Anterograde trafficking of KCa3.1 in polarized epithelia is Rab1- and Rab8-dependent and recycling endosome-independent.

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Claudia A Bertuccio

Full Text Available The intermediate conductance, Ca2+-activated K+ channel (KCa3.1 targets to the basolateral (BL membrane in polarized epithelia where it plays a key role in transepithelial ion transport. However, there are no studies defining the anterograde and retrograde trafficking of KCa3.1 in polarized epithelia. Herein, we utilize Biotin Ligase Acceptor Peptide (BLAP-tagged KCa3.1 to address these trafficking steps in polarized epithelia, using MDCK, Caco-2 and FRT cells. We demonstrate that KCa3.1 is exclusively targeted to the BL membrane in these cells when grown on filter supports. Following endocytosis, KCa3.1 degradation is prevented by inhibition of lysosomal/proteosomal pathways. Further, the ubiquitylation of KCa3.1 is increased following endocytosis from the BL membrane and PR-619, a deubiquitylase inhibitor, prevents degradation, indicating KCa3.1 is targeted for degradation by ubiquitylation. We demonstrate that KCa3.1 is targeted to the BL membrane in polarized LLC-PK1 cells which lack the μ1B subunit of the AP-1 complex, indicating BL targeting of KCa3.1 is independent of μ1B. As Rabs 1, 2, 6 and 8 play roles in ER/Golgi exit and trafficking of proteins to the BL membrane, we evaluated the role of these Rabs in the trafficking of KCa3.1. In the presence of dominant negative Rab1 or Rab8, KCa3.1 cell surface expression was significantly reduced, whereas Rabs 2 and 6 had no effect. We also co-immunoprecipitated KCa3.1 with both Rab1 and Rab8. These results suggest these Rabs are necessary for the anterograde trafficking of KCa3.1. Finally, we determined whether KCa3.1 traffics directly to the BL membrane or through recycling endosomes in MDCK cells. For these studies, we used either recycling endosome ablation or dominant negative RME-1 constructs and determined that KCa3.1 is trafficked directly to the BL membrane rather than via recycling endosomes. These results are the first to describe the anterograde and retrograde trafficking of KCa3

Overexpression of Rab22a hampers the transport between endosomes and the Golgi apparatus

International Nuclear Information System (INIS)

Mesa, Rosana; Magadan, Javier; Barbieri, Alejandro; Lopez, Cecilia; Stahl, Philip D.; Mayorga, Luis S.

2005-01-01

The transport and sorting of soluble and membrane-associated macromolecules arriving at endosomal compartments require a complex set of Rab proteins. Rab22a has been localized to the endocytic compartment; however, very little is known about the function of Rab22a and inconsistent results have been reported in studies performed in different cell lines. To characterize the function of Rab22a in endocytic transport, the wild-type protein (Rab22a WT), a hydrolysis-deficient mutant (Rab22a Q64L), and a mutant with reduced affinity for GTP (Rab22a S19N) were expressed in CHO cells. None of the three Rab22a constructs affected the transport of rhodamine-dextran to lysosomes, the digestion of internalized proteins, or the lysosomal localization of cathepsin D. In contrast with the mild effect of Rab22a on the endosome-lysosome route, cells expressing Rab22a WT and Rab22a Q64L presented a strong delay in the retrograde transport of cholera toxin from endosomes to the Golgi apparatus. Moreover, these cells accumulated the cation independent mannose 6-phosphate receptor in endosomes. These observations indicate that Rab22a can affect the trafficking from endosomes to the Golgi apparatus probably by promoting fusion among endosomes and impairing the proper segregation of membrane domains required for targeting to the trans-Golgi network (TGN)

Arf6, Rab11 and transferrin receptor define distinct populations of recycling endosomes.

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Kobayashi, Hotaka; Fukuda, Mitsunori

2013-09-01

Recycling endosomes are key platforms for endocytic recycling that return internalized molecules back to the plasma membrane. To determine how recycling endosomes perform their functions, searching for proteins and lipids that specifically localized at recycling endosomes has often been performed by colocalization analyses between candidate molecules and conventional recycling endosome markers. However, it remains unclear whether all the conventional markers have identical localizations. Here we report finding that three well-known recycling endosome markers, i.e., Arf6, Rab11 and transferrin receptor (TfR), have different intracellular localizations in PC12 cells. The results of immunofluorescence analyses showed that the signals of endogenous Arf6, Rab11 and TfR in nerve growth factor-stimulated PC12 cells generally differed, although there was some overlapping. Our findings provide new information about recycling endosome markers, and they highlight the heterogeneity of recycling endosomes.

COG11.1 description, new features, and development activities

International Nuclear Information System (INIS)

Buck, R.M.; Heinrichs, D.P.; Lee, C.K.; Lent, E.M.

2013-01-01

COG is a modern, full-featured, Monte Carlo radiation transport code, developed by Lawrence Livermore National Laboratory (LLNL), which provides accurate answers to complex shielding, criticality, and activation problems. COG uses Monte Carlo methods to solve the Boltzmann transport equation for particles traveling through arbitrary 3-dimensional problems. Neutrons, photons, electrons, and protons can be transported. Electron transport uses the EGS transport kernel. The article indicates all the data libraries that are used by COG for the transport of neutrons, photons and protons. COG is written for LINUX PC/Workstations and Windows 7 and Windows XP PC/Workstations. The programming languages used are Fortran77 (99%) and C (1%). The latest COG code version is COG11.1BETA2. This version is available from the Radiation Shielding Information Computer Center and the Nuclear Energy Agency Data Bank

RAB-5 and RAB-10 cooperate to regulate neuropeptide release in Caenorhabditis elegans

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Sasidharan, Nikhil; Sumakovic, Marija; Hannemann, Mandy; Hegermann, Jan; Liewald, Jana F.; Olendrowitz, Christian; Koenig, Sabine; Grant, Barth D.; Rizzoli, Silvio O.; Gottschalk, Alexander; Eimer, Stefan

2012-01-01

Neurons secrete neuropeptides from dense core vesicles (DCVs) to modulate neuronal activity. Little is known about how neurons manage to differentially regulate the release of synaptic vesicles (SVs) and DCVs. To analyze this, we screened all Caenorhabditis elegans Rab GTPases and Tre2/Bub2/Cdc16 (TBC) domain containing GTPase-activating proteins (GAPs) for defects in DCV release from C. elegans motoneurons. rab-5 and rab-10 mutants show severe defects in DCV secretion, whereas SV exocytosis is unaffected. We identified TBC-2 and TBC-4 as putative GAPs for RAB-5 and RAB-10, respectively. Multiple Rabs and RabGAPs are typically organized in cascades that confer directionality to membrane-trafficking processes. We show here that the formation of release-competent DCVs requires a reciprocal exclusion cascade coupling RAB-5 and RAB-10, in which each of the two Rabs recruits the other’s GAP molecule. This contributes to a separation of RAB-5 and RAB-10 domains at the Golgi–endosomal interface, which is lost when either of the two GAPs is inactivated. Taken together, our data suggest that RAB-5 and RAB-10 cooperate to locally exclude each other at an essential stage during DCV sorting. PMID:23100538

Characterization of a Rab11-like GTPase, EhRab11, of Entamoeba histolytica.

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McGugan, Glen C; Temesvari, Lesly A

2003-07-01

The Entamoeba histolytica Rab11 family of small molecular weight GTPases consists of three members, EhRab11, EhRab11B, and EhRab11C. The functions of these Rabs in Entamoeba have not been determined. Therefore, as an approach to elucidate the role of the Rab11 family of GTPases in Entamoeba, immunofluorescence microscopy was undertaken to define the subcellular localization of one member of this family, EhRab11. Under conditions of growth, EhRab11 displayed a punctate pattern in the cytoplasm of trophozoites. EhRab11 did not colocalize with markers for the Golgi apparatus, endoplasmic reticulum, pinosomes, phagosomes, or compartments formed by receptor-mediated endocytosis, suggesting that this Rab may not play a role in vesicle trafficking between these organelles. Under conditions of iron and serum starvation, EhRab11 was translocated to the periphery of the cell. The altered cellular localization was accompanied by multinucleation of the cells as well as the acquisition of detergent resistance by the cells, features that are characteristic of Entamoeba cysts. The translocation of EhRab11 to the periphery of the cell during iron and serum starvation was specific as the subcellular localizations of two other Rab GTPases, EhRab7 and EhRabA, were not altered under the same conditions. In addition, the formation of multinucleated cells by inhibition of cytokinesis was not sufficient to induce the translocation of EhRab11 to the cell periphery. Taken together, the data suggest that iron and serum starvation may induce encystation in E. histolytica and that EhRab11 may play a role in this process. Moreover, these studies are the first to describe a putative role for a Rab GTPase in encystation in Entamoeba sp.

The late endocytic Rab39a GTPase regulates the interaction between multivesicular bodies and chlamydial inclusions.

Science.gov (United States)

Gambarte Tudela, Julian; Capmany, Anahi; Romao, Maryse; Quintero, Cristian; Miserey-Lenkei, Stephanie; Raposo, Graca; Goud, Bruno; Damiani, Maria Teresa

2015-08-15

Given their obligate intracellular lifestyle, Chlamydia trachomatis ensure that they have access to multiple host sources of essential lipids by interfering with vesicular transport. These bacteria hijack Rab6-, Rab11- and Rab14-controlled trafficking pathways to acquire sphingomyelin from the Golgi complex. Another important source of sphingolipids, phospholipids and cholesterol are multivesicular bodies (MVBs). Despite their participation in chlamydial inclusion development and bacterial replication, the molecular mechanisms mediating the interaction between MVBs and chlamydial inclusions remain unknown. In the present study, we demonstrate that Rab39a labels a subset of late endocytic vesicles - mainly MVBs - that move along microtubules. Moreover, Rab39a is actively recruited to chlamydial inclusions throughout the pathogen life cycle by a bacterial-driven process that depends on the Rab39a GTP- or GDP-binding state. Interestingly, Rab39a participates in the delivery of MVBs and host sphingolipids to maturing chlamydial inclusions, thereby promoting inclusion growth and bacterial development. Taken together, our findings indicate that Rab39a favours chlamydial replication and infectivity. This is the first report showing that a late endocytic Rab GTPase is involved in chlamydial infection development. © 2015. Published by The Company of Biologists Ltd.

Recognition and stabilization of geranylgeranylated human Rab5 by the GDP Dissociation Inhibitor (GDI).

Science.gov (United States)

Edler, Eileen; Stein, Matthias

2017-10-25

The small GTPase Rab5 is the key regulator of early endosomal fusion. It is post-translationally modified by covalent attachment of two geranylgeranyl (GG) chains to adjacent cysteine residues of the C-terminal hypervariable region (HVR). The GDP dissociation inhibitor (GDI) recognizes membrane-associated Rab5(GDP) and serves to release it into the cytoplasm where it is kept in a soluble state. A detailed new structural and dynamic model for human Rab5(GDP) recognition and binding with human GDI at the early endosome membrane and in its dissociated state is presented. In the cytoplasm, the GDI protein accommodates the GG chains in a transient hydrophobic binding pocket. In solution, two different binding modes of the isoprenoid chains inserted into the hydrophobic pocket of the Rab5(GDP):GDI complex can be identified. This equilibrium between the two states helps to stabilize the protein-protein complex in solution. Interprotein contacts between the Rab5 switch regions and characteristic patches of GDI residues from the Rab binding platform (RBP) and the C-terminus coordinating region (CCR) reveal insight on the formation of such a stable complex. GDI binding to membrane-anchored Rab5(GDP) is initially mediated by the solvent accessible switch regions of the Rab-specific RBP. Formation of the membrane-associated Rab5(GDP):GDI complex induces a GDI reorientation to establish additional interactions with the Rab5 HVR. These results allow to devise a detailed structural model for the process of extraction of GG-Rab5(GDP) by GDI from the membrane and the dissociation from targeting factors and effector proteins prior to GDI binding.

Contrasting patterns in the evolution of the Rab GTPase family in Archaeplastida

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Romana Petrželková

2014-12-01

Full Text Available Rab GTPases are a vast group of proteins serving a role of master regulators in membrane trafficking in eukaryotes. Previous studies delineated some 23 Rab and Rab-like paralogs ancestral for eukaryotes and mapped their current phylogenetic distribution, but the analyses relied on a limited sampling of the eukaryotic diversity. Taking advantage of the recent growth of genome and transcriptome resources for phylogenetically diverse plants and algae, we reanalyzed the evolution of the Rab family in eukaryotes with the primary plastid, collectively constituting the presumably monophyletic supergroup Archaeplastida. Our most important novel findings are as follows: (i the ancestral set of Rabs in Archaeplastida included not only the paralogs Rab1, Rab2, Rab5, Rab6, Rab7, Rab8, Rab11, Rab18, Rab23, Rab24, Rab28, IFT27, and RTW (=Rabl2, as suggested previously, but also Rab14 and Rab34, because Rab14 exists in glaucophytes and Rab34 is present in glaucophytes and some green algae; (ii except in embryophytes, Rab gene duplications have been rare in Archaeplastida. Most notable is the independent emergence of divergent, possibly functionally novel, in-paralogs of Rab1 and Rab11 in several archaeplastidial lineages; (iii recurrent gene losses have been a significant factor shaping Rab gene complements in archaeplastidial species; for example, the Rab21 paralog was lost at least six times independently within Archaeplastida, once in the lineage leading to the “core” eudicots; (iv while the glaucophyte Cyanophora paradoxa has retained the highest number of ancestral Rab paralogs among all archaeplastidial species studied so far, rhodophytes underwent an extreme reduction of the Rab gene set along their stem lineage, resulting in only six paralogs (Rab1, Rab2, Rab6, Rab7, Rab11, and Rab18 present in modern red algae. Especially notable is the absence of Rab5, a virtually universal paralog essential for the endocytic pathway, suggesting that endocytosis

COG developments

International Nuclear Information System (INIS)

Lloyd, W.R.

1997-01-01

Benchmarking work for the computer program COG is very briefly described. COG is a Monte Carlo computer code that solves the Boltzmann equation for neutron and photon transport, deep penetration problems, and nuclear criticality problems. The results of three critical experiments are compared with COG and KENO-V.a calculation results. The results compare well the experiments, and are within the range of the KENO-V.a results. 1 ref., 2 tabs

What is the clinically relevant change on the ADAS-Cog?

Science.gov (United States)

Schrag, Anette; Schott, Jonathan M

2012-02-01

To establish the minimal clinically relevant change (MCRC) on the Alzheimer's Disease Assessment Scale-Cognitive (ADAS-Cog) for patients with mild Alzheimer's disease (AD). Cohort study. 59 recruiting sites for the Alzheimer's Disease Neuroimaging Initiative. Outpatients with AD in the Alzheimer's Disease Neuroimaging Initiative. The authors applied anchor-based MCRC methodology comparing ADAS-Cog change against clinicians' judgement of clinically relevant worsening between baseline and 6 months in four domains: memory and non-memory cognitive performance; Clinical Dementia Rating Scale; and Functional Assessment Questionnaire. The analysis was repeated for the 6-12-month interval. To support these findings, the authors calculated distribution-based measures including half-baseline SD (1/2 SD) and SEM. 181 patients (baseline ADAS-Cog score 18.5±6.4) had ADAS-Cog data at 0 and 6 months. Those undergoing clinically significant worsening on any of the four anchor questions (n=41-47) had an average ADAS-Cog change of 3.1-3.8 points. Similar results were found for the 177 patients with 6-12-month data. The average 1/2 SD for the baseline ADAS-Cog score was 3.2, and the SEM was 3.7. 3 points decline on the ADAS-Cog may be an appropriate MCRC for clinical trials of patients with early AD. However, further studies assessing the MCRC for improvement on the ADAS-Cog, using patient-based judgement as an anchor, and determining the minimal clinically relevant difference between change on two treatments are required. http://clinicalTrials.gov Identifier: NCT00106899.

Vesicular Trafficking Defects, Developmental Abnormalities, and Alterations in the Cellular Death Process Occur in Cell Lines that Over-Express Dictyostelium GTPase, Rab2, and Rab2 Mutants

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Katherine Maringer

2014-08-01

Full Text Available Small molecular weight GTPase Rab2 has been shown to be a resident of pre-Golgi intermediates and required for protein transport from the ER to the Golgi complex, however, the function of Rab2 in Dictyostelium has yet to be fully characterized. Using cell lines that over-express DdRab2, as well as cell lines over-expressing constitutively active (CA, and dominant negative (DN forms of the GTPase, we report a functional role in vesicular transport specifically phagocytosis, and endocytosis. Furthermore, Rab2 like other GTPases cycles between an active GTP-bound and an inactive GDP-bound state. We found that this GTP/GDP cycle for DdRab2 is crucial for normal Dictyostelium development and cell–cell adhesion. Similar to Rab5 and Rab7 in C. elegans, we found that DdRab2 plays a role in programmed cell death, possibly in the phagocytic removal of apoptotic corpses.

Cogging Torque Reduction Techniques for Spoke-type IPMSM

Science.gov (United States)

Bahrim, F. S.; Sulaiman, E.; Kumar, R.; Jusoh, L. I.

2017-08-01

A spoke-type interior permanent magnet synchronous motor (IPMSM) is extending its tentacles in industrial arena due to good flux-weakening capability and high power density. In many of the application, high strength of permanent magnet causes the undesirable effects of high cogging torque that can aggravate performance of the motor. High cogging torque is significantly produced by IPMSM due to the similar length and the effectiveness of the magnetic air-gap. The address of this study is to analyze and compare the cogging torque effect and performance of four common techniques for cogging torque reduction such as skewing, notching, pole pairing and rotor pole pairing. With the aid of 3-D finite element analysis (FEA) by JMAG software, a 6S-4P Spoke-type IPMSM with various rotor-PM configurations has been designed. As a result, the cogging torque effect reduced up to 69.5% for skewing technique, followed by 31.96%, 29.6%, and 17.53% by pole pairing, axial pole pairing and notching techniques respectively.

RIM, Munc13, and Rab3A interplay in acrosomal exocytosis

International Nuclear Information System (INIS)

Bello, Oscar D.; Zanetti, M. Natalia; Mayorga, Luis S.; Michaut, Marcela A.

2012-01-01

Exocytosis is a highly regulated, multistage process consisting of multiple functionally definable stages, including recruitment, targeting, tethering, priming, and docking of secretory vesicles with the plasma membrane, followed by calcium-triggered membrane fusion. The acrosome reaction of spermatozoa is a complex, calcium-dependent regulated exocytosis. Fusion at multiple sites between the outer acrosomal membrane and the cell membrane causes the release of the acrosomal contents and the loss of the membranes surrounding the acrosome. Not much is known about the molecules that mediate membrane docking in this particular fusion model. In neurons, the formation of the ternary RIM/Munc13/Rab3A complex has been suggested as a critical component of synaptic vesicles docking. Previously, we demonstrated that Rab3A localizes to the acrosomal region in human sperm, stimulates acrosomal exocytosis, and participates in an early stage during membrane fusion. Here, we report that RIM and Munc13 are also present in human sperm and localize to the acrosomal region. Like Rab3A, RIM and Munc13 participate in a prefusion step before the efflux of intra-acrosomal calcium. By means of a functional assay using antibodies and recombinant proteins, we show that RIM, Munc13 and Rab3A interplay during acrosomal exocytosis. Finally, we report by electron transmission microscopy that sequestering RIM and Rab3A alters the docking of the acrosomal membrane to the plasma membrane during calcium-activated acrosomal exocytosis. Our results suggest that the RIM/Munc13/Rab3 A complex participates in acrosomal exocytosis and that RIM and Rab3A have central roles in membrane docking. -- Highlights: ► RIM and Munc13 are present in human sperm and localize to the acrosomal region. ► RIM and Munc13 are necessary for acrosomal exocytosis. ► RIM and Munc13 participate before the acrosomal calcium efflux. ► RIM, Munc13 and Rab3A interplay in human sperm acrosomal exocytosis. ► RIM and Rab3A

Rab proteins: The key regulators of intracellular vesicle transport

International Nuclear Information System (INIS)

Bhuin, Tanmay; Roy, Jagat Kumar

2014-01-01

Vesicular/membrane trafficking essentially regulates the compartmentalization and abundance of proteins within the cells and contributes in many signalling pathways. This membrane transport in eukaryotic cells is a complex process regulated by a large and diverse array of proteins. A large group of monomeric small GTPases; the Rabs are essential components of this membrane trafficking route. Most of the Rabs are ubiquitously expressed proteins and have been implicated in vesicle formation, vesicle motility/delivery along cytoskeleton elements and docking/fusion at target membranes through the recruitment of effectors. Functional impairments of Rabs affecting transport pathways manifest different diseases. Rab functions are accompanied by cyclical activation and inactivation of GTP-bound and GDP-bound forms between the cytosol and membranes which is regulated by upstream regulators. Rab proteins are characterized by their distinct sub-cellular localization and regulate a wide variety of endocytic, transcytic and exocytic transport pathways. Mutations of Rabs affect cell growth, motility and other biological processes. - Highlights: • Rab proteins regulate different signalling pathways. • Deregulation of Rabs is the fundamental causes of a variety of human diseases. • This paper gives potential directions in developing therapeutic targets. • This paper also gives ample directions for modulating pathways central to normal physiology. • These are the huge challenges for drug discovery and delivery in near future

Rab proteins: The key regulators of intracellular vesicle transport

Energy Technology Data Exchange (ETDEWEB)

Bhuin, Tanmay [Cell and Developmental Biology Unit, Department of Zoology, The University of Burdwan, Golapbag 713104 (India); Roy, Jagat Kumar, E-mail: jkroy@bhu.ac.in [Cytogenetics Laboratory, Department of Zoology, Banaras Hindu University, Varanasi 221005 (India)

2014-10-15

Vesicular/membrane trafficking essentially regulates the compartmentalization and abundance of proteins within the cells and contributes in many signalling pathways. This membrane transport in eukaryotic cells is a complex process regulated by a large and diverse array of proteins. A large group of monomeric small GTPases; the Rabs are essential components of this membrane trafficking route. Most of the Rabs are ubiquitously expressed proteins and have been implicated in vesicle formation, vesicle motility/delivery along cytoskeleton elements and docking/fusion at target membranes through the recruitment of effectors. Functional impairments of Rabs affecting transport pathways manifest different diseases. Rab functions are accompanied by cyclical activation and inactivation of GTP-bound and GDP-bound forms between the cytosol and membranes which is regulated by upstream regulators. Rab proteins are characterized by their distinct sub-cellular localization and regulate a wide variety of endocytic, transcytic and exocytic transport pathways. Mutations of Rabs affect cell growth, motility and other biological processes. - Highlights: • Rab proteins regulate different signalling pathways. • Deregulation of Rabs is the fundamental causes of a variety of human diseases. • This paper gives potential directions in developing therapeutic targets. • This paper also gives ample directions for modulating pathways central to normal physiology. • These are the huge challenges for drug discovery and delivery in near future.

BLOC-3 mutated in Hermansky-Pudlak syndrome is a Rab32/38 guanine nucleotide exchange factor.

Science.gov (United States)

Gerondopoulos, Andreas; Langemeyer, Lars; Liang, Jin-Rui; Linford, Andrea; Barr, Francis A

2012-11-20

Hermansky-Pudlak syndrome (HPS) is a human disease characterized by partial loss of pigmentation and impaired blood clotting. These symptoms are caused by defects in the biogenesis of melanosomes and platelet dense granules, often referred to as lysosome-related organelles. Genes mutated in HPS encode subunits of the biogenesis of lysosome-related organelles complexes (BLOCs). BLOC-1 and BLOC-2, together with the AP-3 clathrin adaptor complex, act at early endosomes to sort components required for melanin formation and melanosome biogenesis away from the degradative lysosomal pathway toward early stage melanosomes. However the molecular functions of the Hps1-Hps4 complex BLOC-3 remain mysterious. Like other trafficking pathways, melanosome biogenesis and transport of enzymes involved in pigmentation involves specific Rab GTPases, in this instance Rab32 and Rab38. We now demonstrate that BLOC-3 is a Rab32 and Rab38 guanine nucleotide exchange factor (GEF). Silencing of the BLOC-3 subunits Hps1 and Hps4 results in the mislocalization of Rab32 and Rab38 and reduction in pigmentation. In addition, we show that BLOC-3 can promote specific membrane recruitment of Rab32/38. BLOC-3 therefore defines a novel Rab GEF family with a specific function in the biogenesis of lysosome-related organelles. Copyright © 2012 Elsevier Ltd. All rights reserved.

The COG Strikes Back

DEFF Research Database (Denmark)

Barfoed, Jacob

2014-01-01

The Clausewitzian Center of Gravity (COG) concept is central in western military strategic thinking and serves as a core concept in military planning. However, several interpretations of the concept exist, which contributes to theoretical as well as practical confusion. Moreover, the concept...... contributes to the discussion by combining the COG concept with strategic theory, hereby addressing many of the raised critique points. The article presents three COG-Strategy schools, centered on different/competing interpretations of the Clausewitzian Center of Gravity (CoG) concept as well as different...

Momentum Cogging at the Fermilab Booster

International Nuclear Information System (INIS)

Seiya, K.; Drennan, C.C.; Pellico, W.; Triplett, A.K.; Waller, A.M.

2012-01-01

The Fermilab Booster has an upgrade plan called the Proton Improvement Plan (PIP). The flux throughput goal is 2E17 protons/hour which, is almost double the present flux, 1.1E17 protons/hour. The beam loss in the machine is going to be an issue. The Booster accelerates beam from 400 MeV to 8 GeV and extracts to the Main Injector (MI). The current cogging process synchronizes the extraction kicker gap to the MI by changing radial position of the beam during the cycle. The gap creation occurs at about 700 MeV, which is about 6 ms into the cycle. The cycle-to-cycle variations of the Booster are larger at lower energy. However, changing the radial position at low energy for cogging is limited because of aperture. Momentum cogging is able to move the gap creation to an earlier time by using dipole correctors and radial position feedback, and is able to control the revolution frequency and radial position at the same time. The new cogging is expected to reduce beam loss and not be limited by aperture. The progress of the momentum cogging system development is going to be discussed in this paper.

RIM, Munc13, and Rab3A interplay in acrosomal exocytosis

Energy Technology Data Exchange (ETDEWEB)

Bello, Oscar D.; Zanetti, M. Natalia [Laboratorio de Biologia Celular y Molecular, Instituto de Histologia y Embriologia, IHEM (CONICET-UNCuyo), Facultad de Ciencias Medicas (Argentina); Laboratorio de Biologia Reproductiva, Instituto de Histologia y Embriologia, IHEM (CONICET-UNCuyo), Facultad de Ciencias Medicas (Argentina); Mayorga, Luis S. [Laboratorio de Biologia Celular y Molecular, Instituto de Histologia y Embriologia, IHEM (CONICET-UNCuyo), Facultad de Ciencias Medicas (Argentina); Michaut, Marcela A., E-mail: mmichaut@fcm.uncu.edu.ar [Laboratorio de Biologia Reproductiva, Instituto de Histologia y Embriologia, IHEM (CONICET-UNCuyo), Facultad de Ciencias Medicas (Argentina); Instituto de Ciencias Basicas, Universidad Nacional de Cuyo, Mendoza (5500) (Argentina)

2012-03-10

Exocytosis is a highly regulated, multistage process consisting of multiple functionally definable stages, including recruitment, targeting, tethering, priming, and docking of secretory vesicles with the plasma membrane, followed by calcium-triggered membrane fusion. The acrosome reaction of spermatozoa is a complex, calcium-dependent regulated exocytosis. Fusion at multiple sites between the outer acrosomal membrane and the cell membrane causes the release of the acrosomal contents and the loss of the membranes surrounding the acrosome. Not much is known about the molecules that mediate membrane docking in this particular fusion model. In neurons, the formation of the ternary RIM/Munc13/Rab3A complex has been suggested as a critical component of synaptic vesicles docking. Previously, we demonstrated that Rab3A localizes to the acrosomal region in human sperm, stimulates acrosomal exocytosis, and participates in an early stage during membrane fusion. Here, we report that RIM and Munc13 are also present in human sperm and localize to the acrosomal region. Like Rab3A, RIM and Munc13 participate in a prefusion step before the efflux of intra-acrosomal calcium. By means of a functional assay using antibodies and recombinant proteins, we show that RIM, Munc13 and Rab3A interplay during acrosomal exocytosis. Finally, we report by electron transmission microscopy that sequestering RIM and Rab3A alters the docking of the acrosomal membrane to the plasma membrane during calcium-activated acrosomal exocytosis. Our results suggest that the RIM/Munc13/Rab3 A complex participates in acrosomal exocytosis and that RIM and Rab3A have central roles in membrane docking. -- Highlights: Black-Right-Pointing-Pointer RIM and Munc13 are present in human sperm and localize to the acrosomal region. Black-Right-Pointing-Pointer RIM and Munc13 are necessary for acrosomal exocytosis. Black-Right-Pointing-Pointer RIM and Munc13 participate before the acrosomal calcium efflux. Black

RAB-10-Dependent Membrane Transport Is Required for Dendrite Arborization

Science.gov (United States)

Zou, Wei; Yadav, Smita; DeVault, Laura; Jan, Yuh Nung; Sherwood, David R.

2015-01-01

Formation of elaborately branched dendrites is necessary for the proper input and connectivity of many sensory neurons. Previous studies have revealed that dendritic growth relies heavily on ER-to-Golgi transport, Golgi outposts and endocytic recycling. How new membrane and associated cargo is delivered from the secretory and endosomal compartments to sites of active dendritic growth, however, remains unknown. Using a candidate-based genetic screen in C. elegans, we have identified the small GTPase RAB-10 as a key regulator of membrane trafficking during dendrite morphogenesis. Loss of rab-10 severely reduced proximal dendritic arborization in the multi-dendritic PVD neuron. RAB-10 acts cell-autonomously in the PVD neuron and localizes to the Golgi and early endosomes. Loss of function mutations of the exocyst complex components exoc-8 and sec-8, which regulate tethering, docking and fusion of transport vesicles at the plasma membrane, also caused proximal dendritic arborization defects and led to the accumulation of intracellular RAB-10 vesicles. In rab-10 and exoc-8 mutants, the trans-membrane proteins DMA-1 and HPO-30, which promote PVD dendrite stabilization and branching, no longer localized strongly to the proximal dendritic membranes and instead were sequestered within intracellular vesicles. Together these results suggest a crucial role for the Rab10 GTPase and the exocyst complex in controlling membrane transport from the secretory and/or endosomal compartments that is required for dendritic growth. PMID:26394140

Family-wide characterization of the DENN domain Rab GDP-GTP exchange factors.

Science.gov (United States)

Yoshimura, Shin-ichiro; Gerondopoulos, Andreas; Linford, Andrea; Rigden, Daniel J; Barr, Francis A

2010-10-18

A key requirement for Rab function in membrane trafficking is site-specific activation by GDP-GTP exchange factors (GEFs), but the majority of the 63 human Rabs have no known GEF. We have performed a systematic characterization of the 17 human DENN domain proteins and demonstrated that they are specific GEFs for 10 Rabs. DENND1A/1B localize to clathrin patches at the plasma membrane and activate Rab35 in an endocytic pathway trafficking Shiga toxin to the trans-Golgi network. DENND2 GEFs target to actin filaments and control Rab9-dependent trafficking of mannose-6-phosphate receptor to lysosomes. DENND4 GEFs target to a tubular membrane compartment adjacent to the Golgi, where they activate Rab10, which suggests a function in basolateral polarized sorting in epithelial cells that compliments the non-DENN GEF Sec2 acting on Rab8 in apical sorting. DENND1C, DENND3, DENND5A/5B, MTMR5/13, and MADD activate Rab13, Rab12, Rab39, Rab28, and Rab27A/27B, respectively. Together, these findings provide a basis for future studies on Rab regulation and function.

Validation of COG10 and ENDFB6R7 on the Auk Workstation for General Application to Highly Enriched Uranium Systems

Energy Technology Data Exchange (ETDEWEB)

Percher, Catherine G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2011-08-08

The COG 10 code package1 on the Auk workstation is now validated with the ENBFB6R7 neutron cross section library for general application to highly enriched uranium (HEU) systems by comparison of the calculated keffective to the expected keffective of several relevant experimental benchmarks. This validation is supplemental to the installation and verification of COG 10 on the Auk workstation2.

COG: information exchange. The new initiatives

International Nuclear Information System (INIS)

Guiry, C.

2000-01-01

The CANDU Owners Group (COG) is dedicated to providing programs for cooperation, mutual assistance and exchange of information for the successful support, development, operation, maintenance and economics of CANDU Technology. This paper summarises the COG Mission, COG Vision and COG Values

Rab GTPases Regulate Endothelial Cell Protein C Receptor-Mediated Endocytosis and Trafficking of Factor VIIa

Science.gov (United States)

Nayak, Ramesh C.; Keshava, Shiva; Esmon, Charles T.; Pendurthi, Usha R.; Rao, L. Vijaya Mohan

2013-01-01

Recent studies have established that factor VIIa (FVIIa) binds to the endothelial cell protein C receptor (EPCR). FVIIa binding to EPCR may promote the endocytosis of this receptor/ligand complex. Rab GTPases are known to play a crucial role in the endocytic and exocytic pathways of receptors or receptor/ligand complexes. The present study was undertaken to investigate the role of Rab GTPases in the intracellular trafficking of EPCR and FVIIa. CHO-EPCR cells and human umbilical vein endothelial cells (HUVEC) were transduced with recombinant adenoviral vectors to express wild-type, constitutively active, or dominant negative mutant of various Rab GTPases. Cells were exposed to FVIIa conjugated with AF488 fluorescent probe (AF488-FVIIa), and intracellular trafficking of FVIIa, EPCR, and Rab proteins was evaluated by immunofluorescence confocal microscopy. In cells expressing wild-type or constitutively active Rab4A, internalized AF488-FVIIa accumulated in early/sorting endosomes and its entry into the recycling endosomal compartment (REC) was inhibited. Expression of constitutively active Rab5A induced large endosomal structures beneath the plasma membrane where EPCR and FVIIa accumulated. Dominant negative Rab5A inhibited the endocytosis of EPCR-FVIIa. Expression of constitutively active Rab11 resulted in retention of accumulated AF488-FVIIa in the REC, whereas expression of a dominant negative form of Rab11 led to accumulation of internalized FVIIa in the cytoplasm and prevented entry of internalized FVIIa into the REC. Expression of dominant negative Rab11 also inhibited the transport of FVIIa across the endothelium. Overall our data show that Rab GTPases regulate the internalization and intracellular trafficking of EPCR-FVIIa. PMID:23555015

Molecular cloning of Rab5 (ApRab5) in Aiptasia pulchella and its retention in phagosomes harboring live zooxanthellae.

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Chen, Ming-Chyuan; Cheng, Ying-Min; Hong, Min-Chang; Fang, Lee-Shing

2004-11-19

The intracellular association of symbiotic dinoflagellates (zooxanthellae) with marine cnidarians is the very foundation of the highly productive and diversified coral reef ecosystems. To reveal its underlying molecular mechanisms, we previously cloned ApRab7, a Rab7 homologue of the sea anemone Aiptasia pulchella, and demonstrated its selective exclusion from phagosomes containing live zooxanthellae, but not from those containing either dead or photosynthesis-impaired algae. In this study, Rab5 was characterized, due to its key role in endocytosis and phagocytosis acting upstream of Rab7. The Aiptasia Rab5 homologue (ApRab5) is 79.5% identical to human Rab5C and contains all Rab-specific signature motifs. Subcellular fractionation study showed that ApRab5 is mainly cytosolic. EGFP reporter and phagocytosis studies indicated that membrane-associated ApRab5 is present in early endocytic and phagocytic compartments, and is able to promote their fusion. Significantly, immunofluorescence study showed that the majority of phagosomes containing either resident or newly internalized live zooxanthellae were labeled with ApRab5, while those containing either heat-killed or photosynthesis-impaired algae were mostly negative for ApRab5 staining whereas the opposite was observed for ApRab7. We propose that active phagosomal retention of ApRab5 is part of the mechanisms employed by live zooxanthellae to: (1) persist inside their host cells and (2) exclude ApRab7 from their phagosomes, thereby, establishing and/or maintaining an endosymbiotic relationship with their cnidarian hosts.

Molecular cloning of Rab5 (ApRab5) in Aiptasia pulchella and its retention in phagosomes harboring live zooxanthellae

International Nuclear Information System (INIS)

Chen, M.-C.; Cheng, Y.-M; Hong, M.-C.; Fang, L.-S.

2004-01-01

The intracellular association of symbiotic dinoflagellates (zooxanthellae) with marine cnidarians is the very foundation of the highly productive and diversified coral reef ecosystems. To reveal its underlying molecular mechanisms, we previously cloned ApRab7, a Rab7 homologue of the sea anemone Aiptasia pulchella, and demonstrated its selective exclusion from phagosomes containing live zooxanthellae, but not from those containing either dead or photosynthesis-impaired algae. In this study, Rab5 was characterized, due to its key role in endocytosis and phagocytosis acting upstream of Rab7. The Aiptasia Rab5 homologue (ApRab5) is 79.5% identical to human Rab5C and contains all Rab-specific signature motifs. Subcellular fractionation study showed that ApRab5 is mainly cytosolic. EGFP reporter and phagocytosis studies indicated that membrane-associated ApRab5 is present in early endocytic and phagocytic compartments, and is able to promote their fusion. Significantly, immunofluorescence study showed that the majority of phagosomes containing either resident or newly internalized live zooxanthellae were labeled with ApRab5, while those containing either heat-killed or photosynthesis-impaired algae were mostly negative for ApRab5 staining whereas the opposite was observed for ApRab7. We propose that active phagosomal retention of ApRab5 is part of the mechanisms employed by live zooxanthellae to: (1) persist inside their host cells and (2) exclude ApRab7 from their phagosomes, thereby, establishing and/or maintaining an endosymbiotic relationship with their cnidarian hosts

Identification and characterization of a member of Rab subfamily, Rab8, from Clonorchis sinensis.

Science.gov (United States)

Liang, Pei; He, Lei; Yu, Jinyun; Xie, Zhizhi; Chen, Xueqing; Mao, Qiang; Liang, Chi; Huang, Yan; Lu, Gang; Yu, Xinbing

2015-05-01

The Rabs act as a binary molecular switch that utilizes the conformational changes associated with the GTP/GDP cycle to elicit responses from target proteins. It regulates a broad spectrum of cellular processes including cell proliferation, cytoskeletal assembly, and intracellular membrane trafficking in eukaryotes. The Rab8 from Clonorchis sinensis (CsRab8) was composed of 199 amino acids. The deduced amino acid sequence shared above 50% identities with other species from trematode, tapeworm, mammal, insecta, nematode, and reptile, respectively. The homologous analysis of sequences showed the conservative domains: G1 box (GDSGVGKS), G2 box (T), G3 box (DTAG), G4 box (GNKCDL), and G5 box. In addition, the structure modeling had also shown other functional domains: GTP/Mg(2+) binding sites, switch I region, and switch II region. A phylogenic tree analysis indicated that the CsRab8 was clustered with the Rab from Schistosoma japonicum, and trematode and tapeworm came from the same branch, which was different from an evolutional branch built by other species, such as mammal animal, insecta, nematode, and reptile. The recombinant CsRab8 protein was expressed in Escherichia coli and the purified protein was a soluble molecule by 12% sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis. CsRab8 was identified as a component of excretory/secretory products of C. sinensis by western blot analysis. The transcriptional level of CsRab8 at metacercaria stage was the highest at the four stages and higher by 56.49-folds than that at adult worm, 1.23-folds than that at excysted metacercaria, and 2.69-folds than that at egg stage. Immunohistochemical localization analysis showed that CsRab8 was specifically distributed in the tegument, vitellarium, eggs, and testicle of adult worms, and detected on the vitellarium and tegument of metacercaria. Combined with the results, CsRab8 is indispensable for survival and development of parasites, especially for regulating

Apical transport of influenza A virus ribonucleoprotein requires Rab11-positive recycling endosome.

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Fumitaka Momose

Full Text Available Influenza A virus RNA genome exists as eight-segmented ribonucleoprotein complexes containing viral RNA polymerase and nucleoprotein (vRNPs. Packaging of vRNPs and virus budding take place at the apical plasma membrane (APM. However, little is known about the molecular mechanisms of apical transport of newly synthesized vRNP. Transfection of fluorescent-labeled antibody and subsequent live cell imaging revealed that punctate vRNP signals moved along microtubules rapidly but intermittently in both directions, suggestive of vesicle trafficking. Using a series of Rab family protein, we demonstrated that progeny vRNP localized to recycling endosome (RE in an active/GTP-bound Rab11-dependent manner. The vRNP interacted with Rab11 through viral RNA polymerase. The localization of vRNP to RE and subsequent accumulation to the APM were impaired by overexpression of Rab binding domains (RBD of Rab11 family interacting proteins (Rab11-FIPs. Similarly, no APM accumulation was observed by overexpression of class II Rab11-FIP mutants lacking RBD. These results suggest that the progeny vRNP makes use of Rab11-dependent RE machinery for APM trafficking.

Basolateral Endocytic Recycling Requires RAB-10 and AMPH-1 Mediated Recruitment of RAB-5 GAP TBC-2 to Endosomes

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Liu, Ou; Grant, Barth D.

2015-01-01

The small GTPase RAB-5/Rab5 is a master regulator of the early endosome, required for a myriad of coordinated activities, including the degradation and recycling of internalized cargo. Here we focused on the recycling function of the early endosome and the regulation of RAB-5 by GAP protein TBC-2 in the basolateral C. elegans intestine. We demonstrate that downstream basolateral recycling regulators, GTPase RAB-10/Rab10 and BAR domain protein AMPH-1/Amphiphysin, bind to TBC-2 and help to recruit it to endosomes. In the absence of RAB-10 or AMPH-1 binding to TBC-2, RAB-5 membrane association is abnormally high and recycling cargo is trapped in early endosomes. Furthermore, the loss of TBC-2 or AMPH-1 leads to abnormally high spatial overlap of RAB-5 and RAB-10. Taken together our results indicate that RAB-10 and AMPH-1 mediated down-regulation of RAB-5 is an important step in recycling, required for cargo exit from early endosomes and regulation of early endosome–recycling endosome interactions. PMID:26393361

Down-regulation of Rab5 decreases characteristics associated with maintenance of cell transformation

International Nuclear Information System (INIS)

Silva, Patricio; Soto, Nicolás; Díaz, Jorge; Mendoza, Pablo; Díaz, Natalia; Quest, Andrew F.G.; Torres, Vicente A.

2015-01-01

The early endosomal protein Rab5 is highly expressed in tumor samples, although a causal relationship between Rab5 expression and cell transformation has not been established. Here, we report the functional effects of targeting endogenous Rab5 with specific shRNA sequences in different tumor cell lines. Rab5 down-regulation in B16-F10 cells decreased tumor formation by subcutaneous injection into C57/BL6 mice. Accordingly, Rab5 targeting in B16-F10 and A549, but not MDA-MB-231 cells was followed by decreased cell proliferation, increased apoptosis and decreased anchorage-independent growth. These findings suggest that Rab5 expression is required to maintain characteristics associated with cell transformation. - Highlights: • Rab5 is important to the maintenance of cell transformation characteristics. • Down-regulation of Rab5 decreases cell proliferation and increases apoptosis in different cancer cells. • Rab5 is required for anchorage-independent growth and tumorigenicity in-vivo

COG10, Multiparticle Monte Carlo Code System for Shielding and Criticality Use

International Nuclear Information System (INIS)

2007-01-01

1 - Description of program or function: COG is a modern, full-featured Monte Carlo radiation transport code which provides accurate answers to complex shielding, criticality, and activation problems. COG was written to be state-of-the-art and free of physics approximations and compromises found in earlier codes. COG is fully 3-D, uses point-wise cross sections and exact angular scattering, and allows a full range of biasing options to speed up solutions for deep penetration problems. Additionally, a criticality option is available for computing Keff for assemblies of fissile materials. ENDL or ENDFB cross section libraries may be used. COG home page: http://www-phys.llnl.gov/N_Div/COG/. Cross section libraries are included in the package. COG can use either the LLNL ENDL-90 cross section set or the ENDFB/VI set. Analytic surfaces are used to describe geometric boundaries. Parts (volumes) are described by a method of Constructive Solid Geometry. Surface types include surfaces of up to fourth order, and pseudo-surfaces such as boxes, finite cylinders, and figures of revolution. Repeated assemblies need be defined only once. Parts are visualized in cross-section and perspective picture views. Source and random-walk biasing techniques may be selected to improve solution statistics. These include source angular biasing, importance weighting, particle splitting and Russian roulette, path-length stretching, point detectors, scattered direction biasing, and forced collisions. Criticality - For a fissioning system, COG will compute Keff by transporting batches of neutrons through the system. Activation - COG can compute gamma-ray doses due to neutron-activated materials, starting with just a neutron source. Coupled Problems - COG can solve coupled problems involving neutrons, photons, and electrons. 2 - Methods:COG uses Monte Carlo methods to solve the Boltzmann transport equation for particles traveling through arbitrary 3-dimensional geometries. Neutrons, photons

Errors in ADAS-cog administration and scoring may undermine clinical trials results.

Science.gov (United States)

Schafer, K; De Santi, S; Schneider, L S

2011-06-01

The Alzheimer's Disease Assessment Scale - cognitive subscale (ADAS-cog) is the most widely used cognitive outcome measure in AD trials. Although errors in administration and scoring have been suggested as factors masking accurate estimates and potential effects of treatments, there have been few formal examinations of errors with the ADAS-cog. We provided ADAS-cog administration training using standard methods to raters who were designated as experienced, potential raters by sponsors or contract research organizations for two clinical trials. Training included 1 hour sessions on test administration, scoring, question periods, and required that raters individually view and score a model ADAS-cog administration. Raters scores were compared to the criterion scores established for the model administration. A total of 108 errors were made by 80.6% of the 72 raters; 37.5% made 1 error, 25.0% made 2 errors and 18.0% made 3 or more. Errors were made in all ADAS-cog subsections. The most common were in word finding difficulty (67% of the raters), word recognition (22%), and orientation (22%). For the raters who made 1, 2, or ≥ 3 errors the ADAS-cog score was 17.5 (95% CI, 17.3 - 17.8), 17.8 (17.0 - 18.5), and 18.8 (17.6 - 20.0), respectively, and compared to the criterion score, 18.3. ADAS-cog means differed significantly and the variances were more than twice as large between those who made errors on word finding and those who did not, 17.6 (SD=1.4) vs. 18.8 (SD=0.9), respectively (χ(2) = 37.2, P ADAS-cog scores and clinical trials outcomes. These errors may undermine detection of medication effects by contributing both to a biased point estimate and increased variance of the outcome.

Rab11-family of interacting protein 2 associates with chlamydial inclusions through its Rab-binding domain and promotes bacterial multiplication.

Science.gov (United States)

Leiva, Natalia; Capmany, Anahí; Damiani, María Teresa

2013-01-01

Chlamydia trachomatis, an obligate intracellular pathogen, survives within host cells in a special compartment named 'inclusion' and takes advantage of host vesicular transport pathways for its growth and replication. Rab GTPases are key regulatory proteins of intracellular trafficking. Several Rabs, among them Rab11 and Rab14, are implicated in chlamydial development. FIP2, a member of the Rab11-Family of Interacting Proteins, presents at the C-terminus a Rab-binding domain that interacts with both Rab11 and Rab14. In this study, we determined and characterized the recruitment of endogenous and GFP-tagged FIP2 to the chlamydial inclusions. The recruitment of FIP2 is specific since other members of the Rab11-Family of Interacting Proteins do not associate with the chlamydial inclusions. The Rab-binding domain of FIP2 is essential for its association. Our results indicate that FIP2 binds to Rab11 at the chlamydial inclusion membrane through its Rab-binding domain. The presence of FIP2 at the chlamydial inclusion favours the recruitment of Rab14. Furthermore, our results show that FIP2 promotes inclusion development and bacterial replication. In agreement, the silencing of FIP2 decreases the bacterial progeny. C. trachomatis likely recruits FIP2 to hijack host intracellular trafficking to redirect vesicles full of nutrients towards the inclusion. © 2012 Blackwell Publishing Ltd.

Molecular identification of Rab7 (ApRab7) in Aiptasia pulchella and its exclusion from phagosomes harboring zooxanthellae.

Science.gov (United States)

Chen, Ming-Chyuan; Cheng, Ying-Min; Sung, Ping-Jyun; Kuo, Cham-En; Fang, Lee-Shing

2003-08-29

The establishment and maintenance of the intracellular association between marine cnidarians and their symbiotic microalgae is essential to the well being of coral reef ecosystems; however, little is known concerning its underlying molecular mechanisms. In light of the critical roles of the small GTPase, Rab7, as a key regulator of vesicular trafficking, we cloned and characterized the Rab7 protein in the endosymbiosis system between the sea anemone, Aiptasia pulchella and its algal symbiont, Symbiodinium spp. The Aiptasia homologue of Rab7 proteins, ApRab7 is 88% identical to human Rab7 protein and contains all Rab-specific signature motifs. Results of EGFP reporter analysis, protein fractionation, and immunocytochemistry support that ApRab7 is located in late endocytic and phagocytic compartments and is able to promote their fusion. Significantly, the majority of phagosomes containing live symbionts that either have taken long residency in, or were newly internalized by Aiptasia digestive cells did not contain detectable levels of ApRab7, while most phagosomes containing either heat-killed or photosynthesis-impaired symbionts were positive for ApRab7 staining. Overall, our data suggest that live algal symbionts persist inside their host cells by actively excluding ApRab7 from their phagosomes, and thereby, establish and/or maintain an endosymbiotic relationship with their cnidarian hosts.

Rab-GDI complex dissociation factor expressed through translational frameshifting in filamentous ascomycetes.

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Fabienne Malagnac

Full Text Available In the model fungus Podospora anserina, the PaYIP3 gene encoding the orthologue of the Saccharomyces cerevisiae YIP3 Rab-GDI complex dissociation factor expresses two polypeptides, one of which, the long form, is produced through a programmed translation frameshift. Inactivation of PaYIP3 results in slightly delayed growth associated with modification in repartition of fruiting body on the thallus, along with reduced ascospore production on wood. Long and short forms of PaYIP3 are expressed in the mycelium, while only the short form appears expressed in the maturing fruiting body (perithecium. The frameshift has been conserved over the evolution of the Pezizomycotina, lasting for over 400 million years, suggesting that it has an important role in the wild.

Rab-GDI complex dissociation factor expressed through translational frameshifting in filamentous ascomycetes.

Science.gov (United States)

Malagnac, Fabienne; Fabret, Céline; Prigent, Magali; Rousset, Jean-Pierre; Namy, Olivier; Silar, Philippe

2013-01-01

In the model fungus Podospora anserina, the PaYIP3 gene encoding the orthologue of the Saccharomyces cerevisiae YIP3 Rab-GDI complex dissociation factor expresses two polypeptides, one of which, the long form, is produced through a programmed translation frameshift. Inactivation of PaYIP3 results in slightly delayed growth associated with modification in repartition of fruiting body on the thallus, along with reduced ascospore production on wood. Long and short forms of PaYIP3 are expressed in the mycelium, while only the short form appears expressed in the maturing fruiting body (perithecium). The frameshift has been conserved over the evolution of the Pezizomycotina, lasting for over 400 million years, suggesting that it has an important role in the wild.

RAB1A promotes Vaccinia virus replication by facilitating the production of intracellular enveloped virions

Energy Technology Data Exchange (ETDEWEB)

Pechenick Jowers, Tali; Featherstone, Rebecca J.; Reynolds, Danielle K.; Brown, Helen K. [The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Roslin, Midlothian EH25 9RG, Scotland (United Kingdom); James, John; Prescott, Alan [Division of Cell Signalling and Immunology, College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland (United Kingdom); Haga, Ismar R. [The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Roslin, Midlothian EH25 9RG, Scotland (United Kingdom); Beard, Philippa M., E-mail: pip.beard@roslin.ed.ac.uk [The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Roslin, Midlothian EH25 9RG, Scotland (United Kingdom)

2015-01-15

Vaccinia virus (VACV) is a large double-stranded DNA virus with a complex cytoplasmic replication cycle that exploits numerous cellular proteins. This work characterises the role of a proviral cellular protein, the small GTPase RAB1A, in VACV replication. Using siRNA, we identified RAB1A as required for the production of extracellular enveloped virions (EEVs), but not intracellular mature virions (IMVs). Immunofluorescence and electron microscopy further refined the role of RAB1A as facilitating the wrapping of IMVs to become intracellular enveloped virions (IEVs). This is consistent with the known function of RAB1A in maintenance of ER to Golgi transport. VACV can therefore be added to the growing list of viruses which require RAB1A for optimal replication, highlighting this protein as a broadly proviral host factor. - Highlights: • Characterisation of the role of the small GTPase RAB1A in VACV replication. • RAB1A is not required for production of the primary virion form (IMV). • RAB1A is required for production of processed virion forms (IEVs, CEVs and EEVs). • Consistent with known role of RAB1A in ER to Golgi transport.

Folliculin directs the formation of a Rab34-RILP complex to control the nutrient-dependent dynamic distribution of lysosomes.

Science.gov (United States)

Starling, Georgina P; Yip, Yan Y; Sanger, Anneri; Morton, Penny E; Eden, Emily R; Dodding, Mark P

2016-06-01

The spatial distribution of lysosomes is important for their function and is, in part, controlled by cellular nutrient status. Here, we show that the lysosome associated Birt-Hoge-Dubé (BHD) syndrome renal tumour suppressor folliculin (FLCN) regulates this process. FLCN promotes the peri-nuclear clustering of lysosomes following serum and amino acid withdrawal and is supported by the predominantly Golgi-associated small GTPase Rab34. Rab34-positive peri-nuclear membranes contact lysosomes and cause a reduction in lysosome motility and knockdown of FLCN inhibits Rab34-induced peri-nuclear lysosome clustering. FLCN interacts directly via its C-terminal DENN domain with the Rab34 effector RILP Using purified recombinant proteins, we show that the FLCN-DENN domain does not act as a GEF for Rab34, but rather, loads active Rab34 onto RILP We propose a model whereby starvation-induced FLCN association with lysosomes drives the formation of contact sites between lysosomes and Rab34-positive peri-nuclear membranes that restrict lysosome motility and thus promote their retention in this region of the cell. © 2016 The Authors. Published under the terms of the CC BY 4.0 license.

Identification and characterization of Iporin as a novel interaction partner for rab1

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Konczal Magdalena

2005-03-01

Full Text Available Abstract Background The small GTPase rab1a and its isoform rab1b are essential regulating components in the vesicle transport between the ER and the Golgi apparatus. Rab1 is thought to act as a molecular switch and can change between an active GTP-bound and an inactive GDP-bound conformation. To elucidate the function of rab1, several approaches have been established to isolate effector proteins, which interact with the activated conformation of rab1. To date p115, GM130, golgin-84 and MICAL have been identified as direct interacting partners. Together with rab1, these molecules are components of a protein complex, which mediates and regulates intracellular vesicle transport. Results Here, we report the characterization of Iporin, which is similar to KIAA0375 as a novel rab1-interacting protein. It was initially identified by yeast two-hybrid screening experiments with the active mutant of rab1b (rab1b Q67R as bait. Iporin contains a SH3 domain and two polyproline stretches, which are known to play a role in protein/protein interactions. In addition, Iporin encloses a RUN domain, which seems to be a major part of the rab1binding domain (R1BD. Iporin is ubiquitously expressed and immunofluorescence staining displays a cytosolic punctual distribution. Interestingly, we also show that Iporin interacts with another rab1 interacting partner, the GM130 protein. Conclusion Our results demonstrate that Iporin is a potential new interacting partner of rab1. Iporin is different from already identified rab1 interacting proteins concerning protein structure and cellular localization. We conclude that Iporin might function as a link between the targeting of ER derived vesicles, triggered by the rab1 GTPase and a signaling pathway regulated by molecules containing SH3 and/or poly-proline regions. The characterization of this novel intermolecular relation could help to elucidate how vesicles find their way from ER to the Golgi apparatus.

Rab14 and its exchange factor FAM116 link endocytic recycling and adherens junction stability in migrating cells.

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Linford, Andrea; Yoshimura, Shin-ichiro; Nunes Bastos, Ricardo; Langemeyer, Lars; Gerondopoulos, Andreas; Rigden, Daniel J; Barr, Francis A

2012-05-15

Rab GTPases define the vesicle trafficking pathways underpinning cell polarization and migration. Here, we find that Rab4, Rab11, and Rab14 and the candidate Rab GDP-GTP exchange factors (GEFs) FAM116A and AVL9 are required for cell migration. Rab14 and its GEF FAM116A localize to and act on an intermediate compartment of the transferrin-recycling pathway prior to Rab11 and after Rab5 and Rab4. This Rab14 intermediate recycling compartment has specific functions in migrating cells discrete from early and recycling endosomes. Rab14-depleted cells show increased N-cadherin levels at junctional complexes and cannot resolve cell-cell junctions. This is due to decreased shedding of cell-surface N-cadherin by the ADAM family protease ADAM10/Kuzbanian. In FAM116A- and Rab14-depleted cells, ADAM10 accumulates in a transferrin-positive endocytic compartment, and the cell-surface level of ADAM10 is correspondingly reduced. FAM116 and Rab14 therefore define an endocytic recycling pathway needed for ADAM protease trafficking and regulation of cell-cell junctions. Copyright © 2012 Elsevier Inc. All rights reserved.

Rab3a-Bound CD63 Is Degraded and Rab3a-Free CD63 Is Incorporated into HIV-1 Particles

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Yoshinao Kubo

2017-08-01

Full Text Available CD63, a member of the tetraspanin family, is involved in virion production by human immunodeficiency virus type 1 (HIV-1, but its mechanism is unknown. In this study, we showed that a small GTP-binding protein, Rab3a, interacts with CD63. When Rab3a was exogenously expressed, the amounts of CD63 decreased in cells. The Rab3a-mediated reduction of CD63 was suppressed by lysosomal and proteasomal inhibitors. The amount of CD63 was increased by reducing the endogenous Rab3a level using a specific shRNA. These results indicate that Rab3a binds to CD63 to induce the degradation of CD63. Rab3a is thought to be involved in exocytosis, but we found that another function of Rab3a affects the fate of CD63 in lysosomes. CD63 interacted with Rab3a and was incorporated into HIV-1 particles. However, Rab3a was not detected in HIV-1 virions, thereby indicating that Rab3a-free CD63, but not Rab3a-bound CD63, is incorporated into HIV-1 particles. Overexpression or silencing of Rab3a moderately reduced HIV-1 virion formation. Overexpression of Rab3a decreased CD63 levels, but did not affect the incorporation of CD63 into HIV-1 particles. This study showed that Rab3a binds to CD63 to induce the degradation of CD63, and only Rab3a-free CD63 is incorporated into HIV-1 particles.

Localization and functional analysis of the insect-specific RabX4 in the brain of Bombyx mori.

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Uno, Tomohide; Furutani, Masayuki; Sakamoto, Katsuhiko; Uno, Yuichi; Kanamaru, Kengo; Mizoguchi, Akira; Hiragaki, Susumu; Takeda, Makio

2017-09-01

Rab proteins are small monomeric GTPases/GTP-binding proteins, which form the largest branch of the Ras superfamily. The different Rab GTPases are localized to the cytosolic face of specific intracellular membranes, where they function as regulators of distinct steps in membrane trafficking. RabX4 is an insect-specific Rab protein that has no close homolog in vertebrates. There is little information about insect-specific Rab proteins. RabX4 was expressed in Escherichia coli and subsequently purified. Antibodies against Bombyx mori RabX4 were produced in rabbits for western immunoblotting and immunohistochemistry. Western blotting of neural tissues revealed a single band, at approximately 26 kD. RabX4-like immunohistochemical reactivity was restricted to neurons of the pars intercerebralis and dorsolateral protocerebrum in the brain. Further immunohistochemical analysis revealed that RabX4 colocalized with Rab6 and bombyxin in the corpus allatum, a neuronal organ that secretes neuropeptides synthesized in the brain into the hemolymph. RabX4 expression in the frontal ganglion, part of the insect stomatogastric nervous system that is found in most insect orders, was restricted to two neurons on the outer region and did not colocalize with allatotropin or Rab6. Furthermore, RNA interference of RabX4 decreased bombyxin expression levels in the brain. These findings suggest that RabX4 is involved in the neurosecretion of a secretory organ in Bombyx mori. © 2017 Wiley Periodicals, Inc.

