin 1 and TGF-Beta Family Ligands and Receptors in Lung Tissue of Broilers with Pulmonary Hypertension

    Science.gov (United States)

    Dominguez-Avila, Norma; Ruiz-Castañeda, Gabriel; González-Ramírez, Javier; Fernandez-Jaramillo, Nora; Escoto, Jorge; Sánchez-Muñoz, Fausto; Marquez-Velasco, Ricardo; Bojalil, Rafael; Espinosa-Cervantes, Román; Sánchez, Fausto

    2013-01-01

    Transforming growth factor beta (TGFβ) is a family of genes that play a key role in mediating tissue remodeling in various forms of acute and chronic lung disease. In order to assess their role on pulmonary hypertension in broilers, we determined mRNA expression of genes of the TGFβ family and endothelin 1 in lung samples from 4-week-old chickens raised either under normal or cold temperature conditions. Both in control and cold-treated groups of broilers, endothelin 1 mRNA expression levels in lungs from ascitic chickens were higher than levels from healthy birds (P 0.05). BAMBI mRNA gene expression was lowest in birds with ascites only in the control group as compared with the values from healthy birds (P < 0.05). PMID:24286074

  20. Somatostatin receptors

    DEFF Research Database (Denmark)

    Møller, Lars Neisig; Stidsen, Carsten Enggaard; Hartmann, Bolette

    2003-01-01

    functional units, receptors co-operate. The total receptor apparatus of individual cell types is composed of different-ligand receptors (e.g. SRIF and non-SRIF receptors) and co-expressed receptor subtypes (e.g. sst(2) and sst(5) receptors) in characteristic proportions. In other words, levels of individual......-peptides, receptor agonists and antagonists. Relatively long half lives, as compared to those of the endogenous ligands, have been paramount from the outset. Motivated by theoretical puzzles or the shortcomings of present-day diagnostics and therapy, investigators have also aimed to produce subtype...

  1. Two families with normosmic congenital hypogonadotropic hypogonadism and biallelic mutations in KISS1R (KISS1 receptor: clinical evaluation and molecular characterization of a novel mutation.

    Directory of Open Access Journals (Sweden)

    Frédéric Brioude

    Full Text Available CONTEXT: KISS1R mutations have been reported in few patients with normosmic congenital hypogonadotropic hypogonadism (nCHH (OMIM #146110. OBJECTIVE: To describe in detail nCHH patients with biallelic KISS1R mutations belonging to 2 unrelated families, and to functionally characterize a novel KISS1R mutation. RESULTS: An original mutant, p.Tyr313His, was found in the homozygous state in 3 affected kindred (2 females and 1 male from a consanguineous Portuguese family. This mutation, located in the seventh transmembrane domain, affects a highly conserved amino acid, perturbs the conformation of the transmembrane segment, and impairs MAP kinase signaling and intracellular calcium release. In the second family, a French Caucasian male patient with nCHH was found to carry two recurrent mutations in the compound heterozygous state (p.Leu102Pro/Stop399Arg. In this man, pulsatile GnRH (Gonadotropin Releasing Hormone administration restored pulsatile LH (Luteinizing Hormone secretion and testicular hormone secretion. Later, long-term combined gonadotropin therapy induced spermatogenesis, enabling 3 successive pregnancies that resulted in 2 miscarriages and the birth of a healthy boy. CONCLUSION: We show that a novel loss-of-function mutation (p.Tyr313His in the KISS1R gene can cause familial nCHH, revealing the crucial role of this amino acid in KISS1R function. The observed restoration of gonadotropin secretion by exogenous GnRH administration further supports, in humans, the hypothalamic origin of the gonadotropin deficiency in this genetic form of nCHH.

  2. Peripheral injury of pelvic visceral sensory nerves alters GFRa (GDNF family receptor alpha localization in sensory and autonomic pathways of the sacral spinal cord

    Directory of Open Access Journals (Sweden)