Criticality benchmarks for COG: A new point-wise Monte Carlo code

International Nuclear Information System (INIS)

Alesso, H.P.; Pearson, J.; Choi, J.S.

1989-01-01

COG is a new point-wise Monte Carlo code being developed and tested at LLNL for the Cray computer. It solves the Boltzmann equation for the transport of neutrons, photons, and (in future versions) charged particles. Techniques included in the code for modifying the random walk of particles make COG most suitable for solving deep-penetration (shielding) problems. However, its point-wise cross-sections also make it effective for a wide variety of criticality problems. COG has some similarities to a number of other computer codes used in the shielding and criticality community. These include the Lawrence Livermore National Laboratory (LLNL) codes TART and ALICE, the Los Alamos National Laboratory code MCNP, the Oak Ridge National Laboratory codes 05R, 06R, KENO, and MORSE, the SACLAY code TRIPOLI, and the MAGI code SAM. Each code is a little different in its geometry input and its random-walk modification options. Validating COG consists in part of running benchmark calculations against critical experiments as well as other codes. The objective of this paper is to present calculational results of a variety of critical benchmark experiments using COG, and to present the resulting code bias. Numerous benchmark calculations have been completed for a wide variety of critical experiments which generally involve both simple and complex physical problems. The COG results, which they report in this paper, have been excellent

32 CFR 202.9 - Conducting RAB meetings.

Science.gov (United States)

2010-07-01

... 32 National Defense 2 2010-07-01 2010-07-01 false Conducting RAB meetings. 202.9 Section 202.9... members. Group consensus is not a prerequisite for RAB input. Each member of the RAB may provide advice as an individual; however, when a RAB decides to vote or poll for consensus, only community members...

Munc13-4 Is a Rab11-binding Protein That Regulates Rab11-positive Vesicle Trafficking and Docking at the Plasma Membrane.

Science.gov (United States)

Johnson, Jennifer L; He, Jing; Ramadass, Mahalakshmi; Pestonjamasp, Kersi; Kiosses, William B; Zhang, Jinzhong; Catz, Sergio D

2016-02-12

The small GTPase Rab11 and its effectors control trafficking of recycling endosomes, receptor replenishment and the up-regulation of adhesion and adaptor molecules at the plasma membrane. Despite recent advances in the understanding of Rab11-regulated mechanisms, the final steps mediating docking and fusion of Rab11-positive vesicles at the plasma membrane are not fully understood. Munc13-4 is a docking factor proposed to regulate fusion through interactions with SNAREs. In hematopoietic cells, including neutrophils, Munc13-4 regulates exocytosis in a Rab27a-dependent manner, but its possible regulation of other GTPases has not been explored in detail. Here, we show that Munc13-4 binds to Rab11 and regulates the trafficking of Rab11-containing vesicles. Using a novel Time-resolved Fluorescence Resonance Energy Transfer (TR-FRET) assay, we demonstrate that Munc13-4 binds to Rab11a but not to dominant negative Rab11a. Immunoprecipitation analysis confirmed the specificity of the interaction between Munc13-4 and Rab11, and super-resolution microscopy studies support the interaction of endogenous Munc13-4 with Rab11 at the single molecule level in neutrophils. Vesicular dynamic analysis shows the common spatio-temporal distribution of Munc13-4 and Rab11, while expression of a calcium binding-deficient mutant of Munc13-4 significantly affected Rab11 trafficking. Munc13-4-deficient neutrophils showed normal endocytosis, but the trafficking, up-regulation, and retention of Rab11-positive vesicles at the plasma membrane was significantly impaired. This correlated with deficient NADPH oxidase activation at the plasma membrane in response to Rab11 interference. Our data demonstrate that Munc13-4 is a Rab11-binding partner that regulates the final steps of Rab11-positive vesicle docking at the plasma membrane. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

TBC-8, a putative RAB-2 GAP, regulates dense core vesicle maturation in Caenorhabditis elegans.

Science.gov (United States)

Hannemann, Mandy; Sasidharan, Nikhil; Hegermann, Jan; Kutscher, Lena M; Koenig, Sabine; Eimer, Stefan

2012-01-01

Dense core vesicles (DCVs) are thought to be generated at the late Golgi apparatus as immature DCVs, which subsequently undergo a maturation process through clathrin-mediated membrane remodeling events. This maturation process is required for efficient processing of neuropeptides within DCVs and for removal of factors that would otherwise interfere with DCV release. Previously, we have shown that the GTPase, RAB-2, and its effector, RIC-19, are involved in DCV maturation in Caenorhabditis elegans motoneurons. In rab-2 mutants, specific cargo is lost from maturing DCVs and missorted into the endosomal/lysosomal degradation route. Cargo loss could be prevented by blocking endosomal delivery. This suggests that RAB-2 is involved in retention of DCV components during the sorting process at the Golgi-endosomal interface. To understand how RAB-2 activity is regulated at the Golgi, we screened for RAB-2-specific GTPase activating proteins (GAPs). We identified a potential RAB-2 GAP, TBC-8, which is exclusively expressed in neurons and which, when depleted, shows similar DCV maturation defects as rab-2 mutants. We could demonstrate that RAB-2 binds to its putative GAP, TBC-8. Interestingly, TBC-8 also binds to the RAB-2 effector, RIC-19. This interaction appears to be conserved as TBC-8 also interacted with the human ortholog of RIC-19, ICA69. Therefore, we propose that a dynamic ON/OFF cycling of RAB-2 at the Golgi induced by the GAP/effector complex is required for proper DCV maturation.

The breast cancer antigen 5T4 interacts with Rab11, and is a target and regulator of Rab11 mediated trafficking.

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Harris, Janelle L; Dave, Keyur; Gorman, Jeffrey; Khanna, Kum Kum

2018-06-01

5T4 is a transmembrane glycoprotein with limited expression in normal adult tissues and expression in some solid tumours. It is unclear whether 5T4 is preferentially expressed by stem or differentiated cell types. Modes of 5T4 regulation are unknown despite its ongoing development as a cancer immunotherapy target. Our aims were to clarify the differentiation status of 5T4 expressing cells in breast cancer and to understand the mechanism underlying 5T4 membrane presentation. We analysed 5T4 expression in breast cancer cell populations by flow cytometery and found that 5T4 is highly expressed on differentiated cells, where it localizes to focal adhesions. Using immunoprecipitation and mass spectrometry, we identified interactions between 5T4 and the membrane trafficking proteins Rab11, Rab18 and ARF6. Mechanistically we found that Rab11 and Rab18 have oppositional roles in controlling expression and surface presentation of 5T4. 5T4 depletion stabilizes Rab11 protein expression with a consequent stimulation transferrin surface labelling, indicating that 5T4 represses endocytic activity. Successful immunotherapeutic targeting of 5T4 requires surface presentation and different immunotherapy strategies require surface presentation versus endocytosis. While breast cancer cells with high 5T4 surface expression and rapid cell surface turnover would be susceptible to antibody-drug conjugates that rely on intracellular release, 5T4 positive cells with lower expression or lower turnover may still be responsive to T-cell mediated approaches. We find that endocytosis of 5T4 is strongly Rab11 dependent and as such Rab11 activity could affect the success or failure of 5T4-targetted immunotherapy, particularly for antibody-drug conjugate approaches. In fact, 5T4 itself represses Rab11 expression. This newly uncovered relationship between Rab11 and 5T4 suggests that breast tumours with high 5T4 expression may not have efficient endocytic uptake of 5T4-targetted immunotherapeutics

Membrane localization and dynamics of geranylgeranylated Rab5 hypervariable region.

Science.gov (United States)

Edler, Eileen; Schulze, Eric; Stein, Matthias

2017-08-01

The small GTPase Rab5 is a key regulator of endosomal trafficking processes and a marker for the early endosome. The C-terminal hypervariable region (HVR) of Rab5 is post-translationally modified at residues Cys 212 and Cys 213 to accommodate two geranylgeranyl anchors (C20 carbon chain length) in order to associate Rab5 with the membrane. The structural role of the HVR regarding protein-early endosome membrane recruitment is not resolved due to its high degree of flexibility and lack of crystallographic information. Here, full-atomistic and coarse-grained molecular dynamics simulations of the truncated Rab5 HVR 206-215 in three model membranes of increasing complexity (pure phospholipid bilayer, ternary membrane with cholesterol, six-component early endosome) were performed. Specific electrostatic interactions between the HVR 206-215 Arg 209 residue and the phosphate group of the inositol ring of PI(3)P were detected. This shows that PI(3)P acts as a first contact site of protein recruitment to the early endosome. The free energy change of HVR 206-215 extraction from the bilayer was largest for the physiological negatively charged membrane. 5μs coarse-grained simulations revealed an active recruitment of PI(3)P to the HVR 206-215 supporting the formation of Rab5- and PI(3)P enriched signaling platforms. Copyright © 2017 Elsevier B.V. All rights reserved.

The ADAS-cog and clinically meaningful change in the VISTA clinical trial of galantamine for Alzheimer's disease.

Science.gov (United States)

Rockwood, Kenneth; Fay, Sherri; Gorman, Mary

2010-02-01

A minimum 4-point change at 6 months on the Alzheimer's disease assessment scale-cognitive subscale (ADAS-cog) is deemed clinically important, but this cut-point has been little studied in relation to clinical meaningfulness. In an investigator-initiated, clinical trial of galantamine, we investigated the extent to which a 4-point change classifies goal attainment by individual patients. Secondary analysis of the video imaging synthesis of treating Alzheimer's disease (VISTA) study: a 4-month, multi-centre, parallel-group, double-blind, placebo-controlled, trial of galantamine in 130 mild-moderate Alzheimer's disease patients (4-month open-label follow-up). ADAS-cog responses at 6 months were compared with outcomes on three clinical measures: clinician's interview based impression of change-plus caregiver input (CIBIC+), patient/carer-goal attainment scaling (PGAS) and clinician-GAS (CGAS). Thirty-seven of 99 patients improved by > or = 4 points on the ADAS-cog at 6 months, and 16/99 showed > or = 4-point worsening. ADAS-cog change scores correlated notionally to modestly with changes on the CGAS (r = -0.31), the PGAS (r = -0.29) and the CIBIC+ (r = 0.31). As a group, patients with ADAS-cog improvement were significantly more likely to improve on the clinical measures; those who worsened showed non-significant clinical decline. Individually, about half were misclassified in relation to each clinical measure; often when the ADAS-Cog detected 'no change', clinically meaningful effects could be detected. Even so, no ADAS-Cog cut-point optimally classified patients' clinical responses. A 4-point ADAS-cog change at 6 months is clinically meaningful for groups. Substantial individual misclassification between the ADAS-cog and clinical measures suggests no inherent meaning to a 4-point ADAS-cog change for a given patient.

RAB-10 Regulates Dendritic Branching by Balancing Dendritic Transport

Science.gov (United States)

Taylor, Caitlin A.; Yan, Jing; Howell, Audrey S.; Dong, Xintong; Shen, Kang

2015-01-01

The construction of a large dendritic arbor requires robust growth and the precise delivery of membrane and protein cargoes to specific subcellular regions of the developing dendrite. How the microtubule-based vesicular trafficking and sorting systems are regulated to distribute these dendritic development factors throughout the dendrite is not well understood. Here we identify the small GTPase RAB-10 and the exocyst complex as critical regulators of dendrite morphogenesis and patterning in the C. elegans sensory neuron PVD. In rab-10 mutants, PVD dendritic branches are reduced in the posterior region of the cell but are excessive in the distal anterior region of the cell. We also demonstrate that the dendritic branch distribution within PVD depends on the balance between the molecular motors kinesin-1/UNC-116 and dynein, and we propose that RAB-10 regulates dendrite morphology by balancing the activity of these motors to appropriately distribute branching factors, including the transmembrane receptor DMA-1. PMID:26633194

Regulation of lipid droplet dynamics in Saccharomyces cerevisiae depends on the Rab7-like Ypt7p, HOPS complex and V1-ATPase

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Isabelle Bouchez

2015-07-01

Full Text Available It has now been clearly shown that lipid droplets (LDs play a dynamic role in the cell. This was reinforced by LD proteomics which suggest that a significant number of trafficking proteins are associated with this organelle. Using microscopy, we showed that LDs partly co-localize with the vacuole in S. cerevisiae. Immunoblot experiments confirmed the association of the vacuolar Rab GTPase Rab7-like Ypt7p with LDs. We observed an increase in fatty acid content and LD number in ypt7Δ mutant and also changes in LD morphology and intra LD fusions, revealing a direct role for Ypt7p in LD dynamics. Using co-immunoprecipitation, we isolated potential Ypt7p partners including, Vma13p, the H subunit of the V1 part of the vacuolar (H+ ATPase (V-ATPase. Deletion of the VMA13 gene, as well as deletion of three other subunits of the V1 part of the V-ATPase, also increased the cell fatty acid content and LD number. Mutants of the Homotypic fusion and vacuole protein sorting (HOPS complex showed similar phenotypes. Here, we demonstrated that LD dynamics and membrane trafficking between the vacuole and LDs are regulated by the Rab7-like Ypt7p and are impaired when the HOPS complex and the V1 domain of the V-ATPase are defective.

Alteraciones en el reclutamiento y activación de proteínas Rab durante la infección micobacteriana

OpenAIRE

Diana Castaño; Mauricio Rojas

2010-01-01

En el fagosoma, Mycobacterium spp. altera la activación y reclutamiento de diferentes proteínas "del gen Ras de cerebro de rata", comúnmente conocidas como Rab. En este manuscrito se revisa una serie de reportes que han demostrado que los fagosomas que contienen micobacterias tienen una expresión mayor y sostenida de Rab5, Rab11, Rab14 y Rab22a, y menor o ninguna expresión de Rab7, Rab9 y Rab6. Esto se correlaciona con aumento de la fusión de estos fagosomas con endosomas tempranos y de recic...

TBC-8, a Putative RAB-2 GAP, Regulates Dense Core Vesicle Maturation in Caenorhabditis elegans

Science.gov (United States)

Hannemann, Mandy; Sasidharan, Nikhil; Hegermann, Jan; Kutscher, Lena M.; Koenig, Sabine; Eimer, Stefan

2012-01-01

Dense core vesicles (DCVs) are thought to be generated at the late Golgi apparatus as immature DCVs, which subsequently undergo a maturation process through clathrin-mediated membrane remodeling events. This maturation process is required for efficient processing of neuropeptides within DCVs and for removal of factors that would otherwise interfere with DCV release. Previously, we have shown that the GTPase, RAB-2, and its effector, RIC-19, are involved in DCV maturation in Caenorhabditis elegans motoneurons. In rab-2 mutants, specific cargo is lost from maturing DCVs and missorted into the endosomal/lysosomal degradation route. Cargo loss could be prevented by blocking endosomal delivery. This suggests that RAB-2 is involved in retention of DCV components during the sorting process at the Golgi-endosomal interface. To understand how RAB-2 activity is regulated at the Golgi, we screened for RAB-2–specific GTPase activating proteins (GAPs). We identified a potential RAB-2 GAP, TBC-8, which is exclusively expressed in neurons and which, when depleted, shows similar DCV maturation defects as rab-2 mutants. We could demonstrate that RAB-2 binds to its putative GAP, TBC-8. Interestingly, TBC-8 also binds to the RAB-2 effector, RIC-19. This interaction appears to be conserved as TBC-8 also interacted with the human ortholog of RIC-19, ICA69. Therefore, we propose that a dynamic ON/OFF cycling of RAB-2 at the Golgi induced by the GAP/effector complex is required for proper DCV maturation. PMID:22654674

TBC-8, a putative RAB-2 GAP, regulates dense core vesicle maturation in Caenorhabditis elegans.

Directory of Open Access Journals (Sweden)

Mandy Hannemann

Full Text Available Dense core vesicles (DCVs are thought to be generated at the late Golgi apparatus as immature DCVs, which subsequently undergo a maturation process through clathrin-mediated membrane remodeling events. This maturation process is required for efficient processing of neuropeptides within DCVs and for removal of factors that would otherwise interfere with DCV release. Previously, we have shown that the GTPase, RAB-2, and its effector, RIC-19, are involved in DCV maturation in Caenorhabditis elegans motoneurons. In rab-2 mutants, specific cargo is lost from maturing DCVs and missorted into the endosomal/lysosomal degradation route. Cargo loss could be prevented by blocking endosomal delivery. This suggests that RAB-2 is involved in retention of DCV components during the sorting process at the Golgi-endosomal interface. To understand how RAB-2 activity is regulated at the Golgi, we screened for RAB-2-specific GTPase activating proteins (GAPs. We identified a potential RAB-2 GAP, TBC-8, which is exclusively expressed in neurons and which, when depleted, shows similar DCV maturation defects as rab-2 mutants. We could demonstrate that RAB-2 binds to its putative GAP, TBC-8. Interestingly, TBC-8 also binds to the RAB-2 effector, RIC-19. This interaction appears to be conserved as TBC-8 also interacted with the human ortholog of RIC-19, ICA69. Therefore, we propose that a dynamic ON/OFF cycling of RAB-2 at the Golgi induced by the GAP/effector complex is required for proper DCV maturation.

Rab23 is a flagellar protein in Trypanosoma brucei

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Field Mark C

2011-06-01

Full Text Available Abstract Background Rab small GTPases are important mediators of membrane transport, and orthologues frequently retain similar locations and functions, even between highly divergent taxa. In metazoan organisms Rab23 is an important negative regulator of Sonic hedgehog signaling and is crucial for correct development and differentiation of cellular lineages by virtue of an involvement in ciliary recycling. Previously, we reported that Trypanosoma brucei Rab23 localized to the nuclear envelope 1, which is clearly inconsistent with the mammalian location and function. As T. brucei is unicellular the potential that Rab23 has no role in cell signaling was possible. Here we sought to further investigate the role(s of Rab23 in T. brucei to determine if Rab23 was an example of a Rab protein with divergent function in distinct taxa. Methods/major findings The taxonomic distribution of Rab23 was examined and compared with the presence of flagella/cilia in representative taxa. Despite evidence for considerable secondary loss, we found a clear correlation between a conventional flagellar structure and the presence of a Rab23 orthologue in the genome. By epitope-tagging, Rab23 was localized and found to be present at the flagellum throughout the cell cycle. However, RNAi knockdown did not result in a flagellar defect, suggesting that Rab23 is not required for construction or maintenance of the flagellum. Conclusions The location of Rab23 at the flagellum is conserved between mammals and trypanosomes and the Rab23 gene is restricted to flagellated organisms. These data may suggest the presence of a Rab23-mediated signaling mechanism in trypanosomes.

Molecular characterization and expression analysis of a GTP-binding protein (MiRab5) in Mangifera indica.

Science.gov (United States)

Liu, Zhao-liang; Luo, Cong; Dong, Long; Van Toan, Can; Wei, Peng-xiao; He, Xin-hua

2014-04-25

The Rab family, the largest branch of Ras small GTPases, plays a crucial role in the vesicular transport in plants. The members of Rab family act as molecular switches that regulate the fusion of vesicles with target membranes through conformational changes. However, little is known about the Rab5 gene involved in fruit ripening and stress response. In this study, the MiRab5 gene was isolated from stress-induced Mangifera indica. The full-length cDNA sequence was 984bp and contained an open reading frame of 600bp, which encoded a 200 amino acid protein with a molecular weight of 21.83kDa and a theoretical isoelectric point of 6.99. The deduced amino acid sequence exhibited high homology with tomato (91% similarity) and contains all five characteristic Rab motifs. Real-time quantitative RT-PCR analysis demonstrated that MiRab5 was ubiquitously expressed in various mango tree tissues at different levels. The expression of MiRab5 was up-regulated during later stages of fruit ripening. Moreover, MiRab5 was generally up-regulated in response to various abiotic stresses (cold, salinity, and PEG treatments). Recombinant MiRab5 protein was successfully expressed and purified. SDS-PAGE and western blot analysis indicated that the expressed protein was recognized by the anti-6-His antibody. These results provide insights into the role of the MiRab5 gene family in fruit ripening and stress responses in the mango plant. Copyright © 2014 Elsevier B.V. All rights reserved.

Rab7: roles in membrane trafficking and disease.

Science.gov (United States)

Zhang, Ming; Chen, Li; Wang, Shicong; Wang, Tuanlao

2009-06-01

The endocytosis pathway controls multiple cellular and physiological events. The lysosome is the destination of newly synthesized lysosomal hydrolytic enzymes. Internalized molecules or particles are delivered to the lysosome for degradation through sequential transport along the endocytic pathway. The endocytic pathway is also emerging as a signalling platform, in addition to the well-known role of the plasma membrane for signalling. Rab7 is a late endosome-/lysosome-associated small GTPase, perhaps the only lysosomal Rab protein identified to date. Rab7 plays critical roles in the endocytic processes. Through interaction with its partners (including upstream regulators and downstream effectors), Rab7 participates in multiple regulation mechanisms in endosomal sorting, biogenesis of lysosome [or LRO (lysosome-related organelle)] and phagocytosis. These processes are closely related to substrates degradation, antigen presentation, cell signalling, cell survival and microbial pathogen infection. Consistently, mutations or dysfunctions of Rab7 result in traffic disorders, which cause various diseases, such as neuropathy, cancer and lipid metabolism disease. Rab7 also plays important roles in microbial pathogen infection and survival, as well as in participating in the life cycle of viruses. Here, we give a brief review on the central role of Rab7 in endosomal traffic and summarize the studies focusing on the participation of Rab7 in disease pathogenesis. The underlying mechanism governed by Rab7 and its partners will also be discussed.

PCOGR: Phylogenetic COG ranking as an online tool to judge the specificity of COGs with respect to freely definable groups of organisms

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Kaufmann Michael

2004-10-01

Full Text Available Abstract Background The rapidly increasing number of completely sequenced genomes led to the establishment of the COG-database which, based on sequence homologies, assigns similar proteins from different organisms to clusters of orthologous groups (COGs. There are several bioinformatic studies that made use of this database to determine (hyperthermophile-specific proteins by searching for COGs containing (almost exclusively proteins from (hyperthermophilic genomes. However, public software to perform individually definable group-specific searches is not available. Results The tool described here exactly fills this gap. The software is accessible at http://www.uni-wh.de/pcogr and is linked to the COG-database. The user can freely define two groups of organisms by selecting for each of the (current 66 organisms to belong either to groupA, to the reference groupB or to be ignored by the algorithm. Then, for all COGs a specificity index is calculated with respect to the specificity to groupA, i. e. high scoring COGs contain proteins from the most of groupA organisms while proteins from the most organisms assigned to groupB are absent. In addition to ranking all COGs according to the user defined specificity criteria, a graphical visualization shows the distribution of all COGs by displaying their abundance as a function of their specificity indexes. Conclusions This software allows detecting COGs specific to a predefined group of organisms. All COGs are ranked in the order of their specificity and a graphical visualization allows recognizing (i the presence and abundance of such COGs and (ii the phylogenetic relationship between groupA- and groupB-organisms. The software also allows detecting putative protein-protein interactions, novel enzymes involved in only partially known biochemical pathways, and alternate enzymes originated by convergent evolution.

PCOGR: phylogenetic COG ranking as an online tool to judge the specificity of COGs with respect to freely definable groups of organisms.

Science.gov (United States)

Meereis, Florian; Kaufmann, Michael

2004-10-15

The rapidly increasing number of completely sequenced genomes led to the establishment of the COG-database which, based on sequence homologies, assigns similar proteins from different organisms to clusters of orthologous groups (COGs). There are several bioinformatic studies that made use of this database to determine (hyper)thermophile-specific proteins by searching for COGs containing (almost) exclusively proteins from (hyper)thermophilic genomes. However, public software to perform individually definable group-specific searches is not available. The tool described here exactly fills this gap. The software is accessible at http://www.uni-wh.de/pcogr and is linked to the COG-database. The user can freely define two groups of organisms by selecting for each of the (current) 66 organisms to belong either to groupA, to the reference groupB or to be ignored by the algorithm. Then, for all COGs a specificity index is calculated with respect to the specificity to groupA, i. e. high scoring COGs contain proteins from the most of groupA organisms while proteins from the most organisms assigned to groupB are absent. In addition to ranking all COGs according to the user defined specificity criteria, a graphical visualization shows the distribution of all COGs by displaying their abundance as a function of their specificity indexes. This software allows detecting COGs specific to a predefined group of organisms. All COGs are ranked in the order of their specificity and a graphical visualization allows recognizing (i) the presence and abundance of such COGs and (ii) the phylogenetic relationship between groupA- and groupB-organisms. The software also allows detecting putative protein-protein interactions, novel enzymes involved in only partially known biochemical pathways, and alternate enzymes originated by convergent evolution.

IL4/PGE2 induction of an enlarged early endosomal compartment in mouse macrophages is Rab5-dependent

International Nuclear Information System (INIS)

Wainszelbaum, Marisa J.; Proctor, Brandon M.; Pontow, Suzanne E.; Stahl, Philip D.; Barbieri, M. Alejandro

2006-01-01

The endosomal compartment and the plasma membrane form a complex partnership that controls signal transduction and trafficking of different molecules. The specificity and functionality of the early endocytic pathway are regulated by a growing number of Rab GTPases, particularly Rab5. In this study, we demonstrate that IL4 (a Th-2 cytokine) and prostaglandin E 2 (PGE 2 ) synergistically induce Rab5 and several Rab effector proteins, including Rin1 and EEA1, and promote the formation of an enlarged early endocytic (EEE) compartment. Endosome enlargement is linked to a substantial induction of the mannose receptor (MR), a well-characterized macrophage endocytic receptor. Both MR levels and MR-mediated endocytosis are enhanced approximately 7-fold. Fluid-phase endocytosis is also elevated in treated cells. Light microscopy and fractionation studies reveal that MR colocalizes predominantly with Rab5a and partially with Rab11, an endosomal recycling pathway marker. Using retroviral expression of Rab5a:S34N, a dominant negative mutant, and siRNA Rab5a silencing, we demonstrate that Rab5a is essential for the large endosome phenotype and for localization of MR in these structures. We speculate that the EEE is maintained by activated Rab5, and that the EEE phenotype is part of some macrophage developmental program such as cell fusion, a characteristic of IL4-stimulated cells

Rabies virus co-localizes with early (Rab5) and late (Rab7) endosomal proteins in neuronal and SH-SY5Y cells.

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Ahmad, Waqas; Li, Yingying; Guo, Yidi; Wang, Xinyu; Duan, Ming; Guan, Zhenhong; Liu, Zengshan; Zhang, Maolin

2017-06-01

Rabies virus (RABV) is a highly neurotropic virus that follows clathrin-mediated endocytosis and pH-dependent pathway for trafficking and invasion into endothelial cells. Early (Rab5, EEA1) and late (Rab7, LAMP1) endosomal proteins play critical roles in endosomal sorting, maturity and targeting various molecular cargoes, but their precise functions in the early stage of RABV neuronal infection remain elusive. In this study, the relationship between enigmatic entry of RABV with these endosomal proteins into neuronal and SH-SY5Y cells was investigated. Immunofluorescence, TCID 50 titers, electron microscopy and western blotting were carried out to determine the molecular interaction of the nucleoprotein (N) of RABV with early or late endosomal proteins in these cell lines. The expression of N was also determined by down-regulating Rab5 and Rab7 in both cell lines through RNA interference. The results were indicative that N proficiently colocalized with Rab5/EEA1 and Rab7/LAMP1 in both cell lines at 24 and 48 h post-infection, while N titers significantly decreased in early infection of RABV. Down-regulation of Rab5 and Rab7 did not inhibit N expression, but it prevented productive infection via blocking the normal trafficking of RABV in a low pH environment. Ultrathin sections of cells studied by electron microscope also verified the close association of RABV with Rab5 and Rab7 in neurons. From the data it was concluded that primary entry of RABV strongly correlates with the kinetics of Rab-proteins present on early and late vesicles, which provides helpful clues to explain the early events of RABV in nerve cells.

miR-184 and miR-150 promote renal glomerular mesangial cell aging by targeting Rab1a and Rab31.

Science.gov (United States)

Liu, Xiujuan; Fu, Bo; Chen, Dapeng; Hong, Quan; Cui, Jing; Li, Jin; Bai, Xueyuan; Chen, Xiangmei

2015-08-15

The molecular mechanism of kidney aging is not well understood, but the abnormal expression of miRNAs with aging is considered to be an important contributor. miR-184 and miR-150 were screened using a miRNA microarray and qRT-PCR and found to be significantly upregulated in 24-month-old rats. Rat renal primary glomerular mesangial cells (GMCs) were isolated from 3-month and 24-month-old rats for the in vitro analysis of the roles of miR-184 and miR-150 in kidney aging. Bioinformatics analyses suggested that Rab1a and Rab31, which are associated with cell autophagy, were targeted by both miR-184 and miR-150. miR-184 and miR-150 were increased significantly in aging GMCs versus young cells, while Rab1a and Rab31 were significantly lower in aging cells. Furthermore, dual luciferase reporter assays revealed that miR-184 and miR-150 bound to the 3'-UTR of Rab1a and Rab31 mRNAs. Transfection of miR-184 and miR-150 mimics into young GMCs suppressed the expression of Rab1a and Rab31. Transfected cells showed lower autophagy activities and higher levels of cellular oxidative products, leading to the aging of young GMCs. However, miR-184 and miR-150 inhibitors promoted autophagy and reduced oxidative damage by upregulating Rab1a and Rab31 in old GMCs. In conclusion, miR-184 and miR-150 inhibited autophagy, promoting GMC aging. Copyright © 2015 Elsevier Inc. All rights reserved.

The clinical meaningfulness of ADAS-Cog changes in Alzheimer's disease patients treated with donepezil in an open-label trial.

Science.gov (United States)

Rockwood, Kenneth; Fay, Sherri; Gorman, Mary; Carver, Daniel; Graham, Janice E

2007-08-30

In 6-month anti-dementia drug trials, a 4-point change in the Alzheimer's Disease Assessment Scale-Cognitive Subscale (ADAS-Cog) is held to be clinically important. We examined how this change compared with measures of clinical meaningfulness. This is a secondary analysis of a 12 month open-label study of 100 patients (71 women) diagnosed with mild to moderate AD treated with 5-10 mg of donepezil daily. We studied the observed case, 6-month change from baseline on the ADAS-Cog, the Clinician's Interview Based Impression of Change-Plus Caregiver Input (CIBIC-Plus), patient-Goal Attainment Scaling (PGAS) and clinician-GAS (CGAS). At 6 months, donepezil-treated patients (n = 95) were more likely to show no change (+/- 3 points) on the ADAS-Cog (56%) than to improve (20%) or decline (24%) by 4-points. ADAS-Cog change scores were little correlated with other measures: from -0.09 for PGAS to 0.27 for the CIBIC-Plus. While patients who improved on the ADAS-Cog were less likely to decline on the clinical measures (26%), 43% of patients who declined on the ADAS-Cog improved on at least two of the clinical measures. The ADAS-Cog did not capture all clinically important effects. In general, ADAS-Cog improvement indicates clinical improvement, whereas many people with ADAS-Cog decline do not show clinical decline. The open-label design of this study does not allow us to know whether this is a treatment effect, which requires further investigation.

Rice Rab11 is required for JA-mediated defense signaling

Energy Technology Data Exchange (ETDEWEB)

Hong, Min Ji [Department of Molecular Biotechnology, Dong-A University, Busan 604-714 (Korea, Republic of); BK21 Center for Silver-Bio Industrialization, Dong-A University, Busan 604-714 (Korea, Republic of); Lee, Yun mi [Department of Molecular Biotechnology, Dong-A University, Busan 604-714 (Korea, Republic of); Son, Young Sim [Division of Applied Life Sciences (BK21), Graduate School of Gyeongsang National University, Jinju 660-701 (Korea, Republic of); Im, Chak Han [Eco-Friendliness Research Department, Gyeongsangnam-do Agricultural Research and Extension Services, Jinju 660-360 (Korea, Republic of); Yi, Young Byung [Department of Molecular Biotechnology, Dong-A University, Busan 604-714 (Korea, Republic of); Rim, Yeong Gil [Systems and Synthetic Agrobiotech Center, Gyeongsang National University, Jinju 660-701 (Korea, Republic of); Bahk, Jeong Dong, E-mail: jdbahk@gnu.ac.kr [Division of Applied Life Sciences (BK21), Graduate School of Gyeongsang National University, Jinju 660-701 (Korea, Republic of); Heo, Jae Bok, E-mail: jbheo72@dau.ac.kr [Department of Molecular Biotechnology, Dong-A University, Busan 604-714 (Korea, Republic of); BK21 Center for Silver-Bio Industrialization, Dong-A University, Busan 604-714 (Korea, Republic of)

2013-05-17

Highlights: •OsRab11 interacts with OsOPR8. •OsOPR8 is localized in the cytosol and peroxisome. •OsRab11 enhances the NADPH consumption by OsOPR8. •Transgenic Arabidopsis overexpressing OsRab11 represents a pathogen-resistant phenotype. -- Abstract: Rab proteins play an essential role in regulating vesicular transport in eukaryotic cells. Previously, we characterized OsRab11, which in concert with OsGAP1 and OsGDI3 regulates vesicular trafficking from the trans-Golgi network (TGN) to the plasma membrane or vacuole. To further elucidate the physiological function of OsRab11 in plants, we performed yeast two-hybrid screens using OsRab11 as bait. OsOPR8 was isolated and shown to interact with OsRab11. A co-immunoprecipitation assay confirmed this interaction. The green fluorescent protein-OsOPR8 fusion product was targeted to the cytoplasm and peroxisomes of protoplasts from Arabidopsis thaliana. OsOPR8 exhibited NADPH-dependent reduction activity when 2-cyclohexen-1-one (CyHE) and 12-oxo-phytodienoic acid (OPDA) were supplied as possible substrates. Interestingly, NADPH oxidation by OsOPR8 was increased when wild-type OsRab11 or the constitutively active form of OsRab11 (Q78L) were included in the reaction mix, but not when the dominant negative form of OsRab11 (S28N) was included. OsRab11 was expressed broadly in plants and both OsRab11 and OsOPR8 were induced by jasmonic acid (JA) and elicitor treatments. Overexpressed OsRab11 transgenic plants showed resistance to pathogens through induced expression of JA-responsive genes. In conclusion, OsRab11 may be required for JA-mediated defense signaling by activating the reducing activity of OsOPR8.

Rab7a modulates ER stress and ER morphology.

Science.gov (United States)

Mateus, Duarte; Marini, Elettra Sara; Progida, Cinzia; Bakke, Oddmund

2018-05-01

The Endoplasmic Reticulum (ER) is a membranous organelle with diverse structural and functional domains. Peripheral ER includes interconnected tubules, and dense tubular arrays called "ER matrices" together with bona fide flat cisternae. Transitions between these states are regulated by membrane-associated proteins and cytosolic factors. Recently, the small GTPases Rab10 and Rab18 were reported to control ER shape by regulating ER dynamics and fusion. Here, we present evidence that another Rab protein, Rab7a, modulates the ER morphology by controlling the ER homeostasis and ER stress. Indeed, inhibition of Rab7a expression by siRNA or expression of the dominant negative mutant Rab7aT22 N, leads to enlargement of sheet-like ER structures and spreading towards the cell periphery. Notably, such alterations are ascribable neither to a direct modulation of the ER shaping proteins Reticulon-4b and CLIMP63, nor to interactions with Protrudin, a Rab7a-binding protein known to affect the ER organization. Conversely, depletion of Rab7a leads to basal ER stress, in turn causing ER membrane expansion. Both ER enlargement and basal ER stress are reverted in rescue experiments by Rab7a re-expression, as well as by the ER chemical chaperone tauroursodeoxycholic acid (TUDCA). Collectively, these findings reveal a new role of Rab7a in ER homeostasis, and indicate that genetic and pharmacological ER stress manipulation may restore ER morphology in Rab7a silenced cells. Copyright © 2018 Elsevier B.V. All rights reserved.

阴道毛滴虫Rab1a重组蛋白的表达和细胞内定位%Expression of Recombinant TvRab1a and Intracellular Location of TvRab1a in Trichomonas vaginalis

Institute of Scientific and Technical Information of China (English)

徐晓园; 傅玉才; 许铭炎; 许锦阶; 张仁利

2006-01-01

目的 制备阴道毛滴虫(Trichomonas vaginalis,Tv)Rab1a重组蛋白及其多克隆抗体,并对TvRab1a蛋白进行阴道毛滴虫的细胞内定位.方法 将我们已构建的pQE80L/TvRab1a重组表达质粒转入大肠埃希菌E.coli M15,在IPTG诱导下表达重组蛋白,经Ni-NTA亲和柱层析后获得纯度较高的TvRab1a的重组蛋白;用经复性处理的重组蛋白免疫动物,获得TvRab1a重组蛋白抗血清,免疫印迹Western Blot鉴定抗血清.采用荧光免疫细胞化学对TvRab1a蛋白进行细胞内定位.结果 Western Blot分析显示,TvRab1a重组蛋白可与豚鼠的抗TvRab1a血清反应,同时该抗血清在滴虫提取蛋白中检测到与预测TvRab1a分子量一致的条带;免疫荧光化学检测发现TvRab1a分布于细胞核周围的高尔基复合体与内质网.结论 获得的抗TvRab1a蛋白的多抗血清可用于TvRab1a基因功能的研究;TvRab1a功能场所位于高尔基复合体与内质网.

Comprehensive functional analysis of Rab GTPases in Drosophila nephrocytes.

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Fu, Yulong; Zhu, Jun-Yi; Zhang, Fujian; Richman, Adam; Zhao, Zhanzheng; Han, Zhe

2017-06-01

The Drosophila nephrocyte is a critical component of the fly renal system and bears structural and functional homology to podocytes and proximal tubule cells of the mammalian kidney. Investigations of nephrocyte cell biological processes are fundamental to understanding the insect renal system. Nephrocytes are highly active in endocytosis and vesicle trafficking. Rab GTPases regulate endocytosis and trafficking but specific functions of nephrocyte Rabs remain undefined. We analyzed Rab GTPase expression and function in Drosophila nephrocytes and found that 11 out of 27 Drosophila Rabs were required for normal activity. Rabs 1, 5, 7, 11 and 35 were most important. Gene silencing of the nephrocyte-specific Rab5 eliminated all intracellular vesicles and the specialized plasma membrane structures essential for nephrocyte function. Rab7 silencing dramatically increased clear vacuoles and reduced lysosomes. Rab11 silencing increased lysosomes and reduced clear vacuoles. Our results suggest that Rab5 mediates endocytosis that is essential for the maintenance of functionally critical nephrocyte plasma membrane structures and that Rabs 7 and 11 mediate alternative downstream vesicle trafficking pathways leading to protein degradation and membrane recycling, respectively. Elucidating molecular pathways underlying nephrocyte function has the potential to yield important insights into human kidney cell physiology and mechanisms of cell injury that lead to disease. The Drosophila nephrocyte is emerging as a useful in vivo model system for molecular target identification and initial testing of therapeutic approaches in humans.

The GTPase Rab37 Participates in the Control of Insulin Exocytosis.

Directory of Open Access Journals (Sweden)

Sanda Ljubicic

Full Text Available Rab37 belongs to a subclass of Rab GTPases regulating exocytosis, including also Rab3a and Rab27a. Proteomic studies indicate that Rab37 is associated with insulin-containing large dense core granules of pancreatic β-cells. In agreement with these observations, we detected Rab37 in extracts of β-cell lines and human pancreatic islets and confirmed by confocal microscopy the localization of the GTPase on insulin-containing secretory granules. We found that, as is the case for Rab3a and Rab27a, reduction of Rab37 levels by RNA interference leads to impairment in glucose-induced insulin secretion and to a decrease in the number of granules in close apposition to the plasma membrane. Pull-down experiments revealed that, despite similar functional effects, Rab37 does not interact with known Rab3a or Rab27a effectors and is likely to operate through a different mechanism. Exposure of insulin-secreting cells to proinflammatory cytokines, fatty acids or oxidized low-density lipoproteins, mimicking physiopathological conditions that favor the development of diabetes, resulted in a decrease in Rab37 expression. Our data identify Rab37 as an additional component of the machinery governing exocytosis of β-cells and suggest that impaired expression of this GTPase may contribute to defective insulin release in pre-diabetic and diabetic conditions.

The COG database: an updated version includes eukaryotes

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Sverdlov Alexander V

2003-09-01

KOG set is much greater than the ubiquitous portion of the COG set (~1% of the COGs. In part, this difference is probably due to the small number of included eukaryotic genomes, but it could also reflect the relative compactness of eukaryotes as a clade and the greater evolutionary stability of eukaryotic genomes. Conclusion The updated collection of orthologous protein sets for prokaryotes and eukaryotes is expected to be a useful platform for functional annotation of newly sequenced genomes, including those of complex eukaryotes, and genome-wide evolutionary studies.

Microbial genome analysis: the COG approach.

Science.gov (United States)

Galperin, Michael Y; Kristensen, David M; Makarova, Kira S; Wolf, Yuri I; Koonin, Eugene V

2017-09-14

For the past 20 years, the Clusters of Orthologous Genes (COG) database had been a popular tool for microbial genome annotation and comparative genomics. Initially created for the purpose of evolutionary classification of protein families, the COG have been used, apart from straightforward functional annotation of sequenced genomes, for such tasks as (i) unification of genome annotation in groups of related organisms; (ii) identification of missing and/or undetected genes in complete microbial genomes; (iii) analysis of genomic neighborhoods, in many cases allowing prediction of novel functional systems; (iv) analysis of metabolic pathways and prediction of alternative forms of enzymes; (v) comparison of organisms by COG functional categories; and (vi) prioritization of targets for structural and functional characterization. Here we review the principles of the COG approach and discuss its key advantages and drawbacks in microbial genome analysis. Published by Oxford University Press 2017. This work is written by US Government employees and is in the public domain in the US.

An overexpression screen of Toxoplasma gondii Rab-GTPases reveals distinct transport routes to the micronemes.

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Katrin Kremer

2013-03-01

Full Text Available The basic organisation of the endomembrane system is conserved in all eukaryotes and comparative genome analyses provides compelling evidence that the endomembrane system of the last common eukaryotic ancestor (LCEA is complex with many genes required for regulated traffic being present. Although apicomplexan parasites, causative agents of severe human and animal diseases, appear to have only a basic set of trafficking factors such as Rab-GTPases, they evolved unique secretory organelles (micronemes, rhoptries and dense granules that are sequentially secreted during invasion of the host cell. In order to define the secretory pathway of apicomplexans, we performed an overexpression screen of Rabs in Toxoplasma gondii and identified Rab5A and Rab5C as important regulators of traffic to micronemes and rhoptries. Intriguingly, we found that not all microneme proteins traffic depends on functional Rab5A and Rab5C, indicating the existence of redundant microneme targeting pathways. Using two-colour super-resolution stimulated emission depletion (STED we verified distinct localisations of independent microneme proteins and demonstrate that micronemal organelles are organised in distinct subsets or subcompartments. Our results suggest that apicomplexan parasites modify classical regulators of the endocytic system to carryout essential parasite-specific roles in the biogenesis of their unique secretory organelles.

Influence of Closed Stator Slots on Cogging Torque

DEFF Research Database (Denmark)

Ion, Trifu; Leban, Krisztina Monika; Ritchie, Ewen

2013-01-01

Cogging torque results due interaction of magnetic field of magnets and stator slots, and have negative effects on permanent magnet machines such as vibrations, noise, torque ripples and problems during turbine start-up and cut-in. In order to reduce cogging torque this paper presents a study...... of influence of closed stator slots on cogging torque using magnetic slot wedges....

Rab21, a Novel PS1 Interactor, Regulates γ-Secretase Activity via PS1 Subcellular Distribution.

Science.gov (United States)

Sun, Zhenzhen; Xie, Yujie; Chen, Yintong; Yang, Qinghu; Quan, Zhenzhen; Dai, Rongji; Qing, Hong

2018-05-01

γ-Secretase has been a therapeutical target for its key role in cleaving APP to generate β-amyloid (Aβ), the primary constituents of senile plaques and a hallmark of Alzheimer's disease (AD) pathology. Recently, γ-secretase-associating proteins showed promising role in specifically modulating APP processing while sparing Notch signaling; however, the underlying mechanism is still unclear. A co-immunoprecipitation (Co-IP) coupled with mass spectrometry proteomic assay for Presenilin1 (PS1, the catalytic subunit of γ-secretase) was firstly conducted to find more γ-secretase-associating proteins. Gene ontology analysis of these results identified Rab21 as a potential PS1 interacting protein, and the interaction between them was validated by reciprocal Co-IP and immunofluorescence assay. Then, molecular and biochemical methods were used to investigate the effect of Rab21 on APP processing. Results showed that overexpression of Rab21 enhanced Aβ generation, while silencing of Rab21 reduced the accumulation of Aβ, which resulted due to change in γ-secretase activity rather than α- or β-secretase. Finally, we demonstrated that Rab21 had no effect on γ-secretase complex synthesis or metabolism but enhanced PS1 endocytosis and translocation to late endosome/lysosome. In conclusion, we identified a novel γ-secretase-associating protein Rab21 and illustrate that Rab21 promotes γ-secretase internalization and translocation to late endosome/lysosome. Moreover, silencing of Rab21 decreases the γ-secretase activity in APP processing thus production of Aβ. All these results open new gateways towards the understanding of γ-secretase-associating proteins in APP processing and make inhibition of Rab21 a promising strategy for AD therapy.

LRRK2 mediated Rab8a phosphorylation promotes lipid storage.

Science.gov (United States)

Yu, Miao; Arshad, Muhammad; Wang, Wenmin; Zhao, Dongyu; Xu, Li; Zhou, Linkang

2018-02-27

Several mutations in leucine rich repeat kinase 2 (LRRK2) gene have been associated with pathogenesis of Parkinson's disease (PD), a neurodegenerative disorder marked by resting tremors, and rigidity, leading to Postural instability. It has been revealed that mutations that lead to an increase of kinase activity of LRRK2 protein are significantly associated with PD pathogenesis. Recent studies have shown that some Rab GTPases, especially Rab8, serve as substrates of LRRK2 and undergo phosphorylation in its switch II domain upon interaction. Current study was performed in order to find out the effects of the phosphorylation of Rab8 and its mutants on lipid metabolism and lipid droplets growth. The phosphorylation status of Rab8a was checked by phos-tag gel. Point mutant construct were generated to investigate the function of Rab8a. 3T3L1 cells were transfected with indicated plasmids and the lipid droplets were stained with Bodipy. Fluorescent microscopy experiments were performed to examine the sizes of lipid droplets. The interactions between Rab8a and Optineurin were determined by immunoprecipitation and western blot. Our assays demonstrated that Rab8a was phosphorylated by mutated LRRK2 that exhibits high kinase activity. Phosphorylation of Rab8a on amino acid residue T72 promoted the formation of large lipid droplets. T72D mutant of Rab8a had higher activity to promote the formation of large lipid droplets compared with wild type Rab8a, with increase in average diameter of lipid droplets from 2.10 μm to 2.46 μm. Moreover, phosphorylation of Rab8a weakened the interaction with its effector Optineurin. Y1699C mutated LRRK2 was able to phosphorylate Rab8a and phosphorylation of Rab8a on site 72 plays important role in the fusion and enlargement of lipid droplets. Taken together, our study suggests an indirect relationship between enhanced lipid storage capacity and PD pathogenesis.

A novel missense mutation (G43S) in the switch I region of Rab27A causing Griscelli syndrome

DEFF Research Database (Denmark)

Westbroek, W.; Tuchman, M.; Tinloy, B.

2008-01-01

The autosomal recessive Griscelli syndrome type II (GSII) is caused by mutations in the RAB27A gene. Typical clinical features include immunological impairment, silver-gray scalp hair, eyelashes and eyebrows and hypomelanosis of the skin. Rabs help determine the specificity of membrane trafficking......-immunoprecipitation studies showed that Rab27A(G43S) fails to interact with its effector Melanophilin, indicating that the switch I region functions in the recruitment of Rab effector proteins Udgivelsesdato: 2008/6...

The stability of AQT processing speed, ADAS-Cog and MMSE during acetylcholinesterase inhibitor treatment in Alzheimer's disease.

Science.gov (United States)

Wiig, E H; Annas, P; Basun, H; Andreasen, N; Lannfelt, L; Zetterberg, H; Blennow, K; Minthon, L

2010-03-01

To explore the longitudinal stability of measures of cognition during treatment with acetylcholinesterase inhibitors (AchEI) in patients with Alzheimer's disease (AD). Cognitive status was measured in a cohort of 60 patients at 6 months after initiation of treatment with AchEI (baseline) and after an additional 6 months of treatment (endpoint). A Quick Test of Cognitive Speed (AQT), Alzheimer's Disease Assessment Scale-Cognitive Subscale (ADAS-Cog), and MMSE were administered concurrently. Correlations (rho) between age and AQT processing speed were non-significant, but were significant for ADAS-Cog and Mini Mental State Examination (MMSE). AQT and ADAS-Cog means did not differ significantly between baseline and endpoint. There was a small, significant reduction in MMSE point scores. Measures of stability (Spearman's rho) were moderate-to-high for all tests. Means for subgroups did not differ as a function of medication type. AQT processing speed, ADAS-Cog, and MMSE measures proved stable during the second 6 months of treatment with AChEI.

RAB10 Interacts with the Male Germ Cell-Specific GTPase-Activating Protein during Mammalian Spermiogenesis

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Ying-Hung Lin

2017-01-01

Full Text Available According to recent estimates, 2%–15% of couples are sterile, and approximately half of the infertility cases are attributed to male reproductive factors. However, the reasons remain undefined in approximately 25% of male infertility cases, and most infertility cases exhibit spermatogenic defects. Numerous genes involved in spermatogenesis still remain unknown. We previously identified Male Germ Cells Rab GTPase-Activating Proteins (MGCRABGAPs through cDNA microarray analysis of human testicular tissues with spermatogenic defects. MGCRABGAP contains a conserved RABGAP catalytic domain, TBC (Tre2/Bub2/Cdc16. RABGAP family proteins regulate cellular function (e.g., cytoskeletal remodeling, vesicular trafficking, and cell migration by inactivating RAB proteins. MGCRABGAP is a male germ cell-specific protein expressed in elongating and elongated spermatids during mammalian spermiogenesis. The purpose of this study was to identify proteins that interact with MGCRABGAP during mammalian spermiogenesis using a proteomic approach. We found that MGCRABGAP exhibited GTPase-activating bioability, and several MGCRABGAP interactors, possible substrates (e.g., RAB10, RAB5C, and RAP1, were identified using co-immunoprecipitation (co-IP and nano liquid chromatography-mass spectrometry/mass spectrometry (nano LC-MS/MS. We confirmed the binding ability between RAB10 and MGCRABGAP via co-IP. Additionally, MGCRABGAP–RAB10 complexes were specifically colocalized in the manchette structure, a critical structure for the formation of spermatid heads, and were slightly expressed at the midpiece of mature spermatozoa. Based on these results, we propose that MGCRABGAP is involved in mammalian spermiogenesis by modulating RAB10.

Detecting treatment effects with combinations of the ADAS-cog items in patients with mild and moderate Alzheimer's disease.

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Ihl, Ralf; Ferris, Steven; Robert, Philippe; Winblad, Bengt; Gauthier, Serge; Tennigkeit, Frank

2012-01-01

When complex cognitive functions are measured with multi-item scales like the Alzheimer's Disease Assessment Scale - cognitive subscale (ADAS-cog), it seems valuable information can be lost due to combination of the ADAS-cog items results into a total score. We hypothesized, that an analysis of the results of different ADAS-cog item combinations may reveal drug treatment effects in distinct cognitive domains and/or enhance the sensitivity to detect such treatment effects. Here, we present a novel approach called 'subsetting analysis' for assessment of drug treatment effects with multi-item scales, like the ADAS-cog. The subsetting approach is a mathematical algorithm designed to select and group scale items in a subset detecting drug treatment effects in a particular study population. The approach was applied in a post-hoc analysis of ADAS-cog results from two randomized, placebo-controlled and double-blind clinical trials with memantine in mild to moderate Alzheimer's disease (AD). The subsetting analysis of the ADAS-cog combined database aimed at selecting the scale items showing no worsening at study end compared to baseline due to memantine treatment in mild AD (Mini-Mental State Examination (MMSE >19)) patients. Two ADAS-cog subsets were finally revealed by the analysis: a subset of five ADAS-cog items, identified as most sensitive to memantine effects in mild AD patients, and a subset of six ADAS-cog items shown to detect significant memantine effects in moderate AD patients. The subsetting approach of analyzing ADAS-cog data is a powerful alternative for gaining information about drug effects on cognitive performance in mild and moderate AD patients. Copyright © 2011 John Wiley & Sons, Ltd.

Golgi-associated Rab14, a new regulator for Chlamydia trachomatis infection outcome.

Science.gov (United States)

Capmany, Anahí; Leiva, Natalia; Damiani, María Teresa

2011-09-01

Chlamydia trachomatis is the causing agent of the most frequent bacterial sexually-transmitted diseases worldwide and is an underlying cause of chronic pelvic inflammatory diseases and cervical cancer. It is an obligate intracellular bacterium that establishes a close relationship with the Golgi complex and parasites the biosynthetic machinery of host cells. In a recent study, we have demonstrated that Rab14, a newly-described Golgi-associated Rab, is involved in the delivery of sphingolipids to the growing bacteria-containing vacuole. The interference with Rab14-controlled trafficking pathways delays chlamydial inclusion enlargement, decreases bacterial lipid uptake, negatively impact on bacterial differentiation, and reduces bacterial progeny and infectivity. C. trachomatis manipulation of host trafficking pathways for the acquisition of endogenously-biosynthesized nutrients arises as one of the characteristics of this highly evolved pathogen. The development of therapeutic strategies targeted to interfere with bacterium-host cell interaction is a new challenge for pharmacological approaches to control chlamydial infections.

Structural plasticity mediates distinct GAP-dependent GTP hydrolysis mechanisms in Rab33 and Rab5.

Science.gov (United States)

Majumdar, Soneya; Acharya, Abhishek; Prakash, Balaji

2017-12-01

The classical GTP hydrolysis mechanism, as seen in Ras, employs a catalytic glutamine provided in cis by the GTPase and an arginine supplied in trans by a GTPase activating protein (GAP). The key idea emergent from a large body of research on small GTPases is that GTPases employ a variety of different hydrolysis mechanisms; evidently, these variations permit diverse rates of GTPase inactivation, crucial for temporal regulation of different biological processes. Recently, we unified these variations and argued that a steric clash between active site residues (corresponding to positions 12 and 61 of Ras) governs whether a GTPase utilizes the cis-Gln or the trans-Gln (from the GAP) for catalysis. As the cis-Gln encounters a steric clash, the Rab GTPases employ the so-called dual finger mechanism where the interacting GAP supplies a trans-Gln for catalysis. Using experimental and computational methods, we demonstrate how the cis-Gln of Rab33 overcomes the steric clash when it is stabilized by a residue in the vicinity. In effect, this demonstrates how both cis-Gln- and trans-Gln-mediated mechanisms could operate in the same GTPase in different contexts, i.e. depending on the GAP that regulates its action. Interestingly, in the case of Rab5, which possesses a higher intrinsic GTP hydrolysis rate, a similar stabilization of the cis-Gln appears to overcome the steric clash. Taken together with the mechanisms seen for Rab1, it is evident that the observed variations in Rab and their GAP partners allow structural plasticity, or in other words, the choice of different catalytic mechanisms. © 2017 Federation of European Biochemical Societies.

Functional Characterization of Monomeric GTPase Rab1 in the Secretory Pathway of Leishmania*

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Bahl, Surbhi; Parashar, Smriti; Malhotra, Himanshu; Raje, Manoj; Mukhopadhyay, Amitabha

2015-01-01

Leishmania secretes a large number of its effectors to the extracellular milieu. However, regulation of the secretory pathway in Leishmania is not well characterized. Here, we report the cloning, expression, and characterization of the Rab1 homologue from Leishmania. We have found that LdRab1 localizes in Golgi in Leishmania. To understand the role of LdRab1 in the secretory pathway of Leishmania, we have generated transgenic parasites overexpressing GFP-LdRab1:WT, GFP-LdRab1:Q67L (a GTPase-deficient dominant positive mutant of Rab1), and GFP-LdRab1:S22N (a GDP-locked dominant negative mutant of Rab1). Surprisingly, our results have shown that overexpression of GFP-LdRab1:Q67L or GFP-LdRab1:S22N does not disrupt the trafficking and localization of hemoglobin receptor in Leishmania. To determine whether the Rab1-dependent secretory pathway is conserved in parasites, we have analyzed the role of LdRab1 in the secretion of secretory acid phosphatase and Ldgp63 in Leishmania. Our results have shown that overexpression of GFP-LdRab1:Q67L or GFP-LdRab1:S22N significantly inhibits the secretion of secretory acid phosphatase by Leishmania. We have also found that overexpression of GFP-LdRab1:Q67L or GFP-LdRab1:S22N retains RFP-Ldgp63 in Golgi and blocks the secretion of Ldgp63, whereas the trafficking of RFP-Ldgp63 in GFP-LdRab1:WT-expressing cells is unaltered in comparison with control cells. Taken together, our results have shown that the Rab1-regulated secretory pathway is well conserved, and hemoglobin receptor trafficking follows an Rab1-independent secretory pathway in Leishmania. PMID:26499792

Functional Characterization of Monomeric GTPase Rab1 in the Secretory Pathway of Leishmania.

Science.gov (United States)

Bahl, Surbhi; Parashar, Smriti; Malhotra, Himanshu; Raje, Manoj; Mukhopadhyay, Amitabha

2015-12-11

Leishmania secretes a large number of its effectors to the extracellular milieu. However, regulation of the secretory pathway in Leishmania is not well characterized. Here, we report the cloning, expression, and characterization of the Rab1 homologue from Leishmania. We have found that LdRab1 localizes in Golgi in Leishmania. To understand the role of LdRab1 in the secretory pathway of Leishmania, we have generated transgenic parasites overexpressing GFP-LdRab1:WT, GFP-LdRab1:Q67L (a GTPase-deficient dominant positive mutant of Rab1), and GFP-LdRab1:S22N (a GDP-locked dominant negative mutant of Rab1). Surprisingly, our results have shown that overexpression of GFP-LdRab1:Q67L or GFP-LdRab1:S22N does not disrupt the trafficking and localization of hemoglobin receptor in Leishmania. To determine whether the Rab1-dependent secretory pathway is conserved in parasites, we have analyzed the role of LdRab1 in the secretion of secretory acid phosphatase and Ldgp63 in Leishmania. Our results have shown that overexpression of GFP-LdRab1:Q67L or GFP-LdRab1:S22N significantly inhibits the secretion of secretory acid phosphatase by Leishmania. We have also found that overexpression of GFP-LdRab1:Q67L or GFP-LdRab1:S22N retains RFP-Ldgp63 in Golgi and blocks the secretion of Ldgp63, whereas the trafficking of RFP-Ldgp63 in GFP-LdRab1:WT-expressing cells is unaltered in comparison with control cells. Taken together, our results have shown that the Rab1-regulated secretory pathway is well conserved, and hemoglobin receptor trafficking follows an Rab1-independent secretory pathway in Leishmania. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

COG Software Architecture Design Description Document

International Nuclear Information System (INIS)

Buck, R.M.; Lent, E.M.

2009-01-01

This COG Software Architecture Design Description Document describes the organization and functionality of the COG Multiparticle Monte Carlo Transport Code for radiation shielding and criticality calculations, at a level of detail suitable for guiding a new code developer in the maintenance and enhancement of COG. The intended audience also includes managers and scientists and engineers who wish to have a general knowledge of how the code works. This Document is not intended for end-users. This document covers the software implemented in the standard COG Version 10, as released through RSICC and IAEA. Software resources provided by other institutions will not be covered. This document presents the routines grouped by modules and in the order of the three processing phases. Some routines are used in multiple phases. The routine description is presented once - the first time the routine is referenced. Since this is presented at the level of detail for guiding a new code developer, only the routines invoked by another routine that are significant for the processing phase that is being detailed are presented. An index to all routines detailed is included. Tables for the primary data structures are also presented.

PCOGR: Phylogenetic COG ranking as an online tool to judge the specificity of COGs with respect to freely definable groups of organisms

OpenAIRE

Meereis, Florian; Kaufmann, Michael

2004-01-01

Abstract Background The rapidly increasing number of completely sequenced genomes led to the establishment of the COG-database which, based on sequence homologies, assigns similar proteins from different organisms to clusters of orthologous groups (COGs). There are several bioinformatic studies that made use of this database to determine (hyper)thermophile-specific proteins by searching for COGs containing (almost) exclusively proteins from (hyper)thermophilic genomes. However, public softwar...

Toward the identification of molecular cogs.

Science.gov (United States)

Dziubiński, Maciej; Lesyng, Bogdan

2016-04-05

Computer simulations of molecular systems allow determination of microscopic interactions between individual atoms or groups of atoms, as well as studies of intramolecular motions. Nevertheless, description of structural transformations at the mezoscopic level and identification of causal relations associated with these transformations is very difficult. Structural and functional properties are related to free energy changes. Therefore, to better understand structural and functional properties of molecular systems, it is required to deepen our knowledge of free energy contributions arising from molecular subsystems in the course of structural transformations. The method presented in this work quantifies the energetic contribution of each pair of atoms to the total free energy change along a given collective variable. Next, with the help of a genetic clustering algorithm, the method proposes a division of the system into two groups of atoms referred to as molecular cogs. Atoms which cooperate to push the system forward along a collective variable are referred to as forward cogs, and those which work in the opposite direction as reverse cogs. The procedure was tested on several small molecules for which the genetic clustering algorithm successfully found optimal partitionings into molecular cogs. The primary result of the method is a plot depicting the energetic contributions of the identified molecular cogs to the total Potential of Mean Force (PMF) change. Case-studies presented in this work should help better understand the implications of our approach, and were intended to pave the way to a future, publicly available implementation. © 2015 Wiley Periodicals, Inc.

Examining the reliability of ADAS-Cog change scores.

Science.gov (United States)

Grochowalski, Joseph H; Liu, Ying; Siedlecki, Karen L

2016-09-01

The purpose of this study was to estimate and examine ways to improve the reliability of change scores on the Alzheimer's Disease Assessment Scale, Cognitive Subtest (ADAS-Cog). The sample, provided by the Alzheimer's Disease Neuroimaging Initiative, included individuals with Alzheimer's disease (AD) (n = 153) and individuals with mild cognitive impairment (MCI) (n = 352). All participants were administered the ADAS-Cog at baseline and 1 year, and change scores were calculated as the difference in scores over the 1-year period. Three types of change score reliabilities were estimated using multivariate generalizability. Two methods to increase change score reliability were evaluated: reweighting the subtests of the scale and adding more subtests. Reliability of ADAS-Cog change scores over 1 year was low for both the AD sample (ranging from .53 to .64) and the MCI sample (.39 to .61). Reweighting the change scores from the AD sample improved reliability (.68 to .76), but lengthening provided no useful improvement for either sample. The MCI change scores had low reliability, even with reweighting and adding additional subtests. The ADAS-Cog scores had low reliability for measuring change. Researchers using the ADAS-Cog should estimate and report reliability for their use of the change scores. The ADAS-Cog change scores are not recommended for assessment of meaningful clinical change.

High Rab27A expression indicates favorable prognosis in CRC.

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Shi, Chuanbing; Yang, Xiaojun; Ni, Yijiang; Hou, Ning; Xu, Li; Zhan, Feng; Zhu, Huijun; Xiong, Lin; Chen, Pingsheng

2015-06-13

Rab27A is a peculiar member in Rab family and has been suggested to play essential roles in the development of human cancers. However, the association between Rab27A expression and clinicopathological characteristics of colorectal cancer (CRC) has not been elucidated yet. One-step quantitative real-time polymerase chain reaction (qPCR) test with 18 fresh-frozen CRC samples and immunohistochemistry (IHC) analysis in 112 CRC cases were executed to evaluate the relationship between Rab27A expression and the clinicopathological features of CRC. Cox regression and Kaplan-Meier survival analyses were performed to identify the prognostic factors for 112 CRC patients. The results specified that the expression levels of Rab27A mRNA and protein were significantly higher in CRC tissues than that in matched non-cancerous tissues, in both qPCR test (p = 0.029) and IHC analysis (p = 0.020). The IHC data indicated that the Rab27A protein expression in CRC was statistically correlated with lymph node metastasis (p = 0.022) and TNM stage (p = 0.026). Cox multi-factor analysis and Kaplan-Meier method suggested Rab27A protein expression (p = 0.012) and tumor differentiation (p = 0.004) were significantly associated with the overall survival of CRC patients. The data indicated the differentiate expression of Rab27A in CRC tissues and matched non-cancerous tissues. Rab27A may be used as a valuable prognostic biomarker for CRC patients.

Role of Rab5 in the formation of macrophage-derived foam cell.

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Chan, Lokwern; Hong, Jin; Pan, Junjie; Li, Jian; Wen, Zhichao; Shi, Haiming; Ding, Jianping; Luo, Xinping

2017-09-12

Foam cells play a key role in the occurrence and pathogenesis of atherosclerosis. Its formation starts with the ingestion of oxidized low-density lipoprotein (oxLDL). The process is associated with Ras related protein in brain 5 (Rab5) which plays a critical role in regulating endocytosis and early endosomal trafficking. Base on this, we presumed that Rab5 might participate in the maturation of foam cell. The aim of this study is to investigate the effect of Rab5 on macrophage cholesterol during the evolvement of macrophage when induced by oxLDL to the formation of foam cell. Immunohistochemistry was performed to analyze the distribution of macrophages and Rab5 in atherosclerotic plaque. RNA inteference study and transfection of inactive mutant (GFP-Rab5-S34N) and active mutant (GFP-Rab5-Q79L) in U937-derived macrophage were utilized to investigate the impact of Rab5 on the process of macrophage cholesterol, which could be detected by oil red O staining, determination of intracellular lipid content, filipin staining, nile red staining and the costaining of early endosome antigen-1 (EEA-1) and 1,1'-dioctadecyl-3,3,3',3'-tetramethylin dicarbocyanine (Dil)-labelled oxLDL (Dil-oxLDL). Rab5 was found abundantly localized in macrophage rich areas of human atherosclerotic lesions. On the foam cell study, the expression of Rab5 was increased after the incubation of oxLDL. The inteference study indicated the depletion of Rab5 led to the decreases of oil red O staining areas, total cholesterol and cholesterol esters in U937-derived marophages. Moreover, the fluorescence intensity of filipin and nile red staining were lower in GFP-Rab5-S34N as compared with GFP-Rab5-Q79L. The confocal study demonstrated less Dil-oxLDL was internalized in GFP-Rab5-S34N as compared with GFP-Rab5-Q79L; the result showed also the decrease in colocalization of internalized Dil-oxLDL and EEA-1 for GFP-Rab5-S34N as compared with GFP-Rab5-Q79L. Rab5 plays an important role in modulating the

Rab32 is important for autophagy and lipid storage in Drosophila.

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Chao Wang

Full Text Available Lipids are essential components of all organisms. Within cells, lipids are mainly stored in a specific type of organelle, called the lipid droplet. The molecular mechanisms governing the dynamics of lipid droplets have been little explored. The protein composition of lipid droplets has been analyzed in numerous proteomic studies, and a large number of lipid droplet-associated proteins have been identified, including Rab small GTPases. Rab proteins are known to participate in many intracellular membranous events; however, their exact role in lipid droplets is largely unexplored. Here we systematically investigate the roles of Drosophila Rab family proteins in lipid storage in the larval adipose tissue, fat body. Rab32 and several other Rabs were found to affect the size of lipid droplets as well as lipid levels. Further studies showed that Rab32 and Rab32 GEF/Claret may be involved in autophagy, consequently affecting lipid storage. Loss-of-function mutants of several components in the autophagy pathway result in similar effects on lipid storage. These results highlight the potential functions of Rabs in regulating lipid metabolism.

Revealing localization and regulation of GTPase PmRab7 in lymphoid cells of Penaeus monodon after WSSV infection

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Amrendra Kumar

2016-10-01

Full Text Available Objective: To identify white spot syndrome virus (WSSV entry into the host-cells of the cultured shrimp Penaeus monodon, we have attempted to localize PmRab7 (Ras-related in brain which is playing a vital role in the WSSV internalization. Methods: In this study, we have cloned PmRab7 and expressed in Escherichia coli, further purified rPmRab7 was used for antibody production, isolation of lysosomal sub-cellular fractions and western blot against lysosomal protein. Moreover, high fold-change in PmRab7 regulation with increasing copy number of WSSV has been studied by using real-time PCR. Results: 651 bp amplicon size gene was successfully amplified, ligated amplicon with pTZ T-tail vector confirmed by colony PCR and retriction enzyme digestion on agarose gel. Subcloned (pRSET-B 651 bp gene transformed successfully in Rosetta and after 6 h of induction expressed rPmRab7 was on SDS page, furthermore soluble fraction of rPmRab7 (26 kDa was purified by ni-NTA column. AntiPmRab7 antibody was received by Merk Pvt. Ltd., and western blot analysis revealed that PmRab7 is present in the lysosomal sub-cellular fraction. Copy number of WSSV was increased 5 fold in 24 h and 20 fold in 72 h of infection and subsequently transcrtipt of PmRab7 was Ct = 1.0 to Ct = 8.5. Conclusions: Presence of PmRab7 on lysosome clearly indicating PmRab7 participating in lysosomal maturation, other hand WSSV may follow the same route of entry. WSSV internalization has directly linked with regulation of PmRab7.

The ADAS-Cog revisited: novel composite scales based on ADAS-Cog to improve efficiency in MCI and early AD trials.

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Raghavan, Nandini; Samtani, Mahesh N; Farnum, Michael; Yang, Eric; Novak, Gerald; Grundman, Michael; Narayan, Vaibhav; DiBernardo, Allitia

2013-02-01

The Alzheimer's Disease Assessment Scale-Cognitive (ADAS-Cog) has been used widely as a cognitive end point in Alzheimer's Disease (AD) clinical trials. Efforts to treat AD pathology at earlier stages have also used ADAS-Cog, but failure in these trials can be difficult to interpret because the scale has well-known ceiling effects that limit its use in mild cognitive impairment (MCI) and early AD. A wealth of data exists in ADAS-Cog from both historical trials and contemporary longitudinal natural history studies that can provide insights about parts of the scale that may be better suited for MCI and early AD trials. Using Alzheimer's Disease Neuroimaging Initiative study data, we identified the most informative cognitive measures from the ADAS-Cog and other available scales. We used cross-sectional analyses to characterize trajectories of ADAS-Cog and its individual subscales, as well as other cognitive, functional, or global measures across disease stages. Informative measures were identified based on standardized mean of 2-year change from baseline and were combined into novel composite endpoints. We assessed performance of the novel endpoints based on sample size requirements for a 2-year clinical trial. A bootstrap validation procedure was also undertaken to assess the reproducibility of the standardized mean changes of the selected measures and the corresponding composites. All proposed novel endpoints have improved standardized mean changes and thus improved statistical power compared with the ADAS-Cog 11. Further improvements were achieved by using cognitive-functional composites. Combining the novel composites with an enrichment strategy based on cerebral spinal fluid beta-amyloid (Aβ(1-42)) in a 2-year trial yielded gains in power of 20% to 40% over ADAS-Cog 11, regardless of the novel measure considered. An empirical, data-driven approach with existing instruments was used to derive novel composite scales based on ADAS-Cog 11 with improved performance

Yersinia pestis Requires Host Rab1b for Survival in Macrophages.

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Michael G Connor

2015-10-01

Full Text Available Yersinia pestis is a facultative intracellular pathogen that causes the disease known as plague. During infection of macrophages Y. pestis actively evades the normal phagosomal maturation pathway to establish a replicative niche within the cell. However, the mechanisms used by Y. pestis to subvert killing by the macrophage are unknown. Host Rab GTPases are central mediators of vesicular trafficking and are commonly targeted by bacterial pathogens to alter phagosome maturation and killing by macrophages. Here we demonstrate for the first time that host Rab1b is required for Y. pestis to effectively evade killing by macrophages. We also show that Rab1b is specifically recruited to the Yersinia containing vacuole (YCV and that Y. pestis is unable to subvert YCV acidification when Rab1b expression is knocked down in macrophages. Furthermore, Rab1b knockdown also altered the frequency of association between the YCV with the lysosomal marker Lamp1, suggesting that Rab1b recruitment to the YCV directly inhibits phagosome maturation. Finally, we show that Rab1b knockdown also impacts the pH of the Legionella pneumophila containing vacuole, another pathogen that recruits Rab1b to its vacuole. Together these data identify a novel role for Rab1b in the subversion of phagosome maturation by intracellular pathogens and suggest that recruitment of Rab1b to the pathogen containing vacuole may be a conserved mechanism to control vacuole pH.

Rab3 proteins involved in vesicle biogenesis and priming in embryonic mouse chromaffin cells

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Schonn, Jean-Sébastien; van Weering, Jan R T; Mohrmann, Ralf

2010-01-01

The four Rab3 paralogs A-D are involved in exocytosis, but their mechanisms of action are hard to study due to functional redundancy. Here we used a quadruple Rab3 knock-out (rab3a, rab3b, rab3c, rab3d null, here denoted ABCD(-/-)) mouse line to investigate Rab3 function in embryonic mouse adrena...

Rab GTPases in Immunity and Inflammation.

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Prashar, Akriti; Schnettger, Laura; Bernard, Elliott M; Gutierrez, Maximiliano G

2017-01-01

Strict spatiotemporal control of trafficking events between organelles is critical for maintaining homeostasis and directing cellular responses. This regulation is particularly important in immune cells for mounting specialized immune defenses. By controlling the formation, transport and fusion of intracellular organelles, Rab GTPases serve as master regulators of membrane trafficking. In this review, we discuss the cellular and molecular mechanisms by which Rab GTPases regulate immunity and inflammation.

Rab7b at the intersection of intracellular trafficking and cell migration.

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Distefano, Marita Borg; Kjos, Ingrid; Bakke, Oddmund; Progida, Cinzia

2015-01-01

Rab proteins are small GTPases essential for controlling and coordinating intracellular traffic. The small GTPase Rab7b regulates the retrograde transport from late endosomes toward the Trans-Golgi Network (TGN), and is important for the proper trafficking of several receptors such as Toll-like receptors (TLRs) and sorting receptors. We recently identified the actin motor protein myosin II as a new interaction partner for Rab7b, and found that Rab7b transport is dependent on myosin II. Interestingly, we also discovered that Rab7b influences the phosphorylation state of myosin II by controlling the activation status of the small GTPase RhoA. Consequently, Rab7b is important for the remodeling of actin filaments in processes such as stress fiber formation, cell adhesion, polarization and cell migration. Our finding that Rab7b can control actomyosin reorganization reveals yet another important role for Rab proteins, in addition to their already established role as master regulators of intracellular transport. Here we discuss our findings and speculate how they can explain the importance of Rab7b in dendritic cells (DCs).

Control of MarRAB Operon in Escherichia coli via Autoactivation and Autorepression

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Prajapat, Mahendra Kumar; Jain, Kirti; Saini, Supreet

2015-01-01

Choice of network topology for gene regulation has been a question of interest for a long time. How do simple and more complex topologies arise? In this work, we analyze the topology of the marRAB operon in Escherichia coli, which is associated with control of expression of genes associated with conferring resistance to low-level antibiotics to the bacterium. Among the 2102 promoters in E. coli, the marRAB promoter is the only one that encodes for an autoactivator and an autorepressor. What advantages does this topology confer to the bacterium? In this work, we demonstrate that, compared to control by a single regulator, the marRAB regulatory arrangement has the least control cost associated with modulating gene expression in response to environmental stimuli. In addition, the presence of dual regulators allows the regulon to exhibit a diverse range of dynamics, a feature that is not observed in genes controlled by a single regulator. PMID:26445450

Role of Rab family GTPases and their effectors in melanosomal logistics.

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Ohbayashi, Norihiko; Fukuda, Mitsunori

2012-04-01

Rab GTPases constitute a family of small GTPases that regulate a variety of membrane trafficking events in all eukaryotic cells by recruiting their specific effector molecules. Recent accumulating evidence indicates that members of the mammalian Rab small GTPase family are involved in certain physiological and pathological processes. In particular, functional impairments of specific Rab proteins, e.g. Rab38 and Rab27A, their regulators or their effectors cause pigmentation disorders in humans and coat colour variations in mice because such impairments cause defects in melanosomal logistics, i.e. defects in melanosome biogenesis and transport. Genetic and biochemical analyses of the gene products responsible for mammalian pigmentation disorders in the past decade have revealed that Rab-mediated endosomal transport systems and melanosome transport systems play crucial roles in the efficient darkening of mammalian hair and skin. In this article, we review current knowledge regarding melanosomal logistics, with particular focus on the roles of Rab small GTPases and their effectors.

Structural basis for the recruitment and activation of the Legionella phospholipase VipD by the host GTPase Rab5

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Lucas, María; Gaspar, Andrew H.; Pallara, Chiara; Rojas, Adriana Lucely; Fernández-Recio, Juan; Machner, Matthias P.; Hierro, Aitor

2014-01-01

A challenge for microbial pathogens is to assure that their translocated effector proteins target only the correct host cell compartment during infection. The Legionella pneumophila effector vacuolar protein sorting inhibitor protein D (VipD) localizes to early endosomal membranes and alters their lipid and protein composition, thereby protecting the pathogen from endosomal fusion. This process requires the phospholipase A1 (PLA1) activity of VipD that is triggered specifically on VipD binding to the host cell GTPase Rab5, a key regulator of endosomes. Here, we present the crystal structure of VipD in complex with constitutively active Rab5 and reveal the molecular mechanism underlying PLA1 activation. An active site-obstructing loop that originates from the C-terminal domain of VipD is repositioned on Rab5 binding, thereby exposing the catalytic pocket within the N-terminal PLA1 domain. Substitution of amino acid residues located within the VipD–Rab5 interface prevented Rab5 binding and PLA1 activation and caused a failure of VipD mutant proteins to target to Rab5-enriched endosomal structures within cells. Experimental and computational analyses confirmed an extended VipD-binding interface on Rab5, explaining why this L. pneumophila effector can compete with cellular ligands for Rab5 binding. Together, our data explain how the catalytic activity of a microbial effector can be precisely linked to its subcellular localization. PMID:25114243

Rab18 dynamics in adipocytes in relation to lipogenesis, lipolysis and obesity.

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Marina R Pulido

Full Text Available Lipid droplets (LDs are organelles that coordinate lipid storage and mobilization, both processes being especially important in cells specialized in managing fat, the adipocytes. Proteomic analyses of LDs have consistently identified the small GTPase Rab18 as a component of the LD coat. However, the specific contribution of Rab18 to adipocyte function remains to be elucidated. Herein, we have analyzed Rab18 expression, intracellular localization and function in relation to the metabolic status of adipocytes. We show that Rab18 production increases during adipogenic differentiation of 3T3-L1 cells. In addition, our data show that insulin induces, via phosphatidylinositol 3-kinase (PI3K, the recruitment of Rab18 to the surface of LDs. Furthermore, Rab18 overexpression increased basal lipogenesis and Rab18 silencing impaired the lipogenic response to insulin, thereby suggesting that this GTPase promotes fat accumulation in adipocytes. On the other hand, studies of the β-adrenergic receptor agonist isoproterenol confirmed and extended previous evidence for the participation of Rab18 in lipolysis. Together, our data support the view that Rab18 is a common mediator of lipolysis and lipogenesis and suggests that the endoplasmic reticulum (ER is the link that enables Rab18 action on these two processes. Finally, we describe, for the first time, the presence of Rab18 in human adipose tissue, wherein the expression of this GTPase exhibits sex- and depot-specific differences and is correlated to obesity. Taken together, these findings indicate that Rab18 is involved in insulin-mediated lipogenesis, as well as in β-adrenergic-induced lipolysis, likely facilitating interaction of LDs with ER membranes and the exchange of lipids between these compartments. A role for Rab18 in the regulation of adipocyte biology under both normal and pathological conditions is proposed.

The Rab GTPase Rab8 as a shared regulator of ciliogenesis and immune synapse assembly: From a conserved pathway to diverse cellular structures.

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Patrussi, Laura; Baldari, Cosima T

2016-01-01

Rab GTPases, which form the largest branch of the Ras GTPase superfamily, regulate almost every step of vesicle-mediated trafficking. Among them, Rab8 is an essential participant in primary cilium formation. In a report recently published in the Journal of Cell Science, Finetti and colleagues identify Rab8 as a novel player in vesicular traffic in the non-ciliated T lymphocytes, which contributes to the assembly of the specialized signaling platform known as the immune synapse. By interacting with the v-SNARE VAMP-3, Rab8 is indeed responsible for the final docking/fusion step in T cell receptor (TCR) recycling to the immune synapse. A second important take-home message which comes to light from this work is that VAMP-3 also interacts with Rab8 at the base of the cilium in NIH-3T3 cells, where it regulates ciliary growth and targeting of Smoothened at the plasma membrane. Hence the data presented in this report, in addition to identifying Rab8 as a novel player in vesicular traffic to the immune synapse, reveal how both ciliated and non-ciliated cells take advantage of a conserved pathway to build highly specific cellular structures.

Cloning and molecular characterization of the salt-regulated jojoba ScRab cDNA encoding a small GTP-binding protein.

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Mizrahi-Aviv, Ela; Mills, David; Benzioni, Aliza; Bar-Zvi, Dudy

2002-10-01

Salt stress results in a massive change in gene expression. An 837 bp cDNA designated ScRab was cloned from shoot cultures of the salt tolerant jojoba (Simmondsia chinesis). The cloned cDNA encodes a full length 200 amino acid long polypeptide that bears high homology to the Rab subfamily of small GTP binding proteins, particularly, the Rab5 subfamily. ScRab expression is reduced in shoots grown in the presence of salt compared to shoots from non-stressed cultures. His6-tagged ScRAB protein was expressed in E. coli, and purified to homogeneity. The purified protein bound radiolabelled GTP. The unlabelled guanine nucleotides GTP, GTP gamma S and GDP but not ATP, CTP or UTP competed with GTP binding.

Rab11 family expression in the human placenta: Localization at the maternal-fetal interface

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Artemiuk, Patrycja A.; Hanscom, Sara R.; Lindsay, Andrew J.; Wuebbolt, Danielle; Breathnach, Fionnuala M.; Tully, Elizabeth C.; Khan, Amir R.; McCaffrey, Mary W.

2017-01-01

Rab proteins are a family of small GTPases involved in a variety of cellular processes. The Rab11 subfamily in particular directs key steps of intracellular functions involving vesicle trafficking of the endosomal recycling pathway. This Rab subfamily works through a series of effector proteins including the Rab11-FIPs (Rab11 Family-Interacting Proteins). While the Rab11 subfamily has been well characterized at the cellular level, its function within human organ systems is still being explored. In an effort to further study these proteins, we conducted a preliminary investigation of a subgroup of endosomal Rab proteins in a range of human cell lines by Western blotting. The results from this analysis indicated that Rab11a, Rab11c(Rab25) and Rab14 were expressed in a wide range of cell lines, including the human placental trophoblastic BeWo cell line. These findings encouraged us to further analyse the localization of these Rabs and their common effector protein, the Rab Coupling Protein (RCP), by immunofluorescence microscopy and to extend this work to normal human placental tissue. The placenta is a highly active exchange interface, facilitating transfer between mother and fetus during pregnancy. As Rab11 proteins are closely involved in transcytosis we hypothesized that the placenta would be an interesting human tissue model system for Rab investigation. By immunofluorescence microscopy, Rab11a, Rab11c(Rab25), Rab14 as well as their common FIP effector RCP showed prominent expression in the placental cell lines. We also identified the expression of these proteins in human placental lysates by Western blot analysis. Further, via fluorescent immunohistochemistry, we noted abundant localization of these proteins within key functional areas of primary human placental tissues, namely the outer syncytial layer of placental villous tissue and the endothelia of fetal blood vessels. Overall these findings highlight the expression of the Rab11 family within the human

Rab GTPases in Immunity and Inflammation

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Akriti Prashar

2017-09-01

Full Text Available Strict spatiotemporal control of trafficking events between organelles is critical for maintaining homeostasis and directing cellular responses. This regulation is particularly important in immune cells for mounting specialized immune defenses. By controlling the formation, transport and fusion of intracellular organelles, Rab GTPases serve as master regulators of membrane trafficking. In this review, we discuss the cellular and molecular mechanisms by which Rab GTPases regulate immunity and inflammation.

Psy-disciplinary cogs in the teacher education machine

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Petersen, Eva Bendix; Millei, Zsuzsa

2015-01-01

set out to explore how the psy- disciplines currently manifest and operate as significant cogs in the teacher education machine. Responding to Law and Urry’s (2004) call for a more “messy” social science, we offer an impressionistic assemblage ethnography, where we pick up and consider the psy...... -disciplinary cogs that we happen upon in our everyday lives as lecturers in Australian initial teacher education. We offer an incomplete list of some of these cogs, and indicate the ways in which they uphold psy-disciplinary knowledges, and the psy- gaze, as relevant and significant. We conclude by reflecting...

A study of the Alzheimer's Disease Assessment Scale-Cognitive (ADAS-Cog) in an Icelandic elderly population.

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Hannesdóttir, Kristin; Snaedal, Jón

2002-01-01

The Alzheimer's Disease Assessment Scale (ADAS) is designed for screening of cognitive and non-cognitive dysfunctions characteristic of persons with probable Alzheimer's disease (AD). The cognitive part of the scale (ADAS-Cog) is both convenient for screening of probable AD and as a measure of cognitive functioning during drug intervention. The aim of this study was to translate the ADAS-Cognitive sub-test (ADAS-Cog) into Icelandic and to study its application in an elderly Icelandic population. The Mini-Mental State Examination (MMSE) and the ADAS-Cog were administered to 20 AD patients and 20 controls. Each patient was also rated on the Global Deterioration Scale (GDS). The probable AD patients were divided into two groups based on their GDS: 3-4 and 5-6 points. The patients were also divided into two groups based on their MMSE score: very mild to mild (23-30 points) and mild to moderate (15-22 points). Furthermore, the subjects were divided into two age groups: 65-76 and 77-92 years. Results revealed a highly significant difference on MMSE (22.3 +/- 3.4; 26.8 +/- 1.6; P ADAS-Cog (18.4 +/- 7.7; 7.3 +/- 3.5; P ADAS-Cog plays an important role in the diagnostic makeup of AD along with other detailed investigations, such as neuropsychological assessment.

PKC and Rab13 mediate Ca2+ signal-regulated GLUT4 traffic.

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Deng, Bangli; Zhu, Xiaocui; Zhao, Yihe; Zhang, Da; Pannu, Alisha; Chen, Liming; Niu, Wenyan

2018-01-08

Exercise/muscle contraction increases cell surface glucose transporter 4 (GLUT4), leading to glucose uptake to regulate blood glucose level. Elevating cytosolic Ca 2+ mediates this effect, but the detailed mechanism is not clear yet. We used calcium ionophore ionomycin to raise intracellular cytosolic Ca 2+ level to explore the underlying mechanism. We showed that in L6 myoblast muscle cells stably expressing GLUT4myc, ionomycin increased cell surface GLUT4myc levels and the phosphorylation of AS160, TBC1D1. siPKCα and siPKCθ but not siPKCδ and siPKCε inhibited the ionomycin-increased cell surface GLUT4myc level. siPKCα, siPKCθ inhibited the phosphorylation of AS160 and TBC1D1 induced by ionomycin. siPKCα and siPKCθ prevented ionomycin-inhibited endocytosis of GLUT4myc. siPKCθ, but not siPKCα inhibited ionomycin-stimulated exocytosis of GLUT4myc. siRab13 but not siRab8a, siRab10 and siRab14 inhibited the exocytosis of GLUT4myc promoted by ionomycin. In summary, ionomycin-promoted exocytosis of GLUT4 is partly reversed by siPKCθ, whereas ionomycin-inhibited endocytosis of GLUT4 requires both siPKCα and siPKCθ. PKCα and PKCθ contribute to ionomycin-induced phosphorylation of AS160 and TBC1D1. Rab13 is required for ionomycin-regulated GLUT4 exocytosis. Copyright © 2017 Elsevier Inc. All rights reserved.

A new Brief computerized cognitive screening battery (CompCogs for early diagnosis of Alzheimer's disease

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Helenice Charchat Fichman

Full Text Available Abstract Screening tests for early diagnosis of dementia are of great clinical relevance. The ideal test set must be brief and reliable, and should probe cognitive components impaired in Alzheimer's disease (AD. Objectives: To develop a new Computerized Cognitive Screening test (CompCogs, and to investigate its validity for the early diagnosis of AD, and evaluate its heuristic value in understanding the processing of information in AD. Methods: The computerized neuropsychological performance battery, originally including six tests, was applied in forty seven patients with probable mild AD and 97 controls matched for age and education. This computerized neuropsychological test battery, developed with MEL Professional, allows control of timing and order of stimuli presentation, as well as recording of response type and latency. A brief-screening version, CompCogs, was selected using the most discriminative neuropsychological test variables derived from logistic regression analysis. Full battery administration lasted about 40 minutes, while the CompCogs took only 15 minutes. Results: CompCogs included the Face test (correct response and Word and Forms with Short term memory tests (reaction time. CompCogs presented 91.8% sensitivity and 93.6% specificity for the diagnosis of AD using ROC analyses of AD diagnosis probability derived by logistic regression. Conclusions: CompCogs showed high validity for AD early diagnosis and, therefore, may be a useful alternative screening instrument.

Characterization of the human RAB38 and RAB7 genes: exclusion of new major pathological loci for Japanese OCA.

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Suzuki, Tamio; Miyamura, Yoshinori; Inagaki, Katsuhiko; Tomita, Yasushi

2003-08-01

Oculocutaneous albinisms (OCAs) are due to various gene mutations that cause a disruption of melanogenesis in the melanocyte. Four different genes associated with human OCA have been reported, however, not all of OCA patients can be classified according to these four genes. We have sought to find a new major locus for Japanese OCA. Recently two genes, RAB38 and RAB7, were reported to play an important role in melanogenesis in the melanocyte, suggesting that these two genes could be good candidates for new OCA loci. To determine the structures of the human RAB38 and RAB7 genes, and examine if the two genes are new major loci for Japanese OCA. We screened mutations in these genes of 25 Japanese OCA patients who lacked mutations in the OCA1 and OCA2 genes with SSCP/heteroduplexes method. We determined the both genes, and their genomic organizations to design the primers for SSCP/heteroduplexes method. And then we screened mutations, but no mutation was detected. Neither of the genes is a new major locus for Japanese OCA.

Role of rab proteins in epithelial membrane traffic

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van Ijzendoorn, SCD; Mostov, KE; Hoekstra, D

2003-01-01

Small GTPase rab proteins play an important role in various aspects of membrane traffic, including cargo selection, vesicle budding, vesicle motility, tethering, docking, and fusion. Recent data suggest also that rabs, and their divalent effector proteins, organize organelle subdomains and as such

Rab20 regulates phagosome maturation in RAW264 macrophages during Fc gamma receptor-mediated phagocytosis.

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Youhei Egami

Full Text Available Rab20, a member of the Rab GTPase family, is known to be involved in membrane trafficking, however its implication in FcγR-mediated phagocytosis is unclear. We examined the spatiotemporal localization of Rab20 during phagocytosis of IgG-opsonized erythrocytes (IgG-Es in RAW264 macrophages. By the live-cell imaging of fluorescent protein-fused Rab20, it was shown that Rab20 was transiently associated with the phagosomal membranes. During the early stage of phagosome formation, Rab20 was not localized on the membranes of phagocytic cups, but was gradually recruited to the newly formed phagosomes. Although Rab20 was colocalized with Rab5 to some extent, the association of Rab20 with the phagosomes persisted even after the loss of Rab5 from the phagosomal membranes. Then, Rab20 was colocalized with Rab7 and Lamp1, late endosomal/lysosomal markers, on the internalized phagosomes. Moreover, our analysis of Rab20 mutant expression revealed that the maturation of phagosomes was significantly delayed in cells expressing the GDP-bound mutant Rab20-T19N. These data suggest that Rab20 is an important component of phagosome and regulates the phagosome maturation during FcγR-mediated phagocytosis.

Classifying the molecular functions of Rab GTPases in membrane trafficking using deep convolutional neural networks.

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Le, Nguyen-Quoc-Khanh; Ho, Quang-Thai; Ou, Yu-Yen

2018-06-13

Deep learning has been increasingly used to solve a number of problems with state-of-the-art performance in a wide variety of fields. In biology, deep learning can be applied to reduce feature extraction time and achieve high levels of performance. In our present work, we apply deep learning via two-dimensional convolutional neural networks and position-specific scoring matrices to classify Rab protein molecules, which are main regulators in membrane trafficking for transferring proteins and other macromolecules throughout the cell. The functional loss of specific Rab molecular functions has been implicated in a variety of human diseases, e.g., choroideremia, intellectual disabilities, cancer. Therefore, creating a precise model for classifying Rabs is crucial in helping biologists understand the molecular functions of Rabs and design drug targets according to such specific human disease information. We constructed a robust deep neural network for classifying Rabs that achieved an accuracy of 99%, 99.5%, 96.3%, and 97.6% for each of four specific molecular functions. Our approach demonstrates superior performance to traditional artificial neural networks. Therefore, from our proposed study, we provide both an effective tool for classifying Rab proteins and a basis for further research that can improve the performance of biological modeling using deep neural networks. Copyright © 2018 Elsevier Inc. All rights reserved.

Role of Conserved Oligomeric Golgi Complex in the Abnormalities of Glycoprotein Processing in Breast Cancer Cells

Science.gov (United States)

2006-05-01

of COG complex function we utilized RNA interference assay to knockdown COG3p subunit of COG complex in normal and breast cancer cells and other tumor...protein trafficking, but the role of the COG complex in the abnormal glycosylation and secretion of tumor markers in breast cancer cells remains... COG complex in breast cancer cells MCF7 had been elevated 2-4 times in comparison to HB2 cells (Figure 5 A). The expression of HeLa COG3 CD44 ab

α1B-Adrenergic Receptors Differentially Associate with Rab Proteins during Homologous and Heterologous Desensitization

Science.gov (United States)

Castillo-Badillo, Jean A.; Sánchez-Reyes, Omar B.; Alfonzo-Méndez, Marco A.; Romero-Ávila, M. Teresa; Reyes-Cruz, Guadalupe; García-Sáinz, J. Adolfo

2015-01-01

Internalization of G protein-coupled receptors can be triggered by agonists or by other stimuli. The process begins within seconds of cell activation and contributes to receptor desensitization. The Rab GTPase family controls endocytosis, vesicular trafficking, and endosomal fusion. Among their remarkable properties is the differential distribution of its members on the surface of various organelles. In the endocytic pathway, Rab 5 controls traffic from the plasma membrane to early endosomes, whereas Rab 4 and Rab 11 regulate rapid and slow recycling from early endosomes to the plasma membrane, respectively. Moreover, Rab 7 and Rab 9 regulate the traffic from late endosomes to lysosomes and recycling to the trans-Golgi. We explore the possibility that α1B-adrenergic receptor internalization induced by agonists (homologous) and by unrelated stimuli (heterologous) could involve different Rab proteins. This possibility was explored by Fluorescence Resonance Energy Transfer (FRET) using cells coexpressing α1B-adrenergic receptors tagged with the red fluorescent protein, DsRed, and different Rab proteins tagged with the green fluorescent protein. It was observed that when α1B-adrenergic receptors were stimulated with noradrenaline, the receptors interacted with proteins present in early endosomes, such as the early endosomes antigen 1, Rab 5, Rab 4, and Rab 11 but not with late endosome markers, such as Rab 9 and Rab 7. In contrast, sphingosine 1-phosphate stimulation induced rapid and transient α1B-adrenergic receptor interaction of relatively small magnitude with Rab 5 and a more pronounced and sustained one with Rab 9; interaction was also observed with Rab 7. Moreover, the GTPase activity of the Rab proteins appears to be required because no FRET was observed when dominant-negative Rab mutants were employed. These data indicate that α1B-adrenergic receptors are directed to different endocytic vesicles depending on the desensitization type (homologous vs

Toward improved guideline quality: using the COGS statement with GEM.

Science.gov (United States)

Shiffman, Richard N; Michel, Georges

2004-01-01

The Conference on Guideline Standardization (COGS) was convened to create a standardized documentation checklist for clinical practice guidelines in an effort to promote guideline quality and facilitate implementation. The statement was created by a multidisciplinary panel using a rigorous consensus development methodology. The Guideline Elements Model (GEM) provides a standardized approach to representing guideline documents using XML. In this work, we demonstrate the sufficiency of GEM for describing COGS components. Using the mapping between COGS and GEM elements we built an XSLT application to examine a guideline's adherence (or non-adherence) to the COGS checklist. Once a guideline has been marked up according to the GEM hierarchy, its knowledge content can be reused in multiple ways.

Rab1A is required for assembly of classical swine fever virus particle.

Science.gov (United States)

Lin, Jihui; Wang, Chengbao; Liang, Wulong; Zhang, Jing; Zhang, Longxiang; Lv, Huifang; Dong, Wang; Zhang, Yanming

2018-01-15

Rab1A belongs to the small Rab GTPase family and is involved in the lifecycle of numerous viruses. Here, knockdown of Rab1A inhibited CSFV growth. Further study revealed that Rab1A depletion decreased intracellular and extracellular CSFV titers, but did not affect intracellular virus genome copies and E2 protein expression within a virus lifecycle, which suggested that Rab1A is required for CSFV particle assembly rather than for genome replication or virion release. This was proofed by blocking the spread of virus using neutralizing antibodies, through which the negative effects of Rab1A knockdown on multi-cycle replication of CSFV were eliminated. Moreover, co-immunoprecipitation and confocal microscopy assays showed that Rab1A bound to CSFV NS5A protein, indicating that Rab1A and viral NS5A proteins may work cooperatively during CSFV particle assembly. In conclusion, this study demonstrated for the first time that Rab1A is required for CSFV particle assembly and binds to viral particle assembly-related NS5A protein. Copyright © 2017 Elsevier Inc. All rights reserved.

Rab27a regulates epithelial sodium channel (ENaC) activity through synaptotagmin-like protein (SLP-5) and Munc13-4 effector mechanism

International Nuclear Information System (INIS)

Saxena, Sunil K.; Horiuchi, Hisanori; Fukuda, Mitsunori

2006-01-01

Liddle's syndrome (excessive absorption of sodium ions) and PHA-1 (pseudohypoaldosteronism type 1) with decreased sodium absorption are caused by the mutations in the amiloride-sensitive epithelial sodium channel ENaC. Rab proteins are small GTPases involved in vesicle transport, docking, and fusion. Earlier, we reported that Rab27a inhibits ENaC-mediated currents through protein-protein interaction in HT-29 cells. We hereby report that Rab27a-dependent inhibition is associated with the GTP/GDP status as constitutively active or GTPase-deficient mutant Q78L inhibits amiloride-sensitive currents whereas GDP-locked inactive mutant T23N showed no effect. In order to further explore the molecular mechanism of this regulation, we performed competitive assays with two Rab27a-binding proteins: synaptotagmin-like protein (SLP-5) and Munc13-4 (a putative priming factor for exocytosis). Both proteins eliminate negative modulation of Rab27a on ENaC function. The SLP-5 reversal of Rab27a effect was restricted to C-terminal C2A/C2B domains assigned for putative phospholipids-binding function while the Rab27a-binding SHD motif imparted higher inhibition. The ENaC-mediated currents remain unaffected by Rab27a though SLP-5 appears to strongly bind it. The immunoprecipitation experiments suggest that in the presence of excessive Munc13-4 and SLP-5 proteins, Rab27a interaction with ENaC is diminished. Munc13-4 and SLP-5 limit the Rab27a availability to ENaC, thus minimizing its effect on channel function. These observations decisively prove that Rab27a inhibits ENaC function through a complex mechanism that involves GTP/GDP status, and protein-protein interactions involving Munc13-4 and SLP-5 effector proteins

Two Novel Rab2 Interactors Regulate Dense-core Vesicle Maturation

Science.gov (United States)

Ailion, Michael; Hannemann, Mandy; Dalton, Susan; Pappas, Andrea; Watanabe, Shigeki; Hegermann, Jan; Liu, Qiang; Han, Hsiao-Fen; Gu, Mingyu; Goulding, Morgan Q.; Sasidharan, Nikhil; Schuske, Kim; Hullett, Patrick; Eimer, Stefan; Jorgensen, Erik M.

2014-01-01

Summary Peptide neuromodulators are released from a unique organelle: the dense-core vesicle. Dense-core vesicles are generated at the trans-Golgi, and then sort cargo during maturation before being secreted. To identify proteins that act in this pathway, we performed a genetic screen in Caenorhabditis elegans for mutants defective in dense-core vesicle function. We identified two conserved Rab2-binding proteins: RUND-1, a RUN domain protein, and CCCP-1, a coiled-coil protein. RUND-1 and CCCP-1 colocalize with RAB-2 at the Golgi, and rab-2, rund-1 and cccp-1 mutants have similar defects in sorting soluble and transmembrane dense-core vesicle cargos. RUND-1 also interacts with the Rab2 GAP protein TBC-8 and the BAR domain protein RIC-19, a RAB-2 effector. In summary, a new pathway of conserved proteins controls the maturation of dense-core vesicles at the trans-Golgi network. PMID:24698274

Rab4GTPase modulates CFTR function by impairing channel expression at plasma membrane

International Nuclear Information System (INIS)

Saxena, Sunil K.; Kaur, Simarna; George, Constantine

2006-01-01

Cystic fibrosis (CF), an autosomal recessive disorder, is caused by the disruption of biosynthesis or the function of a membrane cAMP-activated chloride channel, CFTR. CFTR regulatory mechanisms include recruitment of channel proteins to the cell surface from intracellular pools and by protein-protein interactions. Rab proteins are small GTPases involved in regulated trafficking controlling vesicle docking and fusion. Rab4 controls recycling events from endosome to the plasma membrane, fusion, and degradation. The colorectal cell line HT-29 natively expresses CFTR and responds to cAMP stimulation with an increase in CFTR-mediated currents. Rab4 over-expression in HT-29 cells inhibits both basal and cAMP-stimulated CFTR-mediated currents. GTPase-deficient Rab4Q67L and GDP locked Rab4S22N both inhibit channel activity, which appears characteristically different. Active status of Rab4 was confirmed by GTP overlay assay, while its expression was verified by Western blotting. The pull-down and immunoprecipitation experiments suggest that Rab4 physically interacts with CFTR through protein-protein interaction. Biotinylation with cell impermeant NHS-Sulfo-SS-Biotin implies that Rab4 impairs CFTR expression at cell surface. The enhanced cytosolic CFTR indicates that Rab4 expression restrains CFTR appearance at the cell membrane. The study suggests that Rab4 regulates the channel through multiple mechanisms that include protein-protein interaction, GTP/GDP exchange, and channel protein trafficking. We propose that Rab4 is a dynamic molecule with a significant role in CFTR function

rab3 mediates cortical granule exocytosis in the sea urchin egg.

Science.gov (United States)

Conner, S; Wessel, G M

1998-11-15

Egg activation at fertilization in the sea urchin results in the exocytosis of approximately 15,000 cortical granules that are docked at the plasma membrane. Previously, we reported that several integral membrane proteins modeled in the SNARE hypothesis, synaptotagmin, VAMP, and syntaxin, in addition to a small GTPase of the ras superfamily, rab3, were present on cortical granules (Conner, S., Leaf, D., and Wessel, G., Mol. Reprod. Dev. 48, 1-13, 1997). Here we report that rab3 is associated with cortical granules throughout oogenesis, during cortical granule translocation, and while docked at the egg plasma membrane. Following cortical granule exocytosis, however, rab3 reassociates with a different population of vesicles, at least some of which are of endocytic origin. Because of its selective association with cortical granules in eggs and oocytes, we hypothesize that rab3 functions in cortical granule exocytosis. To test this hypothesis, we used a strategy of interfering with rab3 function by peptide competition with its effector domain, a conserved region within specific rab types. We first identified the effector domain sequence in Lytechinus variegatus eggs and find the sequence 94% identical to the effector domain of rab3 in Stronglocentrotus purpuratus. Then, with synthetic peptides to different regions of the rab3 protein, we find that cortical granule exocytosis is inhibited in eggs injected with effector domain peptides, but not with peptides from the hypervariable region or with a scrambled effector peptide. Additionally, effector-peptide-injected eggs injected with IP3 are blocked in their ability to exocytose cortical granules, suggesting that the inhibition is directly on the membrane fusion event and not the result of interference with the signal transduction mechanism leading to calcium release. We interpret these results to mean that rab3 functions in the regulation of cortical granule exocytosis following vesicle docking. Copyright 1998 Academic

Cloning and Expression of A Rab1a Gene from Trichomonas vaginalis%阴道毛滴虫Rab1a基因的cDNA克隆及重组表达

Institute of Scientific and Technical Information of China (English)

徐晓园; 傅玉才; 许铭炎; 史咏梅; 刘红

2006-01-01

目的克隆和分析阴道毛滴虫(Trichomonas vaginalis,Tv)Rab1a基因,构建Rab1a基因表达重组载体并表达其融合蛋白,以进一步探讨其功能.方法提取阴道毛滴虫基因组DNA为模板,扩增TvRab1a基因,用pQE80L载体与TvRab1a cDNA克隆构建原核表达重组体并表达融合蛋白,纯化表达产物并由SDS-PAGE鉴定.结果在阴道毛滴虫cDNA文库克隆中发现了Rab1a基因,序列分析显示Rab1a基因的基因组DNA序列含有一个25 bp大小的内含子.成功构建了pQE/Rab1a原核表达重组体,并表达出预期大小的重组蛋白质.结论分析表明TvRab1a基因是阴道毛滴虫Rab1鸟苷三磷酸酶同源基因,它含有一个25 bp的内含子.获得了该基因的重组蛋白,将对TvRab1a基因的功能进行进一步研究.

[6]-Gingerol, from Zingiber officinale, potentiates GLP-1 mediated glucose-stimulated insulin secretion pathway in pancreatic β-cells and increases RAB8/RAB10-regulated membrane presentation of GLUT4 transporters in skeletal muscle to improve hyperglycemia in Leprdb/db type 2 diabetic mice.

Science.gov (United States)

Samad, Mehdi Bin; Mohsin, Md Nurul Absar Bin; Razu, Bodiul Alam; Hossain, Mohammad Tashnim; Mahzabeen, Sinayat; Unnoor, Naziat; Muna, Ishrat Aklima; Akhter, Farjana; Kabir, Ashraf Ul; Hannan, J M A

2017-08-09

[6]-Gingerol, a major component of Zingiber officinale, was previously reported to ameliorate hyperglycemia in type 2 diabetic mice. Endocrine signaling is involved in insulin secretion and is perturbed in db/db Type-2 diabetic mice. [6]-Gingerol was reported to restore the disrupted endocrine signaling in rodents. In this current study on Lepr db/db diabetic mice, we investigated the involvement of endocrine pathway in the insulin secretagogue activity of [6]-Gingerol and the mechanism(s) through which [6]-Gingerol ameliorates hyperglycemia. Lepr db/db type 2 diabetic mice were orally administered a daily dose of [6]-Gingerol (200 mg/kg) for 28 days. We measured the plasma levels of different endocrine hormones in fasting and fed conditions. GLP-1 levels were modulated using pharmacological approaches, and cAMP/PKA pathway for insulin secretion was assessed by qRT-PCR and ELISA in isolated pancreatic islets. Total skeletal muscle and its membrane fractions were used to measure glycogen synthase 1 level and Glut4 expression and protein levels. 4-weeks treatment of [6]-Gingerol dramatically increased glucose-stimulated insulin secretion and improved glucose tolerance. Plasma GLP-1 was found to be significantly elevated in the treated mice. Pharmacological intervention of GLP-1 levels regulated the effect of [6]-Gingerol on insulin secretion. Mechanistically, [6]-Gingerol treatment upregulated and activated cAMP, PKA, and CREB in the pancreatic islets, which are critical components of GLP-1-mediated insulin secretion pathway. [6]-Gingerol upregulated both Rab27a GTPase and its effector protein Slp4-a expression in isolated islets, which regulates the exocytosis of insulin-containing dense-core granules. [6]-Gingerol treatment improved skeletal glycogen storage by increased glycogen synthase 1 activity. Additionally, GLUT4 transporters were highly abundant in the membrane of the skeletal myocytes, which could be explained by the increased expression of Rab8 and Rab

Protein: FBA6 [TP Atlas

Lifescience Database Archive (English)

Full Text Available FBA6 vesicular transport RAB11FIP3 ARFO1, KIAA0665 RAB11FIP3 Rab11 family-interacting pr...otein 3 Arfophilin-1, EF hands-containing Rab-interacting protein, MU-MB-17.148 9606 Homo sapiens O75154 9727 2HV8 2D7C 9727 21790911 ...

Calculation of Cogging Torque in Hybrid Stepping Motors | Agber ...

African Journals Online (AJOL)

When the windings of a hybrid stepping motor are unexcited the permanent magnet's flux produces cogging torque. This torque has both desirable and undesirable features depending on the application that the motor is put into. This paper formulates an analytical method for predicting cogging torque using measured ...

FOXC1 modulates MYOC secretion through regulation of the exocytic proteins RAB3GAP1, RAB3GAP2 and SNAP25.

Directory of Open Access Journals (Sweden)

Alexandra Rasnitsyn

Full Text Available The neurodegenerative disease glaucoma is one of the leading causes of blindness in the world. Glaucoma is characterized by progressive visual field loss caused by retinal ganglion cell (RGC death. Both surgical glaucoma treatments and medications are available, however, they only halt glaucoma progression and are unable to reverse damage. Furthermore, many patients do not respond well to treatments. It is therefore important to better understand the mechanisms involved in glaucoma pathogenesis. Patients with Axenfeld-Rieger syndrome (ARS offer important insight into glaucoma progression. ARS patients are at 50% risk of developing early onset glaucoma and respond poorly to treatments, even when surgical treatments are combined with medications. Mutations in the transcription factor FOXC1 cause ARS. Alterations in FOXC1 levels cause ocular malformations and disrupt stress response in ocular tissues, thereby contributing to glaucoma progression. In this study, using biochemical and molecular techniques, we show that FOXC1 regulates the expression of RAB3GAP1, RAB3GAP2 and SNAP25, three genes with central roles in both exocytosis and endocytosis, responsible for extracellular trafficking. FOXC1 positively regulates RAB3GAP1 and RAB3GAP2, while either increase or decrease in FOXC1 levels beyond its normal range results in decreased SNAP25. In addition, we found that FOXC1 regulation of RAB3GAP1, RAB3GAP2 and SNAP25 affects secretion of Myocilin (MYOC, a protein associated with juvenile onset glaucoma and steroid-induced glaucoma. The present work reveals that FOXC1 is an important regulator of exocytosis and establishes a new link between FOXC1 and MYOC-associated glaucoma.

Rab from the white shrimp Litopenaeus vannamei: characterization and its regulation upon environmental stress.

Science.gov (United States)

Wang, Lei; Wang, Xiao-Rong; Liu, Jin; Chen, Chu-Xian; Liu, Yuan; Wang, Wei-Na

2015-10-01

With the destruction of the ecological environment, shrimp cultivation in China has been seriously affected by outbreaks of infectious diseases. Rab, which belong to small GTPase Ras superfamily, can regulate multiple steps in eukaryotic vesicle trafficking including vesicle budding, vesicle tethering, and membrane fusion. Knowledge of Rab in shrimp is essential to understanding regulation and detoxification mechanisms of environmental stress. In this study, we analyzed the functions of Rab from the Pacific white shrimp, Litopenaeus vannamei. Full-length cDNA of Rab was obtained, which was 751 bp long, with open reading frame encoding 206 amino acids. In this study, for the first time, the gene expression of Rab of L. vannamei was analyzed by quantitative real-time PCR after exposure to five kinds of environmental stresses (bacteria, pH, Cd, salinity and low temperature). The results demonstrate that Rab is sensitive and involved in bacteria, pH, and Cd stress responses and Rab is more sensitive to bacteria than other stresses. Therefore we infer that Rab may have relationship with the anti-stress mechanism induced by environment stress in shrimp and Rab could be used as critical biomarkers for environmental quality assessment.

Cogging Force Issues of Permanent Magnet Linear Generator for Electric Vehicle

Directory of Open Access Journals (Sweden)

Izzeldin Idris Abdalla

2017-09-01

Full Text Available Alternatives to hydraulic drives that used on vehicles are necessary in order to reduce the Carbon dioxide (CO2 emission and oil consumption. Hence better performance and efficiency of the vehicles can be achieved by using free piston engine, in which the piston reciprocate linearly with a permanent magnet linear generator (PMLG without the need of a crankshaft. The PMLG has high performance, but suffering from the cogging force. The cogging force induces undesired vibration and acoustic noise and makes a ripple in the thrust force. Moreover, the cogging force deteriorates the control characteristics, particularly in terms of the position control and speed precisely. This paper proposes Somaloy to replace the laminated silicon steel sheets in order to reduce the cogging force in a PMLG. Through a finite-element analysis, it has been shown that, the stator core made of Somaloy minimizes the cogging force of the PMLG, moreover, giving larger flux-linkage and back-electromotive force (B-EMF, respectively.

The Alzheimer's Disease Assessment Scale-Cognitive-Plus (ADAS-Cog-Plus): an expansion of the ADAS-Cog to improve responsiveness in MCI.

Science.gov (United States)

Skinner, Jeannine; Carvalho, Janessa O; Potter, Guy G; Thames, April; Zelinski, Elizabeth; Crane, Paul K; Gibbons, Laura E

2012-12-01

The Alzheimer's Disease Assessment Scale cognitive subscale (ADAS-Cog) is widely used in AD, but may be less responsive to change when used in people with mild cognitive impairment (MCI). Participants from the Alzheimer's Disease Neuroimaging Initiative were administered a neuropsychological battery and 1.5 T MRI scans over 2-3 years. Informants were queried regarding functional impairments. Some participants had lumbar punctures to obtain cerebrospinal fluid (CSF). We added executive functioning (EF) and functional ability (FA) items to the ADAS-Cog to generate candidate augmented measures. We calibrated these candidates using baseline data (n = 811) and selected the best candidate that added EF items alone and that added EF and FA items. We selected candidates based on their responsiveness over three years in a training sample of participants with MCI (n = 160). We compared traditional ADAS-Cog scores with the two candidates based on their responsiveness in a validation sample of participants with MCI (n = 234), ability to predict conversion to dementia (n = 394), strength of association with baseline MRI (n = 394) and CSF biomarkers (n = 193). The selected EF candidate added category fluency (ADAS Plus EF), and the selected EF and FA candidate added category fluency, Digit Symbol, Trail Making, and five items from the Functional Assessment Questionnaire (ADAS Plus EF&FA). The ADAS Plus EF& FA performed as well as or better than traditional ADAS-Cog scores. Adding EF and FA items to the ADAS-Cog may improve responsiveness among people with MCI without impairing validity.

GTP- and GDP-Dependent Rab27a Effectors in Pancreatic Beta-Cells.

Science.gov (United States)

Yamaoka, Mami; Ishizaki, Toshimasa; Kimura, Toshihide

2015-01-01

Small guanosine triphosphatases (GTPases) participate in a wide variety of cellular functions including proliferation, differentiation, adhesion, and intracellular transport. Conventionally, only the guanosine 5'-triphosphate (GTP)-bound small GTPase interacts with effector proteins, and the resulting downstream signals control specific cellular functions. Therefore, the GTP-bound form is regarded as active, and the focus has been on searching for proteins that bind the GTP form to look for their effectors. The Rab family small GTPase Rab27a is highly expressed in some secretory cells and is involved in the control of membrane traffic. The present study reviews recent progress in our understanding of the roles of Rab27a and its effectors in pancreatic beta-cells. In the basal state, GTP-bound Rab27a controls insulin secretion at pre-exocytic stages via its GTP-dependent effectors. We previously identified novel guanosine 5'-diphosphate (GDP)-bound Rab27-interacting proteins. Interestingly, GDP-bound Rab27a controls endocytosis of the secretory membrane via its interaction with these proteins. We also demonstrated that the insulin secretagogue glucose converts Rab27a from its GTP- to GDP-bound forms. Thus, GTP- and GDP-bound Rab27a regulate pre-exocytic and endocytic stages in membrane traffic, respectively. Since the physiological importance of GDP-bound GTPases has been largely overlooked, we consider that the investigation of GDP-dependent effectors for other GTPases is necessary for further understanding of cellular function.

The DiaCog: A Prototype Tool for Visualizing Online Dialog Games' Interactions

Science.gov (United States)

Yengin, Ilker; Lazarevic, Bojan

2014-01-01

This paper proposes and explains the design of a prototype learning tool named the DiaCog. The DiaCog visualizes dialog interactions within an online dialog game by using dynamically created cognitive maps. As a purposefully designed tool for enhancing learning effectiveness the DiaCog might be applicable to dialogs at discussion boards within a…

ANALIZA OGLAŠEVALSKE KAMPANJE THE COG

OpenAIRE

Hojnik, Samo

2016-01-01

Diplomsko delo »Analiza oglaševalske kampanje The Cog« preko teoretičnih marketinških modelov in načrta oglaševalske kampanje analizira oglaševalsko kampanjo »The Cog«, naročnika Honda, ki je bila izbrana za najboljšo v avtomobilski industriji za britansko tržišče. Osredotoča se na pomen ustvarjalnosti v oglaševanju in njenem vplivu na uspeh in učinkovitost oglaševalske kampanje. Analiza kampanje pokaže, da je obravnavana kampanja zajela v teoretičnem delu predvidene elemente uspešne oglaševa...

RABL6A, a Novel RAB-Like Protein, Controls Centrosome Amplification and Chromosome Instability in Primary Fibroblasts

Science.gov (United States)

Zhang, Xuefeng; Hagen, Jussara; Muniz, Viviane P.; Smith, Tarik; Coombs, Gary S.; Eischen, Christine M.; Mackie, Duncan I.; Roman, David L.; Van Rheeden, Richard; Darbro, Benjamin; Tompkins, Van S.; Quelle, Dawn E.

2013-01-01

RABL6A (RAB-like 6 isoform A) is a novel protein that was originally identified based on its association with the Alternative Reading Frame (ARF) tumor suppressor. ARF acts through multiple p53-dependent and p53-independent pathways to prevent cancer. How RABL6A functions, to what extent it depends on ARF and p53 activity, and its importance in normal cell biology are entirely unknown. We examined the biological consequences of RABL6A silencing in primary mouse embryo fibroblasts (MEFs) that express or lack ARF, p53 or both proteins. We found that RABL6A depletion caused centrosome amplification, aneuploidy and multinucleation in MEFs regardless of ARF and p53 status. The centrosome amplification in RABL6A depleted p53−/− MEFs resulted from centrosome reduplication via Cdk2-mediated hyperphosphorylation of nucleophosmin (NPM) at threonine-199. Thus, RABL6A prevents centrosome amplification through an ARF/p53-independent mechanism that restricts NPM-T199 phosphorylation. These findings demonstrate an essential role for RABL6A in centrosome regulation and maintenance of chromosome stability in non-transformed cells, key processes that ensure genomic integrity and prevent tumorigenesis. PMID:24282525

RINL, guanine nucleotide exchange factor Rab5-subfamily, is involved in the EphA8-degradation pathway with odin.

Directory of Open Access Journals (Sweden)

Hiroaki Kajiho

Full Text Available The Rab family of small guanosine triphosphatases (GTPases plays a vital role in membrane trafficking. Its active GTP-bound state is driven by guanine nucleotide-exchange factors (GEFs. Ras and Rab interactor (or Ras interaction/interference-like (RINL, which contains a conserved VPS9 domain critical for GEF action, was recently identified as a new Rab5 subfamily GEF in vitro. However, its detailed function and interacting molecules have not yet been fully elucidated. Here we found that RINL has GEF activity for the Rab5 subfamily proteins by measuring their GTP-bound forms in cultured cells. We also found that RINL interacts with odin, a member of the ankyrin-repeat and sterile-alpha motif (SAM domain-containing (Anks protein family. In addition, the Eph tyrosine kinase receptor EphA8 formed a ternary complex with both RINL and odin. Interestingly, RINL expression in cultured cells reduced EphA8 levels in a manner dependent on both its GEF activity and interaction with odin. In addition, knockdown of RINL increased EphA8 level in HeLa cells. Our findings suggest that RINL, as a GEF for Rab5 subfamily, is implicated in the EphA8-degradation pathway via its interaction with odin.

Expanded microbial genome coverage and improved protein family annotation in the COG database.