    Shelley Lynne Forrest

    2015-04-01

    Full Text Available GDNF (glial cell line-derived neurotrophic factor, neurturin and artemin use their co-receptors (GFRα1, GFRα2 and GFRα3, respectively and the tyrosine kinase Ret for downstream signalling. In rodent dorsal root ganglia (DRG most of the unmyelinated and some myelinated sensory afferents express at least one GFRα. The adult function of these receptors is not completely elucidated but their activity after peripheral nerve injury can facilitate peripheral and central axonal regeneration, recovery of sensation, and sensory hypersensitivity that contributes to pain. Our previous immunohistochemical studies of spinal cord and sciatic nerve injuries in adult rodents have identified characteristic changes in GFRα1, GFRα2 or GFRα3 in central spinal cord axons of sensory neurons located in dorsal root ganglia. Here we extend and contrast this analysis by studying injuries of the pelvic and hypogastric nerves that contain the majority of sensory axons projecting to the pelvic viscera (e.g., bladder and lower bowel. At 7 d, we detected some effects of pelvic but not hypogastric nerve transection on the ipsilateral spinal cord. In sacral (L6-S1 cord ipsilateral to nerve injury, GFRα1-immunoreactivity (IR was increased in medial dorsal horn and CGRP-IR was decreased in lateral dorsal horn. Pelvic nerve injury also upregulated GFRα1- and GFRα3-IR terminals and GFRα1-IR neuronal cell bodies in the sacral parasympathetic nucleus that provides the spinal parasympathetic preganglionic output to the pelvic nerve. This evidence suggests peripheral axotomy has different effects on somatic and visceral sensory input to the spinal cord, and identifies sensory-autonomic interactions as a possible site of post-injury regulation.

  3. Antidiabetic effects of chamomile flowers extract in obese mice through transcriptional stimulation of nutrient sensors of the peroxisome proliferator-activated receptor (PPAR family.

    Directory of Open Access Journals (Sweden)

    Christopher Weidner

    Full Text Available Given the significant increases in the incidence of metabolic diseases, efficient strategies for preventing and treating of these common disorders are urgently needed. This includes the development of phytopharmaceutical products or functional foods to prevent or cure metabolic diseases. Plant extracts from edible biomaterial provide a potential resource of structurally diverse molecules that can synergistically interfere with complex disorders. In this study we describe the safe application of ethanolic chamomile (Matricaria recutita flowers extract (CFE for the treatment and prevention of type 2 diabetes and associated disorders. We show in vitro that this extract activates in particular nuclear receptor peroxisome proliferator-activated receptor gamma (PPARγ and its isotypes. In a cellular context, in human primary adipocytes CFE administration (300 µg/ml led to specific expression of target genes of PPARγ, whereas in human hepatocytes CFE-induced we detected expression changes of genes that were regulated by PPARα. In vivo treatment of insulin-resistant high-fat diet (HFD-fed C57BL/6 mice with CFE (200 mg/kg/d for 6 weeks considerably reduced insulin resistance, glucose intolerance, plasma triacylglycerol, non-esterified fatty acids (NEFA and LDL/VLDL cholesterol. Co-feeding of lean C57BL/6 mice a HFD with 200 mg/kg/d CFE for 20 weeks showed effective prevention of fatty liver formation and hepatic inflammation, indicating additionally hepatoprotective effects of the extract. Moreover, CFE treatment did not reveal side effects, which have otherwise been associated with strong synthetic PPAR-targeting molecules, such as weight gain, liver disorders, hemodilution or bone cell turnover. Taken together, modulation of PPARs and other factors by chamomile flowers extract has the potential to prevent or treat type 2 diabetes and related disorders.

  4. The influence of MIR137 on white matter fractional anisotropy and cortical surface area in individuals with familial risk for psychosis.

    Science.gov (United States)

    Vogel, Bob O; Lett, Tristram A; Erk, Susanne; Mohnke, Sebastian; Wackerhagen, Carolin; Brandl, Eva J; Romanczuk-Seiferth, Nina; Otto, Kristina; Schweiger, Janina I; Tost, Heike; Nöthen, Markus M; Rietschel, Marcella; Degenhardt, Franziska; Witt, Stephanie H; Meyer-Lindenberg, Andreas; Heinz, Andreas; Walter, Henrik