Science.gov (United States)

Galperin, Michael Y; Makarova, Kira S; Wolf, Yuri I; Koonin, Eugene V

2015-01-01

Microbial genome sequencing projects produce numerous sequences of deduced proteins, only a small fraction of which have been or will ever be studied experimentally. This leaves sequence analysis as the only feasible way to annotate these proteins and assign to them tentative functions. The Clusters of Orthologous Groups of proteins (COGs) database (http://www.ncbi.nlm.nih.gov/COG/), first created in 1997, has been a popular tool for functional annotation. Its success was largely based on (i) its reliance on complete microbial genomes, which allowed reliable assignment of orthologs and paralogs for most genes; (ii) orthology-based approach, which used the function(s) of the characterized member(s) of the protein family (COG) to assign function(s) to the entire set of carefully identified orthologs and describe the range of potential functions when there were more than one; and (iii) careful manual curation of the annotation of the COGs, aimed at detailed prediction of the biological function(s) for each COG while avoiding annotation errors and overprediction. Here we present an update of the COGs, the first since 2003, and a comprehensive revision of the COG annotations and expansion of the genome coverage to include representative complete genomes from all bacterial and archaeal lineages down to the genus level. This re-analysis of the COGs shows that the original COG assignments had an error rate below 0.5% and allows an assessment of the progress in functional genomics in the past 12 years. During this time, functions of many previously uncharacterized COGs have been elucidated and tentative functional assignments of many COGs have been validated, either by targeted experiments or through the use of high-throughput methods. A particularly important development is the assignment of functions to several widespread, conserved proteins many of which turned out to participate in translation, in particular rRNA maturation and tRNA modification. The new version of the

Rab5 regulates internalisation of P2X4 receptors and potentiation by ivermectin.

Science.gov (United States)

Stokes, Leanne

2013-03-01

The P2X4 receptor is an ATP-gated ion channel expressed in neurons, endothelia and immune cells. Plasma membrane expression of P2X4 is regulated by dynamin-dependent endocytosis, and this study identifies a Rab5-dependent pathway of receptor internalisation. Expression of Rab5 constructs altered the distribution of P2X4 in HEK-293 cells, and both constitutive internalisation and agonist-induced desensitisation of P2X4 were increased by co-expression of wild-type Rab5 or constitutively active Rab5 (Q79L). Expression of inactive dynamin K44A and Rab5 S34N constructs abolished agonist-induced desensitisation, suggesting internalisation as the underlying mechanism. Blocking P2X4 internalisation in this way also abolished potentiation of ATP-induced currents by the allosteric modulator ivermectin. This suggests that the dynamin-Rab5 internalisation pathway is essential for the ivermectin potentiation effect. In agreement with this hypothesis, the co-expression of wild-type dynamin, wild-type Rab5 or active Rab5 (Q79L) could increase the potentiation of the ATP-induced P2X4 response by ivermectin. These findings highlight Rab5 GTPase as a key regulator of P2X4 receptor cell surface expression and internalisation.

PDGF-regulated rab4-dependent recycling of alphavbeta3 integrin from early endosomes is necessary for cell adhesion and spreading.

Science.gov (United States)

Roberts, M; Barry, S; Woods, A; van der Sluijs, P; Norman, J

2001-09-18

It has been postulated that the regulation of integrin vesicular traffic facilitates cell migration by internalizing integrins at the rear of the cell and transporting them forward within vesicles for exocytosis at the leading edge to form new contacts with the extracellular matrix. The rab family of GTPases control key targeting events in the endo/exocytic pathway; therefore, these GTPases may be involved in the regulation of cell-matrix contact assembly. The endo/exocytic cycle of alphavbeta3 and alpha5beta1 integrins was studied using mouse 3T3 fibroblast cell lines. In serum-starved cells, internalized integrins were transported through rab4-positive, early endosomes and arrived at the rab11-positive, perinuclear recycling compartment approximately 30 min after endocytosis. From the recycling compartment, integrins were recycled to the plasma membrane in a rab11-dependent fashion. Following treatment with PDGF, alphavbeta3 integrin, but not alpha5beta1, was rapidly recycled directly back to the plasma membrane from the early endosomes via a rab4-dependent mechanism without the involvement of rab11. This rapid recycling pathway directed alphavbeta3 to numerous small puncta distributed evenly across the dorsal surface of the cell, and the integrin only became localized into focal complexes at later times following PDGF addition. Interestingly, inhibition of PDGF-stimulated alphavbeta3 recycling using dominant-negative rab4 mutants compromised cell adhesion and spreading on vitronectin (a ligand for alphavbeta3), but adhesion to fibronectin (a ligand for alpha5beta1 and alphavbeta3) was unchanged. We propose that growth factor-regulated, rab4-dependent recycling of alphavbeta3 integrin from early endosomes to the plasma membrane is a critical upstream event in the assembly of cell-matrix contacts.

A role for Na+,K+-ATPase α1 in regulating Rab27a localisation on melanosomes.

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Antonia E G Booth

Full Text Available The mechanism(s by which Rab GTPases are specifically recruited to distinct intracellular membranes remains elusive. Here we used Rab27a localisation onto melanosomes as a model to investigate Rab targeting. We identified the α1 subunit of Na+,K+-ATPase (ATP1a1 as a novel Rab27a interacting protein in melanocytes and showed that this interaction is direct with the intracellular M4M5 loop of ATP1a1 and independent of nucleotide bound status of the Rab. Knockdown studies in melanocytes revealed that ATP1a1 plays an essential role in Rab27a-dependent melanosome transport. Specifically, expression of ATP1a1, like the Rab27a GDP/GTP exchange factor (Rab3GEP, is essential for targeting and activation of Rab27a to melanosomes. Finally, we showed that the ability of Rab27a mutants to target to melanosomes correlates with the efficiency of their interaction with ATP1a1. Altogether these studies point to a new role for ATP1a1 as a regulator of Rab27a targeting and activation.

The Role of Rab Proteins in Neuronal Cells and in the Trafficking of Neurotrophin Receptors

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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.

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

Sheep internal parasites on Rab and Pag

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Relja Beck

2010-01-01

Full Text Available The purpose of our research was to determine which groups and species of internal parasites endanger the health of sheep on the islands of Rab and Pag. The research was carried out in 10 flocks on both islands taking the fresh dung out of 30% of the total number of sheep in each flock. It was ascertained that the gastrointestinal parasites and protozoa of Eimeria genus are present in most flocks on both islands. The presence of the fluke Dicrocoelium dendriticum was ascertained in considerably larger number of flocks on the island of Rab than on the island of Pag. On the other hand, the presence of parasites of Moniezia and Nematodirus genus was ascertained in larger number of flocks on the island of Pag. In two flocks on Rab parasites of Protostrongylus genus were ascertained while on the island of Pag they were not found in any flock.

Molecular characterization and expression of Rab7 from Clonorchis sinensis and its potential role in autophagy.

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Jia, Feifei; Li, Ye; Huang, Yan; Chen, Tingjin; Li, Shan; Xu, Yanquan; Wu, Zhongdao; Li, Xuerong; Yu, Xinbing

2013-07-01

Accumulating evidences suggest that Rab7 GTPase is important for the normal progression of autophagy. However, the role of Rab7 GTPase in regulation of autophagy in Clonorchis sinensis is not known. In this study, a gene encoding Rab7 was isolated from C. sinensis adult cDNA. Recombinant CsRab7 was expressed and purified from Escherichia coli. CsRab7 transcripts were detected in the cDNA of adult worm, metacercaria, cercaria, and egg of C. sinensis, and were highly expressed in the metacercaria. Immunohistochemical localization results revealed that CsRab7 was specifically deposited on the vitellarium and eggs of adult worm. Furthermore, EGFP signal of CsRab7WT and the active mutant CsRab7Q67L were associated with autophagic vesicles in transiently transfected 293T cells. It is concluded from the present study that CsRab7 GTPase possibly contributes to the development of C. sinensis and that the autophagy pathway could be an important site of action with respect to the developmental role of CsRab7 in C. sinensis.

The GTPase Rab43 Controls the Anterograde ER-Golgi Trafficking and Sorting of GPCRs

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Chunman Li

2017-10-01

Full Text Available G-protein-coupled receptors (GPCRs constitute the largest superfamily of cell-surface signaling proteins. However, mechanisms underlying their surface targeting and sorting are poorly understood. Here, we screen the Rab family of small GTPases in the surface transport of multiple GPCRs. We find that manipulation of Rab43 function significantly alters the surface presentation and signaling of all GPCRs studied without affecting non-GPCR membrane proteins. Rab43 specifically regulates the transport of nascent GPCRs from the endoplasmic reticulum (ER to the Golgi. More interestingly, Rab43 directly interacts with GPCRs in an activation-dependent fashion. The Rab43-binding domain identified in the receptors effectively converts non-GPCR membrane protein transport into a Rab43-dependent pathway. These data reveal a crucial role for Rab43 in anterograde ER-Golgi transport of nascent GPCRs, as well as the ER sorting of GPCR members by virtue of its ability to interact directly.

Two Rab5 Homologs Are Essential for the Development and Pathogenicity of the Rice Blast Fungus Magnaporthe oryzae

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Cheng D. Yang

2017-05-01

Full Text Available The rice blast fungus, Magnaporthe oryzae, infects many economically important cereal crops, particularly rice. It has emerged as an important model organism for studying the growth, development, and pathogenesis of filamentous fungi. RabGTPases are important molecular switches in regulation of intracellular membrane trafficking in all eukaryotes. MoRab5A and MoRab5B are Rab5 homologs in M. oryzae, but their functions in the fungal development and pathogenicity are unknown. In this study, we have employed a genetic approach and demonstrated that both MoRab5A and MoRab5B are crucial for vegetative growth and development, conidiogenesis, melanin synthesis, vacuole fusion, endocytosis, sexual reproduction, and plant pathogenesis in M. oryzae. Moreover, both MoRab5A and MoRab5B show similar localization in hyphae and conidia. To further investigate possible functional redundancy between MoRab5A and MoRab5B, we overexpressed MoRAB5A and MoRAB5B, respectively, in MoRab5B:RNAi and MoRab5A:RNAi strains, but neither could rescue each other’s defects caused by the RNAi. Taken together, we conclude that both MoRab5A and MoRab5B are necessary for the development and pathogenesis of the rice blast fungus, while they may function independently.

Disruption of endocytic trafficking protein Rab7 impairs invasiveness of cholangiocarcinoma cells.

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Suwandittakul, Nantana; Reamtong, Onrapak; Molee, Pattamaporn; Maneewatchararangsri, Santi; Sutherat, Maleerat; Chaisri, Urai; Wongkham, Sopit; Adisakwattana, Poom

2017-09-07

Alterations and mutations of endo-lysosomal trafficking proteins have been associated with cancer progression. Identification and characterization of endo-lysosomal trafficking proteins in invasive cholangiocarcinoma (CCA) cells may benefit prognosis and drug design for CCA. To identify and characterize endo-lysosomal trafficking proteins in invasive CCA. A lysosomal-enriched fraction was isolated from a TNF-α induced invasive CCA cell line (KKU-100) and uninduced control cells and protein identification was performed with nano-LC MS/MS. Novel lysosomal proteins that were upregulated in invasive CCA cells were validated by real-time RT-PCR. We selected Rab7 for further studies of protein level using western blotting and subcellular localization using immunofluorescence. The role of Rab7 in CCA invasion was determined by siRNA gene knockdown and matrigel transwell assay. Rab7 mRNA and protein were upregulated in invasive CCA cells compared with non-treated controls. Immunofluorescence studies demonstrated that Rab7 was expressed predominantly in invasive CCA cells and was localized in the cytoplasm and lysosomes. Suppression of Rab7 translation significantly inhibited TNF-α-induced cell invasion compared to non-treated control (p= 0.044). Overexpression of Rab7 in CCA cells was associated with cell invasion, supporting Rab7 as a novel candidate for the development of diagnostic and therapeutic strategies for CCA.

[Validation of the Hungarian version of Alzheimer's Disease Assessment Scale-Cognitive Subscale (ADAS-Cog) in patients with mild cognitive impairment].

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Papp, Edina; Pákáski, Magdolna; Drótos, Gergely; Kálmán, János

2012-01-01

Early recognition of mild cognitive impairment (MCI) has increasing clinical relevance in the treatment process of dementia, since it is considered as prodromal period. A great variety of instruments have been developed for measuring cognitive performance of the demented patients. The cognitive subscale of the Alzheimer's Disease Assessment Scale (ADAS-Cog) is one of the most frequently applied instrument to determine the severity of dementia and the efficiency of pharmacotherapy. The aim of this study is to examine the sensitivity parameters of the Hungarian ADAS-Cog in differentiating healthy elderly from MCI patients, furthermore to compare the sociodemographic data of the two groups. Fourty-five patients with MCI and 47 healthy subjects (HS) participated in the study. Their age variated between 52 and 88 years, the mean age was 68.8 (standard deviation=8.6). The mean of the years of education was 11.8 (standard deviation=3.5). Mental state was determined by ADAS-Cog and Mini-Mental State Examination (MMSE) and Beck Depression Inventory (BDI) was used to exclude depression. Data analysis was performed with SPSS 17. There were no significant differences between the two groups considering the sociodemographic data. The total score of ADAS-Cog is the most sensitive index (AUC: 0.875, sensitivity: 95.6%) for determining MCI, although the ratio of false positive cases was very high (specificity: 70.2%). The cut-off scores of the ADAS-Cog in the Hungarian sample were higher than the findings in previous researches. Positive correlation between age and ADAS-Cog total score was only significant in the HS group. On the other hand, negative correlation was found between education and ADAS-Cog total score in the MCI group. These results indicate that the currently used Hungarian ADAS-Cog is able to distinguish between MCI patients and HS groups. However, the adaptation of the Hungarian version will be necessary during the further standardization process including the

Psychometric evaluation of ADAS-Cog and NTB for measuring drug response.

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Karin, A; Hannesdottir, K; Jaeger, J; Annas, P; Segerdahl, M; Karlsson, P; Sjögren, N; von Rosen, T; Miller, F

2014-02-01

To conduct a psychometric analysis to determine the adequacy of instruments that measure cognition in Alzheimer's disease trials. Both the Alzheimer's Disease Assessment Scale - Cognition (ADAS-Cog) and the Neuropsychological Test Battery (NTB) are validated outcome measures for clinical trials in Alzheimer's disease and are approved also for regulatory purposes. However, it is not clear how comparable they are in measuring cognitive function. In fact, many recent trials in Alzheimer's disease patients have failed and it has been questioned if ADAS-Cog still is a sensitive measure. The present paper examines the psychometric properties of ADAS-Cog and NTB, based on a post hoc analysis of data from a clinical trial (NCT01024660), which was conducted by AstraZeneca, in mild-to-moderate Alzheimer's disease (AD) patients, with a Mini Mental State Examination (MMSE) Total score 16-24. Acceptability, reliability, different types of validity and ability to detect change were assessed using relevant statistical methods. Total scores of both tests, as well as separate domains of both tests, including the Wechsler Memory Scale (WMS), Rey Auditory Verbal Learning Test (RAVLT) and Delis-Kaplan Executive Function System (D-KEFS) Verbal Fluency Condition, were analyzed. Overall, NTB performed well, with acceptable reliability and ability to detect change, while ADAS-Cog had insufficient psychometric properties, including ceiling effects in 8 out of a total of 11 ADAS-Cog items in mild AD patients, as well as low test-retest reliability in some of the items. Based on a direct comparison on the same patient sample, we see advantages of the NTB compared with the ADAS-Cog for the evaluation of cognitive function in the population of mild-to-moderate AD patients. The results suggest that not all of ADAS-Cog items are relevant for both mild and moderate AD population. This validation study demonstrates satisfactory psychometric properties of the NTB, while ADAS-Cog was found to be

Structural basis for Rab1 de-AMPylation by the Legionella pneumophila effector SidD.

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Yang Chen

Full Text Available The covalent attachment of adenosine monophosphate (AMP to proteins, a process called AMPylation (adenylylation, has recently emerged as a novel theme in microbial pathogenesis. Although several AMPylating enzymes have been characterized, the only known virulence protein with de-AMPylation activity is SidD from the human pathogen Legionella pneumophila. SidD de-AMPylates mammalian Rab1, a small GTPase involved in secretory vesicle transport, thereby targeting the host protein for inactivation. The molecular mechanisms underlying Rab1 recognition and de-AMPylation by SidD are unclear. Here, we report the crystal structure of the catalytic region of SidD at 1.6 Å resolution. The structure reveals a phosphatase-like fold with additional structural elements not present in generic PP2C-type phosphatases. The catalytic pocket contains a binuclear metal-binding site characteristic of hydrolytic metalloenzymes, with strong dependency on magnesium ions. Subsequent docking and molecular dynamics simulations between SidD and Rab1 revealed the interface contacts and the energetic contribution of key residues to the interaction. In conjunction with an extensive structure-based mutational analysis, we provide in vivo and in vitro evidence for a remarkable adaptation of SidD to its host cell target Rab1 which explains how this effector confers specificity to the reaction it catalyses.

Rab3A, a possible marker of cortical granules, participates in cortical granule exocytosis in mouse eggs

Energy Technology Data Exchange (ETDEWEB)

Bello, Oscar Daniel; Cappa, Andrea Isabel; Paola, Matilde de; Zanetti, María Natalia [Instituto de Histología y Embriología, CONICET – Universidad Nacional de Cuyo, Av. Libertador 80, 5500 Mendoza (Argentina); Fukuda, Mitsunori [Department of Developmental Biology and Neurosciences, Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-8578 (Japan); Fissore, Rafael A. [Department of Veterinary and Animal Sciences, University of Massachusetts Amherst, 661 North Pleasant Street, Amherst, MA 01003 (United States); Mayorga, Luis S. [Instituto de Histología y Embriología, CONICET – Universidad Nacional de Cuyo, Av. Libertador 80, 5500 Mendoza (Argentina); Michaut, Marcela A., E-mail: mmichaut@gmail.com [Instituto de Histología y Embriología, CONICET – Universidad Nacional de Cuyo, Av. Libertador 80, 5500 Mendoza (Argentina); Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Cuyo (Argentina)

2016-09-10

Fusion of cortical granules with the oocyte plasma membrane is the most significant event to prevent polyspermy. This particular exocytosis, also known as cortical reaction, is regulated by calcium and its molecular mechanism is still not known. Rab3A, a member of the small GTP-binding protein superfamily, has been implicated in calcium-dependent exocytosis and is not yet clear whether Rab3A participates in cortical granules exocytosis. Here, we examine the involvement of Rab3A in the physiology of cortical granules, particularly, in their distribution during oocyte maturation and activation, and their participation in membrane fusion during cortical granule exocytosis. Immunofluorescence and Western blot analysis showed that Rab3A and cortical granules have a similar migration pattern during oocyte maturation, and that Rab3A is no longer detected after cortical granule exocytosis. These results suggested that Rab3A might be a marker of cortical granules. Overexpression of EGFP-Rab3A colocalized with cortical granules with a Pearson correlation coefficient of +0.967, indicating that Rab3A and cortical granules have almost a perfect colocalization in the egg cortical region. Using a functional assay, we demonstrated that microinjection of recombinant, prenylated and active GST-Rab3A triggered cortical granule exocytosis, indicating that Rab3A has an active role in this secretory pathway. To confirm this active role, we inhibited the function of endogenous Rab3A by microinjecting a polyclonal antibody raised against Rab3A prior to parthenogenetic activation. Our results showed that Rab3A antibody microinjection abolished cortical granule exocytosis in parthenogenetically activated oocytes. Altogether, our findings confirm that Rab3A might function as a marker of cortical granules and participates in cortical granule exocytosis in mouse eggs. - Highlights: • Rab3A has a similar migration pattern to cortical granules in mouse oocytes. • Rab3A can be a marker of

Turning of COGS moves forward findings for hormonally mediated cancers.

Science.gov (United States)

Sakoda, Lori C; Jorgenson, Eric; Witte, John S

2013-04-01

The large-scale Collaborative Oncological Gene-environment Study (COGS) presents new findings that further characterize the genetic bases of breast, ovarian and prostate cancers. We summarize and provide insights into this collection of papers from COGS and discuss the implications of the results and future directions for such efforts.

Cellular vacuoles induced by Mycoplasma pneumoniae CARDS toxin originate from Rab9-associated compartments.

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Coreen Johnson

Full Text Available Recently, we identified an ADP-ribosylating and vacuolating cytotoxin in Mycoplasma pneumoniae designated Community Acquired Respiratory Distress Syndrome (CARDS toxin. In this study we show that vacuoles induced by recombinant CARDS (rCARDS toxin are acidic and derive from the endocytic pathway as determined by the uptake of neutral red and the fluid-phase marker, Lucifer yellow, respectively. Also, we demonstrate that the formation of rCARDS toxin-associated cytoplasmic vacuoles is inhibited by the vacuolar ATPase inhibitor, bafilomycin A1, and the ionophore, monensin. To examine the ontogeny of these vacuoles, we analyzed the distribution of endosomal and lysosomal membrane markers during vacuole formation and observed the enrichment of the late endosomal GTPase, Rab9, around rCARDS toxin-induced vacuoles. Immunogold-labeled Rab9 and overexpression of green fluorescent-tagged Rab9 further confirmed vacuolar association. The late endosomal- and lysosomal-associated membrane proteins, LAMP1 and LAMP2, also localized to the vacuolar membranes, while the late endosomal protein, Rab7, and early endosomal markers, Rab5 and EEA1, were excluded. HeLa cells expressing dominant-negative (DN Rab9 exhibited markedly reduced vacuole formation in the presence of rCARDS toxin, in contrast to cells expressing DN-Rab7, highlighting the importance of Rab9 function in rCARDS toxin-induced vacuolation. Our findings reveal the unique Rab9-association with rCARDS toxin-induced vacuoles and its possible relationship to the characteristic histopathology that accompanies M. pneumoniae infection.

A Bacterial Pathogen Targets a Host Rab-Family GTPase Defense Pathway with a GAP.

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Spanò, Stefania; Gao, Xiang; Hannemann, Sebastian; Lara-Tejero, María; Galán, Jorge E

2016-02-10

Cell-autonomous defense mechanisms are potent strategies that protect individual cells against intracellular pathogens. The Rab-family GTPase Rab32 was previously shown to restrict the intracellular human pathogen Salmonella Typhi, but its potential broader role in antimicrobial defense remains unknown. We show that Rab32 represents a general cell-autonomous, antimicrobial defense that is counteracted by two Salmonella effectors. Mice lacking Rab-32 or its nucleotide exchange factor BLOC-3 are permissive to S. Typhi infection and exhibit increased susceptibility to S. Typhimurium. S. Typhimurium counters this defense pathway by delivering two type III secretion effectors, SopD2, a Rab32 GAP, and GtgE, a specific Rab32 protease. An S. Typhimurium mutant strain lacking these two effectors exhibits markedly reduced virulence, which is fully restored in BLOC-3-deficient mice. These results demonstrate that a cell-autonomous, Rab32-dependent host defense pathway plays a central role in the defense against vacuolar pathogens and describe a mechanism evolved by a bacterial pathogen to counter it. Copyright © 2016 Elsevier Inc. All rights reserved.

The CogBIAS longitudinal study protocol: cognitive and genetic factors influencing psychological functioning in adolescence.

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Booth, Charlotte; Songco, Annabel; Parsons, Sam; Heathcote, Lauren; Vincent, John; Keers, Robert; Fox, Elaine

2017-12-29

Optimal psychological development is dependent upon a complex interplay between individual and situational factors. Investigating the development of these factors in adolescence will help to improve understanding of emotional vulnerability and resilience. The CogBIAS longitudinal study (CogBIAS-L-S) aims to combine cognitive and genetic approaches to investigate risk and protective factors associated with the development of mood and impulsivity-related outcomes in an adolescent sample. CogBIAS-L-S is a three-wave longitudinal study of typically developing adolescents conducted over 4 years, with data collection at age 12, 14 and 16. At each wave participants will undergo multiple assessments including a range of selective cognitive processing tasks (e.g. attention bias, interpretation bias, memory bias) and psychological self-report measures (e.g. anxiety, depression, resilience). Saliva samples will also be collected at the baseline assessment for genetic analyses. Multilevel statistical analyses will be performed to investigate the developmental trajectory of cognitive biases on psychological functioning, as well as the influence of genetic moderation on these relationships. CogBIAS-L-S represents the first longitudinal study to assess multiple cognitive biases across adolescent development and the largest study of its kind to collect genetic data. It therefore provides a unique opportunity to understand how genes and the environment influence the development and maintenance of cognitive biases and provide insight into risk and protective factors that may be key targets for intervention.

A COG Concept for Winning More Than Just Battles

DEFF Research Database (Denmark)

Barfoed, Jacob

2018-01-01

This article presents a solution to a revised Center of Gravity (COG) concept, that can focus both on the strategic and the operational level and not least the connection between the two levels.......This article presents a solution to a revised Center of Gravity (COG) concept, that can focus both on the strategic and the operational level and not least the connection between the two levels....

Rab5 induces Rac-independent lamellipodia formation and cell migration

NARCIS (Netherlands)

Spaargaren, M.; Bos, J. L.

1999-01-01

Rab5 is a regulatory GTPase of vesicle docking and fusion that is involved in receptor-mediated endocytosis and pinocytosis. Introduction of active Rab5 in cells stimulates the rate of endocytosis and vesicle fusion, resulting in the formation of large endocytic vesicles, whereas dominant negative

A Novel Cogging Torque Simulation Method for Permanent-Magnet Synchronous Machines

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Chun-Yu Hsiao

2011-12-01

Full Text Available Cogging torque exists between rotor mounted permanent magnets and stator teeth due to magnetic attraction and this is an undesired phenomenon which produces output ripple, vibration and noise in machines. The purpose of this paper is to study the existence and effects of cogging torque, and to present a novel, rapid, half magnet pole pair technique for forecasting and evaluating cogging torque. The technique uses the finite element method as well as Matlab research and development oriented software tools to reduce numerous computing jobs and simulation time. An example of a rotor-skewed structure used to reduce cogging torque of permanent magnet synchronous machines is evaluated and compared with a conventional analysis method for the same motor to verify the effectiveness of the proposed approach. The novel method is proved valuable and suitable for large-capacity machine design.

New Cogging Torque Reduction Methods for Permanent Magnet Machine

Science.gov (United States)

Bahrim, F. S.; Sulaiman, E.; Kumar, R.; Jusoh, L. I.

2017-08-01

Permanent magnet type motors (PMs) especially permanent magnet synchronous motor (PMSM) are expanding its limbs in industrial application system and widely used in various applications. The key features of this machine include high power and torque density, extending speed range, high efficiency, better dynamic performance and good flux-weakening capability. Nevertheless, high in cogging torque, which may cause noise and vibration, is one of the threat of the machine performance. Therefore, with the aid of 3-D finite element analysis (FEA) and simulation using JMAG Designer, this paper proposed new method for cogging torque reduction. Based on the simulation, methods of combining the skewing with radial pole pairing method and skewing with axial pole pairing method reduces the cogging torque effect up to 71.86% and 65.69% simultaneously.

阴道毛滴虫Rab11鸟苷三磷酸酶cDNA克隆和序列分析%Molecular Cloning and Sequence Analysis of Rab11 GTPase in Trichomonas vaginalis

Institute of Scientific and Technical Information of China (English)

张仁利; 许铭炎; 许锦阶; 高世同; 黄达娜; 耿艺介; 傅玉才

2006-01-01

Objective Rab11 GTPases play an essential role in regulating membrane trafficking pathways in eukaryotic cells. Nonetheless, there has been little work done on characterizing the transport machinery of Trichomonas. The aim of this study is to clone and characterize a Rab11 gene of Trichomonas vaginalis.Methods A cDNA expression library was constructed with T. vaginalis total RNA. A cDNA clone, which showed a high degree of homology with Rab proteins of different species, was isolated and sequenced. Sequence analysis was performed using BLASTP, RPS-BLAST and ClustalW programs. The genomic DNA corresponding to the cDNA sequence was amplified using PCR techniques and following by sequencing. Results cDNA with a length of 710 base pairs and an open reading frame of 636 bp was obtained. The deduced amino acid sequence from the open reading frame was found to possess 211 residuals. Sequence analysis demonstrated that this cDNA clone was homologous to the Rab11 subfamily of different species (60% identity and 79% similarity with Arabidopsis thaliana Rab11c, 58% identity and 78% similarity with human Rab11b), and that the amino acid sequence contains all the well known conserved sequence elements of Rab family. Specific Rab motifs were also detected in the deduced amino acid sequence. Phylogenetic analysis showed that its closest homologues are Rab11 proteins from other species. Sequencing of the PCR product of genomic DNA revealed that the genomic DNA sequence encompassing the putative 5'-ATG and 3'-stop codon is identical to the cDNA sequence.Conclusion A cDNA clone corresponding to the T. vaginalis Rab11 gene was obtained.The function of this gene in regulating membrane trafficking pathways of the parasitic protist is still under investigation.%目的近年研究表明Rab11�

Molecular cloning, sequence characterization and expression pattern of Rab18 gene from watermelon (Citrullus lanatus).

Science.gov (United States)

Xinli, Xiao; Lei, Peng

2015-03-04

The complete mRNA sequence of watermelon Rab18 gene was amplified through the rapid amplification of cDNA ends (RACE) method. The full-length mRNA was 1010 bp containing a 645 bp open reading frame, which encodes a protein of 214 amino acids. Sequence analysis revealed that watermelon Rab18 protein shares high homology with the Rab18 of cucumber (99%), muskmelon (98%), Morus notabilis (90%), tomato (89%), wine grape (89%) and potato (88%). Phylogenetic analysis revealed that watermelon Rab18 gene has a closer genetic relationship with Rab18 gene of cucumber and muskmelon. Tissue expression profile analysis indicated that watermelon Rab18 gene was highly expressed in root, stem and leaf, moderately expressed in flower and weakly expressed in fruit.

The Vici Syndrome Protein EPG5 Is a Rab7 Effector that Determines the Fusion Specificity of Autophagosomes with Late Endosomes/Lysosomes.

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Wang, Zheng; Miao, Guangyan; Xue, Xue; Guo, Xiangyang; Yuan, Chongzhen; Wang, Zhaoyu; Zhang, Gangming; Chen, Yingyu; Feng, Du; Hu, Junjie; Zhang, Hong

2016-09-01

Mutations in the human autophagy gene EPG5 cause the multisystem disorder Vici syndrome. Here we demonstrated that EPG5 is a Rab7 effector that determines the fusion specificity of autophagosomes with late endosomes/lysosomes. EPG5 is recruited to late endosomes/lysosomes by direct interaction with Rab7 and the late endosomal/lysosomal R-SNARE VAMP7/8. EPG5 also binds to LC3/LGG-1 (mammalian and C. elegans Atg8 homolog, respectively) and to assembled STX17-SNAP29 Qabc SNARE complexes on autophagosomes. EPG5 stabilizes and facilitates the assembly of STX17-SNAP29-VAMP7/8 trans-SNARE complexes, and promotes STX17-SNAP29-VAMP7-mediated fusion of reconstituted proteoliposomes. Loss of EPG5 activity causes abnormal fusion of autophagosomes with various endocytic vesicles, in part due to elevated assembly of STX17-SNAP25-VAMP8 complexes. SNAP25 knockdown partially suppresses the autophagy defect caused by EPG5 depletion. Our study reveals that EPG5 is a Rab7 effector involved in autophagosome maturation, providing insight into the molecular mechanism underlying Vici syndrome. Copyright © 2016 Elsevier Inc. All rights reserved.

Role of Conserved Oligomeric Golgi Complex in the Abnormalities of Glycoprotein Processing in Breast Cancer Cells

National Research Council Canada - National Science Library

Zolov, Sergey N

2006-01-01

...: protein glycosylation and its sorting. For analysis of COG complex function we utilized RNA interference assay to knockdown COG3p subunit of COG complex in normal and breast cancer cells and other tumor cell lines...

Three sides of the same coin: measuring global cognitive impairment with the MMSE, ADAS-cog and CAMCOG.

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Wouters, Hans; van Gool, Willem A; Schmand, Ben; Zwinderman, Aeilko H; Lindeboom, Robert

2010-08-01

The total scores of the ADAS-cog, MMSE and CAMCOG, comprising various cognitive tasks, are widely used to measure a dimension of global cognitive impairment. It is unknown, however, whether this dimension is common to these instruments. This hampers comparisons when either of these instruments is used. The extent to which these instruments share a common dimension of global cognitive impairment and how their scores relate was examined. Rasch analysis of CAMCOG and MMSE data of participants from a population based study and two memory clinics pooled with ADAS-cog and MMSE data of participants from three RCTs (overall N = 1566) to estimate a common dimension of global cognitive impairment and to examine the goodness of fit of the individual items to this dimension. Using the estimated common dimension of global cognitive impairment, the total scores of the instruments could be related, e.g. a mean level of global cognitive impairment corresponded to a predicted score of 11.4 (ADAS-cog), 72.6 (CAMCOG) and 22.2 (MMSE). When revised according to The Rasch validity analyses, every individual item could be fitted to the dimension. The MMSE, ADAS-cog and CAMCOG reflect a valid common dimension of global cognitive impairment, which enables comparisons of RCTs that use the ADAS-cog and observational studies that use the CAMCOG and MMSE.

Optimizing ADAS-Cog Worksheets: A Survey of Clinical Trial Rater s' Perceptions.

Science.gov (United States)

Meyer, Stephen M; Bertzos, Kristina A; Perez, Magdalena; Connor, Donald J; Schafer, Kimberly; Walter, Sarah

2017-01-01

The Alzheimer's Disease Assessment Scale-Cognitive subscale (ADASCog) remains the most widely used test of longitudinal cognitive functioning in Alzheimer's disease (AD) clinical trials. Unlike most neuropsychological tests, the ADAS-Cog source documentation worksheets are not uniform across clinical trials, and vary by document layout, inclusion of administration and/or scoring instructions, and documentation of subtest scoring (e.g., recording correct versus incorrect scores), among other differences. Many ADAS-Cog test administrators (raters) participate in multiple AD trials and switching between different ADAS-Cog worksheets may increase the likelihood of administration and/or scoring mistakes that lessen the reliability of the instrument. An anonymous online survey sought raters' experiences with ADAS-Cog worksheets and their opinions on the design and content of the worksheets. Results of the survey indicated preference for structure and standardization of the ADASCog worksheets, which has been considered in the development of a standard ADAS-Cog source document by the Alzheimer's Disease Cooperative Study (ADCS) Working Group. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Deficient prepulse inhibition in schizophrenia detected by the multi-site COGS.

Science.gov (United States)

Swerdlow, Neal R; Light, Gregory A; Sprock, Joyce; Calkins, Monica E; Green, Michael F; Greenwood, Tiffany A; Gur, Raquel E; Gur, Ruben C; Lazzeroni, Laura C; Nuechterlein, Keith H; Radant, Allen D; Ray, Amrita; Seidman, Larry J; Siever, Larry J; Silverman, Jeremy M; Stone, William S; Sugar, Catherine A; Tsuang, Debby W; Tsuang, Ming T; Turetsky, Bruce I; Braff, David L

2014-02-01

Startle inhibition by weak prepulses (PPI) is studied to understand the biology of information processing in schizophrenia patients and healthy comparison subjects (HCS). The Consortium on the Genetics of Schizophrenia (COGS) identified associations between PPI and single nucleotide polymorphisms in schizophrenia probands and unaffected relatives, and linkage analyses extended evidence for the genetics of PPI deficits in schizophrenia in the COGS-1 family study. These findings are being extended in a 5-site "COGS-2" study of 1800 patients and 1200 unrelated HCS to facilitate genetic analyses. We describe a planned interim analysis of COGS-2 PPI data. Eyeblink startle was measured in carefully screened HCS and schizophrenia patients (n=1402). Planned analyses of PPI (60 ms intervals) assessed effects of diagnosis, sex and test site, PPI-modifying effects of medications and smoking, and relationships between PPI and neurocognitive measures. 884 subjects met strict inclusion criteria. ANOVA of PPI revealed significant effects of diagnosis (p=0.0005) and sex (pschizophrenia PPI differences were greatest among patients not taking 2nd generation antipsychotics, and were independent of smoking status. Modest but significant relationships were detected between PPI and performance in specific neurocognitive measures. The COGS-2 multi-site study detects schizophrenia-related PPI deficits reported in single-site studies, including patterns related to diagnosis, prepulse interval, sex, medication and other neurocognitive measures. Site differences were detected and explored. The target COGS-2 schizophrenia "endophenotype" of reduced PPI should prove valuable for identifying and confirming schizophrenia risk genes in future analyses. Copyright © 2013 Elsevier B.V. All rights reserved.

The Rab2A GTPase Promotes Breast Cancer Stem Cells and Tumorigenesis via Erk Signaling Activation

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Man-Li Luo

2015-04-01

Full Text Available Proline-directed phosphorylation is regulated by the prolyl isomerase Pin1, which plays a fundamental role in driving breast cancer stem-like cells (BCSCs. Rab2A is a small GTPase critical for vesicle trafficking. Here, we show that Pin1 increases Rab2A transcription to promote BCSC expansion and tumorigenesis in vitro and in vivo. Mechanistically, Rab2A directly interacts with and prevents dephosphorylation/inactivation of Erk1/2 by the MKP3 phosphatase, resulting in Zeb1 upregulation and β-catenin nuclear translocation. In cancer cells, Rab2A is activated via gene amplification, mutation or Pin1 overexpression. Rab2A overexpression or mutation endows BCSC traits to primary normal human breast epithelial cells, whereas silencing Rab2A potently inhibits the expansion and tumorigenesis of freshly isolated BCSCs. Finally, Rab2A overexpression correlates with poor clinical outcome in breast cancer patients. Thus, Pin1/Rab2A/Erk drives BCSC expansion and tumorigenicity, suggesting potential drug targets.

Development and construct validation of the Client-Centredness of Goal Setting (C-COGS) scale.

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Doig, Emmah; Prescott, Sarah; Fleming, Jennifer; Cornwell, Petrea; Kuipers, Pim

2015-07-01

Client-centred philosophy is integral to occupational therapy practice and client-centred goal planning is considered fundamental to rehabilitation. Evaluation of whether goal-planning practices are client-centred requires an understanding of the client's perspective about goal-planning processes and practices. The Client-Centredness of Goal Setting (C-COGS) was developed for use by practitioners who seek to be more client-centred and who require a scale to guide and evaluate individually orientated practice, especially with adults with cognitive impairment related to acquired brain injury. To describe development of the C-COGS scale and examine its construct validity. The C-COGS was administered to 42 participants with acquired brain injury after multidisciplinary goal planning. C-COGS scores were correlated with the Canadian Occupational Performance Measure (COPM) importance scores, and measures of therapeutic alliance, motivation, and global functioning to establish construct validity. The C-COGS scale has three subscales evaluating goal alignment, goal planning participation, and client-centredness of goals. The C-COGS subscale items demonstrated moderately significant correlations with scales measuring similar constructs. Findings provide preliminary evidence to support the construct validity of the C-COGS scale, which is intended to be used to evaluate and reflect on client-centred goal planning in clinical practice, and to highlight factors contributing to best practice rehabilitation.

76 FR 13445 - Lycoming Valley Railroad Company-Operation Exemption-SEDA-COG Joint Rail Authority

Science.gov (United States)

2011-03-11

... Railroad Company-Operation Exemption--SEDA--COG Joint Rail Authority Lycoming Valley Railroad Company (LVRR... milepost 0.4 in Muncy, Lycoming County, Pa. The line is owned or leased by SEDA-COG Joint Rail Authority (SEDA-COG). LVRR states that the line it proposes to operate is an extension of its existing line of...

76 FR 13446 - Juniata Valley Railroad Company-Operation Exemption-SEDA-COG Joint Rail Authority

Science.gov (United States)

2011-03-11

... Railroad Company-Operation Exemption-SEDA-COG Joint Rail Authority Juniata Valley Railroad Company (JVRR... milepost 2.0 in Lewistown, Mifflin County, Pa. The line is owned or leased by SEDA-COG Joint Rail Authority (SEDA-COG). JVRR states that the line it proposes to operate is an extension of its existing line of...

76 FR 13445 - North Shore Railroad Company-Operation Exemption-SEDA-COG Joint Rail Authority

Science.gov (United States)

2011-03-11

... Railroad Company-Operation Exemption-SEDA-COG Joint Rail Authority North Shore Railroad Company (NSRR), a... milepost 2.0 in Berwick, Columbia County, Pa. The line is leased by SEDA-COG Joint Rail Authority (SEDA- COG). NSRR states that the line it proposes to operate is an extension of its existing line of...

Targeting eukaryotic Rab proteins: a smart strategy for chlamydial survival and replication.

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Damiani, María Teresa; Gambarte Tudela, Julián; Capmany, Anahí

2014-09-01

Chlamydia, an obligate intracellular bacterium which passes its entire lifecycle within a membrane-bound vacuole called the inclusion, has evolved a variety of unique strategies to establish an advantageous intracellular niche for survival. This review highlights the mechanisms by which Chlamydia subverts vesicular transport in host cells, particularly by hijacking the master controllers of eukaryotic trafficking, the Rab proteins. A subset of Rabs and Rab interacting proteins that control the recycling pathway or the biosynthetic route are selectively recruited to the chlamydial inclusion membrane. By interfering with Rab-controlled transport steps, this intracellular pathogen not only prevents its own degradation in the phagocytic pathway, but also creates a favourable intracellular environment for growth and replication. Chlamydia, a highly adapted and successful intracellular pathogen, has several redundant strategies to re-direct vesicles emerging from biosynthetic compartments that carry host molecules essential for bacterial development. Although current knowledge is limited, the latest findings have shed light on the role of Rab proteins in the course of chlamydial infections and could open novel opportunities for anti-chlamydial therapy. © 2014 John Wiley & Sons Ltd.

Functional Characterization of Rare RAB12 Variants and Their Role in Musician’s and Other Dystonias

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Eva Hebert

2017-10-01

Full Text Available Mutations in RAB (member of the Ras superfamily genes are increasingly recognized as cause of a variety of disorders including neurological conditions. While musician’s dystonia (MD and writer’s dystonia (WD are task-specific movement disorders, other dystonias persistently affect postures as in cervical dystonia. Little is known about the underlying etiology. Next-generation sequencing revealed a rare missense variant (c.586A>G; p.Ile196Val in RAB12 in two of three MD/WD families. Next, we tested 916 additional dystonia patients; 512 Parkinson’s disease patients; and 461 healthy controls for RAB12 variants and identified 10 additional carriers of rare missense changes among dystonia patients (1.1% but only one carrier in non-dystonic individuals (0.1%; p = 0.005. The detected variants among index patients comprised p.Ile196Val (n = 6; p.Ala174Thr (n = 3; p.Gly13Asp; p.Ala148Thr; and p.Arg181Gln in patients with MD; cervical dystonia; or WD. Two relatives of MD patients with WD also carried p.Ile196Val. The two variants identified in MD patients (p.Ile196Val; p.Gly13Asp were characterized on endogenous levels in patient-derived fibroblasts and in two RAB12-overexpressing cell models. The ability to hydrolyze guanosine triphosphate (GTP, so called GTPase activity, was increased in mutants compared to wildtype. Furthermore, subcellular distribution of RAB12 in mutants was altered in fibroblasts. Soluble Transferrin receptor 1 levels were reduced in the blood of all three tested p.Ile196Val carriers. In conclusion, we demonstrate an enrichment of missense changes among dystonia patients. Functional characterization revealed altered enzyme activity and lysosomal distribution in mutants suggesting a contribution of RAB12 variants to MD and other dystonias.

Enrichment of Phosphatidylethanolamine in Viral Replication Compartments via Co-opting the Endosomal Rab5 Small GTPase by a Positive-Strand RNA Virus.

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Kai Xu

2016-10-01

Full Text Available Positive-strand RNA viruses build extensive membranous replication compartments to support replication and protect the virus from antiviral responses by the host. These viruses require host factors and various lipids to form viral replication complexes (VRCs. The VRCs built by Tomato bushy stunt virus (TBSV are enriched with phosphatidylethanolamine (PE through a previously unknown pathway. To unravel the mechanism of PE enrichment within the TBSV replication compartment, in this paper, the authors demonstrate that TBSV co-opts the guanosine triphosphate (GTP-bound active form of the endosomal Rab5 small GTPase via direct interaction with the viral replication protein. Deletion of Rab5 orthologs in a yeast model host or expression of dominant negative mutants of plant Rab5 greatly decreases TBSV replication and prevents the redistribution of PE to the sites of viral replication. We also show that enrichment of PE in the viral replication compartment is assisted by actin filaments. Interestingly, the closely related Carnation Italian ringspot virus, which replicates on the boundary membrane of mitochondria, uses a similar strategy to the peroxisomal TBSV to hijack the Rab5-positive endosomes into the viral replication compartments. Altogether, usurping the GTP-Rab5-positive endosomes allows TBSV to build a PE-enriched viral replication compartment, which is needed to support peak-level replication. Thus, the Rab family of small GTPases includes critical host factors assisting VRC assembly and genesis of the viral replication compartment.

Enhanced water stress tolerance of transgenic maize plants over-expressing LEA Rab28 gene.

Science.gov (United States)

Amara, Imen; Capellades, Montserrat; Ludevid, M Dolors; Pagès, Montserrat; Goday, Adela

2013-06-15

Late Embryogenesis Abundant (LEA) proteins participate in plant stress responses and contribute to the acquisition of desiccation tolerance. In this report Rab28 LEA gene has been over-expressed in maize plants under a constitutive maize promoter. The expression of Rab28 transcripts led to the accumulation and stability of Rab28 protein in the transgenic plants. Native Rab28 protein is localized to nucleoli in wild type maize embryo cells; here we find by whole-mount immunocytochemistry that in root cells of Rab28 transgenic and wild-type plants the protein is also associated to nucleolar structures. Transgenic plants were tested for stress tolerance and resulted in sustained growth under polyethyleneglycol (PEG)-mediated dehydration compared to wild-type controls. Under osmotic stress transgenic seedlings showed increased leaf and root areas, higher relative water content (RWC), reduced chlorophyll loss and lower Malondialdehyde (MDA) production in relation to wild-type plants. Moreover, transgenic seeds exhibited higher germination rates than wild-type seeds under water deficit. Overall, our results highlight the presence of transgenic Rab28 protein in nucleolar structures and point to the potential of group 5 LEA Rab28 gene as candidate to enhance stress tolerance in maize plants. Copyright © 2013 Elsevier GmbH. All rights reserved.

Cogging Torque Reduction by Slot-Opening Shift for Permanent Magnet Machines

DEFF Research Database (Denmark)

Liu, Ting; Huang, Shoudao; Gao, Jian

2013-01-01

In this paper, an effective cogging torque reduction method based on shifting the slot-openings is presented. Stator teeth are divided into groups and proper slot-opening shift is applied for each group. The cogging torque can then be greatly reduced while the back-EMF waveforms remain symmetrical...

Rab11 is phosphorylated by classical and novel protein kinase C isoenzymes upon sustained phorbol ester activation.

Science.gov (United States)

Pavarotti, Martín; Capmany, Anahí; Vitale, Nicolas; Colombo, María Isabel; Damiani, María Teresa

2012-02-01

Rab11 is a small GTPase that controls diverse intracellular trafficking pathways. However, the molecular machinery that regulates the participation of Rab11 in those different transport events is poorly understood. In resting cells, Rab11 localizes at the endocytic recycling compartment (ERC), whereas the different protein kinase C (PKC) isoforms display a cytosolic distribution. Sustained phorbol ester stimulation induces the translocation of the classical PKCα and PKCβII isoenzymes to the ERC enriched in Rab11, and results in transferrin recycling inhibition. In contrast, novel PKCε and atypical PKCζ isoenzymes neither redistribute to the perinucleus nor modify transferrin recycling transport after phorbol ester stimulation. Although several Rabs have been shown to be phosphorylated, there is to date no evidence indicating Rab11 as a kinase substrate. In this report, we show that Rab11 appears phosphorylated in vivo in phorbol ester-stimulated cells. A bioinformatic analysis of Rab11 allowed us to identify several high-probability Ser/Thr kinase phosphorylation sites. Our results demonstrate that classical PKC (PKCα and PKCβII but not PKCβI) directly phosphorylate Rab11 in vitro. In addition, novel PKCε and PKCη but not PKCδ isoenzymes also phosphorylate Rab11. Mass spectrometry analysis revealed that Ser 177 is the Rab11 residue to be phosphorylated in vitro by either PKCβII or PKCε. In agreement, the phosphomimetic mutant, Rab11 S177D, retains transferrin at the ERC in the absence of phorbol-12-myristate-13-acetate stimulus. This report shows for the first time that Rab11 is differentially phosphorylated by distinct PKC isoenzymes and that this post-translational modification might be a regulatory mechanism of intracellular trafficking. Copyright © 2012 Soçiété Francaise des Microscopies and Société de Biologie Cellulaire de France.

Phagosome maturation in unicellular eukaryote Paramecium: the presence of RILP, Rab7 and LAMP-2 homologues

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E Wyroba

2009-08-01

Full Text Available Phagosome maturation is a complex process enabling degradation of internalised particles. Our data obtained at the gene, protein and cellular level indicate that the set of components involved in this process and known up to now in mammalian cells is functioning in unicellular eukaryote. Rab7-interacting partners: homologues of its effector RILP (Rab-interacting lysosomal protein and LAMP-2 (lysosomal membrane protein 2 as well as a7 subunit of the 26S proteasome were revealed in Paramecium phagolysosomal compartment. We identified the gene/transcript fragments encoding RILP-related proteins (RILP1 and RILP2 in Paramecium by PCR/RT-PCR and sequencing. The deduced amino acid sequences of RILP1 and RILP2 show 60.5% and 58.3% similarity, respectively, to the region involved in regulating of lysosomal morphology and dynein-dynactin recruitment of human RILP. RILP colocalised with Rab7 in Paramecium lysosomes and at phagolysosomal membrane during phagocytosis of both the latex beads and bacteria. In the same compartment LAMP-2 was present and its expression during latex internalisation was 2.5-fold higher than in the control when P2 protein fractions (100 000 x g of equal load were quantified by immunoblotting. LAMP-2 crossreacting polypeptide of ~106 kDa was glycosylated as shown by fluorescent and Western analysis of the same blot preceded by PNGase F treatment. The a7 subunit of 26S proteasome was detected close to the phagosomal membrane in the small vesicles, in some of which it colocalised with Rab7. Immunoblotting confirmed presence of RILPrelated polypeptide and a7 subunit of 26S proteasome in Paramecium protein fractions. These results suggest that Rab7, RILP and LAMP-2 may be involved in phagosome maturation in Paramecium.

STRENGTH ANALYSIS METHODS OF CIRCULAR PULL BROACH COGS

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Cosmin MIRIŢOIU

2010-10-01

Full Text Available A very big importance in a pull broach designing is represented by its mechanic computation, which trots out the pull broach resistance on various blank tooling, pull broach productivity and also the loadings which is subdued to and the stresses that appear during the chipping process. The pull broach geometric complexity leads to one difficulty concerning the resistance computing methods application (and implicitly, simplifying assumptions application. This present study presents a resistance computing of pull broach cogs, which dresses a circular hole trotting out more methods which can be used in this computing, and the teoretic aspects are then trotted out by an example of a numerical computation for a particular case.

Revising the ADAS-cog for a more accurate assessment of cognitive impairment.

Science.gov (United States)

Wouters, Hans; van Gool, Willem A; Schmand, Ben; Lindeboom, Robert

2008-01-01

To examine whether it is appropriate to sum the cognitive part of the Alzheimer Disease Assessment Scale (ADAS-cog) items to assess cognitive impairment. This assumes items to have (1) equal measurement precision and (2) hierarchically ordered categories. Rasch analysis on the basis of pooled data from 3 Randomized Controlled Trials was used to examine these assumptions and to estimate each patient's level of impairment. Analyses were replicated in an independent sample. The original ADAS-cog scoring did not fit the Rasch Model and did not reliably distinguish between impairment levels. Patients with equal test scores had different impairment levels. Similarly, patients with different test scores could have the same impairment level. Revising the ADAS-cog by (1) weighting the items by their measurement precision and (2) collapsing nonhierarchical item categories resulted in good fit and a valid one to one correspondence between sum scores and estimated impairment levels. This revealed that equal differences in ADAS-cog scores did not reflect equal differences in impairment level along the test's score range. It is appropriate to summate the ADAS-cog items provided that the items are weighted and have their categories hierarchically ordered.

Psychometric Properties of the Persian Adaptation of Mini-Cog Test in Iranian Older Adults.

Science.gov (United States)

Rezaei, Mohammad; Rashedi, Vahid; Lotfi, Gohar; Shirinbayan, Peymaneh; Foroughan, Mahshid

2018-04-01

The aim of this study was to assess the psychometric properties of the Mini-Cog in Iranian older adults. It was a cross-sectional study; 50 older people with dementia and 50 without dementia who matched for age, gender, and education entered the study. The diagnostic and statistical manual of mental disorders criteria for dementia were used as gold standard. A battery of scales included the abbreviated mental test score (AMTS), the Geriatric Depression Scale, and the Mini-Cog was performed. Validity and reliability of the Mini-Cog determined using the Pearson product-moment correlation coefficient (Pearson's r), Cronbach's alpha, and Receiver Operating Characteristic (ROC) curve analysis. The Persian version of Mini-Cog showed a good inter-rater reliability ( K = 0.76, p Mini-Cog have an acceptable sensitivity, specificity, and substantial overall agreement with the AMTS.

Cogging force investigation of a free piston permanent magnet linear generator

Science.gov (United States)

Abdalla, I. I.; Zainal, A. E. Z.; Ramlan, N. A.; Firmansyah; Aziz, A. R. A.; Heikal, M. R.

2017-10-01

Better performance and higher efficiency of the vehicles can be achieved by using free piston engine, in which the piston is connected directly to the linear generator and waiving of any mechanical means. The free piston engine has the ability to overcome or reduce many of the challenges, such as the carbon dioxide (CO2) emission and fossil fuel consumption. The cogging force produces undesired vibration and acoustic noise in the generator. However, the cogging force must be minimized as much as possible, in order to have a high performance. This paper studies the effects of ferromagnetic materials on the cogging force of the permanent magnet linear generator (PMLG) to be used in a free piston engine using nonlinear finite-element analysis (FEA) under ANSYS Maxwell. The comparisons have been established for the cogging force of the PMLG under various translator velocities and three different ferromagnetic materials for the stator core, namely, Silicon Steel laminations, Mild Steel and Somaloy. It has been shown that the PMLG with a stator core made of Somaloy has a lower cogging force among them. Furthermore, the induced voltage of the PMLG at different accelerations has been studied. It is found that the PMLG with Mild Steel and Somaloy, respectively give larger induced voltage. Moreover, as the translator speed increase the induced voltage increased.

Evaluating algal growth performance and water use efficiency of pilot-scale revolving algal biofilm (RAB) culture systems.

Science.gov (United States)

Gross, Martin; Mascarenhas, Vernon; Wen, Zhiyou

2015-10-01

A Revolving Algal Biofilm (RAB) growth system in which algal cells are attached to a flexible material rotating between liquid and gas phases has been developed. In this work, different configurations of RAB systems were developed at pilot-scale by retrofitting the attachment materials to a raceway pond (2000-L with 8.5 m(2) footprint area) and a trough reservoir (150 L with 3.5 m(2) footprint area). The algal growth performance and chemical composition, as well as the water evaporative loss and specific water consumption were evaluated over a period of nine months in a greenhouse environment near Boone, Iowa USA. Additionally a raceway pond was run in parallel, which served as a control. On average the raceway-based RAB and the trough-based RAB outperformed the control pond by 309% and 697%, respectively. A maximum productivity of 46.8 g m(-2) day(-1) was achieved on the trough-based RAB system. The evaporative water loss of the RAB system was modeled based on an energy balance analysis and was experimentally validated. While the RAB system, particularly the trough-based RAB, had higher water evaporative loss, the specific water consumption per unit of biomass produced was only 26% (raceway-based RAB) and 7% (trough-based RAB) of that of the control pond. Collectively, this research shows that the RAB system is an efficient algal culture system and has great potential to commercially produce microalgae with high productivity and efficient water use. © 2015 Wiley Periodicals, Inc.

The Rab7 effector PLEKHM1 binds Arl8b to promote cargo traffic to lysosomes.

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Marwaha, Rituraj; Arya, Subhash B; Jagga, Divya; Kaur, Harmeet; Tuli, Amit; Sharma, Mahak

2017-04-03

Endocytic, autophagic, and phagocytic vesicles move on microtubule tracks to fuse with lysosomes. Small GTPases, such as Rab7 and Arl8b, recruit their downstream effectors to mediate this transport and fusion. However, the potential cross talk between these two GTPases is unclear. Here, we show that the Rab7 effector PLEKHM1 simultaneously binds Rab7 and Arl8b, bringing about clustering and fusion of late endosomes and lysosomes. We show that the N-terminal RUN domain of PLEKHM1 is necessary and sufficient for interaction with Arl8b and its subsequent localization to lysosomes. Notably, we also demonstrate that Arl8b mediates recruitment of HOPS complex to PLEKHM1-positive vesicle contact sites. Consequently, Arl8b binding to PLEKHM1 is required for its function in delivery and, therefore, degradation of endocytic and autophagic cargo in lysosomes. Finally, we also show that PLEKHM1 competes with SKIP for Arl8b binding, which dictates lysosome positioning. These findings suggest that Arl8b, along with its effectors, orchestrates lysosomal transport and fusion. © 2017 Marwaha et al.

Comparing of cogging torque reduction methods in permanent magnet machines with fractional slot windings

Science.gov (United States)

Pristup, A. G.; Toporkov, D. M.

2017-10-01

The results of the investigation of the cogging torque in permanent magnet synchronous machines, which is caused by the stator slotting and the rotor eccentricity, are presented in the paper. A new design of the machine has been developed in the course of the investigation, and the value of the cogging torque in this construction is less considerably compared to other constructions. In contrast to the available methods of the cogging torque reduction, the solution suggested not only decreases the level of the cogging torque but also has negligibly small influence on characteristics of the machine with the rotor eccentricity which is typical of the mass production and long-term usage.

Ehrlichia secretes Etf-1 to induce autophagy and capture nutrients for its growth through RAB5 and class III phosphatidylinositol 3-kinase.

Science.gov (United States)

Lin, Mingqun; Liu, Hongyan; Xiong, Qingming; Niu, Hua; Cheng, Zhihui; Yamamoto, Akitsugu; Rikihisa, Yasuko

2016-11-01

Ehrlichia chaffeensis is an obligatory intracellular bacterium that causes a potentially fatal emerging zoonosis, human monocytic ehrlichiosis. E. chaffeensis has a limited capacity for biosynthesis and metabolism and thus depends mostly on host-synthesized nutrients for growth. Although the host cell cytoplasm is rich with these nutrients, as E. chaffeensis is confined within the early endosome-like membrane-bound compartment, only host nutrients that enter the compartment can be used by this bacterium. How this occurs is unknown. We found that ehrlichial replication depended on autophagy induction involving class III phosphatidylinositol 3-kinase (PtdIns3K) activity, BECN1 (Beclin 1), and ATG5 (autophagy-related 5). Ehrlichia acquired host cell preincorporated amino acids in a class III PtdIns3K-dependent manner and ehrlichial growth was enhanced by treatment with rapamycin, an autophagy inducer. Moreover, ATG5 and RAB5A/B/C were routed to ehrlichial inclusions. RAB5A/B/C siRNA knockdown, or overexpression of a RAB5-specific GTPase-activating protein or dominant-negative RAB5A inhibited ehrlichial infection, indicating the critical role of GTP-bound RAB5 during infection. Both native and ectopically expressed ehrlichial type IV secretion effector protein, Etf-1, bound RAB5 and the autophagy-initiating class III PtdIns3K complex, PIK3C3/VPS34, and BECN1, and homed to ehrlichial inclusions. Ectopically expressed Etf-1 activated class III PtdIns3K as in E. chaffeensis infection and induced autophagosome formation, cleared an aggregation-prone mutant huntingtin protein in a class III PtdIns3K-dependent manner, and enhanced ehrlichial proliferation. These data support the notion that E. chaffeensis secretes Etf-1 to induce autophagy to repurpose the host cytoplasm and capture nutrients for its growth through RAB5 and class III PtdIns3K, while avoiding autolysosomal killing.

Validation and cultural adaptation of the Arabic versions of the Mini-Mental Status Examination - 2 and Mini-Cog test.