    2018-05-01

    The rs1625579 variant near the microRNA-137 (MIR137) gene is one of the best-supported schizophrenia variants in genome-wide association studies (GWAS), and microRNA-137 functionally regulates other GWAS identified schizophrenia risk variants. Schizophrenia patients with the MIR137 rs1625579 risk genotype (homozygous for the schizophrenia risk variant) also have aberrant brain structure. It is unclear if the effect of MIR137 among schizophrenia patients is due to potential epistasis with genetic risk for schizophrenia or other factors of the disorder. Here, we investigated the effect of MIR137 genotype on white matter fractional anisotropy (FA), cortical thickness (CT), and surface area (SA) in a sample comprising healthy control subjects, and individuals with familial risk for psychosis (first-degree relatives of patients with schizophrenia or bipolar disorder; N=426). In voxel-wise analyses of FA, we observed a significant genotype-by-group interaction (P FWE <0.05). The familial risk group with risk genotype had lower FA (P FWE <0.05), but there was no genetic association in controls. In vertex-wise analyses of SA, we also observed a significant genotype-by-group interaction (P FWE <0.05). Relatives with MIR137 risk genotype had lower SA, however the risk genotype was associated with higher SA in the controls (all P FWE <0.05). These results show that MIR137 risk genotype is associated with lower FA in psychosis relatives that is similar to previous imaging-genetics findings in patients with schizophrenia. Furthermore, MIR137 genotype may also be a risk factor in a subclinical population with wide reductions in white matter FA and cortical SA. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Ror receptor tyrosine kinases: orphans no more

    OpenAIRE

    Green, Jennifer L.; Kuntz, Steven G.; Sternberg, Paul W.

    2008-01-01

    Receptor tyrosine kinase-like orphan receptor (Ror) proteins are a conserved family of tyrosine kinase receptors that function in developmental processes including skeletal and neuronal development, cell movement and cell polarity. Although Ror proteins were originally named because the associated ligand and signaling pathway were unknown, recent studies in multiple species have now established that Ror proteins are Wnt receptors. Depending on the cellular context, Ror proteins can either act...

  6. Lessons from crystal structures of kainate receptors

    DEFF Research Database (Denmark)

    Møllerud, Stine; Frydenvang, Karla Andrea; Pickering, Darryl S

    2017-01-01

    Kainate receptors belong to the family of ionotropic glutamate receptors. These receptors assemble from five subunits (GluK1-5) into tetrameric ion channels. Kainate receptors are located at both pre- and postsynaptic membranes in the central nervous system where they contribute to excitatory...... synaptic transmission and modulate network excitability by regulating neurotransmitter release. Dysfunction of kainate receptors has been implicated in several neurological disorders such as epilepsy, schizophrenia and depression. Here we provide a review on the current understanding of kainate receptor...

  7. Lack of hormone binding in COS-7 cells expressing a mutated growth hormone receptor found in Laron dwarfism.

    Science.gov (United States)

    Edery, M; Rozakis-Adcock, M; Goujon, L; Finidori, J; Lévi-Meyrueis, C; Paly, J; Djiane, J; Postel-Vinay, M C; Kelly, P A

    1993-01-01

    A single point mutation in the growth hormone (GH) receptor gene generating a Phe-->Ser substitution in the extracellular binding domain of the receptor has been identified in one family with Laron type dwarfism. The mutation was introduced by site-directed mutagenesis into cDNAs encoding the full-length rabbit GH receptor and the extracellular domain or binding protein (BP) of the human and rabbit GH receptor, and also in cDNAs encoding the full length and the extracellular domain of the related rabbit prolactin (PRL) receptor. All constructs were transiently expressed in COS-7 cells. Both wild type and mutant full-length rabbit GH and PRL receptors, as well as GH and prolactin BPs (wild type and mutant), were detected by Western blot in cell membranes and concentrated culture media, respectively. Immunofluorescence studies showed that wild type and mutant full-length GH receptors had the same cell surface and intracellular distribution and were expressed with comparable intensities. In contrast, all mutant forms (full-length receptors or BPs), completely lost their modify the synthesis ligand. These results clearly demonstrate that this point mutation (patients with Laron syndrome) does not modify the synthesis or the intracellular pathway of receptor proteins, but rather abolishes ability of the receptor or BP to bind GH and is thus responsible for the extreme GH resistance in these patients. Images PMID:8450064

  8. Combination of hypomorphic mutations of the Drosophila homologues of aryl hydrocarbon receptor and nucleosome assembly protein family genes disrupts morphogenesis, memory and detoxification.

    Science.gov (United States)

    Kuzin, Boris A; Nikitina, Ekaterina A; Cherezov, Roman O; Vorontsova, Julia E; Slezinger, Mikhail S; Zatsepina, Olga G; Simonova, Olga B; Enikolopov, Grigori N; Savvateeva-Popova, Elena V

    2014-01-01

    Aryl hydrocarbon receptor is essential for biological responses to endogenous and exogenous toxins in mammals. Its Drosophila homolog spineless plays an important role in fly morphogenesis. We have previously shown that during morphogenesis spineless genetically interacts with CG5017 gene, which encodes a nucleosome assembly factor and may affect cognitive function of the fly. We now demonstrate synergistic interactions of spineless and CG5017 in pathways controlling oxidative stress response and long-term memory formation in Drosophila melanogaster. Oxidative stress was induced by low doses of X-ray irradiation of flies carrying hypomorphic mutation of spineless, mutation of CG5017, and their combination. To determine the sensitivity of these mutants to pharmacological modifiers of the irradiation effect, we irradiated flies growing on standard medium supplemented by radiosensitizer furazidin and radioprotector serotonin. The effects of irradiation were investigated by analyzing leg and antenna morphological structures and by using real-time PCR to measure mRNA expression levels for spineless, Cyp6g1 and Gst-theta genes. We also examined long-term memory in these mutants using conditioned courtship suppression paradigm. Our results show that the interaction of spineless and CG5017 is important for regulation of morphogenesis, long-term memory formation, and detoxification during oxidative stress. Since spineless and CG5017 are evolutionary conserved, these results must be considered when evaluating the risk of combining similar mutations in other organisms, including humans.

  9. Combination of hypomorphic mutations of the Drosophila homologues of aryl hydrocarbon receptor and nucleosome assembly protein family genes disrupts morphogenesis, memory and detoxification.

    Directory of Open Access Journals (Sweden)

    Boris A Kuzin

    Full Text Available Aryl hydrocarbon receptor is essential for biological responses to endogenous and exogenous toxins in mammals. Its Drosophila homolog spineless plays an important role in fly morphogenesis. We have previously shown that during morphogenesis spineless genetically interacts with CG5017 gene, which encodes a nucleosome assembly factor and may affect cognitive function of the fly. We now demonstrate synergistic interactions of spineless and CG5017 in pathways controlling oxidative stress response and long-term memory formation in Drosophila melanogaster. Oxidative stress was induced by low doses of X-ray irradiation of flies carrying hypomorphic mutation of spineless, mutation of CG5017, and their combination. To determine the sensitivity of these mutants to pharmacological modifiers of the irradiation effect, we irradiated flies growing on standard medium supplemented by radiosensitizer furazidin and radioprotector serotonin. The effects of irradiation were investigated by analyzing leg and antenna morphological structures and by using real-time PCR to measure mRNA expression levels for spineless, Cyp6g1 and Gst-theta genes. We also examined long-term memory in these mutants using conditioned courtship suppression paradigm. Our results show that the interaction of spineless and CG5017 is important for regulation of morphogenesis, long-term memory formation, and detoxification during oxidative stress. Since spineless and CG5017 are evolutionary conserved, these results must be considered when evaluating the risk of combining similar mutations in other organisms, including humans.

  10. Regulation of β2-adrenergic receptor function by conformationally selective single-domain intrabodies

    DEFF Research Database (Denmark)

    Staus, Dean P; Wingler, Laura M; Strachan, Ryan T

    2014-01-01

    . However, a monomeric single-domain antibody (nanobody) from the Camelid family was recently found to allosterically bind and stabilize an active conformation of the β2-adrenergic receptor (β2AR). Here, we set out to study the functional interaction of 18 related nanobodies with the β2AR to investigate...... their roles as novel tools for studying GPCR biology. Our studies revealed several sequence-related nanobody families with preferences for active (agonist-occupied) or inactive (antagonist-occupied) receptors. Flow cytometry analysis indicates that all nanobodies bind to epitopes displayed...... on the intracellular receptor surface; therefore, we transiently expressed them intracellularly as "intrabodies" to test their effects on β2AR-dependent signaling. Conformational specificity was preserved after intrabody conversion as demonstrated by the ability for the intracellularly expressed nanobodies...