Science.gov (United States)

Albanna, Mohammad; Yehya, Arij; Khairi, Abdalla; Dafeeah, Elnour; Elhadi, Abdelsalam; Rezgui, Lamia; Al Kahlout, Shahada; Yousif, Adil; Uthman, Basim; Al-Amin, Hassen

2017-01-01

The elderly population is increasing around the world, and the prevalence of dementia increases with age. Hence, it is expected that the number of people with dementia will increase significantly in the coming years. The Mini-Mental Status Examination - 2 (MMSE-2) and Mini-Cog are widely used tests to screen for dementia. These scales have good reliability and validity and are easy to administer in clinical and research settings. The purpose of this study was to validate the Arabic versions of MMSE-2 and Mini-Cog. These scales were assessed against the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision ( DSM-IV-TR ) criteria for dementia, as the gold standard. The standard versions of the MMSE-2 and Mini-Cog were translated to Arabic following the back-translation method. Then, a trained rater administered these tests to 134 Arab elderly aged >60 years. A physician, blind to the results of these two tests, assessed the participants for vascular dementia or probable Alzheimer's disease, based on the DSM-IV-TR criteria. The sample included 67.2% Qataris. The mean age was 74.86 years (standard deviation =7.71), and 61.9% did not attend school. The mean of the adjusted scores of MMSE-2 based on age and education level was 19.60 (standard deviation =6.58). According to DSM-IV-TR , 17.2% of the participants had dementia. Sensitivity and specificity of the MMSE-2 and the Mini-Cog together were 71.4% and 61.6%, respectively, which were better than those of each test alone. Together, the Arabic versions of MMSE-2 and Mini-Cog are good screening tools for cognitive impairment in Arabs.

The interaction properties of the human Rab GTPase family--comparative analysis reveals determinants of molecular binding selectivity.

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Matthias Stein

Full Text Available Rab GTPases constitute the largest subfamily of the Ras protein superfamily. Rab proteins regulate organelle biogenesis and transport, and display distinct binding preferences for effector and activator proteins, many of which have not been elucidated yet. The underlying molecular recognition motifs, binding partner preferences and selectivities are not well understood.Comparative analysis of the amino acid sequences and the three-dimensional electrostatic and hydrophobic molecular interaction fields of 62 human Rab proteins revealed a wide range of binding properties with large differences between some Rab proteins. This analysis assists the functional annotation of Rab proteins 12, 14, 26, 37 and 41 and provided an explanation for the shared function of Rab3 and 27. Rab7a and 7b have very different electrostatic potentials, indicating that they may bind to different effector proteins and thus, exert different functions. The subfamily V Rab GTPases which are associated with endosome differ subtly in the interaction properties of their switch regions, and this may explain exchange factor specificity and exchange kinetics.We have analysed conservation of sequence and of molecular interaction fields to cluster and annotate the human Rab proteins. The analysis of three dimensional molecular interaction fields provides detailed insight that is not available from a sequence-based approach alone. Based on our results, we predict novel functions for some Rab proteins and provide insights into their divergent functions and the determinants of their binding partner selectivity.

Deficient Rab11 activity underlies glucose hypometabolism in primary neurons of Huntington’s disease mice

International Nuclear Information System (INIS)

Li, Xueyi; Valencia, Antonio; McClory, Hollis; Sapp, Ellen; Kegel, Kimberly B.; DiFiglia, Marian

2012-01-01

Highlights: ► Primary Huntington’s disease neurons are impaired in taking up glucose. ► Rab11 modulates glucose uptake in neurons. ► Increasing Rab11 activity attenuates the glucose uptake defect in disease neurons. ► We provide a novel mechanism for glucose hypometabolism in Huntington’s disease. -- Abstract: Huntington’s disease (HD) is a progressive neurodegenerative disorder caused by a CAG repeat expansion in the huntingtin gene. Positron emission tomography studies have revealed a decline in glucose metabolism in the brain of patients with HD by a mechanism that has not been established. We examined glucose utilization in embryonic primary cortical neurons of wild-type (WT) and HD knock-in mice, which have 140 CAG repeats inserted in the endogenous mouse huntingtin gene (HD 140Q/140Q ). Primary HD 140Q/140Q cortical neurons took up significantly less glucose than did WT neurons. Expression of permanently inactive and permanently active forms of Rab11 correspondingly altered glucose uptake in WT neurons, suggesting that normal activity of Rab11 is needed for neuronal uptake of glucose. It is known that Rab11 activity is diminished in HD 140Q/140Q neurons. Expression of dominant active Rab11 to enhance the activity of Rab11 normalized glucose uptake in HD 140Q/140Q neurons. These results suggest that deficient activity of Rab11 is a novel mechanism for glucose hypometabolism in HD.

Expression profile of Rab5, Rab7, tryptophan aspartate-containing coat protein, leprae lipoarabinomannan, and phenolic glycolipid-1 on the failure of the phagolysosome process in macrophages of leprosy patients as a viability marker of Mycobacterium leprae.

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Prakoeswa, Cita Rosita Sigit; Wahyuni, Ratna; Iswahyudi; Adriaty, Dinar; Yusuf, Irawan; Sutjipto; Agusni, Indropo; Izumi, Shinzo

2016-06-01

Phagolysosome process in macrophage of leprosy patients' is important in the early phase of eliminating Mycobacterium leprae invasion. This study was to clarify the involvement of Rab5, Rab7, and trytophan aspartate-containing coat protein (TACO) from host macrophage and leprae lipoarabinomannan (Lep-LAM) and phenolic glycolipid-1 (PGL-1) from M. leprae cell wall as the reflection of phagolysosome process in relation to 16 subunit ribosomal RNA (16S rRNA) M. leprae as a marker of viability of M. leprae. Using a cross sectional design study, skin biopsies were obtained from 47 newly diagnosed, untreated leprosy at Dr Soetomo Hospital, Surabaya, Indonesia. RNA isolation and complementary DNA synthesis were performed. Samples were divided into two groups: 16S rRNA M. leprae-positive and 16S rRNA M. leprae-negative. The expressions of Rab5, Rab7, TACO, Lep-LAM, and PGL-1 were assessed with an immunohistochemistry technique. Using Mann-Whitney U analysis, a significant difference in the expression profile of Rab5, Rab7, Lep-LAM, and PGL-1 was found (p.05). Spearman analysis revealed that there was a significant correlation between the score of Rab5, Rab7, Lep-LAM, and PGL-1 and the score of 16S rRNA M. leprae (pleprae infection, Rab5, Rab7, and Lep-LAM play important roles in the failure of phagolysosome process via a membrane trafficking pathway, while PGL-1 plays a role via blocking lysosomal activities. These inventions might be used for the development of an early diagnostic device in the future. Copyright © 2016 Asian-African Society for Mycobacteriology. Published by Elsevier Ltd. All rights reserved.

Model of the multipolar engine with decreased cogging torque by asymmetrical distribution of the magnets

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Goryca, Zbigniew; Paduszyński, Kamil; Pakosz, Artur

2018-03-01

This paper presents the results of field calculations of cogging torque for a 12-pole torque motor with an 18-slot stator. A constant angular velocity magnet and the same size gap between n-1 magnets were assumed. In these conditions, the effect of change of the n-th gap between magnets on the cogging torque was tested. Due to considerable length of the machine the calculations were performed using a 2D model. The n-th gap for which the cogging torque assumed the lowest value was evaluated. The cogging torque of the machine with symmetrical magnetic circuit (the same size of gap between magnets) was compared to the one of the asymmetrical machine. With proper choice of asymmetry, the cogging torque for the machine decreased by four times.

Rab39a interacts with phosphatidylinositol 3-kinase and negatively regulates autophagy induced by lipopolysaccharide stimulation in macrophages.

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Shintaro Seto

Full Text Available Rab39a has pleiotropic functions in phagosome maturation, inflammatory activation and neuritogenesis. Here, we characterized Rab39a function in membrane trafficking of phagocytosis and autophagy induction in macrophages. Rab39a localized to the periphery of LAMP2-positive vesicles and showed the similar kinetics on the phagosome to that of LAMP1. The depletion of Rab39a did not influence the localization of LAMP2 to the phagosome, but it augments the autophagosome formation and LC3 processing by lipopolysaccharide (LPS stimulation. The augmentation of autophagosome formation in Rab39a-knockdown macrophages was suppressed by Atg5 depletion or an inhibitor for phosphatidylinostol 3-kinase (PI3K. Immunoprecipitation analysis revealed that Rab39a interacts with PI3K and that the amino acid residues from 34(th to 41(st in Rab39a were indispensable for this interaction. These results suggest that Rab39a negatively regulates the LPS-induced autophagy in macrophages.

How Do Scores on the ADAS-Cog, MMSE, and CDR-SOB Correspond?

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Balsis, Steve; Benge, Jared F; Lowe, Deborah A; Geraci, Lisa; Doody, Rachelle S

2015-01-01

Clinicians and researchers who measure cognitive dysfunction often use the Alzheimer's Disease Assessment Scale--Cognitive Subscale (ADAS-Cog), the Mini-Mental State Examination (MMSE), or the Clinical Dementia Rating scale (CDR-SOB). But, the use of different measures can make it difficult to compare data across patients or studies. What is needed is a simple chart that shows how scores on these three important measures correspond to each other. Using data from 1709 participants from the Alzheimer's Disease Neuroimaging Initiative and item response theory-based statistics, we analyzed how scores on each measure, the ADAS-Cog, the MMSE, and the CDR-SOB, correspond. Results indicated multiple inflections in CDR-SOB and ADAS-Cog scores within a given MMSE score, suggesting that the CDR-SOB and ADAS-Cog are more precise in measuring the severity of cognitive dysfunction than the MMSE. This study shows how scores on these three popular measures of cognitive dysfunction correspond to each other, which is very useful information for both researchers and clinicians.

Extensive in silico analysis of Mimivirus coded Rab GTPase homolog suggests a possible role in virion membrane biogenesis

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Amrutraj eZade

2015-09-01

Full Text Available Rab GTPases are the key regulators of intracellular membrane trafficking in eukaryotes. Many viruses and intracellular bacterial pathogens have evolved to hijack the host Rab GTPase functions, mainly through activators and effector proteins, for their benefit. Acanthamoeba polyphaga mimivirus (APMV is one of the largest viruses and belongs to the monophyletic clade of nucleo-cytoplasmic large DNA viruses (NCLDV. The inner membrane lining is integral to the APMV virion structure. APMV assembly involves extensive host membrane modifications, like vesicle budding and fusion, leading to the formation of a membrane sheet that is incorporated into the virion. Intriguingly, APMV and all group I members of the Mimiviridae family code for a putative Rab GTPase protein. APMV is the first reported virus to code for a Rab GTPase (encoded by R214 gene. Our thorough in silico analysis of the subfamily specific (SF region of Mimiviridae Rab GTPase sequences suggests that they are related to Rab5, a member of the group II Rab GTPases, of lower eukaryotes. Because of their high divergence from the existing three isoforms, A, B and C of the Rab5-family, we suggest that Mimiviridae Rabs constitute a new isoform, Rab5D. Phylogenetic analysis indicated probable horizontal acquisition from a lower eukaryotic ancestor followed by selection and divergence. Furthermore, interaction network analysis suggests that vps34 (a Class III P13K homolog, coded by APMV L615, Atg-8 and dynamin (host proteins are recruited by APMV Rab GTPase during capsid assembly. Based on these observations, we hypothesize that APMV Rab plays a role in the acquisition of inner membrane during virion assembly.

Improved utilization of ADAS-cog assessment data through item response theory based pharmacometric modeling.

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Ueckert, Sebastian; Plan, Elodie L; Ito, Kaori; Karlsson, Mats O; Corrigan, Brian; Hooker, Andrew C

2014-08-01

This work investigates improved utilization of ADAS-cog data (the primary outcome in Alzheimer's disease (AD) trials of mild and moderate AD) by combining pharmacometric modeling and item response theory (IRT). A baseline IRT model characterizing the ADAS-cog was built based on data from 2,744 individuals. Pharmacometric methods were used to extend the baseline IRT model to describe longitudinal ADAS-cog scores from an 18-month clinical study with 322 patients. Sensitivity of the ADAS-cog items in different patient populations as well as the power to detect a drug effect in relation to total score based methods were assessed with the IRT based model. IRT analysis was able to describe both total and item level baseline ADAS-cog data. Longitudinal data were also well described. Differences in the information content of the item level components could be quantitatively characterized and ranked for mild cognitively impairment and mild AD populations. Based on clinical trial simulations with a theoretical drug effect, the IRT method demonstrated a significantly higher power to detect drug effect compared to the traditional method of analysis. A combined framework of IRT and pharmacometric modeling permits a more effective and precise analysis than total score based methods and therefore increases the value of ADAS-cog data.

Reduction of Cogging Torque in Dual Rotor Permanent Magnet Generator for Direct Coupled Wind Energy Systems

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Paulsamy, Sivachandran

2014-01-01

In wind energy systems employing permanent magnet generator, there is an imperative need to reduce the cogging torque for smooth and reliable cut in operation. In a permanent magnet generator, cogging torque is produced due to interaction of the rotor magnets with slots and teeth of the stator. This paper is a result of an ongoing research work that deals with various methods to reduce cogging torque in dual rotor radial flux permanent magnet generator (DRFPMG) for direct coupled stand alone wind energy systems (SAWES). Three methods were applied to reduce the cogging torque in DRFPMG. The methods were changing slot opening width, changing magnet pole arc width and shifting of slot openings. A combination of these three methods was applied to reduce the cogging torque to a level suitable for direct coupled SAWES. Both determination and reduction of cogging torque were carried out by finite element analysis (FEA) using MagNet Software. The cogging torque of DRFPMG has been reduced without major change in induced emf. A prototype of 1 kW, 120 rpm DRFPMG was fabricated and tested to validate the simulation results. The test results have good agreement with the simulation predictions. PMID:25202746

Reduction of cogging torque in dual rotor permanent magnet generator for direct coupled wind energy systems.

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Paulsamy, Sivachandran

2014-01-01

In wind energy systems employing permanent magnet generator, there is an imperative need to reduce the cogging torque for smooth and reliable cut in operation. In a permanent magnet generator, cogging torque is produced due to interaction of the rotor magnets with slots and teeth of the stator. This paper is a result of an ongoing research work that deals with various methods to reduce cogging torque in dual rotor radial flux permanent magnet generator (DRFPMG) for direct coupled stand alone wind energy systems (SAWES). Three methods were applied to reduce the cogging torque in DRFPMG. The methods were changing slot opening width, changing magnet pole arc width and shifting of slot openings. A combination of these three methods was applied to reduce the cogging torque to a level suitable for direct coupled SAWES. Both determination and reduction of cogging torque were carried out by finite element analysis (FEA) using MagNet Software. The cogging torque of DRFPMG has been reduced without major change in induced emf. A prototype of 1 kW, 120 rpm DRFPMG was fabricated and tested to validate the simulation results. The test results have good agreement with the simulation predictions.

Chlamydia trachomatis intercepts Golgi-derived sphingolipids through a Rab14-mediated transport required for bacterial development and replication.

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Anahí Capmany

2010-11-01

Full Text Available Chlamydia trachomatis are obligate intracellular bacteria that survive and replicate in a bacterial-modified phagosome called inclusion. As other intracellular parasites, these bacteria subvert the phagocytic pathway to avoid degradation in phagolysosomes and exploit trafficking pathways to acquire both energy and nutrients essential for their survival. Rabs are host proteins that control intracellular vesicular trafficking. Rab14, a Golgi-related Rab, controls Golgi to endosomes transport. Since Chlamydia establish a close relationship with the Golgi apparatus, the recruitment and participation of Rab14 on inclusion development and bacteria growth were analyzed. Time course analysis revealed that Rab14 associated with inclusions by 10 h post infection and was maintained throughout the entire developmental cycle. The recruitment was bacterial protein synthesis-dependent but independent of microtubules and Golgi integrity. Overexpression of Rab14 dominant negative mutants delayed inclusion enlargement, and impaired bacteria replication as determined by IFU. Silencing of Rab14 by siRNA also decreased bacteria multiplication and infectivity. By electron microscopy, aberrant bacteria were observed in cells overexpressing the cytosolic negative Rab14 mutant. Our results showed that Rab14 facilitates the delivery of sphingolipids required for bacterial development and replication from the Golgi to chlamydial inclusions. Novel anti-chlamydial therapies could be developed based on the knowledge of how bacteria subvert host vesicular transport events through Rabs manipulation.

Chlamydia trachomatis intercepts Golgi-derived sphingolipids through a Rab14-mediated transport required for bacterial development and replication.

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Capmany, Anahí; Damiani, María Teresa

2010-11-22

Chlamydia trachomatis are obligate intracellular bacteria that survive and replicate in a bacterial-modified phagosome called inclusion. As other intracellular parasites, these bacteria subvert the phagocytic pathway to avoid degradation in phagolysosomes and exploit trafficking pathways to acquire both energy and nutrients essential for their survival. Rabs are host proteins that control intracellular vesicular trafficking. Rab14, a Golgi-related Rab, controls Golgi to endosomes transport. Since Chlamydia establish a close relationship with the Golgi apparatus, the recruitment and participation of Rab14 on inclusion development and bacteria growth were analyzed. Time course analysis revealed that Rab14 associated with inclusions by 10 h post infection and was maintained throughout the entire developmental cycle. The recruitment was bacterial protein synthesis-dependent but independent of microtubules and Golgi integrity. Overexpression of Rab14 dominant negative mutants delayed inclusion enlargement, and impaired bacteria replication as determined by IFU. Silencing of Rab14 by siRNA also decreased bacteria multiplication and infectivity. By electron microscopy, aberrant bacteria were observed in cells overexpressing the cytosolic negative Rab14 mutant. Our results showed that Rab14 facilitates the delivery of sphingolipids required for bacterial development and replication from the Golgi to chlamydial inclusions. Novel anti-chlamydial therapies could be developed based on the knowledge of how bacteria subvert host vesicular transport events through Rabs manipulation.

Genetics in arterial calcification: pieces of a puzzle and cogs in a wheel.

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Rutsch, Frank; Nitschke, Yvonne; Terkeltaub, Robert

2011-08-19

Artery calcification reflects an admixture of factors such as ectopic osteochondral differentiation with primary host pathological conditions. We review how genetic factors, as identified by human genome-wide association studies, and incomplete correlations with various mouse studies, including knockout and strain analyses, fit into "pieces of the puzzle" in intimal calcification in human atherosclerosis, and artery tunica media calcification in aging, diabetes mellitus, and chronic kidney disease. We also describe in sharp contrast how ENPP1, CD73, and ABCC6 serve as "cogs in a wheel" of arterial calcification. Specifically, each is a minor component in the function of a much larger network of factors that exert balanced effects to promote and suppress arterial calcification. For the network to normally suppress spontaneous arterial calcification, the "cogs" ENPP1, CD73, and ABCC6 must be present and in working order. Monogenic ENPP1, CD73, and ABCC6 deficiencies each drive a molecular pathophysiology of closely related but phenotypically different diseases (generalized arterial calcification of infancy (GACI), pseudoxanthoma elasticum (PXE) and arterial calcification caused by CD73 deficiency (ACDC)), in which premature onset arterial calcification is a prominent but not the sole feature.

The Mini-Cog, Clock Drawing Test, and the Mini-Mental State Examination in a German memory clinic: specificity of separation dementia from depression.

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Milian, Monika; Leiherr, Anna-Maria; Straten, Guido; Müller, Stephan; Leyhe, Thomas; Eschweiler, Gerhard W

2013-01-01

The aim of this study was to assess the specificities of the Mini-Cog, the Clock Drawing Test (CDT), and the Mini-Mental State Examination (MMSE) against depression and healthy controls in a German Memory Clinic. Furthermore, we analyzed the specificities of all three screening instruments in dependence of actual depression severity. Data from 142 depressed elderly, 438 dementia patients, and 64 healthy controls were retrospectively analyzed. The CDT and an extraction of the three-item recall of the MMSE were used to constitute the Mini-Cog algorithm. Depression severity was rated by either the Beck Depression Inventory (BDI) or the Geriatric Depression Scale (GDS) depending on the age of the patients. The Mini-Cog achieved a specificity of 79.6% against depressed elderly and 100.0% against healthy subjects (p Mini-Cog and the CDT, but also showed the lowest sensitivity for the detection of dementia. Surprisingly, the depression severity had no effect on the specificity of the Mini-Cog and the CDT, only the MMSE was susceptible for the depression severity. Although the MMSE showed higher specificities, the weighting between the sensitivities and specificities in all tests prove again the Mini-Cog as a short, valid, and sensitive screening tool.

C9orf72’s interaction with Rab GTPases - modulation of membrane traffic and autophagy

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Bor Luen Tang

2016-10-01

Full Text Available Hexanucleotide repeat expansion in an intron of Chromosome 9 open reading frame 72 (C9orf72 is the most common genetic cause of Amyotrophic Lateral Sclerosis (ALS and Frontotemporal Dementia (FTD. While functional haploinsufficiency of C9orf72 resulting from the mutation may play a role in ALS/FTD, the actual cellular role of the protein has been unclear. Recent findings have now shown that C9orf72 physically and functionally interacts with multiple members of the Rab small GTPases family, consequently exerting important influences on cellular membrane traffic and the process of autophagy. Loss of C9orf72 impairs endocytosis in neuronal cell lines, and attenuated autophagosome formation. Interestingly, C9orf72 could influence autophagy both as part of a Guanine nucleotide exchange factor (GEF complex, or as a Rab effector that facilitates transport of the Unc-51-like Autophagy Activating Kinase 1 (Ulk1 autophagy initiation complex. The cellular function of C9orf72 is discussed in the light of these recent findings

Information Exchange among COG Member Stations, Utility/AECL Design and External Nuclear Organizations

International Nuclear Information System (INIS)

Turner, Dave

1998-01-01

The paper presents the COG Information Exchange Program the mandate of which reads: 'To promote the safety reliability and excellence of CANDU plants worldwide by facilitating the sharing of operating experience amongst the members of COG'. To fulfill its mandate the COG operates Information Exchange Program which: 1. Provides a user-friendly facility, COGNET, for staff of COG member organizations to communicate with each other and with external stations, utilities and organizations on topics applicable to CANDU operation, safety, maintenance, design and performance; 2. Offers one-stop shopping for information applicable to the design, operation, maintenance, safety and performance of CANDU's; 3. Reports and compares the performance of all CANDU stations; 4. Organizes opportunities for individuals involved with the operation of CANDU's to meet with their peers and with CANDU industry experts to share operating experience; 5. Facilitates the identification of generic CANDU problems which leads to the addressing of these problems by others through co-operative projects, designer feedback and R and D programs. The paper has the following content: 1. COGNET; 1.1. COGNET Message Forums; 1.2. COGNET Operations Forums; 1.3. COGNET Private Messages; 2. Report Databases and Library; 2.1. REPEX (Technical Reports); 2.2. PCN (CANDU Plant Modifications); 2.3. SEREX (CANDU Station Events); 2.4. INPO (International Events); 3. CANDU Performance; 3.1. COG NEWSLETTERS; 3.2. Performance Indicators; 4. Workshops; 4.1. COG Workshops

Validation and cultural adaptation of the Arabic versions of the Mini–Mental Status Examination – 2 and Mini-Cog test

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Albanna M

2017-03-01

Full Text Available Mohammad Albanna,1,* Arij Yehya,2,* Abdalla Khairi,1 Elnour Dafeeah,1 Abdelsalam Elhadi,3 Lamia Rezgui,4 Shahada Al Kahlout,4 Adil Yousif,5 Basim Uthman,6 Hassen Al-Amin2 1Psychiatry Department, Hamad Medical Corporation, 2Psychiatry Department, Weill Cornell Medicine – Qatar, 3Primary Health Care Corporation, 4Geriatrics Department, Rumailah Hospital, Hamad Medical Corporation, 5Department of Mathematics, Statistics and Physics, College of Arts and Sciences, Qatar University, 6Neurology Department, Weill Cornell Medicine – Qatar, Doha, Qatar *These authors contributed equally to this work Introduction: The elderly population is increasing around the world, and the prevalence of dementia increases with age. Hence, it is expected that the number of people with dementia will increase significantly in the coming years. The Mini–Mental Status Examination – 2 (MMSE-2 and Mini-Cog are widely used tests to screen for dementia. These scales have good reliability and validity and are easy to administer in clinical and research settings. Aim: The purpose of this study was to validate the Arabic versions of MMSE-2 and Mini-Cog. These scales were assessed against the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR criteria for dementia, as the gold standard.Methods: The standard versions of the MMSE-2 and Mini-Cog were translated to Arabic following the back-translation method. Then, a trained rater administered these tests to 134 Arab elderly aged >60 years. A physician, blind to the results of these two tests, assessed the participants for vascular dementia or probable Alzheimer’s disease, based on the DSM-IV-TR criteria.Results: The sample included 67.2% Qataris. The mean age was 74.86 years (standard deviation =7.71, and 61.9% did not attend school. The mean of the adjusted scores of MMSE-2 based on age and education level was 19.60 (standard deviation =6.58. According to DSM-IV-TR, 17.2% of

Expression of Rab25 in non-small cell lung cancer and its clinical significance

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Pu ZHOU

2014-03-01

Full Text Available Objective　To assess the expression of Rab25 protein in non-small cell lung cancer (NSCLC, and explore the correlation of its expression with tumor proliferation and metastasis. Methods　Sixty-one cases of NSCLC specimens (31 cases of squamous cell carcinoma, 26 cases of adenocarcinoma, and 4 cases of adenosquamous carcinoma undergone surgical treatment, and 40 specimens of adjacent normal lung tissues were obtained from Jan. 2009 to Jun. 2010 at Xingqiao Hospital of Third Military Medical University. Immunochemistry method of MaxVision was used to detect the expression of Rab25 in the specimens, and then the correlation of the expression with the clinicopathological parameters (patients' sex, age, smoking history, tumor type, differentiation, volume, TNM stage, lymph metastasis, etc. was analyzed using statistical software SPSS 21.0. Results 　Rab25 protein was mainly expressed in cytoplasm and cell membrane. The positive rate of Rab25 in NSCLC was 93.4%, which was significantly higher than that in adjacent normal tissues (27.5%, P＜0.01. The expression of Rab25 protein was significantly associated with the TNM stage and tumor size (P＜0.05. Conclusions　The expression of Rab25 is obviously higher in NSCLC than in the adjacent normal tissues, and the expression is associated with TNM stage and tumor size. Moreover, the later of the NSCLC stage, the larger of tumor size, and the higher of Rab25 expression will be in the NSCLC tissue. DOI: 10.11855/j.issn.0577-7402.2014.02.16

Administration and scoring variance on the ADAS-Cog.

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Connor, Donald J; Sabbagh, Marwan N

2008-11-01

The Alzheimer's Disease Assessment Scale - Cognitive (ADAS-Cog) is the most commonly used primary outcome instrument in clinical trials for treatments of dementia. Variations in forms, administration procedures and scoring rules, along with rater turnover and intra-rater drift may decrease the reliability of the instrument. A survey of possible variations in the ADAS-Cog was administered to 26 volunteer raters at a clinical trials meeting. Results indicate notable protocol variations in the forms used, administration procedures, and scoring rules. Since change over time is used to determine treatment effect in clinical trials, standardizing the instrument's ambiguities and addressing common problems will greatly increase the instrument's reliability and thereby enhance its sensitivity to treatment effects.

Strain-Specific Altered Regulatory Response of Rab7a and Tau in Creutzfeldt-Jakob Disease and Alzheimer's Disease.

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Zafar, Saima; Younas, Neelam; Correia, Susana; Shafiq, Mohsin; Tahir, Waqas; Schmitz, Matthias; Ferrer, Isidre; Andréoletti, Olivier; Zerr, Inga

2017-01-01

There is an increasing demand for the understanding of pathophysiology on neurodegeneration diseases at early stages. Changes in endocytic machinery and the cytoskeleton-associated response are the first alterations observed in Creutzfeldt-Jakob disease (CJD) and Alzheimer's disease AD brain. In this study, we performed a targeted search for endocytic pathway proteins in the different regions of the brain. We found late endosome marker Rab7a which was significantly upregulated in the frontal cortex region in the rapid progressive CJD form (MM1) and rapid progressive AD (rpAD) forms. However, Rab9 expression was significantly downregulated only in CJD-MM1 brain frontal cortex region. In the cerebellum, Rab7a expression showed significant upregulation in both subtype MM1 and VV2 CJD forms, in contrast to Rab9 which showed significant downregulation in both subtype MM1 and VV2 CJD forms at terminal stage of the disease. To check regulatory response at pre-symptomatic stage of the disease, we checked the regulatory interactive response of Rab7a, Rab9, and known biomarkers PrP C and tau forms in frontal cortex at pre-symptomatic stage of the disease in tg340 mice expressing about fourfold of human PrP-M129 with PrP-null background that had been inoculated with human sCJD MM1 brain tissue homogenates (sCJD MM1 mice). In addition, we analyzed 5XFAD mice, exhibiting five mutations in the APP and presenilin genes related to familial Alzheimer's disease (FAD), to validate specific regulatory response of Rab7a, Rab9, tau, and phosphorylated form of tau by immunostaining 5XFAD mice in comparison with the wild-type age-matched mice brain. The cortical region of 5XFAD mice brain showed accumulated form of Rab7a in puncta that co-label for p-Tau, indicating colocalization by using confocal laser-scanning microscopy and was confirmed by using reverse co-immunoprecipitation. Furthermore, synthetic RNA (siRNA) against the Rab7a gene decreased expression of Rab7a protein, in cortical

Reliability of the Alzheimer's disease assessment scale (ADAS-Cog) in longitudinal studies.

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Khan, Anzalee; Yavorsky, Christian; DiClemente, Guillermo; Opler, Mark; Liechti, Stacy; Rothman, Brian; Jovic, Sofija

2013-11-01

Considering the scarcity of longitudinal assessments of reliability, there is need for a more precise understanding of cognitive decline in Alzheimer's Disease (AD). The primary goal was to assess longitudinal changes in inter-rater reliability, test retest reliability and internal consistency of scores of the ADAS-Cog. 2,618 AD subjects were enrolled in seven randomized, double-blind, placebo-controlled, multicenter-trials from 1986 to 2009. Reliability, internal-consistency and cross-sectional analysis of ADAS-Cog and MMSE across seven visits were examined. Intra-class correlation (ICC) for ADAS-Cog was moderate to high supporting their reliability. Absolute Agreement ICCs 0.392 (Visit-7) to 0.806 (Visit-2) showed a progressive decrease in correlations across time. Item analysis revealed a decrease in item correlations, with the lowest correlations for Visit 7 for Commands (ICC=0.148), Comprehension (ICC=0.092), Spoken Language (ICC=0.044). Suitable assessment of AD treatments is maintained through accurate measurement of clinically significant outcomes. Targeted rater education ADAS-Cog items over-time can improve ability to administer and score the scale.

Mini-Cog and Mini-Mental State Examination: agreement in a cross-sectional study with an elderly sample.

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Costa, Diogo; Severo, Milton; Fraga, Sílvia; Barros, Henrique

2012-01-01

We aimed to compare the Mini-Mental State Examination (MMSE) with the Mini-Cog, measuring agreement in participants' classification, using a general population sample. Cross-sectional evaluation of 609 community dwellers aged ≥60 years was performed by trained interviewers. Cohen's kappa and 95% confidence intervals (CI) were calculated to assess overall agreement, and Cronbach alphas computed to assess reliability. Two-parameter Item Response Theory models (difficulty and discrimination parameters) were used to assess discrimination. Considering MMSE cut-point for scores Mini-Cog's cut-point score Mini-Cog Mini-Cog Mini-Cog's alpha was 0.2776. Co-calibration according to inherent ability is graphically presented. Agreement between scales seems fragile in our sample. The discriminative and reliability analysis suggests a better performance for subsets of the MMSE compared with the Mini-Cog. Usefulness of calibrated scores is discussed. Copyright © 2012 S. Karger AG, Basel.

76 FR 13446 - Nittany Bald and Eagle Railroad Company-Operation Exemption-SEDA-COG Joint Rail Authority

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2011-03-11

... Eagle Railroad Company-Operation Exemption-SEDA- COG Joint Rail Authority Nittany Bald and Eagle... 0.0 and milepost 1.8 in Castanea, Clinton County, Pa. The line is owned or leased by SEDA-COG Joint Rail Authority (SEDA-COG). N&BE states that the line it proposes to operate is an extension of its...

Consortium on the Genetics of Schizophrenia (COGS) assessment of endophenotypes for schizophrenia: an introduction to this Special Issue of Schizophrenia Research.

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Swerdlow, Neal R; Gur, Raquel E; Braff, David L

2015-04-01

The COGS is a multi-site NIMH-sponsored investigation of the genetic basis of 12 primary and multiple secondary quantitative endophenotypes in schizophrenia. Since 2003, COGS has completed studies using a family-based ascertainment strategy (COGS-1), and a case-control ascertainment strategy (COGS-2) (cumulative "n">4000). COGS-1 family study confirmed robust deficits in, and heritability of, these endophenotypes in schizophrenia, and provided evidence for a coherent genetic architecture underlying the risk for neurocognitive and neurophysiological deficits in this disorder. COGS-2 case-control findings, many reported herein, establish a foundation for fine genomic mapping and other analyses of these endophenotypes and risk genes for SZ. Several reports in this Special Issue compare findings of endophenotype deficits generated by fundamentally different COGS-1 vs. COGS-2 ascertainment strategies. Despite the expectation that family-based and case-control designs would establish demographically and potentially biologically distinct patient cohorts, findings generally revealed comparable patterns of endophenotype deficits across studies. The COGS-2 case-control design facilitated the accrual of a larger "n", permitting detailed analyses of factors moderating endophenotype performance. Some COGS-2 endophenotypes not assessed in COGS-1 are also reported, as is a new factor analytic strategy for identifying shared vs. unique factors among the COGS endophenotypes which can be used to develop composite variables with distinct genetic signatures. The path to date of COGS-1 endophenotype and genetic findings, followed by replication and extension in COGS-2, establishes benchmarks for endophenotype deficits in SZ and their moderation by specific factors, and clear expectations for informative findings from upcoming COGS-2 genetic analyses. Published by Elsevier B.V.

Rab22a enhances CD147 recycling and is required for lung cancer cell migration and invasion.

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Zhou, Yang; Wu, Bo; Li, Jiang-Hua; Nan, Gang; Jiang, Jian-Li; Chen, Zhi-Nan

2017-08-01

Rab22a is a member of the Ras-related small GTPase family, which plays a key role in regulating the recycling of cargo proteins entering cells through clathrin-independent endocytosis (CIE). Rab22a is overexpressed in different cancer types, including liver cancer, malignant melanoma, ovarian cancer and osteosarcoma. However, its oncogenic role remains unknown. In this study, we found that silencing of Rab22a suppressed the migration and invasion of lung cancer cells. Furthermore, Rab22a interacts with CD147, and knockdown of Rab22a blocks CD147 recycling and promotes CD147 degradation. Taken together, our findings indicate that Rab22a enhances recycling of CD147, which is required for lung cancer cell migration and invasion,and targeting CD147 recycling may be a rational strategy for lung cancer therapy. Copyright © 2017. Published by Elsevier Inc.

Mutations of the catalytic subunit of RAB3GAP cause Warburg Micro syndrome

DEFF Research Database (Denmark)

Aligianis, Irene A; Johnson, Colin A; Gissen, Paul

2005-01-01

Warburg Micro syndrome (WARBM1) is a severe autosomal recessive disorder characterized by developmental abnormalities of the eye and central nervous system and by microgenitalia. We identified homozygous inactivating mutations in RAB3GAP, encoding RAB3 GTPase activating protein, a key regulator...

Spontaneous CD8 T cell responses against the melanocyte differentiation antigen RAB38/NY-MEL-1 in melanoma patients.

Science.gov (United States)

Walton, Senta M; Gerlinger, Marco; de la Rosa, Olga; Nuber, Natko; Knights, Ashley; Gati, Asma; Laumer, Monika; Strauss, Laura; Exner, Carolin; Schäfer, Niklaus; Urosevic, Mirjana; Dummer, Reinhard; Tiercy, Jean-Marie; Mackensen, Andreas; Jaeger, Elke; Lévy, Frédéric; Knuth, Alexander; Jäger, Dirk; Zippelius, Alfred

2006-12-01

The melanocyte differentiation Ag RAB38/NY-MEL-1 was identified by serological expression cloning (SEREX) and is expressed in the vast majority of melanoma lesions. The immunogenicity of RAB38/NY-MEL-1 has been corroborated previously by the frequent occurrence of specific Ab responses in melanoma patients. To elucidate potential CD8 T cell responses, we applied in vitro sensitization with overlapping peptides spanning the RAB38/NY-MEL-1 protein sequence and the reverse immunology approach. The identified peptide RAB38/NY-MEL-1(50-58) exhibited a marked response in ELISPOT assays after in vitro sensitization of CD8 T cells from HLA-A *0201(+) melanoma patients. In vitro digestion assays using purified proteasomes provided evidence of natural processing of RAB38/NY-MEL-1(50-58) peptide. Accordingly, monoclonal RAB38/NY-MEL-1(50-58)-specific T cell populations were capable of specifically recognizing HLA-A2(+) melanoma cell lines expressing RAB38/NY-MEL-1. Applying fluorescent HLA-A2/RAB38/NY-MEL-1(50-58) multimeric constructs, we were able to document a spontaneously developed memory/effector CD8 T cell response against this peptide in a melanoma patient. To elucidate the Ag-processing pathway, we demonstrate that RAB38/NY-MEL-1(50-58) is produced efficiently by the standard proteasome and the immunoproteasome. In addition to the identification of a RAB38/NY-MEL-1-derived immunogenic CD8 T cell epitope, this study is instrumental for both the onset and monitoring of future RAB38/NY-MEL-1-based vaccination trials.

Summary - COG: A new point-wise Monte Carlo code for burnup credit analysis

International Nuclear Information System (INIS)

Alesso, H.P.

1989-01-01

COG, a new point-wise Monte Carlo code being developed and tested at Lawrence Livermore National Laboratory (LLNL) for the Cray-1, solves the Boltzmann equation for the transport of neutrons, photons, and (in future versions) other particles. Techniques included in the code for modifying the random walk of particles make COG most suitable for solving deep-penetration (shielding) problems and a wide variety of criticality problems. COG is similar to a number of other computer codes used in the shielding community. Each code is a little different in its geometry input and its random-walk modification options. COG is a Monte Carlo code specifically designed for the CRAY (in 1986) to be as precise as the current state of physics knowledge. It has been extensively benchmarked and used as a shielding code at LLNL since 1986, and has recently been extended to accomplish criticality calculations. It will make an excellent tool for future shipping cask studies

Tubular permanent magnet actuators: cogging forces characterization

NARCIS (Netherlands)

Paulides, J.J.H.; Janssen, J.L.G.; Encica, L.; Lomonova, E.A.

2009-01-01

Tubular permanent magnet actuators are evermore used in demanding industrial and automotive applications. However, these actuators can suffer from large cogging forces, which have a destabilizing effect on the servo control system and compromise position and speed control accuracy. This paper

Deficient Rab11 activity underlies glucose hypometabolism in primary neurons of Huntington's disease mice

Energy Technology Data Exchange (ETDEWEB)

Li, Xueyi, E-mail: xli12@partners.org [Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129 (United States); Valencia, Antonio; McClory, Hollis; Sapp, Ellen; Kegel, Kimberly B. [Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129 (United States); DiFiglia, Marian, E-mail: difiglia@helix.mgh.harvard.edu [Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129 (United States)

2012-05-18

Highlights: Black-Right-Pointing-Pointer Primary Huntington's disease neurons are impaired in taking up glucose. Black-Right-Pointing-Pointer Rab11 modulates glucose uptake in neurons. Black-Right-Pointing-Pointer Increasing Rab11 activity attenuates the glucose uptake defect in disease neurons. Black-Right-Pointing-Pointer We provide a novel mechanism for glucose hypometabolism in Huntington's disease. -- Abstract: Huntington's disease (HD) is a progressive neurodegenerative disorder caused by a CAG repeat expansion in the huntingtin gene. Positron emission tomography studies have revealed a decline in glucose metabolism in the brain of patients with HD by a mechanism that has not been established. We examined glucose utilization in embryonic primary cortical neurons of wild-type (WT) and HD knock-in mice, which have 140 CAG repeats inserted in the endogenous mouse huntingtin gene (HD{sup 140Q/140Q}). Primary HD{sup 140Q/140Q} cortical neurons took up significantly less glucose than did WT neurons. Expression of permanently inactive and permanently active forms of Rab11 correspondingly altered glucose uptake in WT neurons, suggesting that normal activity of Rab11 is needed for neuronal uptake of glucose. It is known that Rab11 activity is diminished in HD{sup 140Q/140Q} neurons. Expression of dominant active Rab11 to enhance the activity of Rab11 normalized glucose uptake in HD{sup 140Q/140Q} neurons. These results suggest that deficient activity of Rab11 is a novel mechanism for glucose hypometabolism in HD.

Conservation of the TRAPPII-specific subunits of a Ypt/Rab exchanger complex

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Yoo Eunice

2007-02-01

Full Text Available Abstract Background Ypt/Rab GTPases and their GEF activators regulate intra-cellular trafficking in all eukaryotic cells. In S. cerivisiae, the modular TRAPP complex acts as a GEF for the Golgi gatekeepers: Ypt1 and the functional pair Ypt31/32. While TRAPPI, which acts in early Golgi, is conserved from fungi to animals, not much is known about TRAPPII, which acts in late Golgi and consists of TRAPPI plus three additional subunits. Results Here, we show a phylogenetic analysis of the three TRAPPII-specific subunits. One copy of each of the two essential subunits, Trs120 and Trs130, is present in almost every fully sequenced eukaryotic genome. Moreover, the primary, as well as the predicted secondary, structure of the Trs120- and Trs130-related sequences are conserved from fungi to animals. The mammalian orthologs of Trs120 and Trs130, NIBP and TMEM1, respectively, are candidates for human disorders. Currently, NIBP is implicated in signaling, and TMEM1 is suggested to have trans-membrane domains (TMDs and to function as a membrane channel. However, we show here that the yeast Trs130 does not function as a trans-membrane protein, and the human TMEM1 does not contain putative TMDs. The non-essential subunit, Trs65, is conserved only among many fungi and some unicellular eukaryotes. Multiple alignment analysis of each TRAPPII-specific subunit revealed conserved domains that include highly conserved amino acids. Conclusion We suggest that the function of both NIBP and TMEM1 in the regulation of intra-cellular trafficking is conserved from yeast to man. The conserved domains and amino acids discovered here can be used for functional analysis that should help to resolve the differences in the assigned functions of these proteins in fungi and animals.

Validation and cultural adaptation of the Arabic versions of the Mini–Mental Status Examination – 2 and Mini-Cog test

Science.gov (United States)

Albanna, Mohammad; Yehya, Arij; Khairi, Abdalla; Dafeeah, Elnour; Elhadi, Abdelsalam; Rezgui, Lamia; Al Kahlout, Shahada; Yousif, Adil; Uthman, Basim; Al-Amin, Hassen

2017-01-01

Introduction The elderly population is increasing around the world, and the prevalence of dementia increases with age. Hence, it is expected that the number of people with dementia will increase significantly in the coming years. The Mini–Mental Status Examination – 2 (MMSE-2) and Mini-Cog are widely used tests to screen for dementia. These scales have good reliability and validity and are easy to administer in clinical and research settings. Aim The purpose of this study was to validate the Arabic versions of MMSE-2 and Mini-Cog. These scales were assessed against the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR) criteria for dementia, as the gold standard. Methods The standard versions of the MMSE-2 and Mini-Cog were translated to Arabic following the back-translation method. Then, a trained rater administered these tests to 134 Arab elderly aged >60 years. A physician, blind to the results of these two tests, assessed the participants for vascular dementia or probable Alzheimer’s disease, based on the DSM-IV-TR criteria. Results The sample included 67.2% Qataris. The mean age was 74.86 years (standard deviation =7.71), and 61.9% did not attend school. The mean of the adjusted scores of MMSE-2 based on age and education level was 19.60 (standard deviation =6.58). According to DSM-IV-TR, 17.2% of the participants had dementia. Sensitivity and specificity of the MMSE-2 and the Mini-Cog together were 71.4% and 61.6%, respectively, which were better than those of each test alone. Conclusion Together, the Arabic versions of MMSE-2 and Mini-Cog are good screening tools for cognitive impairment in Arabs. PMID:28352179

Comparative genomic analysis by microbial COGs self-attraction rate.

Science.gov (United States)

Santoni, Daniele; Romano-Spica, Vincenzo

2009-06-21

Whole genome analysis provides new perspectives to determine phylogenetic relationships among microorganisms. The availability of whole nucleotide sequences allows different levels of comparison among genomes by several approaches. In this work, self-attraction rates were considered for each cluster of orthologous groups of proteins (COGs) class in order to analyse gene aggregation levels in physical maps. Phylogenetic relationships among microorganisms were obtained by comparing self-attraction coefficients. Eighteen-dimensional vectors were computed for a set of 168 completely sequenced microbial genomes (19 archea, 149 bacteria). The components of the vector represent the aggregation rate of the genes belonging to each of 18 COGs classes. Genes involved in nonessential functions or related to environmental conditions showed the highest aggregation rates. On the contrary genes involved in basic cellular tasks showed a more uniform distribution along the genome, except for translation genes. Self-attraction clustering approach allowed classification of Proteobacteria, Bacilli and other species belonging to Firmicutes. Rearrangement and Lateral Gene Transfer events may influence divergences from classical taxonomy. Each set of COG classes' aggregation values represents an intrinsic property of the microbial genome. This novel approach provides a new point of view for whole genome analysis and bacterial characterization.

Salmonella Disrupts Host Endocytic Trafficking by SopD2-Mediated Inhibition of Rab7

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Vanessa M. D’Costa

2015-09-01

Full Text Available Intracellular bacterial pathogens of a diverse nature share the ability to evade host immunity by impairing trafficking of endocytic cargo to lysosomes for degradation, a process that is poorly understood. Here, we show that the Salmonella enterica type 3 secreted effector SopD2 mediates this process by binding the host regulatory GTPase Rab7 and inhibiting its nucleotide exchange. Consequently, this limits Rab7 interaction with its dynein- and kinesin-binding effectors RILP and FYCO1 and thereby disrupts host-driven regulation of microtubule motors. Our study identifies a bacterial effector capable of directly binding and thereby modulating Rab7 activity and a mechanism of endocytic trafficking disruption that may provide insight into the pathogenesis of other bacteria. Additionally, we provide a powerful tool for the study of Rab7 function, and a potential therapeutic target.

Incremental Validity of the WJ III COG: Limited Predictive Effects beyond the GIA-E

Science.gov (United States)

McGill, Ryan J.; Busse, R. T.

2015-01-01

This study is an examination of the incremental validity of Cattell-Horn-Carroll (CHC) broad clusters from the Woodcock-Johnson III Tests of Cognitive Abilities (WJ III COG) for predicting scores on the Woodcock-Johnson III Tests of Achievement (WJ III ACH). The participants were children and adolescents, ages 6-18 (n = 4,722), drawn from the WJ…

Wheat TaRab7 GTPase is part of the signaling pathway in responses to stripe rust and abiotic stimuli.

Directory of Open Access Journals (Sweden)

Furong Liu

Full Text Available Small GTP-binding proteins function as regulators of specific intercellular fundamental biological processes. In this study, a small GTP-binding protein Rab7 gene, designated as TaRab7, was identified and characterized from a cDNA library of wheat leaves infected with Puccinia striiformis f. sp. tritici (Pst the wheat stripe rust pathogen. The gene was predicted to encode a protein of 206 amino acids, with a molecular mass of 23.13 KDa and an isoeletric point (pI of 5.13. Further analysis revealed the presence of a conserved signature that is characteristic of Rab7, and phylogenetic analysis demonstrated that TaRab7 has the highest similarity to a small GTP binding protein gene (BdRab7-like from Brachypodium distachyon. Quantitative real-time PCR assays revealed that the expression of TaRab7 was higher in the early stage of the incompatible interactions between wheat and Pst than in the compatible interaction, and the transcription level of TaRab7 was also highly induced by environmental stress stimuli. Furthermore, knocking down TaRab7 expression by virus induced gene silencing enhanced the susceptibility of wheat cv. Suwon 11 to an avirulent race CYR23. These results imply that TaRab7 plays an important role in the early stage of wheat-stripe rust fungus interaction and in stress tolerance.

Long-term changes in ADAS-cog: what is clinically relevant for disease modifying trials in Alzheimer?

Science.gov (United States)

Vellas, B; Andrieu, S; Cantet, C; Dartigues, J F; Gauthier, S

2007-01-01

With the development of long-term disease modifying trials, changes in ADAS-Cog at 18 months will rise certainly many questions. We decided to look in the Real.fr study at the links between changes in cognition, ADAS-Cog and function. A total of 346 Alzheimer's patients with ADAS-cog at entry and at 18 months. were eligible for this analysis. These patients were on average 77.44 years old and 254 (72.36%) were women. The great majority lived at home and about 93% were treated with a cholinesterase inhibitor at baseline. Thirty three patients (9%) had a gain of more than 2 points at the ADAS-cog at 18 months (Group I, improvement); 130 (38%) were considered as stable, the reference group (Group II ) characterized by a stability at the ADAS-cog: decline of 2 points to gain of 2 points, 112 subjects (32%) had a moderate decline between 2 and 7 at the ADAScog (Group III) and finally 71 subjects (21%) had a severe impairment more than seven points at the ADAS-cog. A loss of one Basic ADL is certainly highly relevant, and such a change was found at 18 months in more than half of the subjects, which is not surprising for a long-term evolution in mild to moderate AD. An impairment of more than 7 points at the ADAS-cog was found in 21% of the subjects at 18 months and was associated with loss.

Robust differences in antisaccade performance exist between COGS schizophrenia cases and controls regardless of recruitment strategies.

Science.gov (United States)

Radant, Allen D; Millard, Steven P; Braff, David L; Calkins, Monica E; Dobie, Dorcas J; Freedman, Robert; Green, Michael F; Greenwood, Tiffany A; Gur, Raquel E; Gur, Ruben C; Lazzeroni, Laura C; Light, Gregory A; Meichle, Sean P; Nuechterlein, Keith H; Olincy, Ann; Seidman, Larry J; Siever, Larry J; Silverman, Jeremy M; Stone, William S; Swerdlow, Neal R; Sugar, Catherine A; Tsuang, Ming T; Turetsky, Bruce I; Tsuang, Debby W

2015-04-01

The impaired ability to make correct antisaccades (i.e., antisaccade performance) is well documented among schizophrenia subjects, and researchers have successfully demonstrated that antisaccade performance is a valid schizophrenia endophenotype that is useful for genetic studies. However, it is unclear how the ascertainment biases that unavoidably result from recruitment differences in schizophrenia subjects identified in family versus case-control studies may influence patient-control differences in antisaccade performance. To assess the impact of ascertainment bias, researchers from the Consortium on the Genetics of Schizophrenia (COGS) compared antisaccade performance and antisaccade metrics (latency and gain) in schizophrenia and control subjects from COGS-1, a family-based schizophrenia study, to schizophrenia and control subjects from COGS-2, a corresponding case-control study. COGS-2 schizophrenia subjects were substantially older; had lower education status, worse psychosocial function, and more severe symptoms; and were three times more likely to be a member of a multiplex family than COGS-1 schizophrenia subjects. Despite these variations, which were likely the result of ascertainment differences (as described in the introduction to this special issue), the effect sizes of the control-schizophrenia differences in antisaccade performance were similar in both studies (Cohen's d effect size of 1.06 and 1.01 in COGS-1 and COGS-2, respectively). This suggests that, in addition to the robust, state-independent schizophrenia-related deficits described in endophenotype studies, group differences in antisaccade performance do not vary based on subject ascertainment and recruitment factors. Published by Elsevier B.V.

[Is it pseudo-dementia? The validation of the Adas-Cog questionnaire in Hungary].

Science.gov (United States)

Drótos, Gergely; Pákáski, Magdolna; Papp, Edina; Kálmán, János

2012-01-01

The cognitive subscale of the Alzheimer's Disease Assessment Scale (ADAS-Cog) has been established internationally as an instrument for the assessment of treatment efficacy and cognitive performance in clinical trials. There is no data about the validity and characteristics of ADAS-Cog in Hungarian sample. This study is a part of the Hungarian standardization process of ADAS-Cog. It is crucial to examine the cognitive performance of patients with pseudodementia caused by depression (D) because of its' similarities with Alzheimer's disease (AK). The objective of the study was to analyze the characteristics of the cognitive subscale for further validation purposes. The study aimed at analyzing the ADAS-Cog performance of patients with D and AK in a Hungarian sample to make future studies more accurate through more exact differentiation between the two diseases. Fourty-seven normal elderly control (KNT) subjects, 66 AK patients and 39 patients with D participated in the study. The mental state and the severity of depressive symptoms of the participants were assessed by the means of ADAS-Cog, Mini Mental State Examination (MMSE) and Beck Depression Inventory. The ADAS-Cog is sensitive to the cognitive decline of the depressed group (sensitivity=69.2%, specificity=89.4%, AUC=0.868, p>0.001). While the performance of the two patient groups differed from the KNT, the groups are overlapping and the characteristic of the ROC curve and the optimal cut-off point (D:11.8; AK:12.1) indicates that the differentiation is mediocre. The results suggest that pseudodementia should be considered during the design of studies using ADASCog. Because the cognitive subscale can't accurately differentiate between AK and pseudodementia additional measures like BDI should be administered.

Clinical presentation of Griscelli syndrome type 2 and spectrum of RAB27A mutations

DEFF Research Database (Denmark)

Meeths, Marie; Bryceson, Yenan T; Rudd, Eva

2010-01-01

Griscelli syndrome type 2 (GS2) is an autosomal-recessive immunodeficiency caused by mutations in RAB27A, clinically characterized by partial albinism and haemophagocytic lymphohistocytosis (HLH). We evaluated the frequency of RAB27A mutations in 21 unrelated patients with haemophagocytic syndromes...

Synchronous and Cogged Fan Belt Performance Assessment

Energy Technology Data Exchange (ETDEWEB)

Cutler, Dylan [National Renewable Energy Lab. (NREL), Golden, CO (United States); Dean, Jesse [National Renewable Energy Lab. (NREL), Golden, CO (United States); Acosta, Jason [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2014-02-01

The GSA Regional GPG Team commissioned the National Renewable Energy Laboratory (NREL) to perform monitoring of cogged V-belts and synchronous belts on both a constant volume and a variable air volume fan at the Byron G. Rodgers Federal Building and U.S. Courthouse in Denver, Colorado. These motor/fan combinations were tested with their original, standard V-belts (appropriately tensioned by an operation and maintenance professional) to obtain a baseline for standard operation. They were then switched to the cogged V-belts, and finally to synchronous belts. The power consumption by the motor was normalized for both fan speed and air density changes. This was necessary to ensure that the power readings were not influenced by a change in rotational fan speed or by the power required to push denser air. Finally, energy savings and operation and maintenance savings were compiled into an economic life-cycle cost analysis of the different belt options.

RosettaAntibodyDesign (RAbD): A general framework for computational antibody design

Science.gov (United States)

Adolf-Bryfogle, Jared; Kalyuzhniy, Oleks; Kubitz, Michael; Hu, Xiaozhen; Adachi, Yumiko; Schief, William R.

2018-01-01

A structural-bioinformatics-based computational methodology and framework have been developed for the design of antibodies to targets of interest. RosettaAntibodyDesign (RAbD) samples the diverse sequence, structure, and binding space of an antibody to an antigen in highly customizable protocols for the design of antibodies in a broad range of applications. The program samples antibody sequences and structures by grafting structures from a widely accepted set of the canonical clusters of CDRs (North et al., J. Mol. Biol., 406:228–256, 2011). It then performs sequence design according to amino acid sequence profiles of each cluster, and samples CDR backbones using a flexible-backbone design protocol incorporating cluster-based CDR constraints. Starting from an existing experimental or computationally modeled antigen-antibody structure, RAbD can be used to redesign a single CDR or multiple CDRs with loops of different length, conformation, and sequence. We rigorously benchmarked RAbD on a set of 60 diverse antibody–antigen complexes, using two design strategies—optimizing total Rosetta energy and optimizing interface energy alone. We utilized two novel metrics for measuring success in computational protein design. The design risk ratio (DRR) is equal to the frequency of recovery of native CDR lengths and clusters divided by the frequency of sampling of those features during the Monte Carlo design procedure. Ratios greater than 1.0 indicate that the design process is picking out the native more frequently than expected from their sampled rate. We achieved DRRs for the non-H3 CDRs of between 2.4 and 4.0. The antigen risk ratio (ARR) is the ratio of frequencies of the native amino acid types, CDR lengths, and clusters in the output decoys for simulations performed in the presence and absence of the antigen. For CDRs, we achieved cluster ARRs as high as 2.5 for L1 and 1.5 for H2. For sequence design simulations without CDR grafting, the overall recovery for the

RosettaAntibodyDesign (RAbD): A general framework for computational antibody design.

Science.gov (United States)

Adolf-Bryfogle, Jared; Kalyuzhniy, Oleks; Kubitz, Michael; Weitzner, Brian D; Hu, Xiaozhen; Adachi, Yumiko; Schief, William R; Dunbrack, Roland L

2018-04-01

A structural-bioinformatics-based computational methodology and framework have been developed for the design of antibodies to targets of interest. RosettaAntibodyDesign (RAbD) samples the diverse sequence, structure, and binding space of an antibody to an antigen in highly customizable protocols for the design of antibodies in a broad range of applications. The program samples antibody sequences and structures by grafting structures from a widely accepted set of the canonical clusters of CDRs (North et al., J. Mol. Biol., 406:228-256, 2011). It then performs sequence design according to amino acid sequence profiles of each cluster, and samples CDR backbones using a flexible-backbone design protocol incorporating cluster-based CDR constraints. Starting from an existing experimental or computationally modeled antigen-antibody structure, RAbD can be used to redesign a single CDR or multiple CDRs with loops of different length, conformation, and sequence. We rigorously benchmarked RAbD on a set of 60 diverse antibody-antigen complexes, using two design strategies-optimizing total Rosetta energy and optimizing interface energy alone. We utilized two novel metrics for measuring success in computational protein design. The design risk ratio (DRR) is equal to the frequency of recovery of native CDR lengths and clusters divided by the frequency of sampling of those features during the Monte Carlo design procedure. Ratios greater than 1.0 indicate that the design process is picking out the native more frequently than expected from their sampled rate. We achieved DRRs for the non-H3 CDRs of between 2.4 and 4.0. The antigen risk ratio (ARR) is the ratio of frequencies of the native amino acid types, CDR lengths, and clusters in the output decoys for simulations performed in the presence and absence of the antigen. For CDRs, we achieved cluster ARRs as high as 2.5 for L1 and 1.5 for H2. For sequence design simulations without CDR grafting, the overall recovery for the native

Rab3A Inhibition of Ca2+ -Dependent Dopamine Release From PC12 Cells Involves Interaction With Synaptotagmin I.

Science.gov (United States)

Dai, Zhipan; Tang, Xia; Chen, Jia; Tang, Xiaochao; Wang, Xianchun

2017-11-01

Rab3 and synaptotagmin have been suggested to play important roles in the regulation of neurotransmitter release and, however, the molecular mechanism has not been completely clear. Here, we studied the effects of Rab3A and synaptotagmin I (Syt I) on dopamine release using PC12 cells as a model system. Rab3A was demonstrated to have effects on both Ca 2+ -independent and Ca 2+ -dependent dopamine releases from the PC12 cells. Application of Rab3A (up to 2500 nM) gradually decreased the amount of Ca 2+ -dependently released dopamine, indicating that Rab3A is a negative modulator that was further supported by the increase in dopamine release caused by Rab3A knockdown. Syt I knockdown weakened the Ca 2+ -dependent dopamine release, suggesting that Syt I plays a positive regulatory role in the cellular process. Treatment of the Syt I-knocked down PC12 cells with Rab3A further decreased Ca 2+ -dependent dopamine release and, however, the decrease magnitude was significantly reduced compared with that before Syt I knockdown, thus for the first time demonstrating that the inhibitory effect of Rab3A on Ca 2+ -dependent dopamine release involves the interaction with Syt I. This work has shed new light on the molecular mechanism for Rab3 and synaptotamin regulation of neurotransmitter release. J. Cell. Biochem. 118: 3696-3705, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Essential role of RAB27A in determining constitutive human skin color.