  11. Flavivirus Entry Receptors: An Update

    Directory of Open Access Journals (Sweden)

    Manuel Perera-Lecoin

    2013-12-01

    Full Text Available Flaviviruses enter host cells by endocytosis initiated when the virus particles interact with cell surface receptors. The current model suggests that flaviviruses use at least two different sets of molecules for infectious entry: attachment factors that concentrate and/or recruit viruses on the cell surface and primary receptor(s that bind to virions and direct them to the endocytic pathway. Here, we present the currently available knowledge regarding the flavivirus receptors described so far with specific attention to C-type lectin receptors and the phosphatidylserine receptors, T-cell immunoglobulin and mucin domain (TIM and TYRO3, AXL and MER (TAM. Their role in flavivirus attachment and entry as well as their implication in the virus biology will be discussed in depth.

  12. Roles of a novel Crp/Fnr family transcription factor Lmo0753 in soil survival, biofilm production and surface attachment to fresh produce of Listeria monocytogenes.

    Directory of Open Access Journals (Sweden)

    Joelle K Salazar

    Full Text Available Listeria monocytogenes is a foodborne bacterial pathogen and the causative agent of an infectious disease, listeriosis. L. monocytogenes is ubiquitous in nature and has the ability to persist in food processing environments for extended periods of time by forming biofilms and resisting industrial sanitization. Human listeriosis outbreaks are commonly linked to contaminated dairy products, ready-to-eat meats, and in recent years, fresh produce such as lettuce and cantaloupes. We identified a putative Crp/Fnr family transcription factor Lmo0753 that is highly specific to human-associated genetic lineages of L. monocytogenes. Lmo0753 possesses two conserved functional domains similar to the major virulence regulator PrfA in L. monocytogenes. To determine if Lmo0753 is involved in environmental persistence-related mechanisms, we compared lmo0753 deletion mutants with respective wild type and complementation mutants of two fully sequenced L. monocytogenes genetic lineage II strains 10403S and EGDe for the relative ability of growth under different nutrient availability and temperatures, soil survival, biofilm productivity and attachment to select fresh produce surfaces including romaine lettuce leaves and cantaloupe rinds. Our results collectively suggested that Lmo0753 plays an important role in L. monocytogenes biofilm production and attachment to fresh produce, which may contribute to the environmental persistence and recent emergence of this pathogen in human listeriosis outbreaks linked to fresh produce.

  13. Suppressors for Human Epidermal Growth Factor Receptor 2/4 (HER2/4): A New Family of Anti-Toxoplasmic Agents in ARPE-19 Cells.

    Science.gov (United States)

    Kim, Yeong Hoon; Bhatt, Lokraj; Ahn, Hye-Jin; Yang, Zhaoshou; Lee, Won-Kyu; Nam, Ho-Woo

    2017-10-01

    The effects of tyrosine kinase inhibitors (TKIs) were evaluated on growth inhibition of intracellular Toxoplasma gondii in host ARPE-19 cells. The number of tachyzoites per parasitophorous vacuolar membrane (PVM) was counted after treatment with TKIs. T. gondii protein expression was assessed by western blot. Immunofluorescence assay was performed using Programmed Cell Death 4 (PDCD4) and T. gondii GRA3 antibodies. The TKIs were divided into 3 groups; non-epidermal growth factor receptor (non-EGFR), anti-human EGFR 2 (anti-HER2), and anti-HER2/4 TKIs, respectively. Group I TKIs (nintedanib, AZD9291, and sunitinib) were unable to inhibit proliferation without destroying host cells. Group II TKIs (lapatinib, gefitinib, erlotinib, and AG1478) inhibited proliferation up to 98% equivalent to control pyrimethamine (5 μM) at 20 μM and higher, without affecting host cells. Group III TKIs (neratinib, dacomitinib, afatinib, and pelitinib) inhibited proliferation up to 98% equivalent to pyrimethamine at 1-5 μM, but host cells were destroyed at 10-20 μM. In Group I, TgHSP90 and SAG1 inhibitions were weak, and GRA3 expression was moderately inhibited. In Group II, TgHSP90 and SAG1 expressions seemed to be slightly enhanced, while GRA3 showed none to mild inhibition; however, AG1478 inhibited all proteins moderately. Protein expression was blocked in Group III, comparable to pyrimethamine. PDCD4 and GRA3 were well localized inside the nuclei in Group I, mildly disrupted in Group II, and were completely disrupted in Group III. This study suggests the possibility of a vital T. gondii TK having potential HER2/4 properties, thus anti-HER2/4 TKIs may inhibit intracellular parasite proliferation with minimal adverse effects on host cells.

  14. The nuclear hormone receptor family member NR5A2 controls aspects of multipotent progenitor cell formation and acinar differentiation during pancreatic organogenesis.