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Yasuko Yoshida-Amano

Full Text Available Human skin color is predominantly determined by melanin produced in melanosomes within melanocytes and subsequently distributed to keratinocytes. There are many studies that have proposed mechanisms underlying ethnic skin color variations, whereas the processes involved from melanin synthesis in melanocytes to the transfer of melanosomes to keratinocytes are common among humans. Apart from the activities in the melanogenic rate-limiting enzyme, tyrosinase, in melanocytes and the amounts and distribution patterns of melanosomes in keratinocytes, the abilities of the actin-associated factors in charge of melanosome transport within melanocytes also regulate pigmentation. Mutations in genes encoding melanosome transport-related molecules, such as MYO5A, RAB27A and SLAC-2A, have been reported to cause a human pigmentary disease known as Griscelli syndrome, which is associated with diluted skin and hair color. Thus we hypothesized that process might play a role in modulating skin color variations. To address that hypothesis, the correlations of expression of RAB27A and its specific effector, SLAC2-A, to melanogenic ability were evaluated in comparison with tyrosinase, using human melanocytes derived from 19 individuals of varying skin types. Following the finding of the highest correlation in RAB27A expression to the melanogenic ability, darkly-pigmented melanocytes with significantly higher RAB27A expression were found to transfer significantly more melanosomes to keratinocytes than lightly-pigmented melanocytes in co-culture and in human skin substitutes (HSSs in vivo, resulting in darker skin color in concert with the difference observed in African-descent and Caucasian skins. Additionally, RAB27A knockdown by a lentivirus-derived shRNA in melanocytes concomitantly demonstrated a significantly reduced number of transferred melanosomes to keratinocytes in co-culture and a significantly diminished epidermal melanin content skin color intensity (�

32 CFR 202.4 - Composition of a RAB.

Science.gov (United States)

2010-07-01

... appropriate. At closing installations where BRAC Cleanup Teams (BCT) exist, representatives of the BCT may... installation and the other the community. Co-chairs shall be responsible for directing and managing the RAB...

Assessment of R18, COG1410, and APP96-110 in excitotoxicity and traumatic brain injury

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Chiu Li Shan

2017-11-01

Full Text Available Cationic arginine-rich and poly-arginine peptides (referred to as CARPs have potent neuroprotective properties in in vitro excitotoxicity and in vivo models of stroke. Traumatic brain injury (TBI shares many pathophysiological processes as stroke, including excitotoxicity. Therefore, we evaluated our lead peptide, poly-arginine R18, with the COG1410 and APP96-110 peptides, which have neuroprotective actions following TBI. In an in vitro cortical neuronal glutamic acid excitotoxicity injury model, R18 was highly neuroprotective and reduced neuronal calcium influx, while COG1410 and APP96-110 displayed modest neuroprotection and were less effective at reducing calcium influx. In an impact-acceleration closed-head injury model (Marmarou model, R18, COG1410, and APP96-110 were administered intravenously (300 nmol/kg at 30 minutes after injury in male Sprague-Dawley rats. When compared to vehicle, no peptide significantly improved functional outcomes, however the R18 and COG1410 treatment groups displayed positive trends in the adhesive tape test and rotarod assessments. Similarly, no peptide had a significant effect on hippocampal neuronal loss, however a significant reduction in axonal injury was observed for R18 and COG1410. In conclusion, this study has demonstrated that R18 is significantly more effective than COG1410 and APP96-110 at reducing neuronal injury and calcium influx following excitotoxicity, and that both R18 and COG1410 reduce axonal injury following TBI. Additional dose response and treatment time course studies are required to further assess the efficacy of R18 in TBI.

Bioinformatic and Comparative Localization of Rab Proteins Reveals Functional Insights into the Uncharacterized GTPases Ypt10p and Ypt11p†

Science.gov (United States)

Buvelot Frei, Stéphanie; Rahl, Peter B.; Nussbaum, Maria; Briggs, Benjamin J.; Calero, Monica; Janeczko, Stephanie; Regan, Andrew D.; Chen, Catherine Z.; Barral, Yves; Whittaker, Gary R.; Collins, Ruth N.

2006-01-01

A striking characteristic of a Rab protein is its steady-state localization to the cytosolic surface of a particular subcellular membrane. In this study, we have undertaken a combined bioinformatic and experimental approach to examine the evolutionary conservation of Rab protein localization. A comprehensive primary sequence classification shows that 10 out of the 11 Rab proteins identified in the yeast (Saccharomyces cerevisiae) genome can be grouped within a major subclass, each comprising multiple Rab orthologs from diverse species. We compared the locations of individual yeast Rab proteins with their localizations following ectopic expression in mammalian cells. Our results suggest that green fluorescent protein-tagged Rab proteins maintain localizations across large evolutionary distances and that the major known player in the Rab localization pathway, mammalian Rab-GDI, is able to function in yeast. These findings enable us to provide insight into novel gene functions and classify the uncharacterized Rab proteins Ypt10p (YBR264C) as being involved in endocytic function and Ypt11p (YNL304W) as being localized to the endoplasmic reticulum, where we demonstrate it is required for organelle inheritance. PMID:16980630

Minimization of cogging torque in permanent magnet motors by teeth pairing and magnet arc design using genetic algorithm

International Nuclear Information System (INIS)

Eom, J.-B.; Hwang, S.-M.; Kim, T.-J.; Jeong, W.-B.; Kang, B.-S.

2001-01-01

Cogging torque is often a principal source of vibration and acoustic noise in high precision spindle motor applications. In this paper, cogging torque is analytically calculated using energy method with Fourier series expansion. It shows that cogging torque is effectively minimized by controlling airgap permeance function with teeth pairing design, and by controlling flux density function with magnet arc design. For an optimization technique, genetic algorithm is applied to handle trade-off effects of design parameters. Results show that the proposed method can reduce the cogging torque effectively

Cogging torque optimization in surface-mounted permanent-magnet motors by using design of experiment

Energy Technology Data Exchange (ETDEWEB)

Abbaszadeh, K., E-mail: Abbaszadeh@kntu.ac.ir [Department of Electrical Engineering, K.N. Toosi University of Technology, Tehran (Iran, Islamic Republic of); Rezaee Alam, F.; Saied, S.A. [Department of Electrical Engineering, K.N. Toosi University of Technology, Tehran (Iran, Islamic Republic of)

2011-09-15

Graphical abstract: Magnet segment arrangement in cross section view of one pole for PM machine. Display Omitted Highlights: {yields} Magnet segmentation is an effective method for the cogging torque reduction. {yields} We have used the magnet segmentation method based on the design of experiment. {yields} We have used the RSM design of the design of experiment method. {yields} We have solved optimization via surrogate models like the polynomial regression. {yields} A significant reduction of the cogging torque is obtained by using RSM. - Abstract: One of the important challenges in design of the PM electrical machines is to reduce the cogging torque. In this paper, in order to reduce the cogging torque, a new method for designing of the motor magnets is introduced to optimize of a six pole BLDC motor by using design of experiment (DOE) method. In this method the machine magnets consist of several identical segments which are shifted to a definite angle from each other. Design of experiment (DOE) methodology is used for a screening of the design space and for the generation of approximation models using response surface techniques. In this paper, optimization is often solved via surrogate models, that is, through the construction of response surface models (RSM) like polynomial regression. The experiments were performed based on the response surface methodology (RSM), as a statistical design of experiment approach, in order to investigate the effect of parameters on the response variations. In this investigation, the optimal shifting angles (factors) were identified to minimize the cogging torque. A significant reduction of cogging torque can be achieved with this approach after only a few evaluations of the coupled FE model.

Cogging torque optimization in surface-mounted permanent-magnet motors by using design of experiment

International Nuclear Information System (INIS)

Abbaszadeh, K.; Rezaee Alam, F.; Saied, S.A.

2011-01-01

Graphical abstract: Magnet segment arrangement in cross section view of one pole for PM machine. Display Omitted Highlights: → Magnet segmentation is an effective method for the cogging torque reduction. → We have used the magnet segmentation method based on the design of experiment. → We have used the RSM design of the design of experiment method. → We have solved optimization via surrogate models like the polynomial regression. → A significant reduction of the cogging torque is obtained by using RSM. - Abstract: One of the important challenges in design of the PM electrical machines is to reduce the cogging torque. In this paper, in order to reduce the cogging torque, a new method for designing of the motor magnets is introduced to optimize of a six pole BLDC motor by using design of experiment (DOE) method. In this method the machine magnets consist of several identical segments which are shifted to a definite angle from each other. Design of experiment (DOE) methodology is used for a screening of the design space and for the generation of approximation models using response surface techniques. In this paper, optimization is often solved via surrogate models, that is, through the construction of response surface models (RSM) like polynomial regression. The experiments were performed based on the response surface methodology (RSM), as a statistical design of experiment approach, in order to investigate the effect of parameters on the response variations. In this investigation, the optimal shifting angles (factors) were identified to minimize the cogging torque. A significant reduction of cogging torque can be achieved with this approach after only a few evaluations of the coupled FE model.

The small GTPase Rab5 homologue Ypt5 regulates cell morphology, sexual development, ion-stress response and vacuolar formation in fission yeast

Energy Technology Data Exchange (ETDEWEB)

Tsukamoto, Yuta; Katayama, Chisako [Graduate School of Science, Kobe University, 1-1 Rokkodai-cho Nada, Kobe 657-8501 (Japan); Shinohara, Miki; Shinohara, Akira [Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka 565-0871 (Japan); Maekawa, Shohei [Graduate School of Science, Kobe University, 1-1 Rokkodai-cho Nada, Kobe 657-8501 (Japan); Miyamoto, Masaaki, E-mail: miya@kobe-u.ac.jp [Graduate School of Science, Kobe University, 1-1 Rokkodai-cho Nada, Kobe 657-8501 (Japan); Center for Supports to Research and Education Activities, Kobe University, 1-1 Rokkodai-cho Nada, Kobe 657-8501 (Japan)

2013-11-29

Highlights: •Multiple functions of Rab5 GTPase in fission yeast were found. •Roles of Rab5 in fission yeast were discussed. •Relation between Rab5 and actin cytoskeleton were discussed. -- Abstract: Inner-membrane transport is critical to cell function. Rab family GTPases play an important role in vesicle transport. In mammalian cells, Rab5 is reported to be involved in the regulation of endosome formation, phagocytosis and chromosome alignment. Here, we examined the role of the fission yeast Rab5 homologue Ypt5 using a point mutant allele. Mutant cells displayed abnormal cell morphology, mating, sporulation, endocytosis, vacuole fusion and responses to ion stress. Our data strongly suggest that fission yeast Rab5 is involved in the regulation of various types of cellular functions.

The small GTPase Rab5 homologue Ypt5 regulates cell morphology, sexual development, ion-stress response and vacuolar formation in fission yeast

International Nuclear Information System (INIS)

Tsukamoto, Yuta; Katayama, Chisako; Shinohara, Miki; Shinohara, Akira; Maekawa, Shohei; Miyamoto, Masaaki

2013-01-01

Highlights: •Multiple functions of Rab5 GTPase in fission yeast were found. •Roles of Rab5 in fission yeast were discussed. •Relation between Rab5 and actin cytoskeleton were discussed. -- Abstract: Inner-membrane transport is critical to cell function. Rab family GTPases play an important role in vesicle transport. In mammalian cells, Rab5 is reported to be involved in the regulation of endosome formation, phagocytosis and chromosome alignment. Here, we examined the role of the fission yeast Rab5 homologue Ypt5 using a point mutant allele. Mutant cells displayed abnormal cell morphology, mating, sporulation, endocytosis, vacuole fusion and responses to ion stress. Our data strongly suggest that fission yeast Rab5 is involved in the regulation of various types of cellular functions

Rab23 is overexpressed in human astrocytoma and promotes cell migration and invasion through regulation of Rac1.

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Wang, Minghao; Dong, Qianze; Wang, Yunjie

2016-08-01

Rab23 overexpression has been implicated in several human cancers. However, its biological roles and molecular mechanism in astrocytoma have not been elucidated. The aim of this study is to explore clinical significance and biological roles of Rab23 in astrocytoma. We observed negative Rab23 staining in normal astrocytes and positive staining in 39 out of 86 (45 %) astrocytoma specimens using immunohistochemistry. The positive rate of Rab23 was higher in grades III and IV (56.5 %, 26/46) than grades I + II astrocytomas (32.5 %, 13/40, p Rac1 activity. Treatment of transfected cells with a Rac1 inhibitor decreased Rac1 activity and invasion. In conclusion, Rab23 serves as an important oncoprotein in human astrocytoma by regulating cell invasion and migration through Rac1 activity.

New scoring methodology improves the sensitivity of the Alzheimer's Disease Assessment Scale-Cognitive subscale (ADAS-Cog) in clinical trials.

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Verma, Nishant; Beretvas, S Natasha; Pascual, Belen; Masdeu, Joseph C; Markey, Mia K

2015-11-12

As currently used, the Alzheimer's Disease Assessment Scale-Cognitive subscale (ADAS-Cog) has low sensitivity for measuring Alzheimer's disease progression in clinical trials. A major reason behind the low sensitivity is its sub-optimal scoring methodology, which can be improved to obtain better sensitivity. Using item response theory, we developed a new scoring methodology (ADAS-CogIRT) for the ADAS-Cog, which addresses several major limitations of the current scoring methodology. The sensitivity of the ADAS-CogIRT methodology was evaluated using clinical trial simulations as well as a negative clinical trial, which had shown an evidence of a treatment effect. The ADAS-Cog was found to measure impairment in three cognitive domains of memory, language, and praxis. The ADAS-CogIRT methodology required significantly fewer patients and shorter trial durations as compared to the current scoring methodology when both were evaluated in simulated clinical trials. When validated on data from a real clinical trial, the ADAS-CogIRT methodology had higher sensitivity than the current scoring methodology in detecting the treatment effect. The proposed scoring methodology significantly improves the sensitivity of the ADAS-Cog in measuring progression of cognitive impairment in clinical trials focused in the mild-to-moderate Alzheimer's disease stage. This provides a boost to the efficiency of clinical trials requiring fewer patients and shorter durations for investigating disease-modifying treatments.

The N-Myc down regulated Gene1 (NDRG1) Is a Rab4a effector involved in vesicular recycling of E-cadherin.

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Kachhap, Sushant K; Faith, Dennis; Qian, David Z; Shabbeer, Shabana; Galloway, Nathan L; Pili, Roberto; Denmeade, Samuel R; DeMarzo, Angelo M; Carducci, Michael A

2007-09-05

Cell to cell adhesion is mediated by adhesion molecules present on the cell surface. Downregulation of molecules that form the adhesion complex is a characteristic of metastatic cancer cells. Downregulation of the N-myc down regulated gene1 (NDRG1) increases prostate and breast metastasis. The exact function of NDRG1 is not known. Here by using live cell confocal microscopy and in vitro reconstitution, we report that NDRG1 is involved in recycling the adhesion molecule E-cadherin thereby stabilizing it. Evidence is provided that NDRG1 recruits on recycling endosomes in the Trans Golgi network by binding to phosphotidylinositol 4-phosphate and interacts with membrane bound Rab4aGTPase. NDRG1 specifically interacts with constitutively active Rab4aQ67L mutant protein and not with GDP-bound Rab4aS22N mutant proving NDRG1 as a novel Rab4a effector. Transferrin recycling experiments reveals NDRG1 colocalizes with transferrin during the recycling phase. NDRG1 alters the kinetics of transferrin recycling in cells. NDRG1 knockdown cells show a delay in recycling transferrin, conversely NDRG1 overexpressing cells reveal an increase in rate of transferrin recycling. This novel finding of NDRG1 as a recycling protein involved with recycling of E-cadherin will aid in understanding NDRG1 role as a metastasis suppressor protein.

The N-Myc down regulated Gene1 (NDRG1 Is a Rab4a effector involved in vesicular recycling of E-cadherin.

Directory of Open Access Journals (Sweden)

Sushant K Kachhap

2007-09-01

Full Text Available Cell to cell adhesion is mediated by adhesion molecules present on the cell surface. Downregulation of molecules that form the adhesion complex is a characteristic of metastatic cancer cells. Downregulation of the N-myc down regulated gene1 (NDRG1 increases prostate and breast metastasis. The exact function of NDRG1 is not known. Here by using live cell confocal microscopy and in vitro reconstitution, we report that NDRG1 is involved in recycling the adhesion molecule E-cadherin thereby stabilizing it. Evidence is provided that NDRG1 recruits on recycling endosomes in the Trans Golgi network by binding to phosphotidylinositol 4-phosphate and interacts with membrane bound Rab4aGTPase. NDRG1 specifically interacts with constitutively active Rab4aQ67L mutant protein and not with GDP-bound Rab4aS22N mutant proving NDRG1 as a novel Rab4a effector. Transferrin recycling experiments reveals NDRG1 colocalizes with transferrin during the recycling phase. NDRG1 alters the kinetics of transferrin recycling in cells. NDRG1 knockdown cells show a delay in recycling transferrin, conversely NDRG1 overexpressing cells reveal an increase in rate of transferrin recycling. This novel finding of NDRG1 as a recycling protein involved with recycling of E-cadherin will aid in understanding NDRG1 role as a metastasis suppressor protein.

LMTK1 regulates dendritic formation by regulating movement of Rab11A-positive endosomes.

Science.gov (United States)

Takano, Tetsuya; Urushibara, Tomoki; Yoshioka, Nozomu; Saito, Taro; Fukuda, Mitsunori; Tomomura, Mineko; Hisanaga, Shin-Ichi

2014-06-01

Neurons extend two types of neurites-axons and dendrites-that differ in structure and function. Although it is well understood that the cytoskeleton plays a pivotal role in neurite differentiation and extension, the mechanisms by which membrane components are supplied to growing axons or dendrites is largely unknown. We previously reported that the membrane supply to axons is regulated by lemur kinase 1 (LMTK1) through Rab11A-positive endosomes. Here we investigate the role of LMTK1 in dendrite formation. Down-regulation of LMTK1 increases dendrite growth and branching of cerebral cortical neurons in vitro and in vivo. LMTK1 knockout significantly enhances the prevalence, velocity, and run length of anterograde movement of Rab11A-positive endosomes to levels similar to those expressing constitutively active Rab11A-Q70L. Rab11A-positive endosome dynamics also increases in the cell body and growth cone of LMTK1-deficient neurons. Moreover, a nonphosphorylatable LMTK1 mutant (Ser34Ala, a Cdk5 phosphorylation site) dramatically promotes dendrite growth. Thus LMTK1 negatively controls dendritic formation by regulating Rab11A-positive endosomal trafficking in a Cdk5-dependent manner, indicating the Cdk5-LMTK1-Rab11A pathway as a regulatory mechanism of dendrite development as well as axon outgrowth. © 2014 Takano et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

The Alzheimer's Disease Assessment Scale-Cognitive Subscale (ADAS-Cog): Modifications and Responsiveness in Pre-Dementia Populations. A Narrative Review.

Science.gov (United States)

Kueper, Jacqueline K; Speechley, Mark; Montero-Odasso, Manuel

2018-01-01

The Alzheimer's Disease Assessment Scale-Cognitive Subscale (ADAS-Cog) was developed in the 1980s to assess the level of cognitive dysfunction in Alzheimer's disease. Advancements in the research field have shifted focus toward pre-dementia populations, and use of the ADAS-Cog has extended into these pre-dementia studies despite concerns about its ability to detect important changes at these milder stages of disease progression. If the ADAS-Cog cannot detect important changes, our understanding of pre-dementia disease progression may be compromised and trials may incorrectly conclude that a novel treatment approach is not beneficial. The purpose of this review was to assess the performance of the ADAS-Cog in pre-dementia populations, and to review all modifications that have been made to the ADAS-Cog to improve its measurement performance in dementia or pre-dementia populations. The contents of this review are based on bibliographic searches of electronic databases to locate all studies using the ADAS-Cog in pre-dementia samples or subsamples, and to locate all modified versions. Citations from relevant articles were also consulted. Overall, our results suggest the original ADAS-Cog is not an optimal outcome measure for pre-dementia studies; however, given the prominence of the ADAS-Cog, care must be taken when considering the use of alternative outcome measures. Thirty-one modified versions of the ADAS-Cog were found. Modification approaches that appear most beneficial include altering scoring methodology or adding tests of memory, executive function, and/or daily functioning. Although modifications improve the performance of the ADAS-Cog, this is at the cost of introducing heterogeneity that may limit between-study comparison.

Cognitive Symptom Management and Rehabilitation Therapy (CogSMART) for veterans with traumatic brain injury: pilot randomized controlled trial.

Science.gov (United States)

Twamley, Elizabeth W; Jak, Amy J; Delis, Dean C; Bondi, Mark W; Lohr, James B

2014-01-01

Traumatic brain injury (TBI) can result in cognitive impairments and persistent postconcussive symptoms that limit functional recovery, including return to work. We evaluated a 12 wk compensatory cognitive training intervention (Cognitive Symptom Management and Rehabilitation Therapy [CogSMART]) in the context of supported employment for Veterans with mild to moderate TBI. Participants were randomly assigned to receive 12 wk of supported employment plus CogSMART or enhanced supported employment that controlled for therapist attention (control). CogSMART sessions were delivered by the employment specialist and included psychoeducation regarding TBI; strategies to improve sleep, fatigue, headaches, and tension; and compensatory cognitive strategies in the domains of prospective memory, attention, learning and memory, and executive functioning. Compared with controls, those assigned to supported employment plus CogSMART demonstrated significant reductions in postconcussive symptoms (Cohen d = 0.97) and improvements in prospective memory functioning (Cohen d = 0.72). Effect sizes favoring CogSMART for posttraumatic stress disorder symptom severity, depressive symptom severity, and attainment of competitive work within 14 wk were in the small to medium range (Cohen d = 0.35-0.49). Those who received CogSMART rated the intervention highly. Results suggest that adding CogSMART to supported employment may improve postconcussive symptoms and prospective memory. These effects, as well as smaller effects on psychiatric symptoms and ability to return to work, warrant replication in a larger trial.

Roles of the Drosophila LRRK2 homolog in Rab7-dependent lysosomal positioning.

Science.gov (United States)

Dodson, Mark W; Zhang, Ting; Jiang, Changan; Chen, Shengdi; Guo, Ming

2012-03-15

LRRK2 (PARK8) is the most common genetic determinant of Parkinson's disease (PD), with dominant mutations in LRRK2 causing inherited PD and sequence variation at the LRRK2 locus associated with increased risk for sporadic PD. Although LRRK2 has been implicated in diverse cellular processes encompassing almost all cellular compartments, the precise functions of LRRK2 remain unclear. Here, we show that the Drosophila homolog of LRRK2 (Lrrk) localizes to the membranes of late endosomes and lysosomes, physically interacts with the crucial mediator of late endosomal transport Rab7 and negatively regulates rab7-dependent perinuclear localization of lysosomes. We also show that a mutant form of lrrk analogous to the pathogenic LRRK2(G2019S) allele behaves oppositely to wild-type lrrk in that it promotes rather than inhibits rab7-dependent perinuclear lysosome clustering, with these effects of mutant lrrk on lysosome position requiring both microtubules and dynein. These data suggest that LRRK2 normally functions in Rab7-dependent lysosomal positioning, and that this function is disrupted by the most common PD-causing LRRK2 mutation, linking endolysosomal dysfunction to the pathogenesis of LRRK2-mediated PD.

The cis-regulatory element CCACGTGG is involved in ABA and water-stress responses of the maize gene rab28.

Science.gov (United States)

Pla, M; Vilardell, J; Guiltinan, M J; Marcotte, W R; Niogret, M F; Quatrano, R S; Pagès, M

1993-01-01

The maize gene rab28 has been identified as ABA-inducible in embryos and vegetative tissues. It is also induced by water stress in young leaves. The proximal promoter region contains the conserved cis-acting element CCACGTGG (ABRE) reported for ABA induction in other plant genes. Transient expression assays in rice protoplasts indicate that a 134 bp fragment (-194 to -60 containing the ABRE) fused to a truncated cauliflower mosaic virus promoter (35S) is sufficient to confer ABA-responsiveness upon the GUS reporter gene. Gel retardation experiments indicate that nuclear proteins from tissues in which the rab28 gene is expressed can interact specifically with this 134 bp DNA fragment. Nuclear protein extracts from embryo and water-stressed leaves generate specific complexes of different electrophoretic mobility which are stable in the presence of detergent and high salt. However, by DMS footprinting the same guanine-specific contacts with the ABRE in both the embryo and leaf binding activities were detected. These results indicate that the rab28 promoter sequence CCACGTGG is a functional ABA-responsive element, and suggest that distinct regulatory factors with apparent similar affinity for the ABRE sequence may be involved in the hormone action during embryo development and in vegetative tissues subjected to osmotic stress.

Developing an organizing framework to guide nursing research in the Children’s Oncology Group (COG)

Science.gov (United States)

Kelly, Katherine Patterson; Hooke, Mary C.; Ruccione, Kathleen; Landier, Wendy; Haase, Joan

2014-01-01

Objectives To describe the development and application of an organizing research framework to guide COG Nursing research. Data Sources Research articles, reports and meeting minutes Conclusion An organizing research framework helps to outline research focus and articulate the scientific knowledge being produced by nurses in the pediatric cooperative group. Implication for Nursing Practice The use of an organizing framework for COG nursing research can facilitate clinical nurses’ understanding of how children and families sustain or regain optimal health when faced with a pediatric cancer diagnosis through interventions designed to promote individual and family resilience. The Children’s Oncology Group (COG) is the sole National Cancer Institute (NCI)-supported cooperative pediatric oncology clinical trials group and the largest organization in the world devoted exclusively to pediatric cancer research. It was founded in 2000 following the merger of the four legacy NCI-supported pediatric clinical trials groups (Children’s Cancer Group [CCG], Pediatric Oncology Group [POG], National Wilms Tumor Study Group, and Intergroup Rhabdomyosarcoma Study Group). The COG currently has over 200 member institutions across North America, Australia, New Zealand and Europe and a multidisciplinary membership of over 8,000 pediatric, radiation, and surgical oncologists, nurses, clinical research associates, pharmacists, behavioral scientists, pathologists, laboratory scientists, patient/parent advocates and other pediatric cancer specialists. The COG Nursing Discipline was formed from the merger of the legacy CCG and POG Nursing Committees, and current membership exceeds 2000 registered nurses. The discipline has a well-developed infrastructure that promotes nursing involvement throughout all levels of the organization, including representation on disease, protocol, scientific, executive and other administrative committees (e.g., nominating committee, data safety monitoring

Regulatory elements in vivo in the promoter of the abscisic acid responsive gene rab17 from maize.

Science.gov (United States)

Busk, P K; Jensen, A B; Pagès, M

1997-06-01

The rab17 gene from maize is transcribed in late embryonic development and is responsive to abscisic acid and water stress in embryo and vegetative tissues. In vivo footprinting and transient transformation of rab17 were performed in embryos and vegetative tissues to characterize the cis-elements involved in regulation of the gene. By in vivo footprinting, protein binding was observed to nine elements in the promoter, which correspond to five putative ABREs (abscisic acid responsive elements) and four other sequences. The footprints indicated that distinct proteins interact with these elements in the two developmental stages. In transient transformation, six of the elements were important for high level expression of the rab17 promoter in embryos, whereas only three elements were important in leaves. The cis-acting sequences can be divided in embryo-specific, ABA-specific and leaf-specific elements on the basis of protein binding and the ability to confer expression of rab17. We found one positive, new element, called GRA, with the sequence CACTGGCCGCCC. This element was important for transcription in leaves but not in embryos. Two other non-ABRE elements that stimulated transcription from the rab17 promoter resemble previously described abscisic acid and drought-inducible elements. There were differences in protein binding and function of the five ABREs in the rab17 promoter. The possible reasons for these differences are discussed. The in vivo data obtained suggest that an embryo-specific pathway regulates transcription of the rab genes during development, whereas another pathway is responsible for induction in response to ABA and drought in vegetative tissues.

An Arabic Version of the Cognitive Subscale of the Alzheimer's Disease Assessment Scale (ADAS-Cog): Reliability, Validity, and Normative Data.

Science.gov (United States)

Ben Jemaa, Sonia; Attia Romdhane, Neila; Bahri-Mrabet, Amel; Jendli, Adel; Le Gall, Didier; Bellaj, Tarek

2017-01-01

The Alzheimer's Disease Assessment Scale's cognitive subscale (ADAS-Cog) is the most widely used instrument for screening cognitive dysfunction in Alzheimer's disease. The aim of the present study was to develop an Arabic version of this scale (A-ADAS-Cog), examine its psychometric properties (reliability and validity), and provide normative data. The A-ADAS-Cog), an Arabic version of the Mini-Mental State Examination (A-MMSE), and a Standardized Clinical Dementia Rating Scale (CDR) were administered to three Tunisian groups: 124 normal controls (NC), 33 patients with non-Alzheimer dementia (N-AD), and 25 patients with Alzheimer's disease (AD). The A-ADAS-Cog scores were significantly affected by age and education. A correction table was constructed to control these effects. The results showed that the A-ADAS-Cog has good internal consistency and reliability (α= 0.82 for AD). The test-retest reliability of the A-ADAS-Cog was stable over time (r = 0.97). An evaluation of the construct validity of the A-ADAS-Cog using principal component analysis led to a solution with three factors (memory, language and praxis), which explained 72% of the variance. The concurrent validity of the A-ADAS-Cog was established using the A-MMSE score (r = -0.86), CDR Sum of Boxes score (CDR-SB; r = 0.87), and global CDR score (CDR-Global; r = 0.74). Finally, the A-ADAS-Cog has an excellent discriminating power in the diagnosis of AD (ROC area = 0.92). A cut-off score of 10 (sensitivity = 84% and specificity = 91%) is indicated for the screening of the AD. Overall, the results indicated that the A-ADAS-Cog is psychometrically reliable and valid and provides promising results for screening of dementia in Arabic speaking patients.

Development of the Thai version of Mini-Cog, a brief cognitive screening test.

Science.gov (United States)

Trongsakul, Supaporn; Lambert, Rod; Clark, Allan; Wongpakaran, Nahathai; Cross, Jane

2015-05-01

Cognitive impairment, such as dementia, has emerged as the leading public health problem among the elderly. Therefore, early detection of the disorder and providing appropriate healthcare and management is important, particularly, for the patients with comorbid diabetes who require long-term treatment strategies. In Thailand, because of a large number of elderly patients with diabetes, and time constraints in primary care settings, a short and effective cognitive screening test is required. The Mini-Cog is a short and valid cognitive screening test that was specifically designed for use in primary care settings. The present study translated the English language version into a Thai language version, and then measured the interrater reliability and concurrent validity. The processes of cross-language translation were carried out to develop a Thai language version of the Mini-Cog. A total of 21 Thai older adults with type 2 diabetes with a mean aged of 69 ± 7 years were recruited into a study investigating the interrater reliability and concurrent validity of the Mini-Cog Thai version in one primary care center in Thailand. The Mini-Cog Thai version showed a good interrater reliability (K = 0.80, P validity (r = 0.47, P = 0.007, 95% CI 0.37,0.55) with the Mini-Mental State Examination Thai 2002. The findings show that the Thai version of the Mini-Cog is a reliable, performance-based tool in the screening for cognitive function in primary care settings in Thailand. It is recommended that it could be used as a new cognitive screening test for the aging population in the Thai community. © 2014 Japan Geriatrics Society.

Rab9-dependent retrograde transport and endosomal sorting of the endopeptidase furin

Science.gov (United States)

Chia, Pei Zhi Cheryl; Gasnereau, Isabelle; Lieu, Zi Zhao; Gleeson, Paul A.

2011-01-01

The endopeptidase furin and the trans-Golgi network protein TGN38 are membrane proteins that recycle between the TGN and plasma membrane. TGN38 is transported by a retromer-dependent pathway from early endosomes to the TGN, whereas the intracellular transport of furin is poorly defined. Here we have identified the itinerary and transport requirements of furin. Using internalisation assays, we show that furin transits the early and late endosomes en route to the TGN. The GTPase Rab9 and the TGN golgin GCC185, components of the late endosome-to-TGN pathway, were required for efficient TGN retrieval of furin. By contrast, TGN38 trafficking was independent of Rab9 and GCC185. To identify the sorting signals for the early endosome-to-TGN pathway, the trafficking of furin–TGN38 chimeras was investigated. The diversion of furin from the Rab9-dependent late-endosome-to-TGN pathway to the retromer-dependent early-endosome-to-TGN pathway required both the transmembrane domain and cytoplasmic tail of TGN38. We present evidence to suggest that the length of the transmembrane domain is a contributing factor in endosomal sorting. Overall, these data show that furin uses the Rab9-dependent pathway from late endosomes and that retrograde transport directly from early endosomes is dependent on both the transmembrane domain and the cytoplasmic tail. PMID:21693586

Evaluating rivastigmine in mild-to-moderate Parkinson's disease dementia using ADAS-cog items.

Science.gov (United States)

Schmitt, Frederick A; Aarsland, Dag; Brønnick, Kolbjørn S; Meng, Xiangyi; Tekin, Sibel; Olin, Jason T

2010-08-01

Rivastigmine has been shown to improve cognition in patients with Parkinson's disease dementia (PDD). To further explore the impact of anticholinesterase therapy on PDD, Alzheimer's Disease Assessment Scale-cognitive subscale (ADAS-cog) items were assessed in a retrospective analysis of a 24-week, double-blind, placebo-controlled trial of rivastigmine. Mean changes from baseline at week 24 were calculated for ADAS-cog item scores and for 3 cognitive domain scores. A total of 362 patients were randomized to 3 to 12 mg/d rivastigmine capsules and 179 to placebo. Patients with PDD receiving rivastigmine improved versus placebo on items: word recall, following commands, ideational praxis, remembering test instructions, and comprehension of spoken language (P ADAS-cog is sensitive to broad cognitive changes in PDD. Overall, rivastigmine was associated with improvements on individual cognitive items and general cognitive domains.

Rab27A mediated by NF-κB promotes the stemness of colon cancer cells via up-regulation of cytokine secretion.

Science.gov (United States)

Feng, Feixue; Jiang, Yinghao; Lu, Huanyu; Lu, Xiaozhao; Wang, Shan; Wang, Lifeng; Wei, Mengying; Lu, Wei; Du, Zhichao; Ye, Zichen; Yang, Guodong; Yuan, Fang; Ma, Yanxia; Lei, Xiaoying; Lu, Zifan

2016-09-27

Recent evidences have unveiled critical roles of cancer stem cells (CSCs) in tumorigenicity, but how interactions between CSC and tumor environments help maintain CSC initiation remains obscure. The small GTPases Rab27A regulates autocrine and paracrine cytokines by monitoring exocytosis of extracellular vesicles, and is reported to promote certain tumor progression. We observe that overexpression of Rab27A increased sphere formation efficiency (SFE) by increasing the proportion of CD44+ and PKH26high cells in HT29 cell lines, and accelerating the growth of colosphere with higher percentage of cells at S phase. Mechanism study revealed that the supernatant derived from HT29 sphere after Rab27A overexpression was able to expand sphere numbers with elevated secretion of VEGF and TGF-β. In tumor implanting nude mice model, tumor initiation rates and tumor sizes were enhanced by Rab27A with obvious angiogenesis. As a contrast, knocking down Rab27A impaired the above effects. More importantly, the correlation between higher p65 level and Rab27A in colon sphere was detected, p65 was sufficient to induce up-regulation of Rab27A and a functional NF-κB binding site in the Rab27A promoter was demonstrated. Altogether, our findings reveal a unique mechanism that tumor environment related NF-κB signaling promotes various colon cancer stem cells (cCSCs) properties via an amplified paracrine mechanism regulated by higher Rab27A level.

The Alzheimer’s Disease Assessment Scale–Cognitive Subscale (ADAS-Cog): Modifications and Responsiveness in Pre-Dementia Populations. A Narrative Review

Science.gov (United States)

Kueper, Jacqueline K.; Speechley, Mark; Montero-Odasso, Manuel

2018-01-01

The Alzheimer’s Disease Assessment Scale–Cognitive Subscale (ADAS-Cog) was developed in the 1980s to assess the level of cognitive dysfunction in Alzheimer’s disease. Advancements in the research field have shifted focus toward pre-dementia populations, and use of the ADAS-Cog has extended into these pre-dementia studies despite concerns about its ability to detect important changes at these milder stages of disease progression. If the ADAS-Cog cannot detect important changes, our understanding of pre-dementia disease progression may be compromised and trials may incorrectly conclude that a novel treatment approach is not beneficial. The purpose of this review was to assess the performance of the ADAS-Cog in pre-dementia populations, and to review all modifications that have been made to the ADAS-Cog to improve its measurement performance in dementia or pre-dementia populations. The contents of this review are based on bibliographic searches of electronic databases to locate all studies using the ADAS-Cog in pre-dementia samples or subsamples, and to locate all modified versions. Citations from relevant articles were also consulted. Overall, our results suggest the original ADAS-Cog is not an optimal outcome measure for pre-dementia studies; however, given the prominence of the ADAS-Cog, care must be taken when considering the use of alternative outcome measures. Thirty-one modified versions of the ADAS-Cog were found. Modification approaches that appear most beneficial include altering scoring methodology or adding tests of memory, executive function, and/or daily functioning. Although modifications improve the performance of the ADAS-Cog, this is at the cost of introducing heterogeneity that may limit between-study comparison. PMID:29660938

A novel marRAB operon contributes to the rifampicin resistance in Mycobacterium smegmatis.

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Zhang, Haiwei; Gao, Long; Zhang, Jiaoling; Li, Weihui; Yang, Min; Zhang, Hua; Gao, Chunhui; He, Zheng-Guo

2014-01-01

The multiple-antibiotic resistance regulator (MarR) plays an important role in modulating bacterial antibiotic resistance. However, the regulatory model of the marRAB operon in mycobacteria remains to be characterized. Here we report that a MarR, encoded by Ms6508, and its marRAB operon specifically contribute to rifampicin (RIF) resistance in Mycobacterium smegmatis. We show that the MarR recognizes a conserved 21-bp palindromic motif and negatively regulates the expression of two ABC transporters in the operon, encoded by Ms6509-6510. Unlike other known drug efflux pumps, overexpression of these two ABC transporters unexpectedly increased RIF sensitivity and deletion of these two genes increased mycobacterial resistance to the antibiotic. No change can be detected for the sensitivity of recombinant mycobacterial strains to three other anti-TB drugs. Furthermore, HPLC experiments suggested that Ms6509-Ms6510 could pump RIF into the mycobacterial cells. These findings indicated that the mycobacterial MarR functions as a repressor and constitutively inhibits the expression of the marRAB operon, which specifically contributes to RIF resistance in M. smegmatis. Therefore, our data suggest a new regulatory mechanism of RIF resistance and also provide the new insight into the regulatory model of a marRAB operon in mycobacteria.

The Mini-Cog versus the Mini-Mental State Examination and the Clock Drawing Test in daily clinical practice: screening value in a German Memory Clinic.

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Milian, Monika; Leiherr, Anna-Maria; Straten, Guido; Müller, Stephan; Leyhe, Thomas; Eschweiler, Gerhard W

2012-05-01

The aim of this study was to compare the screening value of the Mini-Cog, Clock Drawing Test (CDT), Mini-Mental State Examination (MMSE) and the algorithm MMSE and/or CDT to separate elderly people with dementia from healthy depending on test time, type and severity of dementia, and demographic variables in a German Memory Clinic. Data from a heterogeneous patient sample and healthy participants (n = 502) were retrospectively analyzed. Of the 438 patients with dementia, 49.1% of the dementia diagnoses were Alzheimer's dementia and 50.9% were non-Alzheimer's dementia. Sixty-four participants were classified as cognitively unimpaired. The CDT and an extraction of the 3-item recall of the MMSE were used to constitute the Mini-Cog algorithm. Overall, the Mini-Cog showed significantly higher discriminatory power (86.8%) than the MMSE (72.6% at a cut-off ≤ 24 and 79.2% at ≤ 25, respectively) and CDT (78.1%) (each p 0.05). The specificity of the Mini-Cog (100.0%) was similar to that of the MMSE (100.0% for both cut-offs) and CDT (96.9%) (p = 0.154). For all age and educational groups the Mini-Cog outmatched the CDT and MMSE, and was less affected by education than MMSE and less susceptible for the dementia stage than the CDT. The Mini-Cog proved to have superior discriminatory power than either CDT or MMSE and is demonstrated to be a valid "short" screening instrument taking 3 to 4 minutes to administer in the geriatric setting.

Molecular Analysis of Gli3, Ihh, Rab23, and Jag1 in a Rabbit Model of Craniosynostosis: Likely Exclusion as the Loci of Origin.

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Gilbert, James R; Taylor, Gwen M; Losee, Joseph E; Mooney, Mark P; Cooper, Gregory M

2018-03-01

Craniosynostosis (CS) involves the premature fusion of one or more cranial sutures. The etiology of CS is complex and mutations in more than 50 distinct genes have been causally linked to the disorder. Many of the genes that have been associated with CS in humans play an essential role in tissue patterning and early craniofacial development. Among these genes are members of the Hedgehog (HH) and Notch signal transduction pathways, including the GLI family member Gli3, Indian Hedgehog ( Ihh), the RAS oncogene family member Rab23, and the Notch ligand JAGGED1 ( Jag1). We have previously described a colony of rabbits with a heritable pattern of coronal suture synostosis, although the genetic basis for synostosis within this model remains unknown. The present study was performed to determine if coding errors in Gli3, Ihh, Rab23, or Jag1 could be causally linked to craniosynostosis in this unique animal model. Sequencing of cDNA templates was performed using samples obtained from wild-type and craniosynostotic rabbits. Several nucleotide polymorphisms were identified in Gli3, Ihh, and Rab23, although these variants failed to segregate by phenotype. No nucleotide polymorphisms were identified in Jag1. These data indicate that the causal locus for heritable craniosynostosis in this rabbit model is not located within the protein coding regions of Gli3, Ihh, Rab23, or Jag1.

Rab3a is critical for trapping alpha-MSH granules in the high Ca²⁺-affinity pool by preventing constitutive exocytosis.

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Simon Sedej

Full Text Available Rab3a is a small GTPase of the Rab3 subfamily that acts during late stages of Ca²⁺-regulated exocytosis. Previous functional analysis in pituitary melanotrophs described Rab3a as a positive regulator of Ca²⁺-dependent exocytosis. However, the precise role of the Rab3a isoform on the kinetics and intracellular [Ca²⁺] sensitivity of regulated exocytosis, which may affect the availability of two major peptide hormones, α-melanocyte stimulating hormone (α-MSH and β-endorphin in plasma, remain elusive. We employed Rab3a knock-out mice (Rab3a KO to explore the secretory phenotype in melanotrophs from fresh pituitary tissue slices. High resolution capacitance measurements showed that Rab3a KO melanotrophs possessed impaired Ca²⁺-triggered secretory activity as compared to wild-type cells. The hampered secretion was associated with the absence of cAMP-guanine exchange factor II/ Epac2-dependent secretory component. This component has been attributed to high Ca²⁺-sensitive release-ready vesicles as determined by slow photo-release of caged Ca²⁺. Radioimmunoassay revealed that α-MSH, but not β-endorphin, was elevated in the plasma of Rab3a KO mice, indicating increased constitutive exocytosis of α-MSH. Increased constitutive secretion of α-MSH from incubated tissue slices was associated with reduced α-MSH cellular content in Rab3a-deficient pituitary cells. Viral re-expression of the Rab3a protein in vitro rescued the secretory phenotype of melanotrophs from Rab3a KO mice. In conclusion, we suggest that Rab3a deficiency promotes constitutive secretion and underlies selective impairment of Ca²⁺-dependent release of α-MSH.

Reviews: Effects of transdermal rivastigmine on ADAS-cog items in mild-to-moderate Alzheimer's disease.

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Grossberg, George T; Schmitt, Frederick A; Meng, Xiangyi; Tekin, Sibel; Olin, Jason

2010-12-01

Alzheimer's disease (AD) patients treated with rivastigmine transdermal patch have shown statistically significant differences versus placebo on the AD Assessment scale-cognitive subscale (ADAS-cog). In this retrospective analysis of a double-blind, placebo- and active-controlled, 24-week clinical trial, the specific effects of rivastigmine patch on individual ADAS-cog items and cognitive domains (memory, language, and praxis) were explored. The mean baseline to week 24 changes were calculated for each ADAS-cog item and domain in this exploratory, hypothesis-generating analysis. Patients on 9.5 mg/24 h rivastigmine patch, 17.4 mg/24 h rivastigmine patch, and 3 to 12 mg/d rivastigmine capsules showed improvements over placebo on the memory and praxis ADAS-cog subscales. The rivastigmine patch groups also showed improvements on the language subscale. Significant differences versus placebo were seen on several individual item scores in the rivastigmine-treated groups. Rivastigmine patch was associated with improvements on the memory, praxis, and language domains of cognition in patients with mild-to-moderate AD.

High RAB25 expression is associated with good clinical outcome in patients with locally advanced head and neck squamous cell carcinoma

International Nuclear Information System (INIS)

Téllez-Gabriel, Marta; Arroyo-Solera, Irene; León, Xavier; Gallardo, Alberto; López, Montserrat; Céspedes, Maria V; Casanova, Isolda; López-Pousa, Antonio; Quer, Miquel; Mangues, Maria A; Barnadas, Agustí; Mangues, Ramón; Pavón, Miguel A

2013-01-01

Currently there are no molecular markers able to predict clinical outcome in locally advanced head and neck squamous cell carcinoma (HNSCC). In a previous microarray study, RAB25 was identified as a potential prognostic marker. The aim of this study was to analyze the association between RAB25 expression and clinical outcome in patients with locally advanced HNSCC treated with standard therapy. In a retrospective immunohistochemical study (n = 97), we observed that RAB25-negative tumors had lower survival (log-rank, P = 0.01) than patients bearing positive tumors. In an independent prospective mRNA study (n = 117), low RAB25 mRNA expression was associated with poor prognosis. Using classification and regression tree analysis (CART) we established two groups of patients according to their RAB25 mRNA level and their risk of death. Low mRNA level was associated with poor local recurrence-free (log-rank, P = 0.005), progression-free (log-rank, P = 0.002) and cancer-specific (log-rank, P < 0.001) survival. Multivariate Cox model analysis showed that low expression of RAB25 was an independent poor prognostic factor for survival (hazard ratio: 3.84, 95% confidence interval: 1.93–7.62, P < 0.001). Patients whose tumors showed high RAB25 expression had a low probability of death after treatment. We also found lower RAB25 expression in tumors than in normal tissue (Mann–Whitney U, P < 0.001). Moreover, overexpression of RAB25 in the UM-SCC-74B HNSCC cell line increased cisplatin sensitivity, and reduced cell migration and invasion. Our findings support a tumor suppressor role for RAB25 in HNSCC and its potential use to identify locally advanced patients with a high probability of survival after genotoxic treatment

CED-10/Rac1 regulates endocytic recycling through the RAB-5 GAP TBC-2.

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Lin Sun

Full Text Available Rac1 is a founding member of the Rho-GTPase family and a key regulator of membrane remodeling. In the context of apoptotic cell corpse engulfment, CED-10/Rac1 acts with its bipartite guanine nucleotide exchange factor, CED-5/Dock180-CED-12/ELMO, in an evolutionarily conserved pathway to promote phagocytosis. Here we show that in the context of the Caenorhabditis elegans intestinal epithelium CED-10/Rac1, CED-5/Dock180, and CED-12/ELMO promote basolateral recycling. Furthermore, we show that CED-10 binds to the RAB-5 GTPase activating protein TBC-2, that CED-10 contributes to recruitment of TBC-2 to endosomes, and that recycling cargo is trapped in recycling endosomes in ced-12, ced-10, and tbc-2 mutants. Expression of GTPase defective RAB-5(Q78L also traps recycling cargo. Our results indicate that down-regulation of early endosome regulator RAB-5/Rab5 by a CED-5, CED-12, CED-10, TBC-2 cascade is an important step in the transport of cargo through the basolateral recycling endosome for delivery to the plasma membrane.

Optimal Design of Stator Interior Permanent Magnet Machine with Minimized Cogging Torque for Wind Power Application

DEFF Research Database (Denmark)

Chen, Zhe; Zhang, Jianzhong; Cheng, Ming

2008-01-01

This paper proposes a new approach to minimize the cogging torque of a stator interior permanent magnet (SIPM) machine. The optimization of stator slot gap and permanent magnet is carried out and the cogging torque ripple is analyzed by using finite element analysis. Experiments on a prototype...

Rab27 GTPases Distribute Extracellular Nanomaps for Invasive Growth and Metastasis: Implications for Prognosis and Treatment

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Olivier De Wever

2013-05-01

Full Text Available The Rab27 family of small GTPases regulates exocytosis of distinct vesicle types including multivesicular endosomes, which results in the release of exosomes. Exosomes are nanometer-sized membrane vesicles that enclose soluble factors such as proteins and nucleic acids within a lipid bilayer and can travel toward distant tissues to influence multiple aspects of cell behavior. In our view that tumors are endocrine organs producing exosomes, Rab27 GTPases and their effector proteins are critical determinants for invasive growth and metastasis. Rab27 proteins and their effectors may serve as prognostic biomarkers or as targets for patient-tailored therapy.

The glyceraldehyde-3-phosphate dehydrogenase and the small GTPase Rab 2 are crucial for Brucella replication.

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Emilie Fugier

2009-06-01

Full Text Available The intracellular pathogen Brucella abortus survives and replicates inside host cells within an endoplasmic reticulum (ER-derived replicative organelle named the "Brucella-containing vacuole" (BCV. Here, we developed a subcellular fractionation method to isolate BCVs and characterize for the first time the protein composition of its replicative niche. After identification of BCV membrane proteins by 2 dimensional (2D gel electrophoresis and mass spectrometry, we focused on two eukaryotic proteins: the glyceraldehyde-3-phosphate dehydrogenase (GAPDH and the small GTPase Rab 2 recruited to the vacuolar membrane of Brucella. These proteins were previously described to localize on vesicular and tubular clusters (VTC and to regulate the VTC membrane traffic between the endoplasmic reticulum (ER and the Golgi. Inhibition of either GAPDH or Rab 2 expression by small interfering RNA strongly inhibited B. abortus replication. Consistent with this result, inhibition of other partners of GAPDH and Rab 2, such as COPI and PKC iota, reduced B. abortus replication. Furthermore, blockage of Rab 2 GTPase in a GDP-locked form also inhibited B. abortus replication. Bacteria did not fuse with the ER and instead remained in lysosomal-associated membrane vacuoles. These results reveal an essential role for GAPDH and the small GTPase Rab 2 in B. abortus virulence within host cells.

Relationships between cognitive impairment on ADAS-cog and regional cerebral blood flow using SPECT in late-onset Alzheimer's disease.

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Takahashi, Michio; Oda, Yasunori; Okubo, Toshiyuki; Shirayama, Yukihiko

2017-09-01

The aim of this study was to examine brain hypoperfusion and its relationship with cognitive dysfunction in late-onset Alzheimer's disease (AD). Forty patients with late-onset AD and not receiving acetylcholinesterase inhibitors were recruited from outpatient clinics. We examined cognitive function using the Alzheimer's Disease Assessment Scale-cognitive subscale (ADAS-cog) and brain perfusion using single-photon emission computed tomography, and analyzed classified gyrus level segments with three-dimensional stereotactic surface projection and the stereotactic extraction estimation method level 3. ADAS-cog subscales were grouped into three domains: language, memory, and praxis. Patients with late-onset AD showed an apparent reduction in regional cerebral blood flow (rCBF) with a z score >1.5 in the frontal, temporal, and limbic lobes, with lesser reduction in the parietal and occipital lobes. Although hypoperfusion in the orbital, rectal, and subcallosal gyri of the frontal lobe was prominent, rCBF in the inferior frontal gyrus of the frontal lobe was significantly correlated with ADAS-cog total and language and praxis subscale scores. The parahippocampal gyrus of the limbic lobe was also significantly correlated with the ADAS-cog total, language, and praxis subscale scores. Additionally, the cingulate of the limbic lobe was significantly related with ADAS-cog memory. In spite of lesser hypoperfusion, the posterior cingulate gyrus of the limbic lobe was significantly related with ADAS-cog total, language, and memory subscale scores. Further, each subdivision of ADAS-cog was found to be related with various brain regions.

ANCAC: amino acid, nucleotide, and codon analysis of COGs--a tool for sequence bias analysis in microbial orthologs.

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Meiler, Arno; Klinger, Claudia; Kaufmann, Michael

2012-09-08

The COG database is the most popular collection of orthologous proteins from many different completely sequenced microbial genomes. Per definition, a cluster of orthologous groups (COG) within this database exclusively contains proteins that most likely achieve the same cellular function. Recently, the COG database was extended by assigning to every protein both the corresponding amino acid and its encoding nucleotide sequence resulting in the NUCOCOG database. This extended version of the COG database is a valuable resource connecting sequence features with the functionality of the respective proteins. Here we present ANCAC, a web tool and MySQL database for the analysis of amino acid, nucleotide, and codon frequencies in COGs on the basis of freely definable phylogenetic patterns. We demonstrate the usefulness of ANCAC by analyzing amino acid frequencies, codon usage, and GC-content in a species- or function-specific context. With respect to amino acids we, at least in part, confirm the cognate bias hypothesis by using ANCAC's NUCOCOG dataset as the largest one available for that purpose thus far. Using the NUCOCOG datasets, ANCAC connects taxonomic, amino acid, and nucleotide sequence information with the functional classification via COGs and provides a GUI for flexible mining for sequence-bias. Thereby, to our knowledge, it is the only tool for the analysis of sequence composition in the light of physiological roles and phylogenetic context without requirement of substantial programming-skills.

Over-expression of a Rab family GTPase from phreatophyte Prosopis juliflora confers tolerance to salt stress on transgenic tobacco.

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George, Suja; Parida, Ajay

2011-03-01

Plant growth and productivity are adversely affected by various abiotic and biotic stress factors. In our previous study, we used Prosopis juliflora, an abiotic stress tolerant tree species of Fabaceae, as a model plant system for isolating genes functioning in abiotic stress tolerance. Here we report the isolation and characterization of a Rab family GTPase from P. juliflora (Pj Rab7) and the ability of this gene to confer salt stress tolerance in transgenic tobacco. Northern analysis for Pj Rab7 in P. juliflora leaf tissue revealed up-regulation of this gene under salt stress under the concentrations and time points analyzed. Pj Rab7 transgenic tobacco lines survived better under conditions of 150 mM NaCl stress compared to control un-transformed plants. Pj Rab7 transgenic plants were found to accumulate more sodium than control plants during salt stress. The results of our studies could be used as a starting point for generation of crop plants tolerant to abiotic stress.

Liver X receptors balance lipid stores in hepatic stellate cells through Rab18, a retinoid responsive lipid droplet protein.

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O'Mahony, Fiona; Wroblewski, Kevin; O'Byrne, Sheila M; Jiang, Hongfeng; Clerkin, Kara; Benhammou, Jihane; Blaner, William S; Beaven, Simon W

2015-08-01

Liver X receptors (LXRs) are determinants of hepatic stellate cell (HSC) activation and liver fibrosis. Freshly isolated HSCs from Lxrαβ(-/-) mice have increased lipid droplet (LD) size, but the functional consequences of this are unknown. Our aim was to determine whether LXRs link cholesterol to retinoid storage in HSCs and how this impacts activation. Primary HSCs from Lxrαβ(-/-) and wild-type mice were profiled by gene array during in vitro activation. Lipid content was quantified by high-performance liquid chromatography and mass spectroscopy. Primary HSCs were treated with nuclear receptor ligands, transfected with small interfering RNA and plasmid constructs, and analyzed by immunocytochemistry. Lxrαβ(-/-) HSCs have increased cholesterol and retinyl esters. The retinoid increase drives intrinsic retinoic acid receptor signaling, and activation occurs more rapidly in Lxrαβ(-/-) HSCs. We identify Rab18 as a novel retinoic acid-responsive, LD-associated protein that helps mediate stellate cell activation. Rab18 mRNA, protein, and membrane insertion increase during activation. Both Rab18 guanosine triphosphatase activity and isoprenylation are required for stellate cell LD loss and induction of activation markers. These phenomena are accelerated in Lxrαβ(-/-) HSCs, where there is greater retinoic acid flux. Conversely, Rab18 knockdown retards LD loss in culture and blocks activation, just like the functional mutants. Rab18 is also induced with acute liver injury in vivo. Retinoid and cholesterol metabolism are linked in stellate cells by the LD-associated protein Rab18. Retinoid overload helps explain the profibrotic phenotype of Lxrαβ(-/-) mice, and we establish a pivotal role for Rab18 GTPase activity and membrane insertion in wild-type stellate cell activation. Interference with Rab18 may have significant therapeutic benefit in ameliorating liver fibrosis. © 2015 by the American Association for the Study of Liver Diseases.

Liver X Receptors Balance Lipid Stores in Hepatic Stellate Cells via Rab18, a Retinoid Responsive Lipid Droplet Protein

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O’Mahony, Fiona; Wroblewski, Kevin; O’Byrne, Sheila M.; Jiang, Hongfeng; Clerkin, Kara; Benhammou, Jihane; Blaner, William S.; Beaven, Simon W.

2014-01-01

Liver X receptors (LXRs) are determinants of hepatic stellate cell (HSC) activation and liver fibrosis. Freshly isolated HSCs from Lxrαβ−/− mice have increased lipid droplet (LD) size but the functional consequences of this are unknown. Our aim was to determine whether LXRs link cholesterol to retinoid storage in HSCs and how this impacts activation. Primary HSCs from Lxrαβ−/− and wild-type (WT) mice were profiled by gene array during in vitro activation. Lipid content was quantified by HPLC and mass spectroscopy. Primary HSCs were treated with nuclear receptor ligands, transfected with siRNA and plasmid constructs, and analyzed by immunocytochemistry. Lxrαβ−/− HSCs have increased cholesterol and retinyl esters (CEs & REs). The retinoid increase drives intrinsic retinoic acid receptor (RAR) signaling and activation occurs more rapidly in Lxrαβ−/− HSCs. We identify Rab18 as a novel retinoic acid responsive, lipid droplet associated protein that helps mediate stellate cell activation. Rab18 mRNA, protein, and membrane insertion increase during activation. Both Rab18 GTPase activity and isoprenylation are required for stellate cell lipid droplet loss and induction of activation markers. These phenomena are accelerated in the Lxrαβ−/− HSCs, where there is greater retinoic acid flux. Conversely, Rab18 knockdown retards lipid droplet loss in culture and blocks activation, just like the functional mutants. Rab18 is also induced with acute liver injury in vivo. Conclusion Retinoid and cholesterol metabolism are linked in stellate cells by the LD associated protein, Rab18. Retinoid overload helps explain the pro-fibrotic phenotype of Lxrαβ−/− mice and we establish a pivotal role for Rab18 GTPase activity and membrane insertion in wild-type stellate cell activation. Interference with Rab18 may have significant therapeutic benefit in ameliorating liver fibrosis. PMID:25482505

Cogs in the endless machine: lakes, climate change and nutrient cycles: a review.

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Moss, Brian

2012-09-15

Lakes have, rather grandly, been described as sentinels, integrators and regulators of climate change (Williamson et al., Limnol. Oceanogr. 2009; 54: 2273-82). Lakes are also part of the continuum of the water cycle, cogs in a machine that processes water and elements dissolved and suspended in myriad forms. Assessing the changes in the functioning of the cogs and the machine with respect to these substances as climate changes is clearly important, but difficult. Many other human-induced influences, not least eutrophication, that impact on catchment areas and consequently on lakes, have generally complicated the recording of recent change in sediment records and modern sets of data. The least confounded evidence comes from remote lakes in mountain and polar regions and suggests effects of warming that include mobilisation of ions and increased amounts of phosphorus. A cottage industry has arisen in deduction and prediction of the future effects of climate change on lakes, but the results are very general and precision is marred not only by confounding influences but by the complexity of the lake system and the infinite variety of possible future scenarios. A common conclusion, however, is that warming will increase the intensity of symptoms of eutrophication. Direct experimentation, though expensive and still unusual and confined to shallow lake and wetland systems is perhaps the most reliable approach. Results suggest increased symptoms of eutrophication, and changes in ecosystem structure, but in some respects are different from those deduced from comparisons along latitudinal gradients or by inference from knowledge of lake behaviour. Experiments have shown marked increases in community respiration compared with gross photosynthesis in mesocosm systems and it may be that the most significant churnings of these cogs in the earth-air-water machine will be in their influence on the carbon cycle, with possibly large positive feedback effects on warming. Copyright �

Similarity-based gene detection: using COGs to find evolutionarily-conserved ORFs.