    Science.gov (United States)

    Hale, Michael A; Swift, Galvin H; Hoang, Chinh Q; Deering, Tye G; Masui, Toshi; Lee, Youn-Kyoung; Xue, Jumin; MacDonald, Raymond J

    2014-08-01

    The orphan nuclear receptor NR5A2 is necessary for the stem-like properties of the epiblast of the pre-gastrulation embryo and for cellular and physiological homeostasis of endoderm-derived organs postnatally. Using conditional gene inactivation, we show that Nr5a2 also plays crucial regulatory roles during organogenesis. During the formation of the pancreas, Nr5a2 is necessary for the expansion of the nascent pancreatic epithelium, for the subsequent formation of the multipotent progenitor cell (MPC) population that gives rise to pre-acinar cells and bipotent cells with ductal and islet endocrine potential, and for the formation and differentiation of acinar cells. At birth, the NR5A2-deficient pancreas has defects in all three epithelial tissues: a partial loss of endocrine cells, a disrupted ductal tree and a >90% deficit of acini. The acinar defects are due to a combination of fewer MPCs, deficient allocation of those MPCs to pre-acinar fate, disruption of acinar morphogenesis and incomplete acinar cell differentiation. NR5A2 controls these developmental processes directly as well as through regulatory interactions with other pancreatic transcriptional regulators, including PTF1A, MYC, GATA4, FOXA2, RBPJL and MIST1 (BHLHA15). In particular, Nr5a2 and Ptf1a establish mutually reinforcing regulatory interactions and collaborate to control developmentally regulated pancreatic genes by binding to shared transcriptional regulatory regions. At the final stage of acinar cell development, the absence of NR5A2 affects the expression of Ptf1a and its acinar specific partner Rbpjl, so that the few acinar cells that form do not complete differentiation. Nr5a2 controls several temporally distinct stages of pancreatic development that involve regulatory mechanisms relevant to pancreatic oncogenesis and the maintenance of the exocrine phenotype. © 2014. Published by The Company of Biologists Ltd.

  15. Scavenger receptors in homeostasis and immunity.

    Science.gov (United States)

    Canton, Johnathan; Neculai, Dante; Grinstein, Sergio

    2013-09-01

    Scavenger receptors were originally identified by their ability to recognize and to remove modified lipoproteins; however, it is now appreciated that they carry out a striking range of functions, including pathogen clearance, lipid transport, the transport of cargo within the cell and even functioning as taste receptors. The large repertoire of ligands recognized by scavenger receptors and their broad range of functions are not only due to the wide range of receptors that constitute this family but also to their ability to partner with various co-receptors. The ability of individual scavenger receptors to associate with different co-receptors makes their responsiveness extremely versatile. This Review highlights recent insights into the structural features that determine the function of scavenger receptors and the emerging role that these receptors have in immune responses, notably in macrophage polarization and in the pathogenesis of diseases such as atherosclerosis and Alzheimer's disease.

  16. Expression patterns of porcine Toll-like receptors family set of genes (TLR1-10) in gut-associated lymphoid tissues alter with age.

    Science.gov (United States)

    Uddin, Muhammad Jasim; Kaewmala, Kanokwan; Tesfaye, Dawit; Tholen, Ernst; Looft, Christian; Hoelker, Michael; Schellander, Karl; Cinar, Mehmet Ulas

    2013-08-01

    The aim was to study the expression pattern of the porcine TLR family (TLR1-10) genes in gut-associated lymphoid tissues (GALT) of varying ages. A total of nine clinically healthy pigs of three ages group (1 day, 2 months and 5 months old) were selected for this experiment (three pigs in each group). Tissues from intestinal mucosa in stomach, duodenum, jejunum and ileum and mesenteric lymph node (MLN) were used. mRNA expression of TLRs (1-10) was detectable in all tissues and TLR3 showed the highest mRNA abundance among TLRs. TLR3 expression in stomach, and TLR1 and TLR6 expression in MLN were higher in adult than newborn pigs. The western blot results of TLR2, 3 and 9 in some cases, did not coincide with the mRNA expression results. The protein localization of TLR2, 3 and 9 showed that TLR expressing cells were abundant in the lamina propria, Peyer's patches in intestine, and around and within the lymphoid follicles in the MLN. This expressions study sheds the first light on the expression patterns of all TLR genes in GALT at different ages of pigs. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. The IkappaB kinase family phosphorylates the Parkinson's disease kinase LRRK2 at Ser935 and Ser910 during Toll-like receptor signaling.

    Directory of Open Access Journals (Sweden)

    Nicolas Dzamko

    Full Text Available Mutations in leucine-rich repeat kinase 2 (LRRK2 are strongly associated with late-onset autosomal dominant Parkinson's disease. LRRK2 is highly expressed in immune cells and recent work points towards a link between LRRK2 and innate immunity. Here we demonstrate that stimulation of the Toll-Like Receptor (TLR pathway by MyD88-dependent agonists in bone marrow-derived macrophages (BMDMs or RAW264.7 macrophages induces marked phosphorylation of LRRK2 at Ser910 and Ser935, the phosphorylation sites that regulate the binding of 14-3-3 to LRRK2. Phosphorylation of these residues is prevented by knock-out of MyD88 in BMDMs, but not the alternative TLR adaptor protein TRIF. Utilising both pharmacological inhibitors, including a new TAK1 inhibitor, NG25, and genetic models, we provide evidence that both the canonical (IKKα and IKKβ and IKK-related (IKKε and TBK1 kinases mediate TLR agonist induced phosphorylation of LRRK2 in vivo. Moreover, all four IKK members directly phosphorylate LRRK2 at Ser910 and Ser935 in vitro. Consistent with previous work describing Ser910 and Ser935 as pharmacodynamic biomarkers of LRRK2 activity, we find that the TLR independent basal phosphorylation of LRRK2 at Ser910 and Ser935 is abolished following treatment of macrophages with LRRK2 kinase inhibitors. However, the increased phosphorylation of Ser910 and Ser935 induced by activation of the MyD88 pathway is insensitive to LRRK2 kinase inhibitors. Finally, employing LRRK2-deficient BMDMs, we present data indicating that LRRK2 does not play a major role in regulating the secretion of inflammatory cytokines induced by activation of the MyD88 pathway. Our findings provide the first direct link between LRRK2 and the IKKs that mediate many immune responses. Further work is required to uncover the physiological roles that phosphorylation of LRRK2 by IKKs play in controlling macrophage biology and to determine how phosphorylation of LRRK2 by IKKs impacts upon the use of Ser

  18. Melatonin Receptor Genes in Vertebrates

    Directory of Open Access Journals (Sweden)

    Hua Dong Yin

    2013-05-01

    Full Text Available Melatonin receptors are members of the G protein-coupled receptor (GPCR family. Three genes for melatonin receptors have been cloned. The MT1 (or Mel1a or MTNR1A and MT2 (or Mel1b or MTNR1B receptor subtypes are present in humans and other mammals, while an additional melatonin receptor subtype, Mel1c (or MTNR1C, has been identified in fish, amphibians and birds. Another melatonin related orphan receptor, GPR50, which does not bind melatonin, is found exclusively in mammals. The hormone melatonin is secreted primarily by the pineal gland, with highest levels occurring during the dark period of a circadian cycle. This hormone acts systemically in numerous organs. In the brain, it is involved in the regulation of various neural and endocrine processes, and it readjusts the circadian pacemaker, the suprachiasmatic nucleus. This article reviews recent studies of gene organization, expression, evolution and mutations of melatonin receptor genes of vertebrates. Gene polymorphisms reveal that numerous mutations are associated with diseases and disorders. The phylogenetic analysis of receptor genes indicates that GPR50 is an outgroup to all other melatonin receptor sequences. GPR50 may have separated from a melatonin receptor ancestor before the split between MTNR1C and the MTNR1A/B ancestor.

  19. Coronavirus spike-receptor interactions

    NARCIS (Netherlands)

    Mou, H.