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Powell, Bradford C; Hutchison, Clyde A

2006-01-19

Experimental verification of gene products has not kept pace with the rapid growth of microbial sequence information. However, existing annotations of gene locations contain sufficient information to screen for probable errors. Furthermore, comparisons among genomes become more informative as more genomes are examined. We studied all open reading frames (ORFs) of at least 30 codons from the genomes of 27 sequenced bacterial strains. We grouped the potential peptide sequences encoded from the ORFs by forming Clusters of Orthologous Groups (COGs). We used this grouping in order to find homologous relationships that would not be distinguishable from noise when using simple BLAST searches. Although COG analysis was initially developed to group annotated genes, we applied it to the task of grouping anonymous DNA sequences that may encode proteins. "Mixed COGs" of ORFs (clusters in which some sequences correspond to annotated genes and some do not) are attractive targets when seeking errors of gene prediction. Examination of mixed COGs reveals some situations in which genes appear to have been missed in current annotations and a smaller number of regions that appear to have been annotated as gene loci erroneously. This technique can also be used to detect potential pseudogenes or sequencing errors. Our method uses an adjustable parameter for degree of conservation among the studied genomes (stringency). We detail results for one level of stringency at which we found 83 potential genes which had not previously been identified, 60 potential pseudogenes, and 7 sequences with existing gene annotations that are probably incorrect. Systematic study of sequence conservation offers a way to improve existing annotations by identifying potentially homologous regions where the annotation of the presence or absence of a gene is inconsistent among genomes.

Similarity-based gene detection: using COGs to find evolutionarily-conserved ORFs

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Hutchison Clyde A

2006-01-01

Full Text Available Abstract Background Experimental verification of gene products has not kept pace with the rapid growth of microbial sequence information. However, existing annotations of gene locations contain sufficient information to screen for probable errors. Furthermore, comparisons among genomes become more informative as more genomes are examined. We studied all open reading frames (ORFs of at least 30 codons from the genomes of 27 sequenced bacterial strains. We grouped the potential peptide sequences encoded from the ORFs by forming Clusters of Orthologous Groups (COGs. We used this grouping in order to find homologous relationships that would not be distinguishable from noise when using simple BLAST searches. Although COG analysis was initially developed to group annotated genes, we applied it to the task of grouping anonymous DNA sequences that may encode proteins. Results "Mixed COGs" of ORFs (clusters in which some sequences correspond to annotated genes and some do not are attractive targets when seeking errors of gene predicion. Examination of mixed COGs reveals some situations in which genes appear to have been missed in current annotations and a smaller number of regions that appear to have been annotated as gene loci erroneously. This technique can also be used to detect potential pseudogenes or sequencing errors. Our method uses an adjustable parameter for degree of conservation among the studied genomes (stringency. We detail results for one level of stringency at which we found 83 potential genes which had not previously been identified, 60 potential pseudogenes, and 7 sequences with existing gene annotations that are probably incorrect. Conclusion Systematic study of sequence conservation offers a way to improve existing annotations by identifying potentially homologous regions where the annotation of the presence or absence of a gene is inconsistent among genomes.

Actin cytoskeleton-dependent Rab GTPase-regulated angiotensin type I receptor lysosomal degradation studied by fluorescence lifetime imaging microscopy

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Li, Hewang; Yu, Peiying; Sun, Yuansheng; Felder, Robin A.; Periasamy, Ammasi; Jose, Pedro A.

2010-09-01

The dynamic regulation of the cellular trafficking of human angiotensin (Ang) type 1 receptor (AT1R) is not well understood. Therefore, we investigated the cellular trafficking of AT1R-enhanced green fluorescent protein (EGFP) (AT1R-EGFP) heterologously expressed in HEK293 cells by determining the change in donor lifetime (AT1R-EGFP) in the presence or absence of acceptor(s) using fluorescence lifetime imaging-fluorescence resonance energy transfer (FRET) microscopy. The average lifetime of AT1R-EGFP in our donor-alone samples was ~2.33 ns. The basal state lifetime was shortened slightly in the presence of Rab5 (2.01+/-0.10 ns) or Rab7 (2.11+/-0.11 ns) labeled with Alexa 555, as the acceptor fluorophore. A 5-min Ang II treatment markedly shortened the lifetime of AT1R-EGFP in the presence of Rab5-Alexa 555 (1.78+/-0.31 ns) but was affected minimally in the presence of Rab7-Alexa 555 (2.09+/-0.37 ns). A 30-min Ang II treatment further decreased the AT1R-EGFP lifetime in the presence of both Rab5- and Rab7-Alexa 555. Latrunculin A but not nocodazole pretreatment blocked the ability of Ang II to shorten the AT1R-EGFP lifetime. The occurrence of FRET between AT1R-EGFP (donor) and LAMP1-Alexa 555 (acceptor) with Ang II stimulation was impaired by photobleaching the acceptor. These studies demonstrate that Ang II-induced AT1R lysosomal degradation through its association with LAMP1 is regulated by Rab5/7 via mechanisms that are dependent on intact actin cytoskeletons.

One-year treatment of Alzheimer's disease with acetylcholinesterase inhibitors: improvement on ADAS-cog and TMT A, no change or worsening on other tests.

Science.gov (United States)

Borkowska, Alina; Ziolkowska-Kochan, Marzena; Rybakowski, Janusz K

2005-08-01

The aim of this study was to assess cognitive functioning measured by selected psychometric and neuropsychological tools in patients with Alzheimer's disease (AD) after 1-year treatment with acetylcholinesterase inhibitors. Seventy-six patients (22 male and 54 female) with a mild to moderate stage of AD, aged 56-86 (mean 68) years, were treated. Forty-seven received donepezil (mean dose 9.3 mg/d) and 29 rivastigmine (mean dose 8.5 mg/d). Cognitive measurements included: the mini mental state examination (MMSE), the Alzheimer disease assessment scale-cognitive (ADAS- cog), the trail making test (TMT) and the Stroop color word interference test. The assessments were made before and after 3, 6 and 12 months of treatment. A significant improvement in ADAS-cog (p ADAS-cog) and psychomotor speed (TMT A), however, such treatment is unable to prevent the deterioration of working memory and executive functions. Copyright (c) 2005 John Wiley & Sons, Ltd.

Item analysis of ADAS-Cog: effect of baseline cognitive impairment in a clinical AD trial.

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Sevigny, Jeffrey J; Peng, Yahong; Liu, Lian; Lines, Christopher R

2010-03-01

We explored the association of Alzheimer's disease (AD) Assessment Scale (ADAS-Cog) item scores with AD severity using cross-sectional and longitudinal data from the same study. Post hoc analyses were performed using placebo data from a 12-month trial of patients with mild-to-moderate AD (N =281 randomized, N =209 completed). Baseline distributions of ADAS-Cog item scores by Mini-Mental State Examination (MMSE) score and Clinical Dementia Rating (CDR) sum of boxes score (measures of dementia severity) were estimated using local and nonparametric regressions. Mixed-effect models were used to characterize ADAS-Cog item score changes over time by dementia severity (MMSE: mild =21-26, moderate =14-20; global CDR: mild =0.5-1, moderate =2). In the cross-sectional analysis of baseline ADAS-Cog item scores, orientation was the most sensitive item to differentiate patients across levels of cognitive impairment. Several items showed a ceiling effect, particularly in milder AD. In the longitudinal analysis of change scores over 12 months, orientation was the only item with noticeable decline (8%-10%) in mild AD. Most items showed modest declines (5%-20%) in moderate AD.

Rab5 GTPase controls chromosome alignment through Lamin disassembly and relocation of the NuMA-like protein Mud to the poles during mitosis

Science.gov (United States)

Capalbo, Luisa; D'Avino, Pier Paolo; Archambault, Vincent; Glover, David M.

2011-01-01

The small GTPase Rab5 is a conserved regulator of membrane trafficking; it regulates the formation of early endosomes, their transport along microtubules, and the fusion to the target organelles. Although several members of the endocytic pathway were recently implicated in spindle organization, it is unclear whether Rab5 has any role during mitosis. Here, we describe that Rab5 is required for proper chromosome alignment during Drosophila mitoses. We also found that Rab5 associated in vivo with nuclear Lamin and mushroom body defect (Mud), the Drosophila counterpart of nuclear mitotic apparatus protein (NuMA). Consistent with this finding, Rab5 was required for the disassembly of the nuclear envelope at mitotic entry and the accumulation of Mud at the spindle poles. Furthermore, Mud depletion caused chromosome misalignment defects that resembled the defects of Rab5 RNAi cells, and double-knockdown experiments indicated that the two proteins function in a linear pathway. Our results indicate a role for Rab5 in mitosis and reinforce the emerging view of the contributions made by cell membrane dynamics to spindle function. PMID:21987826

A Rab-centric perspective of bacterial pathogen-occupied vacuoles.

Science.gov (United States)

Sherwood, Racquel Kim; Roy, Craig R

2013-09-11

The ability to create and maintain a specialized organelle that supports bacterial replication is an important virulence property for many intracellular pathogens. Living in a membrane-bound vacuole presents inherent challenges, including the need to remodel a plasma membrane-derived organelle into a novel structure that will expand and provide essential nutrients to support replication, while also having the vacuole avoid membrane transport pathways that target bacteria for destruction in lysosomes. It is clear that pathogenic bacteria use different strategies to accomplish these tasks. The dynamics by which host Rab GTPases associate with pathogen-occupied vacuoles provide insight into the mechanisms used by different bacteria to manipulate host membrane transport. In this review we highlight some of the strategies bacteria use to maintain a pathogen-occupied vacuole by focusing on the Rab proteins involved in biogenesis and maintenance of these novel organelles. Copyright © 2013 Elsevier Inc. All rights reserved.

[Diagnostic value and functional correlations of the ADAS-Cog scale in Alzheimer's disease: data on NORMACODEM project].

Science.gov (United States)

Monllau, A; Pena-Casanova, J; Blesa, R; Aguilar, M; Bohm, P; Sol, J M; Hernandez, G

2007-10-01

The aims of this study were to assess the criterion validity of Alzheimer's Disease Assessment Scale (ADAS) and its cognitive subscale (ADAS-Cog) for the diagnosis of Alzheimer's disease (AD), and to determine their different cut-off scores and sensitivity and specificity values. In addition, we also attempted to study the possible correlations between cognitive scores (ADAS) and functional measures. 451 subjects were studied (254 controls, 86 subjects with mild cognitive impairment and 111 patients with AD). ADAS total score was obtained by adding the cognitive (ADAS-Cog) and non-cognitive (ADAS-Nocog) scales. Scores were adjusted for age and formal education. For assessing the possible correlation between cognitive and functional measures, the following instruments were administered: Rapid Disability Rating Scale-2 (RDRS-2), Blessed Dementia Rating Scale (BDRS) and the Interview for the Deterioration of Daily Living in Dementia (IDDD). ROC curves and Pearson correlation coefficient. ADAS best cut-off score for dementia was > or = 17 providing sensitivity and specificity values of 90.09% and 85.88 % respectively, while for the ADAS-Cog best cut-off score was > or = 12 with sensitivity and specificity values of 89.19 % and 88.53 % respectively. In both cases scores were adjusted for age and formal education. The area under the ROC curve was 0.95 and 0.94 respectively. Highly significant correlations were found for ADAS and 19 ADAS-Cog with the functional scales studied. Both, ADAS and ADAS-Cog report good validity in terms of sensitivity, specificity and as predictive value for AD. Moreover, significant correlations were found between the functional impairment observed in patients with AD and the overall scores achieved in the ADAS and ADAS-Cog.

The performance of the Mini-Cog in a sample of low educational level elderly.

Science.gov (United States)

Ribeiro Filho, Sergio Telles; Lourenço, Roberto Alves

2009-01-01

To study the criterion validity of the Mini-Cog in low educational level elderly. Design: Cross-sectional and validation design. Setting: Policlínica Piquet Carneiro, an outpatient unit of Rio de Janeiro State University Hospital, in Brazil. Participants: A convenient sample consisting of 306 individuals, 65 yrs or older, selected from April 8 th to July 15 th , 2002. All participants underwent comprehensive geriatric evaluations which included the Mini-Mental State Examination (MMSE) and the cognitive part of the Cambridge Examination for Mental Disorders of the Elderly - Revised (CAMCOG-R). They were classified as demented or non-demented (DSM-IV). A post-hoc analysis was performed on the data from the 3 word recall test of the MMSE, and the Clock Drawing Test from the CAMCOG-R, and respective scores were added and interpreted in accordance with the Mini-Cog protocol. 293 individuals completed all the study steps; 211 had 4 or less years of schooling and were included in the data analysis. 32% had dementia. Mini-Cog sensitivity and specificity was consistently low independently of the different cut-off points considered. The best performance was found at the cut-off point of 2/3 which yielded sensitivity and specificity of 60% and 65%, respectively. The Mini-Cog is not a good cognitive screening tool for individuals with less than five years of formal education.

Cognitive infocommunications (CogInfoCom)

CERN Document Server

Baranyi, Péter; Sallai, Gyula

2015-01-01

This book describes the theoretical foundations of cognitive infocommunications (CogInfoCom), and provides a survey on state-of-the-art solutions and applications within the field. The book covers aspects of cognitive infocommunications in the research fields of affective computing, BCI, future internet, HCI, HRI, sensory substitution, and virtual/augmented interactions. The book focuses on describing the merging between humans and information and communications technology (ICT) at the level of cognitive capabilities with an approach towards developing future cognitive ICT.   · Provides a comprehensive overview of cognitive infocommunications   · Covers theoretical and practical aspects of cognitive infocommunications   · Discusses applications employing various aspects of infocommunication.

PipY, a Member of the Conserved COG0325 Family of PLP-Binding Proteins, Expands the Cyanobacterial Nitrogen Regulatory Network

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José I. Labella

2017-07-01

Full Text Available Synechococcus elongatus PCC 7942 is a paradigmatic model organism for nitrogen regulation in cyanobacteria. Expression of genes involved in nitrogen assimilation is positively regulated by the 2-oxoglutarate receptor and global transcriptional regulator NtcA. Maximal activation requires the subsequent binding of the co-activator PipX. PII, a protein found in all three domains of life as an integrator of signals of the nitrogen and carbon balance, binds to PipX to counteract NtcA activity at low 2-oxoglutarate levels. PII-PipX complexes can also bind to the transcriptional regulator PlmA, whose regulon remains unknown. Here we expand the nitrogen regulatory network to PipY, encoded by the bicistronic operon pipXY in S. elongatus. Work with PipY, the cyanobacterial member of the widespread family of COG0325 proteins, confirms the conserved roles in vitamin B6 and amino/keto acid homeostasis and reveals new PLP-related phenotypes, including sensitivity to antibiotics targeting essential PLP-holoenzymes or synthetic lethality with cysK. In addition, the related phenotypes of pipY and pipX mutants are consistent with genetic interactions in the contexts of survival to PLP-targeting antibiotics and transcriptional regulation. We also showed that PipY overexpression increased the length of S. elongatus cells. Taken together, our results support a universal regulatory role for COG0325 proteins, paving the way to a better understanding of these proteins and of their connections with other biological processes.

Puzzling with online games (BAM-COG): reliability, validity, and feasibility of an online self-monitor for cognitive performance in aging adults.

Science.gov (United States)

Aalbers, Teun; Baars, Maria A E; Olde Rikkert, Marcel G M; Kessels, Roy P C

2013-12-03

Online interventions are aiming increasingly at cognitive outcome measures but so far no easy and fast self-monitors for cognition have been validated or proven reliable and feasible. This study examines a new instrument called the Brain Aging Monitor-Cognitive Assessment Battery (BAM-COG) for its alternate forms reliability, face and content validity, and convergent and divergent validity. Also, reference values are provided. The BAM-COG consists of four easily accessible, short, yet challenging puzzle games that have been developed to measure working memory ("Conveyer Belt"), visuospatial short-term memory ("Sunshine"), episodic recognition memory ("Viewpoint"), and planning ("Papyrinth"). A total of 641 participants were recruited for this study. Of these, 397 adults, 40 years and older (mean 54.9, SD 9.6), were eligible for analysis. Study participants played all games three times with 14 days in between sets. Face and content validity were based on expert opinion. Alternate forms reliability (AFR) was measured by comparing scores on different versions of the BAM-COG and expressed with an intraclass correlation (ICC: two-way mixed; consistency at 95%). Convergent validity (CV) was provided by comparing BAM-COG scores to gold-standard paper-and-pencil and computer-assisted cognitive assessment. Divergent validity (DV) was measured by comparing BAM-COG scores to the National Adult Reading Test IQ (NART-IQ) estimate. Both CV and DV are expressed as Spearman rho correlation coefficients. Three out of four games showed adequate results on AFR, CV, and DV measures. The games Conveyer Belt, Sunshine, and Papyrinth have AFR ICCs of .420, .426, and .645 respectively. Also, these games had good to very good CV correlations: rho=.577 (P=.001), rho=.669 (Pgame Viewpoint provided less desirable results with an AFR ICC of .167, CV rho=.202 (P=.15), and DV rho=-.162 (P=.21). This study provides evidence for the use of the BAM-COG test battery as a feasible, reliable, and

The Cogs Are Coming: The Cognitive Augmentation Revolution

Science.gov (United States)

Fulbright, Ron

2016-01-01

We are at the beginning of a new era in human history--the cognitive augmentation era. Until now, humans have had to do all of the thinking. The future will make it possible for humans to partner with cognitive systems doing some of the thinking themselves and in many ways thinking that is superior to humans. Together, humans and "cogs"…

Akt regulates the subcellular localization of the Rab27a-binding protein JFC1 by phosphorylation.

Science.gov (United States)

Johnson, Jennifer L; Pacquelet, Sandrine; Lane, William S; Eam, Boreth; Catz, Sergio D

2005-08-01

Here, we show that the Rab27a-binding protein JFC1/Slp1 (synaptotagmin-like protein) is regulated by Akt-mediated phosphorylation. Using the phosphatase and tensin homolog-null LNCaP cells and the phosphatidylinositol 3-kinase inhibitor LY294002, we show that the phosphorylation of endogenous JFC1 is dependent on the phosphatidylinositol 3-kinase/Akt pathway. JFC1 was phosphorylated in cells expressing a constitutively active Akt, confirming that it is an Akt substrate in vivo. Direct phosphorylation of JFC1 by Akt was confirmed in vitro. Using microcapillary high-performance liquid chromatography tandem mass spectrometry, we identified five Akt-phosphorylation sites in JFC1. By mutagenesis analysis and subsequent immunoprecipitation (IP), we established that Akt phosphorylates JFC1 at serine 241. JFC1 and Rab27a colocalize in the proximity of the plasma membrane in LNCaP cells. The interaction was confirmed by IP analysis and was abolished by the point mutation W83S in JFC1. Phosphorylation did not alter the ability of JFC1 to bind to Rab27a. Instead, phosphorylation by Akt dramatically decreased when JFC1 was bound to Rab27a. Finally, we show that as a consequence of in vivo phosphorylation, JFC1 dissociates from the membrane, promoting JFC1 redistribution to the cytosol. Our results suggest that Akt regulates JFC1/Slp1 function by phosphorylation and may have implications on Rab27a-containing vesicle secretion.

French version of the Functional Assessment of Cancer Therapy-Cognitive Function (FACT-Cog) version 3.

Science.gov (United States)

Joly, F; Lange, M; Rigal, O; Correia, H; Giffard, B; Beaumont, J L; Clisant, S; Wagner, L

2012-12-01

Impairment of cognitive function, a common complaint in patients receiving chemotherapy, is usually measured through neuropsychological tests. Patient self-evaluation of cognitive difficulties is an important complement to those tests. The Functional Assessment of Cancer Therapy-Cognitive Function (FACT-Cog) is a self-report questionnaire with potential to be used in standard clinical practice as a tool for evaluating patient's cognitive function before, during, and after chemotherapy. The purpose of our study was to conduct linguistic validation of the French version of the FACT-Cog. Both qualitative and quantitative methods were used in this study. After undergoing a rigorous translation methodology, the French FACT-Cog version was pretested in France with 35 cancer patients undergoing chemotherapy treatment. Interviews were conducted with all patients to ascertain their understanding of each item. The validation of the final version was conducted among 63 cancer patients, and sociodemographic information was collected as well as brief measure of cognitive function and depression score. Patient comments obtained through the cognitive debriefing interviews indicated that patients understand the French FACT-Cog items as they are intended and that the measure is culturally appropriate. Internal consistency reliability of the subscales, evaluated using Cronbach's coefficient alpha, was high for all four subscales: Perceived Cognitive Impairments = 0.93, Impact On QOL = 0.85, Comments From Others = 0.70, and Perceived Cognitive Abilities = 0.89. All item-total correlations for each subscale were greater than 0.20, and most were greater than 0.50. Results from this study effectively demonstrate that the French FACT-Cog is a reliable instrument for the self-reporting of cognitive abilities in patients undergoing chemotherapy.

How well do the ADAS-cog and its subscales measure cognitive dysfunction in Alzheimer's disease?

Science.gov (United States)

Benge, Jared F; Balsis, Steve; Geraci, Lisa; Massman, Paul J; Doody, Rachelle S

2009-01-01

The Alzheimer's Disease Assessment Scale-cognitive (ADAS-cog) is regularly used to assess cognitive dysfunction in Alzheimer's disease (AD) clinical trials. Yet, little is known about how the instrument and its subscales measure cognition across the spectrum of AD. The current investigation used item response theory (IRT) analyses to assess the measurement properties of the ADAS-cog across the range of cognitive dysfunction in AD. We used IRT-based analyses to establish the relationship between cognitive dysfunction and the probability of obtaining observed scores on each subscale and the test as a whole. Data were obtained from 1,087 patients with AD and amnestic mild cognitive impairment. Results showed that the ADAS-cog and its subscales provide maximum information at moderate levels of cognitive dysfunction. Raw score differences toward the lower and higher ends of the scale corresponded to large differences in cognitive dysfunction, whereas raw score differences toward the middle of the scale corresponded to smaller differences. The utility of the ADAS-cog and its subscales is optimal in the moderate range of cognitive dysfunction, but raw score differences in that region correspond to relatively small differences in cognitive dysfunction. Implications for tracking and staging dementia and for clinical trials are discussed. Copyright 2009 S. Karger AG, Basel.

Apolipoprotein E-Mimetic Peptide COG1410 Promotes Autophagy by Phosphorylating GSK-3β in Early Brain Injury Following Experimental Subarachnoid Hemorrhage

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Xinshen Li

2018-03-01

Full Text Available COG1410, a mimetic peptide derived from the apolipoprotein E (apoE receptor binding region, exerts positive effect on neurological deficits in early brain injury (EBI after experimental subarachnoid hemorrhage (SAH. Currently the neuroprotective effect of COG1410 includes inhibiting BBB disruption, reducing neuronal apoptosis, and neuroinflammation. However, the effect and mechanism of COG1410 to subcellular organelles disorder have not been fully investigated. As the main pathway for recycling long-lived proteins and damaged organelles, neuronal autophagy is activated in SAH and exhibits neuroprotective effects by reducing the insults of EBI. Pharmacologically elevated autophagy usually contributes to alleviated brain injury, while few of the agents achieved clinical transformation. In this study, we explored the activation of autophagy during EBI by measuring the Beclin-1 and LC3B-II protein levels. Administration of COG1410 notably elevated the autophagic markers expression in neurons, simultaneously reversed the neurological deficits. Furthermore, the up-regulated autophagy by COG1410 was further promoted by p-GSK-3β agonist, whereas decreased by p-GSK-3β inhibitor. Taken together, these data suggest that the COG1410 might be a promising therapeutic strategy for EBI via promoting autophagy in SAH.

The Mollö Cog Re-Examined and Re-Evaluated

DEFF Research Database (Denmark)

Von Arbin, Staffan; Daly, Aoife

2012-01-01

As part of a research project on medieval trade and maritime transportation in the former Norwegian province of Bohuslän, western Sweden, a dendrochronological analysis of the so-called Mollö cog was undertaken. The wreck, which was first salvaged in 1980, was previously dated by 14 C analysis...

Rac1-Rab11-FIP3 regulatory hub coordinates vesicle traffic with actin remodeling and T-cell activation.

Science.gov (United States)

Bouchet, Jérôme; Del Río-Iñiguez, Iratxe; Lasserre, Rémi; Agüera-Gonzalez, Sonia; Cuche, Céline; Danckaert, Anne; McCaffrey, Mary W; Di Bartolo, Vincenzo; Alcover, Andrés

2016-06-01

The immunological synapse generation and function is the result of a T-cell polarization process that depends on the orchestrated action of the actin and microtubule cytoskeleton and of intracellular vesicle traffic. However, how these events are coordinated is ill defined. Since Rab and Rho families of GTPases control intracellular vesicle traffic and cytoskeleton reorganization, respectively, we investigated their possible interplay. We show here that a significant fraction of Rac1 is associated with Rab11-positive recycling endosomes. Moreover, the Rab11 effector FIP3 controls Rac1 intracellular localization and Rac1 targeting to the immunological synapse. FIP3 regulates, in a Rac1-dependent manner, key morphological events, like T-cell spreading and synapse symmetry. Finally, Rab11-/FIP3-mediated regulation is necessary for T-cell activation leading to cytokine production. Therefore, Rac1 endosomal traffic is key to regulate T-cell activation. © 2016 The Authors.

MUC1 intra-cellular trafficking is clathrin, dynamin, and rab5 dependent

International Nuclear Information System (INIS)

Liu Xiaolong; Yuan Zhenglong; Chung, Maureen

2008-01-01

MUC1, a transmembrane glycoprotein, is abnormally over-expressed in most human adenocarcinomas. MUC1 association with cytoplasmic cell signal regulators and nuclear accumulation are important for its tumor related activities. Little is known about how MUC1 translocates from the cell membrane to the cytoplasm. In this study, live cell imaging was used to study MUC1 intracellular trafficking. The interaction between EGFR and MUC1 was mapped by FRET analysis and EGF stimulated MUC1 endocytosis was observed directly through live cell imaging. MUC1-CT endocytosis was clathrin and dynamin dependent. Rab5 over-expression resulted in decreased cell membrane localization of MUC1, with accumulation of MUC1 endocytic vesicles in the peri-nuclear region. Conversely, over-expression of a Rab5 dominant negative mutant (S34N) resulted in redistribution of MUC1 from the peri-nuclear region to the cytoplasm. Collectively, these results indicated that MUC1 intra-cellular trafficking occurs through a regulated process that was stimulated by direct EGFR and MUC1 interaction, mediated by clathrin coated pits that were dynamin dependent and regulated by Rab5

ANCAC: amino acid, nucleotide, and codon analysis of COGs – a tool for sequence bias analysis in microbial orthologs

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Meiler Arno

2012-09-01

Full Text Available Abstract Background The COG database is the most popular collection of orthologous proteins from many different completely sequenced microbial genomes. Per definition, a cluster of orthologous groups (COG within this database exclusively contains proteins that most likely achieve the same cellular function. Recently, the COG database was extended by assigning to every protein both the corresponding amino acid and its encoding nucleotide sequence resulting in the NUCOCOG database. This extended version of the COG database is a valuable resource connecting sequence features with the functionality of the respective proteins. Results Here we present ANCAC, a web tool and MySQL database for the analysis of amino acid, nucleotide, and codon frequencies in COGs on the basis of freely definable phylogenetic patterns. We demonstrate the usefulness of ANCAC by analyzing amino acid frequencies, codon usage, and GC-content in a species- or function-specific context. With respect to amino acids we, at least in part, confirm the cognate bias hypothesis by using ANCAC’s NUCOCOG dataset as the largest one available for that purpose thus far. Conclusions Using the NUCOCOG datasets, ANCAC connects taxonomic, amino acid, and nucleotide sequence information with the functional classification via COGs and provides a GUI for flexible mining for sequence-bias. Thereby, to our knowledge, it is the only tool for the analysis of sequence composition in the light of physiological roles and phylogenetic context without requirement of substantial programming-skills.

ANCAC: amino acid, nucleotide, and codon analysis of COGs – a tool for sequence bias analysis in microbial orthologs

Science.gov (United States)

2012-01-01

Background The COG database is the most popular collection of orthologous proteins from many different completely sequenced microbial genomes. Per definition, a cluster of orthologous groups (COG) within this database exclusively contains proteins that most likely achieve the same cellular function. Recently, the COG database was extended by assigning to every protein both the corresponding amino acid and its encoding nucleotide sequence resulting in the NUCOCOG database. This extended version of the COG database is a valuable resource connecting sequence features with the functionality of the respective proteins. Results Here we present ANCAC, a web tool and MySQL database for the analysis of amino acid, nucleotide, and codon frequencies in COGs on the basis of freely definable phylogenetic patterns. We demonstrate the usefulness of ANCAC by analyzing amino acid frequencies, codon usage, and GC-content in a species- or function-specific context. With respect to amino acids we, at least in part, confirm the cognate bias hypothesis by using ANCAC’s NUCOCOG dataset as the largest one available for that purpose thus far. Conclusions Using the NUCOCOG datasets, ANCAC connects taxonomic, amino acid, and nucleotide sequence information with the functional classification via COGs and provides a GUI for flexible mining for sequence-bias. Thereby, to our knowledge, it is the only tool for the analysis of sequence composition in the light of physiological roles and phylogenetic context without requirement of substantial programming-skills. PMID:22958836

Charcot Marie Tooth 2B Peripheral Sensory Neuropathy: How Rab7 Mutations Impact NGF Signaling?

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Harry Liu

2017-02-01

Full Text Available Charcot-Marie-Tooth 2B peripheral sensory neuropathy (CMT2B is a debilitating autosomal dominant hereditary sensory neuropathy. Patients with this disease lose pain sensation and frequently need amputation. Axonal dysfunction and degeneration of peripheral sensory neurons is a major clinical manifestation of CMT2B. However, the cellular and molecular pathogenic mechanisms remain undefined. CMT2B is caused by missense point mutations (L129F, K157N, N161T/I, V162M in Rab7 GTPase. Strong evidence suggests that the Rab7 mutation(s enhances the cellular levels of activated Rab7 proteins, thus resulting in increased lysosomal activity and autophagy. As a consequence, trafficking and signaling of neurotrophic factors such as nerve growth factor (NGF in the long axons of peripheral sensory neurons are particularly vulnerable to premature degradation. A “gain of toxicity” model has, thus, been proposed based on these observations. However, studies of fly photo-sensory neurons indicate that the Rab7 mutation(s causes a “loss of function”, resulting in haploinsufficiency. In the review, we summarize experimental evidence for both hypotheses. We argue that better models (rodent animals and human neurons of CMT2B are needed to precisely define the disease mechanisms.

Charcot Marie Tooth 2B Peripheral Sensory Neuropathy: How Rab7 Mutations Impact NGF Signaling?

Science.gov (United States)

Liu, Harry; Wu, Chengbiao

2017-02-04

Charcot-Marie-Tooth 2B peripheral sensory neuropathy (CMT2B) is a debilitating autosomal dominant hereditary sensory neuropathy. Patients with this disease lose pain sensation and frequently need amputation. Axonal dysfunction and degeneration of peripheral sensory neurons is a major clinical manifestation of CMT2B. However, the cellular and molecular pathogenic mechanisms remain undefined. CMT2B is caused by missense point mutations (L129F, K157N, N161T/I, V162M) in Rab7 GTPase. Strong evidence suggests that the Rab7 mutation(s) enhances the cellular levels of activated Rab7 proteins, thus resulting in increased lysosomal activity and autophagy. As a consequence, trafficking and signaling of neurotrophic factors such as nerve growth factor (NGF) in the long axons of peripheral sensory neurons are particularly vulnerable to premature degradation. A "gain of toxicity" model has, thus, been proposed based on these observations. However, studies of fly photo-sensory neurons indicate that the Rab7 mutation(s) causes a "loss of function", resulting in haploinsufficiency. In the review, we summarize experimental evidence for both hypotheses. We argue that better models (rodent animals and human neurons) of CMT2B are needed to precisely define the disease mechanisms.

The performance of the Mini-Cog in a sample of low educational level elderly

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Sergio Telles Ribeiro Filho

Full Text Available Abstract Objectives: To study the criterion validity of the Mini-Cog in low educational level elderly. Design: Cross-sectional and validation design. Setting: Policlínica Piquet Carneiro, an outpatient unit of Rio de Janeiro State University Hospital, in Brazil. Participants: A convenient sample consisting of 306 individuals, 65 yrs or older, selected from April 8th to July 15th, 2002. Methods: All participants underwent comprehensive geriatric evaluations which included the Mini-Mental State Examination (MMSE and the cognitive part of the Cambridge Examination for Mental Disorders of the Elderly - Revised (CAMCOG-R. They were classified as demented or non-demented (DSM-IV. A post-hoc analysis was performed on the data from the 3 word recall test of the MMSE, and the Clock Drawing Test from the CAMCOG-R, and respective scores were added and interpreted in accordance with the Mini-Cog protocol. Results: 293 individuals completed all the study steps; 211 had 4 or less years of schooling and were included in the data analysis. 32% had dementia. Mini-Cog sensitivity and specificity was consistently low independently of the different cut-off points considered. The best performance was found at the cut-off point of 2/3 which yielded sensitivity and specificity of 60% and 65%, respectively. Conclusion: The Mini-Cog is not a good cognitive screening tool for individuals with less than five years of formal education.

A comparison of the COG and MCNP codes in computational neutron capture therapy modeling, Part I: boron neutron capture therapy models.

Science.gov (United States)

Culbertson, C N; Wangerin, K; Ghandourah, E; Jevremovic, T

2005-08-01

The goal of this study was to evaluate the COG Monte Carlo radiation transport code, developed and tested by Lawrence Livermore National Laboratory, for neutron capture therapy related modeling. A boron neutron capture therapy model was analyzed comparing COG calculational results to results from the widely used MCNP4B (Monte Carlo N-Particle) transport code. The approach for computing neutron fluence rate and each dose component relevant in boron neutron capture therapy is described, and calculated values are shown in detail. The differences between the COG and MCNP predictions are qualified and quantified. The differences are generally small and suggest that the COG code can be applied for BNCT research related problems.

Leishmania donovani resides in modified early endosomes by upregulating Rab5a expression via the downregulation of miR-494

Science.gov (United States)

Verma, Jitender Kumar; Rastogi, Ruchir

2017-01-01

Several intracellular pathogens arrest the phagosome maturation in the host cells to avoid transport to lysosomes. In contrast, the Leishmania containing parasitophorous vacuole (PV) is shown to recruit lysosomal markers and thus Leishmania is postulated to be residing in the phagolysosomes in macrophages. Here, we report that Leishmania donovani specifically upregulates the expression of Rab5a by degrading c-Jun via their metalloprotease gp63 to downregulate the expression of miR-494 in THP-1 differentiated human macrophages. Our results also show that miR-494 negatively regulates the expression of Rab5a in cells. Subsequently, L. donovani recruits and retains Rab5a and EEA1 on PV to reside in early endosomes and inhibits transport to lysosomes in human macrophages. Similarly, we have also observed that Leishmania PV also recruits Rab5a by upregulating its expression in human PBMC differentiated macrophages. However, the parasite modulates the endosome by recruiting Lamp1 and inactive pro-CathepsinD on PV via the overexpression of Rab5a in infected cells. Furthermore, siRNA knockdown of Rab5a or overexpression of miR-494 in human macrophages significantly inhibits the survival of the parasites. These results provide the first mechanistic insights of parasite-mediated remodeling of endo-lysosomal trafficking to reside in a specialized early endocytic compartment. PMID:28650977

Predictors of placebo group decline in the Alzheimer's disease Assessment Scale-cognitive subscale (ADAS-Cog) in 24 week clinical trials of Alzheimer's disease.

Science.gov (United States)

Irizarry, Michael C; Webb, David J; Bains, Chanchal; Barrett, Steven J; Lai, Robert Y; Laroche, Janette P; Hosford, David; Maher-Edwards, Gareth; Weil, John G

2008-07-01

One limitation of several recent 24 week Alzheimer's disease (AD) clinical trials was the lack of cognitive decline detected by the AD Assessment Scale-cognitive subscale (ADAS-cog) in the placebo groups, possibly obscuring true medication effects. Data from 733 individuals in the placebo arms of six AD clinical trials performed 1996-1997 were pooled to examine the relationship of clinical, demographic, and genetic characteristics with the 24 week change in ADAS-cog. Baseline cognitive and functional status and the screening-to-baseline change in ADAS-cog were the strongest independent predictors of the 24 week change in ADAS-cog. The ADAS-cog did not detect progression in patients with mild dementia (screening Mini-Mental State Exam, MMSE, >or=20). The change in ADAS-cog from screening to baseline was inversely correlated with the 24 week change score; it was more difficult to detect cognitive decline at 24 weeks if individuals markedly worsened from screening to baseline. The effects of baseline MMSE and screening-to-baseline change in ADAS-cog generalized to the placebo group (N=106) of another AD study performed in 2004-2005. Overcoming lack of placebo decline in AD clinical trials will require scales more sensitive to cognitive decline in mild AD and strategies to reduce within-person variability in outcome measures.

Investigation Effects of Narrowing Rotor Pole Embrace to Efficiency and Cogging Torque at PM BLDC Motor

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Cemil Ocak

2016-02-01

Full Text Available Engineers think that pole embrace size of a PM BLDC motor affects directly the efficiency and the torque. Dealing with theexperimental research, in the studywe have investigated the effects of narrowing rotor pole embrace step by step by changing sizes parametrically. By doing so, high efficiency and low cogging torque would have been obtained for a 20 W PM BLDC motor. In order to do this,pole arc to pole pitch ratio of magnets at the rotor poles has been changed parametrically (0.5 to 1 by genetic algorithm methodfirst. Then the electromagnetic field dispersions, output parameters of the motor, new rotor constructions have been obtained; and new pole embrace has been derived from the variation of pole arc to pole pitch ratio. We have also calculatedthe magnetic flux distribution, output power, torque, cogging torque and efficiency values analytically and the effects of new pole embrace to motor efficiency and torque have been simulated. The developed 18 slots, 6 poles, surface mounted inner runner configuration rotor machine is proposed as to be used insmall dentistry apparatus.

Cogs in the endless machine: Lakes, climate change and nutrient cycles: A review

Energy Technology Data Exchange (ETDEWEB)

Moss, Brian, E-mail: brmoss@liverpool.ac.uk

2012-09-15

Lakes have, rather grandly, been described as sentinels, integrators and regulators of climate change (). Lakes are also part of the continuum of the water cycle, cogs in a machine that processes water and elements dissolved and suspended in myriad forms. Assessing the changes in the functioning of the cogs and the machine with respect to these substances as climate changes is clearly important, but difficult. Many other human-induced influences, not least eutrophication, that impact on catchment areas and consequently on lakes, have generally complicated the recording of recent change in sediment records and modern sets of data. The least confounded evidence comes from remote lakes in mountain and polar regions and suggests effects of warming that include mobilisation of ions and increased amounts of phosphorus. A cottage industry has arisen in deduction and prediction of the future effects of climate change on lakes, but the results are very general and precision is marred not only by confounding influences but by the complexity of the lake system and the infinite variety of possible future scenarios. A common conclusion, however, is that warming will increase the intensity of symptoms of eutrophication. Direct experimentation, though expensive and still unusual and confined to shallow lake and wetland systems is perhaps the most reliable approach. Results suggest increased symptoms of eutrophication, and changes in ecosystem structure, but in some respects are different from those deduced from comparisons along latitudinal gradients or by inference from knowledge of lake behaviour. Experiments have shown marked increases in community respiration compared with gross photosynthesis in mesocosm systems and it may be that the most significant churnings of these cogs in the earth-air-water machine will be in their influence on the carbon cycle, with possibly large positive feedback effects on warming. -- Highlights: Black-Right-Pointing-Pointer Climate change has had

Bioinformatic and Comparative Localization of Rab Proteins Reveals Functional Insights into the Uncharacterized GTPases Ypt10p and Ypt11p†

OpenAIRE

Buvelot Frei, Stéphanie; Rahl, Peter B.; Nussbaum, Maria; Briggs, Benjamin J.; Calero, Monica; Janeczko, Stephanie; Regan, Andrew D.; Chen, Catherine Z.; Barral, Yves; Whittaker, Gary R.; Collins, Ruth N.

2006-01-01

A striking characteristic of a Rab protein is its steady-state localization to the cytosolic surface of a particular subcellular membrane. In this study, we have undertaken a combined bioinformatic and experimental approach to examine the evolutionary conservation of Rab protein localization. A comprehensive primary sequence classification shows that 10 out of the 11 Rab proteins identified in the yeast (Saccharomyces cerevisiae) genome can be grouped within a major subclass, each comprising ...

阴道毛滴虫TvRab11C基因的克隆及原核表达%Cloning and prokaryotic expression of TvRab11C gene of Trichomonas vaginalis

Institute of Scientific and Technical Information of China (English)

刘畅; 丁鹤; 宫鹏涛; 李建华; 李淑红; 李赫; 张国才; 张西臣

2012-01-01

目的 克隆并原核表达阴道毛滴虫TvRab11C(G3 Ras-related protein Rab11C)基因.方法 利用PCR技术扩增阴道毛滴虫TvRab1 1C基因,与原核表达载体pET-28a连接,构建重组原核表达质粒pET-28a-TvRab1 1C,转化大肠杆菌BL21(DE3),IPTG诱导表达,SDS-PAGE分析表达产物的可溶性,Western blot分析表达产物的反应原性.结果 重组原核表达质粒pET-28a-TvRab11C经双酶切及测序证明构建正确;表达的重组蛋白相对分子质量约为30000,主要以包涵体形式存在,可被抗阴道毛滴虫多克隆抗体识别.结论 成功克隆了阴道毛滴虫TvRab11C基因,并在E.coli BL21 (DE3)中获得了表达,为进一步研究TvRas基因和G蛋白与阴道毛滴虫寄生能力和致病性的关系奠定了基础.%Objective To clone the TvRabllC gene of Trichomonas vaginalis and express in prokaryotic cells. Methods The TvRabllC gene was amplified by PCR from T. vaginalis and inserted into prokaryotic expression vector pET-28a. The constructed recombinant plasmid pET-28a-TvRabllC was transformed to E. coli BL21 (DE3) and induced by IPTG. The expressed product was analyzed for solubility by SDS-PAGE and for reactogenicity by Western blot. Results Both restriction analysis and sequencing proved that recombinant plasmid pET-28a-TvRabllC was constructed correctly. The expressed recombinant protein,with a relative molecular mass of about 30 000,mainly existed in a form of inclusion body,and was recognized by polyclonal antibody against T. vaginalis. Conclusion The TvRas gene of T. vaginalis was successfully cloned and expressed in E. coli BL21 (DE3),which laid a foundation of further study on relationship of TvRas gene and protein to the parasitic ability and pathogenicity of T. vaginalis.

Using the Cognitive Abilities Test (CogAT) 7 Nonverbal Battery to Identify the Gifted/Talented: An Investigation of Demographic Effects and Norming Plans

Science.gov (United States)

Carman, Carol A.; Walther, Christine A. P.; Bartsch, Robert A.

2018-01-01

The nonverbal battery of the Cognitive Abilities Test (CogAT) is one of the two most common nonverbal measures used in gifted identification, yet the relationships between demographic variables and CogAT7 performance has not yet been fully examined. Additionally, the effect of using the CogAT7 nonverbal battery on the identification of diverse…

RF cogging in the FNAL Booster Accelerator

International Nuclear Information System (INIS)

William A. Pellico and Robert C. Webber

2000-01-01

The Fermilab Booster operates at a Radio Frequency (RF) harmonic number of 84 with beam in all buckets. One or two bunches of beam are systematically lost in the 8 GeV extraction process as beam is swept across a magnetic septum during the extraction kicker rise time. The prompt radiation and component activation resulting from this localized high energy beam loss become serious concerns as Booster beam throughput must be increased more than tenfold to meet the requirements of RUN II, NUMI, and MiniBooNE experiments. Synchronizing a gap in the beam to the firing of the extraction kickers, a relatively easy and standard practice in many machines, can eliminate the problem. This seemingly simple operation is greatly complicated in the Booster by the need to synchronize extraction to beam already circulating in the Main Injector. Coupled with the inflexibility of the Booster resonant magnetic cycle, cycle to cycle variations, and constraints inherent in the accelerator physics, that requirement forces active control of the gap's azimuthal position throughout the acceleration process as the revolution frequency sweeps rapidly. Until recently, the complexities of actually implementing and demonstrating this process in the Booster had not been worked out. This paper describes a successful demonstration of gap cogging in the Booster

The Escherichia coli COG1738 Member YhhQ Is Involved in 7-Cyanodeazaguanine (preQ0 Transport

Directory of Open Access Journals (Sweden)

Rémi Zallot

2017-02-01

Full Text Available Queuosine (Q is a complex modification of the wobble base in tRNAs with GUN anticodons. The full Q biosynthesis pathway has been elucidated in Escherichia coli. FolE, QueD, QueE and QueC are involved in the conversion of guanosine triphosphate (GTP to 7-cyano-7-deazaguanine (preQ0, an intermediate of increasing interest for its central role in tRNA and DNA modification and secondary metabolism. QueF then reduces preQ0 to 7-aminomethyl-7-deazaguanine (preQ1. PreQ1 is inserted into tRNAs by tRNA guanine(34 transglycosylase (TGT. The inserted base preQ1 is finally matured to Q by two additional steps involving QueA and QueG or QueH. Most Eubacteria harbor the full set of Q synthesis genes and are predicted to synthesize Q de novo. However, some bacteria only encode enzymes involved in the second half of the pathway downstream of preQ0 synthesis, including the signature enzyme TGT. Different patterns of distribution of the queF, tgt, queA and queG or queH genes are observed, suggesting preQ0, preQ1 or even the queuine base being salvaged in specific organisms. Such salvage pathways require the existence of specific 7-deazapurine transporters that have yet to be identified. The COG1738 family was identified as a candidate for a missing preQ0/preQ1 transporter in prokaryotes, by comparative genomics analyses. The existence of Q precursor salvage was confirmed for the first time in bacteria, in vivo, through an indirect assay. The involvement of the COG1738 in salvage of a Q precursor was experimentally validated in Escherichia coli, where it was shown that the COG1738 family member YhhQ is essential for preQ0 transport.

A novel mouse model of Warburg Micro syndrome reveals roles for RAB18 in eye development and organisation of the neuronal cytoskeleton

Directory of Open Access Journals (Sweden)

Sarah M. Carpanini

2014-06-01

Full Text Available Mutations in RAB18 have been shown to cause the heterogeneous autosomal recessive disorder Warburg Micro syndrome (WARBM. Individuals with WARBM present with a range of clinical symptoms, including ocular and neurological abnormalities. However, the underlying cellular and molecular pathogenesis of the disorder remains unclear, largely owing to the lack of any robust animal models that phenocopy both the ocular and neurological features of the disease. We report here the generation and characterisation of a novel Rab18-mutant mouse model of WARBM. Rab18-mutant mice are viable and fertile. They present with congenital nuclear cataracts and atonic pupils, recapitulating the characteristic ocular features that are associated with WARBM. Additionally, Rab18-mutant cells exhibit an increase in lipid droplet size following treatment with oleic acid. Lipid droplet abnormalities are a characteristic feature of cells taken from WARBM individuals, as well as cells taken from individuals with other neurodegenerative conditions. Neurological dysfunction is also apparent in Rab18-mutant mice, including progressive weakness of the hind limbs. We show that the neurological defects are, most likely, not caused by gross perturbations in synaptic vesicle recycling in the central or peripheral nervous system. Rather, loss of Rab18 is associated with widespread disruption of the neuronal cytoskeleton, including abnormal accumulations of neurofilament and microtubule proteins in synaptic terminals, and gross disorganisation of the cytoskeleton in peripheral nerves. Global proteomic profiling of peripheral nerves in Rab18-mutant mice reveals significant alterations in several core molecular pathways that regulate cytoskeletal dynamics in neurons. The apparent similarities between the WARBM phenotype and the phenotype that we describe here indicate that the Rab18-mutant mouse provides an important platform for investigation of the disease pathogenesis and therapeutic

A novel mouse model of Warburg Micro syndrome reveals roles for RAB18 in eye development and organisation of the neuronal cytoskeleton.

Science.gov (United States)

Carpanini, Sarah M; McKie, Lisa; Thomson, Derek; Wright, Ann K; Gordon, Sarah L; Roche, Sarah L; Handley, Mark T; Morrison, Harris; Brownstein, David; Wishart, Thomas M; Cousin, Michael A; Gillingwater, Thomas H; Aligianis, Irene A; Jackson, Ian J

2014-06-01

Mutations in RAB18 have been shown to cause the heterogeneous autosomal recessive disorder Warburg Micro syndrome (WARBM). Individuals with WARBM present with a range of clinical symptoms, including ocular and neurological abnormalities. However, the underlying cellular and molecular pathogenesis of the disorder remains unclear, largely owing to the lack of any robust animal models that phenocopy both the ocular and neurological features of the disease. We report here the generation and characterisation of a novel Rab18-mutant mouse model of WARBM. Rab18-mutant mice are viable and fertile. They present with congenital nuclear cataracts and atonic pupils, recapitulating the characteristic ocular features that are associated with WARBM. Additionally, Rab18-mutant cells exhibit an increase in lipid droplet size following treatment with oleic acid. Lipid droplet abnormalities are a characteristic feature of cells taken from WARBM individuals, as well as cells taken from individuals with other neurodegenerative conditions. Neurological dysfunction is also apparent in Rab18-mutant mice, including progressive weakness of the hind limbs. We show that the neurological defects are, most likely, not caused by gross perturbations in synaptic vesicle recycling in the central or peripheral nervous system. Rather, loss of Rab18 is associated with widespread disruption of the neuronal cytoskeleton, including abnormal accumulations of neurofilament and microtubule proteins in synaptic terminals, and gross disorganisation of the cytoskeleton in peripheral nerves. Global proteomic profiling of peripheral nerves in Rab18-mutant mice reveals significant alterations in several core molecular pathways that regulate cytoskeletal dynamics in neurons. The apparent similarities between the WARBM phenotype and the phenotype that we describe here indicate that the Rab18-mutant mouse provides an important platform for investigation of the disease pathogenesis and therapeutic interventions. �

Recurrent De Novo Mutations Disturbing the GTP/GDP Binding Pocket of RAB11B Cause Intellectual Disability and a Distinctive Brain Phenotype.

Science.gov (United States)

Lamers, Ideke J C; Reijnders, Margot R F; Venselaar, Hanka; Kraus, Alison; Jansen, Sandra; de Vries, Bert B A; Houge, Gunnar; Gradek, Gyri Aasland; Seo, Jieun; Choi, Murim; Chae, Jong-Hee; van der Burgt, Ineke; Pfundt, Rolph; Letteboer, Stef J F; van Beersum, Sylvia E C; Dusseljee, Simone; Brunner, Han G; Doherty, Dan; Kleefstra, Tjitske; Roepman, Ronald

2017-11-02

The Rab GTPase family comprises ∼70 GTP-binding proteins, functioning in vesicle formation, transport and fusion. They are activated by a conformational change induced by GTP-binding, allowing interactions with downstream effectors. Here, we report five individuals with two recurrent de novo missense mutations in RAB11B; c.64G>A; p.Val22Met in three individuals and c.202G>A; p.Ala68Thr in two individuals. An overlapping neurodevelopmental phenotype, including severe intellectual disability with absent speech, epilepsy, and hypotonia was observed in all affected individuals. Additionally, visual problems, musculoskeletal abnormalities, and microcephaly were present in the majority of cases. Re-evaluation of brain MRI images of four individuals showed a shared distinct brain phenotype, consisting of abnormal white matter (severely decreased volume and abnormal signal), thin corpus callosum, cerebellar vermis hypoplasia, optic nerve hypoplasia and mild ventriculomegaly. To compare the effects of both variants with known inactive GDP- and active GTP-bound RAB11B mutants, we modeled the variants on the three-dimensional protein structure and performed subcellular localization studies. We predicted that both variants alter the GTP/GDP binding pocket and show that they both have localization patterns similar to inactive RAB11B. Evaluation of their influence on the affinity of RAB11B to a series of binary interactors, both effectors and guanine nucleotide exchange factors (GEFs), showed induction of RAB11B binding to the GEF SH3BP5, again similar to inactive RAB11B. In conclusion, we report two recurrent dominant mutations in RAB11B leading to a neurodevelopmental syndrome, likely caused by altered GDP/GTP binding that inactivate the protein and induce GEF binding and protein mislocalization. Copyright © 2017 American Society of Human Genetics. All rights reserved.

Coordinated regulation by two VPS9 domain-containing guanine nucleotide exchange factors in small GTPase Rab5 signaling pathways in fission yeast

International Nuclear Information System (INIS)

Tsukamoto, Yuta; Kagiwada, Satoshi; Shimazu, Sayuri; Takegawa, Kaoru; Noguchi, Tetsuko; Miyamoto, Masaaki

2015-01-01

The small GTPase Rab5 is reported to regulate various cellular functions, such as vesicular transport and endocytosis. VPS9 domain-containing proteins are thought to activate Rab5(s) by their guanine-nucleotide exchange activities. Numerous VPS9 proteins have been identified and are structurally conserved from yeast to mammalian cells. However, the functional relationships among VPS9 proteins in cells remain unclear. Only one Rab5 and two VPS9 proteins were identified in the Schizosaccharomyces pombe genome. Here, we examined the cellular function of two VPS9 proteins and the relationship between these proteins in cellular functions. Vps901-GFP and Vps902-GFP exhibited dotted signals in vegetative and differentiated cells. vps901 deletion mutant (Δvps901) cells exhibited a phenotype deficient in the mating process and responses to high concentrations of ions, such as calcium and metals, and Δvps901Δvps902 double mutant cells exhibited round cell shapes similar to ypt5-909 (Rab5 mutant allele) cells. Deletion of both vps901 and vps902 genes completely abolished the mating process and responses to various stresses. A lack of vacuole formation and aberrant inner cell membrane structures were also observed in Δvps901Δvps902 cells by electron microscopy. These data strongly suggest that Vps901 and Vps902 are cooperatively involved in the regulation of cellular functions, such as cell morphology, sexual development, response to ion stresses, and vacuole formation, via Rab5 signaling pathways in fission yeast cells. - Highlights: • Roles of Rab5 activator VPS9 proteins in cellular functions. • Cooperation between VPS9 proteins in Rab5 signaling pathway. • Roles of each VPS9 protein in Rab5 signaling pathway are discussed

Coordinated regulation by two VPS9 domain-containing guanine nucleotide exchange factors in small GTPase Rab5 signaling pathways in fission yeast

Energy Technology Data Exchange (ETDEWEB)

Tsukamoto, Yuta [Department of Biology, Graduate School of Science, Kobe University, 1-1 Rokkodai-cho, Nada, Kobe 657-8501 (Japan); Kagiwada, Satoshi [Department of Biological Sciences, Faculty of Science, Nara Women' s University, Kitauoyanishi-machi, Nara 630-8506 (Japan); Shimazu, Sayuri [Center for Supports to Research and Education Activities, Kobe University, 1-1 Rokkodai-cho, Nada, Kobe 657-8501 (Japan); Takegawa, Kaoru [Department of Bioscience and Biotechnology, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581 (Japan); Noguchi, Tetsuko [Department of Biological Sciences, Faculty of Science, Nara Women' s University, Kitauoyanishi-machi, Nara 630-8506 (Japan); Miyamoto, Masaaki, E-mail: miya@kobe-u.ac.jp [Department of Biology, Graduate School of Science, Kobe University, 1-1 Rokkodai-cho, Nada, Kobe 657-8501 (Japan); Center for Supports to Research and Education Activities, Kobe University, 1-1 Rokkodai-cho, Nada, Kobe 657-8501 (Japan)

2015-03-20

The small GTPase Rab5 is reported to regulate various cellular functions, such as vesicular transport and endocytosis. VPS9 domain-containing proteins are thought to activate Rab5(s) by their guanine-nucleotide exchange activities. Numerous VPS9 proteins have been identified and are structurally conserved from yeast to mammalian cells. However, the functional relationships among VPS9 proteins in cells remain unclear. Only one Rab5 and two VPS9 proteins were identified in the Schizosaccharomyces pombe genome. Here, we examined the cellular function of two VPS9 proteins and the relationship between these proteins in cellular functions. Vps901-GFP and Vps902-GFP exhibited dotted signals in vegetative and differentiated cells. vps901 deletion mutant (Δvps901) cells exhibited a phenotype deficient in the mating process and responses to high concentrations of ions, such as calcium and metals, and Δvps901Δvps902 double mutant cells exhibited round cell shapes similar to ypt5-909 (Rab5 mutant allele) cells. Deletion of both vps901 and vps902 genes completely abolished the mating process and responses to various stresses. A lack of vacuole formation and aberrant inner cell membrane structures were also observed in Δvps901Δvps902 cells by electron microscopy. These data strongly suggest that Vps901 and Vps902 are cooperatively involved in the regulation of cellular functions, such as cell morphology, sexual development, response to ion stresses, and vacuole formation, via Rab5 signaling pathways in fission yeast cells. - Highlights: • Roles of Rab5 activator VPS9 proteins in cellular functions. • Cooperation between VPS9 proteins in Rab5 signaling pathway. • Roles of each VPS9 protein in Rab5 signaling pathway are discussed.

Detection of dementia in primary care: comparison of the original and a modified Mini-Cog Assessment with the Mini-Mental State Examination.

Science.gov (United States)

Kamenski, Gustav; Dorner, Thomas; Lawrence, Kitty; Psota, Georg; Rieder, Anita; Schwarz, Franz; Sepandj, Asita; Spiegel, Wolfgang; Strotzka, Stefan

2009-12-01

Background Dementia is considered widely under-detected in primary care, and general practitioners (GPs) frequently ask for easy to use tools to assist in its early detection.Aim To determine the degree of correlation between the Mini-Cog Assessment (Mini-Cog) as performed by GPs and the Mini-Mental State Examination (MMSE).Design of study This was a prospective study (2005, 2006) comparing two cognitive screening instruments.Setting Ten general practices in Austria, with patients with a hitherto undiagnosed suspicion of dementia seen consecutively.Method Sensitivity, specificity and positive and negative predictive values (PPVs and NPVs) of the Mini-Cog (applying both a colour-coded and the original rating method) were assessed for degree of correlation with the MMSE. In phase one GPs examined patients suspected of having dementia using the Mini-Cog; in phase two a neurologist retested them applying the MMSE, a clock-drawing test (CDT) and a routine clinical examination. A questionnaire on the practicability of the Mini-Cog was answered by GPs.Results Of the 107 patients who participated 86 completed the whole study protocol. The Mini-Cog, as performed by the ten GPs, displayed a sensitivity of 0.85 (95% CI: 0.71, 0.98), a specificity of 0.58 (95% CI: 0.46, 0.71), a PPV of 0.47 (95% CI: 0.33, 0.61) and an NPV of 0.90 (95% CI: 0.80, 0.99) as against the MMSE carried out by neurologists. The GPs judged the Mini-Cog useful and time saving.Conclusion The Mini-Cog has a high sensitivity and acceptable specificity in the general practice setting and has proved to be a practicable tool for the diagnosis of dementia in primary care.