    2015-01-01

    Coronaviruses cause important diseases in humans and animals. Coronavirus infection starts with the virus binding with its spike proteins to molecules present on the surface of host cells that act as receptors. This spike-receptor interaction is highly specific and determines the virus’ cell, tissue

  20. Identifying a Mechanism for Crosstalk Between the Estrogen and Glucocorticoid Receptors | Center for Cancer Research

    Science.gov (United States)

    Estrogen has long been known to play important roles in the development and progression of breast cancer. Its receptor (ER), a member of the steroid receptor family, binds to estrogen response elements (EREs) in DNA and regulates gene transcription. More recently, another steroid receptor family member, the glucocorticoid receptor (GR), has been implicated in breast cancer

  1. An insulin receptor mutant (Asp707 → Ala), involved in leprechaunism, is processed and transported to the cell surface but unable to bind insulin

    NARCIS (Netherlands)

    L.M. 't Hart (Leen); D. Lindhout (Dick); G.C.M. van der Zon (Gerard); H. Kayserilli (Hülya); M.Y. Apak (Memnune); W.J. Kleijer (Wim); E.R. van der Vorm (Eric); J.A. Maassen (Johannes)

    1996-01-01

    textabstractWe have identified a homozygous mutation near the carboxyl terminus of the insulin receptor (IR) α subunit from a leprechaun patient, changing Asp707 into Ala. Fibroblasts from this patient had no high affinity insulin binding sites. To examine the effect of the mutation on IR

  2. Surface display of the receptor-binding region of the Lactobacillus brevis S-layer protein in Lactococcus lactis provides nonadhesive lactococci with the ability to adhere to intestinal epithelial cells.

    Science.gov (United States)

    Avall-Jääskeläinen, Silja; Lindholm, Agneta; Palva, Airi

    2003-04-01

    Lactobacillus brevis is a promising lactic acid bacterium for use as a probiotic dietary adjunct and a vaccine vector. The N-terminal region of the S-layer protein (SlpA) of L. brevis ATCC 8287 was recently shown to mediate adhesion to various human cell lines in vitro. In this study, a surface display cassette was constructed on the basis of this SlpA receptor-binding domain, a proteinase spacer, and an autolysin anchor. The cassette was expressed under control of the nisA promoter in Lactococcus lactis NZ9000. Western blot assay of lactococcal cell wall extracts with anti-SlpA antibodies confirmed that the SlpA adhesion domain of the fusion protein was expressed and located within the cell wall layer. Whole-cell enzyme-linked immunosorbent assay and immunofluorescence microscopy verified that the SlpA adhesion-mediating region was accessible on the lactococcal cell surface. In vitro adhesion assays with the human intestinal epithelial cell line Intestine 407 indicated that the recombinant lactococcal cells had gained an ability to adhere to Intestine 407 cells significantly greater than that of wild-type L. lactis NZ9000. Serum inhibition assay further confirmed that adhesion of recombinant lactococci to Intestine 407 cells was indeed mediated by the N terminus-encoding part of the slpA gene. The ability of the receptor-binding region of SlpA to adhere to fibronectin was also confirmed with this lactococcal surface display system. These results show that, with the aid of the receptor-binding region of the L. brevis SlpA protein, the ability to adhere to gut epithelial cells can indeed be transferred to another, nonadhesive, lactic acid bacterium.

  3. Cucumis sativus L-type lectin receptor kinase (CsLecRK) gene family response to Phytophthora melonis, Phytophthora capsici and water immersion in disease resistant and susceptible cucumber cultivars.

    Science.gov (United States)

    Wu, Tingquan; Wang, Rui; Xu, Xiaomei; He, Xiaoming; Sun, Baojuan; Zhong, Yujuan; Liang, Zhaojuan; Luo, Shaobo; Lin, Yu'e

    2014-10-10

    L-type lectin receptor kinase (LecRK) proteins are an important family involved in diverse biological processes such as pollen development, senescence, wounding, salinity and especially in innate immunity in model plants such as Arabidopsis and tobacco. Till date, LecRK proteins or genes of cucumber have not been reported. In this study, a total of 25 LecRK genes were identified in the cucumber genome, unequally distributed across its seven chromosomes. According to similarity comparison of their encoded proteins, the Cucumis sativus LecRK (CsLecRK) genes were classified into six major clades (from Clade I to CladeVI). Expression of CsLecRK genes were tested using QRT-PCR method and the results showed that 25 CsLecRK genes exhibited different responses to abiotic (water immersion) and biotic (Phytophthora melonis and Phytophthora capsici inoculation) stresses, as well as that between disease resistant cultivar (JSH) and disease susceptible cultivar (B80). Among the 25 CsLecRK genes, we found CsLecRK6.1 was especially induced by P. melonis and P. capsici in JSH plants. All these results suggested that CsLecRK genes may play important roles in biotic and abiotic stresses. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Prostaglandin Receptor Signaling in Disease</