Autophagy regulation revealed by SapM-induced block of autophagosome-lysosome fusion via binding RAB7

International Nuclear Information System (INIS)

Hu, Dong; Wu, Jing; Wang, Wan; Mu, Min; Zhao, Runpeng; Xu, Xuewei; Chen, Zhaoquan; Xiao, Jian; Hu, Fengyu; Yang, Yabo; Zhang, Rongbo

2015-01-01

The mechanism underlying autophagy alteration by mycobacterium tuberculosis remains unclear. Our previous study shows LpqH, a lipoprotein of mycobacterium tuberculosis, can cause autophagosomes accumulation in murine macrophages. It is well known that SapM, another virulence factor, plays an important role in blocking phagosome-endosome fusion. However, the mechanism that SapM interferes with autophagy remains poorly defined. In this study, we report that SapM suppresses the autophagy flux by blocking autophagosome fusion with lysosome. Exposure to SapM results in accumulations of autophagosomes and decreased co-localization of autophagosome with lysosome. Molecularly, Rab7, a small GTPase, is blocked by SapM through its CT domain and is prevented from involvement of autophagosome-lysosome fusion. In conclusion, our study reveals that SapM takes Rab7 as a previously unknown target to govern a distinct molecular mechanism underlying autophagosome-lysosome fusion, which may bring light to a new thought about developing potential drugs or vaccines against tuberculosis. - Highlights: • A mechanism for disrupting autophagosome-lysosome fusion induced by SapM. • Rab7 is involved in SapM-inhibited autophagy. • SapM interacts with Rab7 by CT-domain. • CT-domain is indispensable to SapM-inhibited autophagy

Autophagy regulation revealed by SapM-induced block of autophagosome-lysosome fusion via binding RAB7

Energy Technology Data Exchange (ETDEWEB)

Hu, Dong, E-mail: austhudong@126.com [Institute of Infection and Immunology, Department of Medical Immunology, Medical School, Anhui University of Science and Technology, Huainan (China); Wu, Jing, E-mail: wujing8008@126.com [Institute of Infection and Immunology, Department of Medical Immunology, Medical School, Anhui University of Science and Technology, Huainan (China); Wang, Wan; Mu, Min; Zhao, Runpeng; Xu, Xuewei; Chen, Zhaoquan [Institute of Infection and Immunology, Department of Medical Immunology, Medical School, Anhui University of Science and Technology, Huainan (China); Xiao, Jian [School of Pharmacy, Wenzhou Medical College, Wenzhou (China); Hu, Fengyu; Yang, Yabo [Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou (China); Zhang, Rongbo, E-mail: lory456@126.com [Institute of Infection and Immunology, Department of Medical Immunology, Medical School, Anhui University of Science and Technology, Huainan (China)

2015-05-29

The mechanism underlying autophagy alteration by mycobacterium tuberculosis remains unclear. Our previous study shows LpqH, a lipoprotein of mycobacterium tuberculosis, can cause autophagosomes accumulation in murine macrophages. It is well known that SapM, another virulence factor, plays an important role in blocking phagosome-endosome fusion. However, the mechanism that SapM interferes with autophagy remains poorly defined. In this study, we report that SapM suppresses the autophagy flux by blocking autophagosome fusion with lysosome. Exposure to SapM results in accumulations of autophagosomes and decreased co-localization of autophagosome with lysosome. Molecularly, Rab7, a small GTPase, is blocked by SapM through its CT domain and is prevented from involvement of autophagosome-lysosome fusion. In conclusion, our study reveals that SapM takes Rab7 as a previously unknown target to govern a distinct molecular mechanism underlying autophagosome-lysosome fusion, which may bring light to a new thought about developing potential drugs or vaccines against tuberculosis. - Highlights: • A mechanism for disrupting autophagosome-lysosome fusion induced by SapM. • Rab7 is involved in SapM-inhibited autophagy. • SapM interacts with Rab7 by CT-domain. • CT-domain is indispensable to SapM-inhibited autophagy.

Insight into the molecular switch mechanism of human Rab5a from molecular dynamics simulations

Energy Technology Data Exchange (ETDEWEB)

Wang, Jing-Fang, E-mail: jfwang@gordonlifescience.org [Key Laboratory of Systems Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031 (China); Shanghai Center for Bioinformation Technology, 100 Qinzhou Road, Shanghai 200235 (China); Gordon Life Science Institute, 13784 Torrey Del Mar Drive, San Diego, CA 92130 (United States); Chou, Kuo-Chen [Gordon Life Science Institute, 13784 Torrey Del Mar Drive, San Diego, CA 92130 (United States)

2009-12-18

Rab5a is currently a most interesting target because it is responsible for regulating the early endosome fusion in endocytosis and possibly the budding process. We utilized longtime-scale molecular dynamics simulations to investigate the internal motion of the wild-type Rab5a and its A30P mutant. It was observed that, after binding with GTP, the global flexibility of the two proteins is increasing, while the local flexibility in their sensitive sites (P-loop, switch I and II regions) is decreasing. Also, the mutation of Ala30 to Pro30 can cause notable flexibility variations in the sensitive sites. However, this kind of variations is dramatically reduced after binding with GTP. Such a remarkable feature is mainly caused by the water network rearrangements in the sensitive sites. These findings might be of use for revealing the profound mechanism of the displacements of Rab5a switch regions, as well as the mechanism of the GDP dissociation and GTP association.

Clinical global impression of cognition in schizophrenia (CGI-CogS): reliability and validity of a co-primary measure of cognition.

Science.gov (United States)

Ventura, Joseph; Cienfuegos, Angel; Boxer, Oren; Bilder, Robert

2008-11-01

Cognitive deficits are core features of schizophrenia that have been associated reliably with functional outcomes and now are a focus of treatment research. New rating scales are needed to complement current psychometric testing procedures, both to enable wider clinical use, and to serve as endpoints in clinical trials. Subjects were 35 schizophrenia patient-and-caregiver pairs recruited from the UCLA and West Los Angeles VA Outpatient Psychiatry Departments. Participants were assessed with the Clinical Global Impression of Cognition in Schizophrenia (CGI-CogS), an interview-based rating scale of cognitive functioning, on 3 occasions (baseline, 1 month, and 3 months). A computerized neurocognitive battery (Cogtest), an assessment of functioning, and symptom measures were administered at two occasions (baseline and one month). The CGI-CogS ratings generally showed a high level of internal consistency (Cronbach's alpha=.69 to .96), adequate levels of inter-rater reliability (ICC's=.71 to .80), and high test-retest stability (ICC's=.92 to .95). Correlations of caregiver and rater global (but not "patient only rating") CGI-CogS ratings with neurocognitive performance were in the moderate range (r's=-.27 to -.48), while most of the correlations with functional outcome were moderate to high (r's=-.41 to -.72). In fact, the CGI-CogS ratings were significantly more correlated with Social Functioning than were objective neurocognitive test scores (p=.02) and showed a trend in the same direction for predicting Instrumental Functioning (p=.06). We found moderate correlations between CGI-CogS global ratings and PANSS positive (r's=.36 to .49) and SANS negative symptoms (r=.41 to .61), but not with BPRS depression (r's=.11 to .13). An interview-based measure of cognition demonstrated high internal consistency, good inter-rater reliability, and high test-retest reliability. Caregiver ratings appear to add important clinical information over patient-only ratings. The CGI-Cog

The monomeric GTPase RabA2 is required for progression and maintenance of membrane integrity of infection threads during root nodule symbiosis.

Science.gov (United States)

Dalla Via, Virginia; Traubenik, Soledad; Rivero, Claudio; Aguilar, O Mario; Zanetti, María Eugenia; Blanco, Flavio Antonio

2017-04-01

Progression of the infection canal that conducts rhizobia to the nodule primordium requires a functional Rab GTPase located in Golgi/trans-Golgi that also participate in root hair polar growth. Common bean (Phaseolus vulgaris) symbiotically associates with its partner Rhizobium etli, resulting in the formation of root nitrogen-fixing nodules. Compatible bacteria can reach cortical cells in a tightly regulated infection process, in which the specific recognition of signal molecules is a key step to select the symbiotic partner. In this work, we show that RabA2, a monomeric GTPase from common bean, is required for the progression of the infection canal, referred to as the infection thread (IT), toward the cortical cells. Expression of miss-regulated mutant variants of RabA2 resulted in an increased number of abortive infection events, including bursting of ITs and a reduction in the number of nodules. Nodules formed in these plants were small and contained infected cells with disrupted symbiosome membranes, indicating either early senescence of these cells or defects in the formation of the symbiosome membrane during bacterial release. RabA2 localized to mobile vesicles around the IT, but mutations that affect GTP hydrolysis or GTP/GDP exchange modified this localization. Colocalization of RabA2 with ArfA1 and a Golgi marker indicates that RabA2 localizes in Golgi stacks and the trans-Golgi network. Our results suggest that RabA2 is part of the vesicle transport events required to maintain the integrity of the membrane during IT progression.

The ADAS-cog in Alzheimer's disease clinical trials: psychometric evaluation of the sum and its parts.

Science.gov (United States)

Cano, Stefan J; Posner, Holly B; Moline, Margaret L; Hurt, Stephen W; Swartz, Jina; Hsu, Tim; Hobart, Jeremy C

2010-12-01

The Alzheimer's Disease Assessment Scale Cognitive Behavior Section (ADAS-cog), a measure of cognitive performance, has been used widely in Alzheimer's disease trials. Its key role in clinical trials should be supported by evidence that it is both clinically meaningful and scientifically sound. Its conceptual and neuropsychological underpinnings are well-considered, but its performance as an instrument of measurement has received less attention. Objective To examine the traditional psychometric properties of the ADAS-cog in a large sample of people with Alzheimer's disease. Data from three clinical trials of donepezil (Aricept) in mild-to-moderate Alzheimer's disease (n=1421; MMSE 10-26) were analysed at both the scale and component level. Five psychometric properties were examined using traditional psychometric methods. These methods of examination underpin upcoming Food and Drug Administration recommendations for patient rating scale evaluation. At the scale-level, criteria tested for data completeness, scaling assumptions (eg, component total correlations: 0.39-0.67), targeting (no floor or ceiling effects), reliability (eg, Cronbach's α: = 0.84; test-retest intraclass correlations: 0.93) and validity (correlation with MMSE: -0.63) were satisfied. At the component level, 7 of 11 ADAS-cog components had substantial ceiling effects (range 40-64%). Performance was satisfactory at the scale level, but most ADAS-cog components were too easy for many patients in this sample and did not reflect the expected depth and range of cognitive performance. The clinical implication of this finding is that the ADAS-cog's estimate of cognitive ability, and its potential ability to detect differences in cognitive performance under treatment, could be improved. However, because of the limitations of traditional psychometric methods, further evaluations would be desirable using additional rating scale analysis techniques to pinpoint specific improvements.

California Verbal Learning Test-II performance in schizophrenia as a function of ascertainment strategy: comparing the first and second phases of the Consortium on the Genetics of Schizophrenia (COGS).

Science.gov (United States)

Stone, William S; Mesholam-Gately, Raquelle I; Braff, David L; Calkins, Monica E; Freedman, Robert; Green, Michael F; Greenwood, Tiffany A; Gur, Raquel E; Gur, Ruben C; Lazzeroni, Laura C; Light, Gregory A; Nuechterlein, Keith H; Olincy, Ann; Radant, Allen D; Siever, Larry J; Silverman, Jeremy M; Sprock, Joyce; Sugar, Catherine A; Swerdlow, Neal R; Tsuang, Debby W; Tsuang, Ming T; Turetsky, Bruce I; Seidman, Larry J

2015-04-01

The first phase of the Consortium on the Genetics of Schizophrenia (COGS-1) showed performance deficits in learning and memory on the California Verbal Learning Test, Second Edition (CVLT-II) in individuals with schizophrenia (SZ), compared to healthy comparison subjects (HCS). A question is whether the COGS-1 study, which used a family study design (i.e. studying relatively intact families), yielded "milder" SZ phenotypes than those acquired subsequently in the COGS-2 case-control design that did not recruit unaffected family members. CVLT-II performance was compared for the COGS-1 and COGS-2 samples. Analyses focused on learning, recall and recognition variables, with age, gender and education as covariates. Analyses of COGS-2 data explored effects of additional covariates and moderating factors in CVLT-II performance. 324 SZ subjects and 510 HCS had complete CVLT-II and covariate data in COGS-1, while 1356 SZ and 1036 HCS had complete data in COGS-2. Except for recognition memory, analysis of covariance showed significantly worse performance in COGS-2 on all CVLT-II variables for SZ and HCS, and remained significant in the presence of the covariates. Performance in each of the 5 learning trials differed significantly. However, effect sizes comparing cases and controls were comparable across the two studies. COGS-2 analyses confirmed SZ performance deficits despite effects of multiple significant covariates and moderating factors. CVLT-II performance was worse in COGS-2 than in COGS-1 for both the SZ and the HCS in this large cohort, likely due to cohort effects. Demographically corrected data yield a consistent pattern of performance across the two studies in SZ. Copyright © 2014. Published by Elsevier B.V.

Constraints on Generality (COG): A Proposed Addition to All Empirical Papers.

Science.gov (United States)

Simons, Daniel J; Shoda, Yuichi; Lindsay, D Stephen

2017-11-01

Psychological scientists draw inferences about populations based on samples-of people, situations, and stimuli-from those populations. Yet, few papers identify their target populations, and even fewer justify how or why the tested samples are representative of broader populations. A cumulative science depends on accurately characterizing the generality of findings, but current publishing standards do not require authors to constrain their inferences, leaving readers to assume the broadest possible generalizations. We propose that the discussion section of all primary research articles specify Constraints on Generality (i.e., a "COG" statement) that identify and justify target populations for the reported findings. Explicitly defining the target populations will help other researchers to sample from the same populations when conducting a direct replication, and it could encourage follow-up studies that test the boundary conditions of the original finding. Universal adoption of COG statements would change publishing incentives to favor a more cumulative science.

Detecting Treatment Group Differences in Alzheimer's Disease Clinical Trials: A Comparison of Alzheimer's Disease Assessment Scale - Cognitive Subscale (ADAS-Cog) and the Clinical Dementia Rating - Sum of Boxes (CDR-SB).

Science.gov (United States)

Wessels, A M; Dowsett, S A; Sims, J R

2018-01-01

The Alzheimer's Disease Assessment Scale's cognitive subscale (ADAS-Cog) has been widely used as an outcome measure in Alzheimer's Disease (AD) clinical trials. In its original form (ADAS-Cog11), the scale has been used successfully in mild-to-moderate AD dementia populations, but its use is more limited in the study of earlier disease (mild cognitive impairment [MCI] or mild dementia due to AD) owing to lack of appropriate sensitivity of some items. With recent focus on earlier treatment, efforts have focused on the development of more sensitive tools, including the Clinical Dementia Rating-Sum of Boxes (CDR-SB), a global assessment tool to evaluate both cognition and function. The ability of the ADAS-Cog and CDR-SB to detect treatment group differences in the clinical trial environment has not been systematically studied. The aim of this analysis was to compare the utility of these tools in detecting treatment group differences, by reviewing study findings identified through advanced searches of clinicaltrials.gov and Ovid, and press releases and scientific presentations. Findings from placebo-controlled studies of ≥ 6m duration and enrolling >100 participants were included; reporting of both the ADAS-Cog and CDR-SB at endpoint was also a requirement. Of the >300 records identified, 34 studies fulfilled the criteria. There were significant placebo versus active drug group differences based on findings from at least one measure for 14 studies. The ADAS-Cog detected treatment differences more frequently than the CDR-SB. Based on these and previously published findings, the ADAS-Cog appears more useful than the CDR-SB in detecting treatment group differences.

CSFV proliferation is associated with GBF1 and Rab2

Indian Academy of Sciences (India)

2016-12-29

Dec 29, 2016 ... 2.4 GBF1and Rab2 shRNA vector construction and cell ... CSFV RNA in ST cells at the earliest time point were selected as ... Real-time PCR for detection of GBF1 ..... pathways are also regulated by GBF1 and are involved in.

Feel the Force of Cogs, Pulleys and Water Power

Science.gov (United States)

Pugh, Julie

2016-01-01

Quarry Bank Mill in Cheshire was built in 1784 and was one of the first water-powered cotton mills of the Industrial Revolution. While the machines are now powered by electricity, the water wheel still turns and the machines run. Linking the two are cogs, shafts and belts, so it is possible to see how the power of the river was captured and then…

Efficacy of Cognitive-Functional (Cog-Fun) Occupational Therapy Intervention Among Children With ADHD: An RCT.

Science.gov (United States)

Hahn-Markowitz, Jeri; Berger, Itai; Manor, Iris; Maeir, Adina

2016-09-16

To examine the efficacy of a Cognitive-Functional (Cog-Fun) intervention for children with ADHD. Random allocation of 107 children to study or control groups preceded 10 parent-child weekly Cog-Fun sessions emphasizing executive strategy training in games and daily activities. Controls received treatment after crossover. Study participants were followed up 3 months post-treatment. Outcomes included parent/teacher ratings of executive functions, ADHD symptoms, and parent ratings of quality of life. Eight children withdrew prior to treatment. All children in both groups who began treatment completed it. Mixed effects ANOVA revealed significant Time × Group interaction effects on all parent-reported outcomes. Treatment effects were moderate to large, replicated after crossover in the control group and not moderated by medication. Parent-reported treatment gains in the study group were maintained at follow-up. No significant Time × Group interaction effects were found on teacher outcomes. Cog-Fun occupational therapy (OT) intervention shows positive context-specific effects on parent, but not teacher, ratings. © The Author(s) 2016.

Reliability of the Client-Centeredness of Goal Setting (C-COGS) Scale in Acquired Brain Injury Rehabilitation.

Science.gov (United States)

Doig, Emmah; Prescott, Sarah; Fleming, Jennifer; Cornwell, Petrea; Kuipers, Pim

2016-01-01

To examine the internal reliability and test-retest reliability of the Client-Centeredness of Goal Setting (C-COGS) scale. The C-COGS scale was administered to 42 participants with acquired brain injury after completion of multidisciplinary goal planning. Internal reliability of scale items was examined using item-partial total correlations and Cronbach's α coefficient. The scale was readministered within a 1-mo period to a subsample of 12 participants to examine test-retest reliability by calculating exact and close percentage agreement for each item. After examination of item-partial total correlations, test items were revised. The revised items demonstrated stronger internal consistency than the original items. Preliminary evaluation of test-retest reliability was fair, with an average exact percent agreement across all test items of 67%. Findings support the preliminary reliability of the C-COGS scale as a tool to evaluate and promote client-centered goal planning in brain injury rehabilitation. Copyright © 2016 by the American Occupational Therapy Association, Inc.

CogWnet: A Resource Management Architecture for Cognitive Wireless Networks

KAUST Repository

Alqerm, Ismail

2013-07-01

With the increasing adoption of wireless communication technologies, there is a need to improve management of existing radio resources. Cognitive radio is a promising technology to improve the utilization of wireless spectrum. Its operating principle is based on building an integrated hardware and software architecture that configures the radio to meet application requirements within the constraints of spectrum policy regulations. However, such an architecture must be able to cope with radio environment heterogeneity. In this paper, we propose a cognitive resource management architecture, called CogWnet, that allocates channels, re-configures radio transmission parameters to meet QoS requirements, ensures reliability, and mitigates interference. The architecture consists of three main layers: Communication Layer, which includes generic interfaces to facilitate the communication between the cognitive architecture and TCP/IP stack layers; Decision-Making Layer, which classifies the stack layers input parameters and runs decision-making optimization algorithms to output optimal transmission parameters; and Policy Layer to enforce policy regulations on the selected part of the spectrum. The efficiency of CogWnet is demonstrated through a testbed implementation and evaluation.

Ectopic expression of a vesicle trafficking gene, OsRab7, from Oryza ...

African Journals Online (AJOL)

Jane

2011-07-18

Jul 18, 2011 ... OsRab7, from Oryza sativa, confers tolerance to several ... Key Laboratory of Molecular Biology and Gene Engineering, College of Life Science, Nanchang University, ... The reverse transcription was performed using MMLV.

Immune function of a Rab-related protein by modulating the JAK-STAT signaling pathway in the silkworm, Bombyx mori.

Science.gov (United States)

Chen, Chen; Eldein, Salah; Zhou, Xiaosan; Sun, Yu; Gao, Jin; Sun, Yuxuan; Liu, Chaoliang; Wang, Lei

2018-01-01

The Rab-family GTPases mainly regulate intracellular vesicle transport, and play important roles in the innate immune response in invertebrates. However, the function and signal transduction of Rab proteins in immune reactions remain unclear in silkworms. In this study, we analyzed a Rab-related protein of silkworm Bombyx mori (BmRABRP) by raising antibodies against its bacterially expressed recombinant form. Tissue distribution analysis showed that BmRABRP mRNA and protein were high expressed in the Malpighian tubule and fat body, respectively. However, among the different stages, only the fourth instar larvae and pupae showed significant BmRABRP levels. After challenge with four pathogenic microorganisms (Escherichia coli, BmNPV, Beauveria bassiana, Micrococcus luteus), the expression of BmRABRP mRNA in the fat body was significantly upregulated. In contrast, the BmRABRP protein was significantly upregulated after infection with BmNPV, while it was downregulated by E. coli, B. bassiana, and M. luteus. A specific dsRNA was used to explore the immune function and relationship between BmRABRP and the JAK-STAT signaling pathway. After BmRABRP gene interference, significant reduction in the number of nodules and increased mortality suggested that BmRABRP plays an important role in silkworm's response to bacterial challenge. In addition, four key genes (BmHOP, BmSTAT, BmSOCS2, and BmSOCS6) of the JAK-STAT signaling pathway showed significantly altered expressions after BmRABRP silencing. BmHOP and BmSOCS6 expressions were significantly decreased, while BmSTAT and BmSOCS2 were significantly upregulated. Our results suggested that BmRABRP is involved in the innate immune response against pathogenic microorganisms through the JAK-STAT signaling pathway in silkworm. © 2017 Wiley Periodicals, Inc.

Worldwide Consortium for the Grid (W2COG) Research Initiative Phase 1

National Research Council Canada - National Science Library

Gunderson, Christopher; Denning, Peter

2006-01-01

.... Compared to a typical DoD Think Tank "study", W2COG more than returned value of OSD's investment by delivering a number of successful process pilots for: 1. Rapid (30-60 day), low cost (10s of $K...

Detecting non-orthology in the COGs database and other approaches grouping orthologs using genome-specific best hits.

Science.gov (United States)

Dessimoz, Christophe; Boeckmann, Brigitte; Roth, Alexander C J; Gonnet, Gaston H

2006-01-01

Correct orthology assignment is a critical prerequisite of numerous comparative genomics procedures, such as function prediction, construction of phylogenetic species trees and genome rearrangement analysis. We present an algorithm for the detection of non-orthologs that arise by mistake in current orthology classification methods based on genome-specific best hits, such as the COGs database. The algorithm works with pairwise distance estimates, rather than computationally expensive and error-prone tree-building methods. The accuracy of the algorithm is evaluated through verification of the distribution of predicted cases, case-by-case phylogenetic analysis and comparisons with predictions from other projects using independent methods. Our results show that a very significant fraction of the COG groups include non-orthologs: using conservative parameters, the algorithm detects non-orthology in a third of all COG groups. Consequently, sequence analysis sensitive to correct orthology assignments will greatly benefit from these findings.

A RabGAP regulates life-cycle duration via trimeric G-protein cascades in Dictyostelium discoideum.

Directory of Open Access Journals (Sweden)

Hidekazu Kuwayama

Full Text Available BACKGROUND: The life-cycle of cellular slime molds comprises chronobiologically regulated processes. During the growth phase, the amoeboid cells proliferate at a definite rate. Upon starvation, they synthesize cAMP as both first and second messengers in signalling pathways and form aggregates, migrating slugs, and fruiting bodies, consisting of spores and stalk cells, within 24 h. In Dictyostelium discoideum, because most growth-specific events cease during development, proliferative and heterochronic mutations are not considered to be interrelated and no genetic factor governing the entire life-cycle duration has ever been identified. METHODOLOGY/PRINCIPAL FINDINGS: Using yeast 2-hybrid library screening, we isolated a Dictyostelium discoideum RabGAP, Dd Rbg-3, as a candidate molecule by which the Dictyostelium Gα2 subunit directs its effects. Rab GTPase-activating protein, RabGAP, acts as a negative regulator of Rab small GTPases, which orchestrate the intracellular membrane trafficking involved in cell proliferation. Deletion mutants of Dd rbg-3 exhibited an increased growth rate and a shortened developmental period, while an overexpression mutant demonstrated the opposite effects. We also show that Dd Rbg-3 interacts with 2 Gα subunits in an activity-dependent manner in vitro. Furthermore, both human and Caenorhabditis elegans rbg-3 homologs complemented the Dd rbg-3-deletion phenotype in D. discoideum, indicating that similar pathways may be generally conserved in multicellular organisms. CONCLUSIONS/SIGNIFICANCE: Our findings suggest that Dd Rbg-3 acts as a key element regulating the duration of D. discoideum life-span potentially via trimeric G-protein cascades.

Slot opening optimization of surface mounted permanent magnet motor for cogging torque reduction

International Nuclear Information System (INIS)

Abbaszadeh, K.; Rezaee Alam, F.; Teshnehlab, M.

2012-01-01

Highlights: ► The slot opening shift method is an efficient method for cogging torque reduction. ► Using slot opening skew method, the trapezoidal waveform of back-emf is maintained. ► Using the conventional slot skewing, the wave shape of back-emf is sinusoidal. ► The novelty of paper is using of air–gap permeance harmonics as objective function. ► Other novelty of this paper is using the different optimization algorithms. - Abstract: In this paper, slot opening skew method is used for cogging torque reduction. A three layer stator model is considered for a six-pole PM-BLDC motor (a PM-BLDC motor with 18-slots, six-poles and length of 5 cm) and then a 2D dual model is extracted for this 3D slot opening skew model. The angular shifts of slot opening position in the first and third layers than middle layer are considered as optimization parameters. Slot opening shape is optimized by using different optimization algorithms, such as, the response surface methodology (RSM), the genetic algorithm (GA) and the particle swarm optimization (PSO). In order to using of GA and PSO, the analytical relationship is derived for the air–gap permeance function. The optimization results of these algorithms are being consistent with each other and are verified with FEA results. The results show the significant reduction of cogging torque about 77%.

Cognitive-Functional (Cog-Fun) Dyadic Intervention for Children with ADHD and Their Parents: Impact on Parenting Self-Efficacy.

Science.gov (United States)

Hahn-Markowitz, Jeri; Berger, Itai; Manor, Iris; Maeir, Adina

2018-03-01

The family context of children with ADHD plays a role in intervention outcomes, especially when parents are involved in treatment. Parental participation in evidence-based treatment for ADHD may play a role in improving their own parenting self-efficacy (PSE) as well as child outcomes. This study examined the impact of Cognitive-Functional (Cog-Fun) intervention in occupational therapy (OT) for school-aged children with ADHD, on PSE. In this randomized controlled trial with crossover design, 107 children were allocated to intervention and waitlist control groups. Intervention participants (n = 50) received Cog-Fun after baseline assessment and waitlist controls (n = 49) received treatment 3 months later. Intervention participants received 3-month follow-up assessment. Treatment included 10 parent-child Cog-Fun weekly sessions. PSE was assessed with the Tool to measure Parenting Self-Efficacy (TOPSE). All children who began treatment completed it. Mixed ANOVA revealed significant Time x Group interaction effects on TOPSE scales of Play and Enjoyment, Control, Self-Acceptance, Knowledge and Learning and Total score, which showed significant improvement with moderate treatment effects for the intervention group. Results were replicated in the control group after crossover. The findings of this study suggest that Cog-Fun OT intervention may be effective for improving aspects of PSE among parents of children with ADHD.

Rab11-FIP3 Regulation of Lck Endosomal Traffic Controls TCR Signal Transduction.

Science.gov (United States)

Bouchet, Jérôme; Del Río-Iñiguez, Iratxe; Vázquez-Chávez, Elena; Lasserre, Rémi; Agüera-González, Sonia; Cuche, Céline; McCaffrey, Mary W; Di Bartolo, Vincenzo; Alcover, Andrés

2017-04-01

The role of endosomes in receptor signal transduction is a long-standing question, which remains largely unanswered. The T cell Ag receptor and various components of its proximal signaling machinery are associated with distinct endosomal compartments, but how endosomal traffic affects T cell signaling remains ill-defined. In this article, we demonstrate in human T cells that the subcellular localization and function of the protein tyrosine kinase Lck depends on the Rab11 effector FIP3 (Rab11 family interacting protein-3). FIP3 overexpression or silencing and its ability to interact with Rab11 modify Lck subcellular localization and its delivery to the immunological synapse. Importantly, FIP3-dependent Lck localization controls early TCR signaling events, such as tyrosine phosphorylation of TCRζ, ZAP70, and LAT and intracellular calcium concentration, as well as IL-2 gene expression. Interestingly, FIP3 controls both steady-state and poststimulation phosphotyrosine and calcium levels. Finally, our findings indicate that FIP3 modulates TCR-CD3 cell surface expression via the regulation of steady-state Lck-mediated TCRζ phosphorylation, which in turn controls TCRζ protein levels. This may influence long-term T cell activation in response to TCR-CD3 stimulation. Therefore, our data underscore the importance of finely regulated endosomal traffic in TCR signal transduction and T cell activation leading to IL-2 production. Copyright © 2017 by The American Association of Immunologists, Inc.

Secretion of soluble vascular endothelial growth factor receptor 1 (sVEGFR1/sFlt1 requires Arf1, Arf6, and Rab11 GTPases.

Directory of Open Access Journals (Sweden)

Jae-Joon Jung

Full Text Available The soluble form of vascular endothelial growth factor receptor 1 (sVEGFR-1/sFlt1 is generated by alternative splicing of the FLT1 gene. Secretion of sFlt1 from endothelial cells plays an important role in blood vessel sprouting and morphogenesis. However, excess sFlt1 secretion is associated with diseases such as preeclampsia and chronic kidney disease. To date, the secretory transport process involved in the secretion of sFlt1 is poorly understood. In the present study, we investigated the itinerary of sFlt1 trafficking along the secretory pathway. To understand the timecourse of sFlt1 secretion, endothelial cells stably expressing sFlt1 were metabolically radiolabeled with [(35S]-methionine and cysteine. Our results indicate that after initial synthesis the levels of secreted [(35S]-sFlt1 in the extracellular medium peaks at 8 hours. Treatment with brefeldin A (BFA, a drug which blocks trafficking between the endoplasmic reticulum (ER and the Golgi complex, inhibited extracellular release of sFlt1 suggesting that ER to Golgi and intra-Golgi trafficking of sFlt1 are essential for its secretion. Furthermore, we show that ectopic expression of dominant-negative mutant forms of Arf1, Arf6, and Rab11 as well as siRNA-mediated knockdown of these GTPases block secretion of sFlt1 during normoxic and hypoxic conditions suggesting role for these small GTPases. This work is the first to report role of regulatory proteins involved in sFlt1 trafficking along the secretory pathway and may provide insights and new molecular targets for the modulation of sFlt-1 release during physiological and pathological conditions.

Revising the ADAS-cog for a more accurate assessment of cognitive impairment

NARCIS (Netherlands)

Wouters, Hans; van Gool, Willem A; Schmand, Ben; Lindeboom, Robert

2008-01-01

BACKGROUND: To examine whether it is appropriate to sum the cognitive part of the Alzheimer Disease Assessment Scale (ADAS-cog) items to assess cognitive impairment. This assumes items to have (1) equal measurement precision and (2) hierarchically ordered categories. METHODS: Rasch analysis on the

Validation study of the Alzheimer's disease assessment scale-cognitive subscale (ADAS-Cog) for the Portuguese patients with mild cognitive impairment and Alzheimer's disease.

Science.gov (United States)

Nogueira, Joana; Freitas, Sandra; Duro, Diana; Almeida, Jorge; Santana, Isabel

2018-03-23

The Alzheimer's disease assessment scale-Cognitive Subscale (ADAS-Cog) is a battery to assess cognitive performance in Alzheimer's disease (AD) and was developed according to the core characteristics of cognitive decline in AD: memory, language, praxis, constructive ability, and orientation. The aim of this study was to explore the diagnostic accuracy and discriminative capacity of the ADAS-Cog for Mild Cognitive Impairment (MCI) and AD, using cut-off points for the Portuguese population. The European Portuguese version of the ADAS-Cog was administrated to 650 participants, divided into a control group (n = 210), an MCI group (n = 240), and an AD group (n = 200). The clinical groups fulfilled standard international diagnostic criteria. Controls were healthy cognitive participants actively integrated in the community. The neuropsychological assessment protocol included the ADAS-Cog, the Mini Mental State Examination (MMSE), the Montreal Cognitive Assessment (MoCA), and the Adults and Older Adults Functional Assessment Inventory (IAFAI). The ADAS-Cog revealed good psychometric indicators, and the total scores were significantly different between the three groups (p  9 points (AUC = .835; sensitivity = 58% and specificity = 91%) and AD > 12 points (AUC = .996; sensitivity = 94% and specificity = 98%). Our findings confirmed the capacity of the ADAS-Cog total score to identify cognitive impairment in AD patients, with poor sensitivity for MCI, in a Portuguese cohort.

Rab11b mediates melanin transfer between donor melanocytes and acceptor keratinocytes via coupled exo/endocytosis.

Science.gov (United States)

Tarafder, Abul K; Bolasco, Giulia; Correia, Maria S; Pereira, Francisco J C; Iannone, Lucio; Hume, Alistair N; Kirkpatrick, Niall; Picardo, Mauro; Torrisi, Maria R; Rodrigues, Inês P; Ramalho, José S; Futter, Clare E; Barral, Duarte C; Seabra, Miguel C

2014-04-01

The transfer of melanin from melanocytes to keratinocytes is a crucial process underlying maintenance of skin pigmentation and photoprotection against UV damage. Here, we present evidence supporting coupled exocytosis of the melanin core, or melanocore, by melanocytes and subsequent endocytosis by keratinocytes as a predominant mechanism of melanin transfer. Electron microscopy analysis of human skin samples revealed three lines of evidence supporting this: (1) the presence of melanocores in the extracellular space; (2) within keratinocytes, melanin was surrounded by a single membrane; and (3) this membrane lacked the melanosomal membrane protein tyrosinase-related protein 1 (TYRP1). Moreover, co-culture of melanocytes and keratinocytes suggests that melanin exocytosis is specifically induced by keratinocytes. Furthermore, depletion of Rab11b, but not Rab27a, caused a marked decrease in both keratinocyte-stimulated melanin exocytosis and transfer to keratinocytes. Thus, we propose that the predominant mechanism of melanin transfer is keratinocyte-induced exocytosis, mediated by Rab11b through remodeling of the melanosome membrane, followed by subsequent endocytosis by keratinocytes.

Tree-Rings, Timbers and Trees: A dendrochronological survey of the 14th-century cog, Doel 1

DEFF Research Database (Denmark)

Haneca, Kristof; Daly, Aoife

2014-01-01

In 2000, the remains of a cog, Doel 1, were found in Doel, Belgium. Wood species identification of all ship timbers and smaller elements was performed. European oak was the dominant species, followed by alder that was used for the fairings. In total 150 ring-width series were recorded. The constr......In 2000, the remains of a cog, Doel 1, were found in Doel, Belgium. Wood species identification of all ship timbers and smaller elements was performed. European oak was the dominant species, followed by alder that was used for the fairings. In total 150 ring-width series were recorded...

Adding delayed recall to the ADAS-cog improves measurement precision in mild Alzheimer's disease: Implications for predicting instrumental activities of daily living.

Science.gov (United States)

Lowe, Deborah A; Balsis, Steve; Benge, Jared F; Doody, Rachelle S

2015-12-01

As research increasingly focuses on preclinical stages of Alzheimer's disease (AD), instruments must be retooled to identify early cognitive markers of AD. A supplemental delayed recall subtest for the Alzheimer's Disease Assessment Scale-cognitive (ADAS-cog; Mohs, Rosen, & Davis, 1983; Rosen, Mohs, & Davis, 1984) is commonly implemented, but it is not known precisely where along the spectrum of cognitive dysfunction this subtest yields incremental information beyond what is gained from the standard ADAS-cog, or whether it can improve prediction of functional outcomes. An item response theory approach can analyze this in a psychometrically rigorous way. Seven hundred eighty-eight patients with AD or amnestic complaints or impairment completed a battery including the ADAS-cog and 2 activities of daily living measures. The delayed recall subtest slightly improved the ADAS-cog's measurement precision in the mild range of cognitive dysfunction and increased prediction of instrumental activities of daily living for individuals with subjective memory impairment. (c) 2015 APA, all rights reserved).

Metric properties of the mini-mental Parkinson and SCOPA-COG scales for rating cognitive deterioration in Parkinson's disease.

Science.gov (United States)

Serrano-Dueñas, Marcos; Calero, Belén; Serrano, Soledad; Serrano, Maite; Coronel, Paulina

2010-11-15

Parkinson's disease (PD) is a chronic neurodegenerative disorder that causes cognitive impairment and dementia in ∼30% of patients. Compare metric qualities of Mini-Mental Parkinson (MMP) and scales for outcomes in Parkinson's disease-cognition (SCOPA-COG) with respect to their relative reliability, validity and ability to predict symptoms (mobility, quality of life, social repercussions, and mood) in PD patients. Outpatients (n=123, 78 males/45 females) diagnosed with PD were included in the study. A multilevel (hierarchical) modeling analysis was performed along with tests of reliability and validity to ascertain which of the two models better predicts symptoms related to PD. The MMP differed significantly between patients with Hoehn and Yahr (H&Y) stages 1, 2 or versus 4/5 (grouped together). The SCOPA-COG showed differences only between patients in H&Y stages 2 versus 4/5. Both scales were dependent on educational background and age. The SCOPA-COG had a higher coefficient of variation (0.303) than the MMP (0.184), indicating that it was the more discriminative of the two. The SCOPA-COG has some advantages over the MMP, the most important being a greater discriminative ability. Multilevel hierarchical analysis clarified the necessity of stratifying the PD population according to educational background, years of illness, and H&Y stage when using these scales. © 2010 Movement Disorder Society.

Site-directed mutagenesis, in vivo electroporation and mass spectrometry in search for determinants of the subcellular targeting of Rab7b paralogue in the model eukaryote Paramecium octaurelia.

Science.gov (United States)

Wyroba, E; Kwaśniak, P; Miller, K; Kobyłecki, K; Osińska, M

2016-04-11

Protein products of the paralogous genes resulting from the whole genome duplication may acquire new function. The role of post-translational modifications (PTM) in proper targeting of Paramecium Rab7b paralogue - distinct from that of Rab7a directly involved in phagocytosis - was studied using point mutagenesis, proteomic analysis and double immunofluorescence after in vivo electroporation of the mutagenized protein. Here we show that substitution of Thr200 by Ala200 resulted in diminished incorporation of [P32] by 37.4% and of 32 [C14-]UDP-glucose by 24%, respectively, into recombinant Rab7b_200 in comparison to the non-mutagenized control. Double confocal imaging revealed that Rab7b_200 was mistargeted upon electroporation into living cells contrary to non- mutagenized recombinant Rab7b correctly incorporated in the cytostome area. We identified the peptide ion at m/z=677.63+ characteristic for the glycan group attached to Thr200 in Rab7b using nano LC-MS/MS and comparing the peptide map of this protein with that after deglycosylation with the mixture of five enzymes of different specificity. Based on the mass of this peptide ion and quantitative radioactive assays with [P32]and  [C14-]UDP- glucose, the suggested composition of the adduct attached to Thr200 might be (Hex)1(HexNAc)1(Phos)3 or (HexNAc)1 (Deoxyhexose)1 (Phos)1 (HexA)1. These data indicate that PTM of Thr200 located in the hypervariable C-region of Rab7b in Paramecium is crucial for the proper localization/function of this protein. Moreover, these proteins differ also in other PTM: the number of phosphorylated amino acids in Rab7b is much higher than in Rab7a.

Site‐directed mutagenesis, in vivo electroporation and mass spectrometry in search for determinants of the subcellular targeting of Rab7b paralogue in the model eukaryote Paramecium octaurelia

Directory of Open Access Journals (Sweden)

E. Wyroba

2016-04-01

Full Text Available Protein products of the paralogous genes resulting from the whole genome duplication may acquire new function. The role of post‐translational modifications (PTM in proper targeting of Paramecium Rab7b paralogue – distinct from that of Rab7a directly involved in phagocytosis ‐ was studied using point mutagenesis, proteomic analysis and double immunofluorescence after in vivo electroporation of the mutagenized protein. Here we show that substitution of Thr200 by Ala200 resulted in diminished incorporation of [P32] by 37.4% and of 32 [C14–]UDP‐glucose by 24%, respectively, into recombinant Rab7b_200 in comparison to the non‐mutagenized control. Double confocal imaging revealed that Rab7b_200 was mistargeted upon electroporation into living cells contrary to non‐ mutagenized recombinant Rab7b correctly incorporated in the cytostome area. We identified the peptide ion at m/z=677.63+ characteristic for the glycan group attached to Thr200 in Rab7b using nano LC‐MS/MS and comparing the peptide map of this protein with that after deglycosylation with the mixture of five enzymes of different specificity. Based on the mass of this peptide ion and quantitative radioactive assays with [P32]and  [C14‐]UDP‐ glucose, the suggested composition of the adduct attached to Thr200 might be (Hex1(HexNAc1(Phos3 or (HexNAc1 (Deoxyhexose1 (Phos1 (HexA1. These data indicate that PTM of Thr200 located in the hypervariable C‐region of Rab7b in Paramecium is crucial for the proper localization/function of this protein. Moreover, these proteins differ also in other PTM: the number of phosphorylated amino acids in Rab7b is much higher than in Rab7a.   

The functional interplay of Rab11, FIP3 and Rho proteins on the endosomal recycling pathway controls cell shape and symmetry.

Science.gov (United States)

Bouchet, Jérôme; McCaffrey, Mary W; Graziani, Andrea; Alcover, Andrés

2018-07-04

Several families of small GTPases regulate a variety of fundamental cellular processes, encompassing growth factor signal transduction, vesicular trafficking and control of the cytoskeleton. Frequently, their action is hierarchical and complementary, but much of the detail of their functional interactions remains to be clarified. It is well established that Rab family members regulate a variety of intracellular vesicle trafficking pathways. Moreover, Rho family GTPases are pivotal for the control of the actin and microtubule cytoskeleton. However, the interplay between these 2 types of GTPases has been rarely reported. We discuss here our recent findings showing that Rab11, a key regulator of endosomal recycling, and Rac1, a central actin cytoskeleton regulator involved in lamellipodium formation and cell migration, interplay on endosomes through the Rab11 effector FIP3. In the context of the rapidly reactive T lymphocytes, Rab11-Rac1 endosomal functional interplay is important to control cell shape changes and cell symmetry during lymphocyte spreading and immunological synapse formation and ultimately modulate T cell activation.

Small G proteins in insulin action: Rab and Rho families at the crossroads of signal transduction and GLUT4 vesicle traffic.

Science.gov (United States)

Ishikura, S; Koshkina, A; Klip, A

2008-01-01

Insulin stimulates glucose uptake into muscle and adipose tissues through glucose transporter 4 (GLUT4). GLUT4 cycles between the intracellular compartments and the plasma membrane. GLUT4 traffic-regulating insulin signals are largely within the insulin receptor-insulin receptor substrate-phosphatidylinositol 3-kinase (IR-IRS-PI3K) axis. In muscle cells, insulin signal bifurcates downstream of the PI3K into one arm leading to the activation of the Ser/Thr kinases Akt and atypical protein kinase C, and another leading to the activation of Rho family protein Rac1 leading to actin remodelling. Activated Akt inactivates AS160, a GTPase-activating protein for Rab family small G proteins. Here we review the roles of Rab and Rho proteins, particularly Rab substrates of AS160 and Rac1, in insulin-stimulated GLUT4 traffic. We discuss: (1) how distinct steps in GLUT4 traffic may be regulated by discrete Rab proteins, and (2) the importance of Rac1 activation in insulin-induced actin remodelling in muscle cells, a key element for the net gain in surface GLUT4.

The validity and reliability of the Turkish version of Alzheimer's Disease Assessment Scale-Cognitive Subscale (ADAS-Cog) in patients with mild and moderate Alzheimer's disease and normal subjects.

Science.gov (United States)

Mavioglu, H; Gedizlioglu, M; Akyel, S; Aslaner, T; Eser, E

2006-03-01

The cognitive subscale of the Alzheimer's Disease Assesment Scale (ADAS-Cog) is the most widely used test in clinical trials dealing with Alzheimer's disease (AD). The aim of this study was to investigate the validity and reliability of the Turkish version of ADAS-Cog. Twenty-nine patients with AD, fulfilling NINCDS-ADRDA criteria of probable AD, who were in stage 3-5 according to the Global Deterioration Scale (GDS), and 27 non-demented control subjects with similar age, gender and educational status were recruited for the study. The Turkish version of ADAS-Cog, Standardized Mini Mental Status Examination (MMSE) and Short Orientation-Memory-Concentration Test (SOMCT) were applied to both of the groups. Inter-rater reliability, internal consistency, test-retest reliability; face validity, differential validity and convergent validity were statistically analyzed. Both MMSE and ADAS-Cog have significantly differentiated patients with AD and control subjects (p ADAS-Cog scores in AD group (r: -0.739). ADAS-Cog was also highly significantly correlated with GDS (r: 0.720) and SOMCT (r: 0.738). For the group with AD, control and whole cohort coefficients of internal consistency, Cronbach's alpha: 0.800, 0.515, 0.873 were found respectively. Inter-rater reliability for total ADAS-Cog score was found as ICC: 0.99 and 0.98 and test-retest reliability was found as ICC: 0.91 and 0.95 for demented and nondemented subjects, respectively. The Turkish version of ADAS-Cog has been found to be highly reliable and valid in differentiating patients with mild and moderate AD from nondemented subjects.

Derivation of a new ADAS-cog composite using tree-based multivariate analysis: prediction of conversion from mild cognitive impairment to Alzheimer disease.

Science.gov (United States)

Llano, Daniel A; Laforet, Genevieve; Devanarayan, Viswanath

2011-01-01

Model-based statistical approaches were used to compare the ability of the Alzheimer's Disease Assessment Scale-cognitive subscale (ADAS-cog), cerebrospinal fluid (CSF), fluorodeoxyglucose positron emission tomography and volumetric magnetic resonance imaging (MRI) markers to predict 12-month progression from mild cognitive impairment (MCI) to Alzheimer disease (AD). Using the Alzheimer's Disease Neuroimaging Initiative (ADNI) data set, properties of the 11-item ADAS-cog (ADAS.11), the 13-item ADAS-cog (ADAS.All) and novel composite scores were compared, using weighting schemes derived from the Random Forests (RF) tree-based multivariate model. Weighting subscores using the RF model of ADAS.All enhanced discrimination between elderly controls, MCI and AD patients. The ability of the RF-weighted ADAS-cog composite and individual scores, along with neuroimaging or biochemical biomarkers to predict MCI to AD conversion over 12 months was also assessed. Although originally optimized to discriminate across diagnostic categories, the ADAS. All, weighted according to the RF model, did nearly as well or better than individual or composite baseline neuroimaging or CSF biomarkers in prediction of 12-month conversion from MCI to AD. These suggest that a modified subscore weighting scheme applied to the 13-item ADAS-cog is comparable to imaging or CSF markers in prediction of conversion from MCI to AD at 12 months. Copyright © 2011 by Lippincott Williams & Wilkins

A comparison of the COG and MCNP codes in computational neutron capture therapy modeling, Part II: gadolinium neutron capture therapy models and therapeutic effects.

Science.gov (United States)

Wangerin, K; Culbertson, C N; Jevremovic, T

2005-08-01

The goal of this study was to evaluate the COG Monte Carlo radiation transport code, developed and tested by Lawrence Livermore National Laboratory, for gadolinium neutron capture therapy (GdNCT) related modeling. The validity of COG NCT model has been established for this model, and here the calculation was extended to analyze the effect of various gadolinium concentrations on dose distribution and cell-kill effect of the GdNCT modality and to determine the optimum therapeutic conditions for treating brain cancers. The computational results were compared with the widely used MCNP code. The differences between the COG and MCNP predictions were generally small and suggest that the COG code can be applied to similar research problems in NCT. Results for this study also showed that a concentration of 100 ppm gadolinium in the tumor was most beneficial when using an epithermal neutron beam.

Molecular cogs of the insect circadian clock.

Science.gov (United States)

Shirasu, Naoto; Shimohigashi, Yasuyuki; Tominaga, Yoshiya; Shimohigashi, Miki

2003-08-01

During the last five years, enormous progress has been made in understanding the molecular basis of circadian systems, mainly by molecular genetic studies using the mouse and fly. Extensive evidence has revealed that the core clock machinery involves "clock genes" and "clock proteins" functioning as molecular cogs. These participate in transcriptional/translational feedback loops and many homologous clock-components in the fruit fly Drosophila are also expressed in mammalian clock tissues with circadian rhythms. Thus, the mechanisms of the central clock seem to be conserved across animal kingdom. However, some recent studies imply that the present widely accepted molecular models of circadian clocks may not always be supported by the experimental evidence.

Mutations in the small GTPase gene RAB39B are responsible for X-linked mental retardation associated with autism, epilepsy, and macrocephaly.

Science.gov (United States)

Giannandrea, Maila; Bianchi, Veronica; Mignogna, Maria Lidia; Sirri, Alessandra; Carrabino, Salvatore; D'Elia, Errico; Vecellio, Matteo; Russo, Silvia; Cogliati, Francesca; Larizza, Lidia; Ropers, Hans-Hilger; Tzschach, Andreas; Kalscheuer, Vera; Oehl-Jaschkowitz, Barbara; Skinner, Cindy; Schwartz, Charles E; Gecz, Jozef; Van Esch, Hilde; Raynaud, Martine; Chelly, Jamel; de Brouwer, Arjan P M; Toniolo, Daniela; D'Adamo, Patrizia

2010-02-12

Human Mental Retardation (MR) is a common and highly heterogeneous pediatric disorder affecting around 3% of the general population; at least 215 X-linked MR (XLMR) conditions have been described, and mutations have been identified in 83 different genes, encoding proteins with a variety of function, such as chromatin remodeling, synaptic function, and intracellular trafficking. The small GTPases of the RAB family, which play an essential role in intracellular vesicular trafficking, have been shown to be involved in MR. We report here the identification of mutations in the small GTPase RAB39B gene in two male patients. One mutation in family X (D-23) introduced a stop codon seven amino acids after the start codon (c.21C > A; p.Y7X). A second mutation, in the MRX72 family, altered the 5' splice site (c.215+1G > A) and normal splicing. Neither instance produced a protein. Mutations segregate with the disease in the families, and in some family members intellectual disabilities were associated with autism spectrum disorder, epileptic seizures, and macrocephaly. We show that RAB39B, a novel RAB GTPase of unknown function, is a neuronal-specific protein that is localized to the Golgi compartment. Its downregulation leads to an alteration in the number and morphology of neurite growth cones and a significant reduction in presynaptic buttons, suggesting that RAB39B is required for synapse formation and maintenance. Our results demonstrate developmental and functional neuronal alteration as a consequence of downregulation of RAB39B and emphasize the critical role of vesicular trafficking in the development of neurons and human intellectual abilities. Copyright (c) 2010 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

Characterization of the Mammalian CORVET and HOPS Complexes and Their Modular Restructuring for Endosome Specificity

NARCIS (Netherlands)

van der Kant, Rik; Jonker, Caspar T. H.; Wijdeven, Ruud H.; Bakker, Jeroen; Janssen, Lennert; Klumperman, Judith; Neefjes, Jacques

2015-01-01

Trafficking of cargo through the endosomal system depends on endosomal fusion events mediated by SNARE proteins, Rab-GTPases, and multisubunit tethering complexes. The CORVET and HOPS tethering complexes, respectively, regulate early and late endosomal tethering and have been characterized in detail

Identification and biochemical analysis of Slac2-c/MyRIP as a Rab27A-, myosin Va/VIIa-, and actin-binding protein.

Science.gov (United States)

Kuroda, Taruho S; Fukuda, Mitsunori

2005-01-01

Slac2-c/MyRIP is a specific Rab27A-binding protein that contains an N-terminal synaptotagmin-like protein (Slp) homology domain (SHD, a newly identified GTP-Rab27A-binding motif), but in contrast to the Slp family proteins, it lacks C-terminal tandem C2 domains. In vitro Slac2-c simultaneously directly interacts with both Rab27A and an actin-based motor protein, myosin Va, via its N-terminal SHD and middle region, respectively, consistent with the fact that the overall structure of Slac2-c is similar to that of Slac2-a/melanophilin, a linker protein between Rab27A and myosin Va in the melanosome transport in melanocytes. Unlike Slac2-a, however, the middle region of Slac2-c interacts with two types of myosins, myosin Va and myosin VIIa. In addition, the most C-terminal part of both Slac2-a and Slac2-c functions as an actin-binding domain: it directly interacts with globular and fibrous actin in vitro, and the actin-binding domain of Slac2-a and Slac2-c colocalizes with actin filaments when it is expressed in living cells (i.e., PC12 cells and mouse melanocytes). In this chapter we describe the methods that have been used to analyze the protein-protein interactions of Slac2-c, specifically with Rab27A, myosin Va/VIIa, and actin.

Alteraciones en el reclutamiento y activación de proteínas Rab durante la infección micobacteriana

Directory of Open Access Journals (Sweden)

Diana Castaño

2010-08-01

La expresión de mutantes constitutivamente activos de las Rab de endosomas tempranos impide la maduración de fagosomas que contienen esferas de látex o micobacterias inactivadas por calor. Mientras que su silenciamiento, mediante ARN de interferencia o mediante dominantes negativos, induce la maduración de fagosomas micobacterianos. Los mecanismos exactos por los que las micobacterias alteran la dinámica de expresión de estas GTPasas, afectando la maduración fagolisosómica, no se han establecido. El problema podría explicarse por defectos en el reclutamiento de las proteínas que interactúan con Rab, como la cinasa-3 del fosfatidilinositol y el antígeno endosómico temprano 1. La identificación de los mecanismos empleados por Mycobacterium spp. para interrumpir el ciclo de activación de las Rab, será esencial para comprender la fisiopatología de la infección micobacteriana y útil como posibles blancos farmacológicos.

Adaptation and validation of the Alzheimer's Disease Assessment Scale - Cognitive (ADAS-Cog) in a low-literacy setting in sub-Saharan Africa.

Science.gov (United States)

Paddick, Stella-Maria; Kisoli, Aloyce; Mkenda, Sarah; Mbowe, Godfrey; Gray, William Keith; Dotchin, Catherine; Ogunniyi, Adesola; Kisima, John; Olakehinde, Olaide; Mushi, Declare; Walker, Richard William

2017-08-01

This study aimed to assess the feasibility of a low-literacy adaptation of the Alzheimer's Disease Assessment Scale - Cognitive (ADAS-Cog) for use in rural sub-Saharan Africa (SSA) for interventional studies in dementia. No such adaptations currently exist. Tanzanian and Nigerian health professionals adapted the ADAS-Cog by consensus. Validation took place in a cross-sectional sample of 34 rural-dwelling older adults with mild/moderate dementia alongside 32 non-demented controls in Tanzania. Participants were oversampled for lower educational level. Inter-rater reliability was conducted by two trained raters in 22 older adults (13 with dementia) from the same population. Assessors were blind to diagnostic group. Median ADAS-Cog scores were 28.75 (interquartile range (IQR), 22.96-35.54) in mild/moderate dementia and 12.75 (IQR 9.08-16.16) in controls. The area under the receiver operating characteristic curve (AUC) was 0.973 (95% confidence interval (CI) 0.936-1.00) for dementia. Internal consistency was high (Cronbach's α 0.884) and inter-rater reliability was excellent (intra-class correlation coefficient 0.905, 95% CI 0.804-0.964). The low-literacy adaptation of the ADAS-Cog had good psychometric properties in this setting. Further evaluation in similar settings is required.

Trans-complex formation by proteolipid channels in the terminal phase of membrane fusion

DEFF Research Database (Denmark)

Peters, C; Bayer, M J; Bühler, S

2001-01-01

-complex formation occurs downstream from trans-SNARE pairing, and depends on both the Rab-GTPase Ypt7 and calmodulin. The maintenance of existing complexes and completion of fusion are independent of trans-SNARE pairs. Reconstituted proteolipids form sealed channels, which can expand to form aqueous pores in a Ca2...

Loss-of-function of the ciliopathy protein Cc2d2a disorganizes the vesicle fusion machinery at the periciliary membrane and indirectly affects Rab8-trafficking in zebrafish photoreceptors.

Science.gov (United States)

Ojeda Naharros, Irene; Gesemann, Matthias; Mateos, José M; Barmettler, Gery; Forbes, Austin; Ziegler, Urs; Neuhauss, Stephan C F; Bachmann-Gagescu, Ruxandra

2017-12-01

Ciliopathies are human disorders caused by dysfunction of primary cilia, ubiquitous organelles involved in transduction of environmental signals such as light sensation in photoreceptors. Concentration of signal detection proteins such as opsins in the ciliary membrane is achieved by RabGTPase-regulated polarized vesicle trafficking and by a selective barrier at the ciliary base, the transition zone (TZ). Dysfunction of the TZ protein CC2D2A causes Joubert/Meckel syndromes in humans and loss of ciliary protein localization in animal models, including opsins in retinal photoreceptors. The link between the TZ and upstream vesicle trafficking has been little explored to date. Moreover, the role of the small GTPase Rab8 in opsin-carrier vesicle (OCV) trafficking has been recently questioned in a mouse model. Using correlative light and electron microscopy and live imaging in zebrafish photoreceptors, we provide the first live characterization of Rab8-mediated trafficking in photoreceptors in vivo. Our results support a possibly redundant role for both Rab8a/b paralogs in OCV trafficking, based on co-localization of Rab8 and opsins in vesicular structures, and joint movement of Rab8-tagged particles with opsin. We further investigate the role of the TZ protein Cc2d2a in Rab8-mediated trafficking using cc2d2a zebrafish mutants and identify a requirement for Cc2d2a in the latest step of OCV trafficking, namely vesicle fusion. Progressive accumulation of opsin-containing vesicles in the apical portion of photoreceptors lacking Cc2d2a is caused by disorganization of the vesicle fusion machinery at the periciliary membrane with mislocalization and loss of the t-SNAREs SNAP25 and Syntaxin3 and of the exocyst component Exoc4. We further observe secondary defects on upstream Rab8-trafficking with cytoplasmic accumulation of Rab8. Taken together, our results support participation of Rab8 in OCV trafficking and identify a novel role for the TZ protein Cc2d2a in fusion of incoming

Archaeal Clusters of Orthologous Genes (arCOGs): An Update and Application for Analysis of Shared Features between Thermococcales, Methanococcales, and Methanobacteriales

OpenAIRE

Makarova, Kira; Wolf, Yuri; Koonin, Eugene

2015-01-01

With the continuously accelerating genome sequencing from diverse groups of archaea and bacteria, accurate identification of gene orthology and availability of readily expandable clusters of orthologous genes are essential for the functional annotation of new genomes. We report an update of the collection of archaeal Clusters of Orthologous Genes (arCOGs) to cover, on average, 91% of the protein-coding genes in 168 archaeal genomes. The new arCOGs were constructed using refined algorithms for...

Recovery of high-purity hydrogen from COG

Energy Technology Data Exchange (ETDEWEB)

Tsukiyama, Y

1982-01-01

A general account of the latest trends in the recovery of high-purity hydrogen from coke oven gas (COG), the article being based on both Japanese and overseas literature: 1) Deep-freeze separation: impurities are liquefied and removed. This method make use of the fact that hydrogen is hard to liquefy. 2) The PSA method: high-purity hydrogen is recovered by the adsorption of other constituents at high pressures. This technique makes use of the fact that the adsorption capacity of an adsorbent varies with the partial pressure of the substances being adsorbed. 3) Membrane separation: a permeation separation method that uses a functional polymer separation membrane, and that depends on the fact that hydrogen has a low molecular weight in comparison with the other constituents. (19 refs.) (In Japanese)

Novel gas sensor with dual response under CO(g) exposure: Optical and electrical stimuli

Science.gov (United States)

Rocha, L. S. R.; Cilense, M.; Ponce, M. A.; Aldao, C. M.; Oliveira, L. L.; Longo, E.; Simoes, A. Z.

2018-05-01

In this work, a lanthanum (La) doped ceria (CeO2) film, which depicted a dual gas sensing response (electric and optical) for CO(g) detection, was obtained by the microwave-assisted hydrothermal (HAM) synthesis and deposited by the screen-printing technique, in order to prevent deaths by intoxication with this life-threatening gas. An electric response under CO(g) exposure was obtained, along with an extremely fast optical response for a temperature of 380 °C, associated with Ce+4 reduction and vacancy generation. A direct optical gap was found to be around 2.31 eV from UV-Vis results, which corresponds to a transition from valence band to 4f states. Due to the anomalous electron configuration of cerium atoms with 4f electrons in its reduced state, they are likely to present an electric conduction based on the small polaron theory with a hopping mechanism responsible for its dual sensing response with a complete reversible behaviour.

Domain-specific cognitive effects of tramiprosate in patients with mild to moderate Alzheimer's disease: ADAS-cog subscale results from the Alphase Study.

Science.gov (United States)

Saumier, D; Duong, A; Haine, D; Garceau, D; Sampalis, J

2009-11-01

Tramiprosate (homotaurine, ALZHEMEDTM) was recently investigated for its efficacy, safety and disease-modification effects in a Phase III clinical study in mild to moderate Alzheimer's disease (AD) patients (the Alphase study). The primary cognitive endpoint measure of that study was the Alzheimer's Disease Assessment Scale-cognitive subscale (ADAS-cog). To characterize potential cognitive benefits of tramiprosate, the present study describes exploratory analyses performed on scores obtained from the specific ADAS-cog subscales in order to determine whether specific domains of cognition may be differentially affected by tramiprosate, which would not have been evident from the measure's total score. Multi-center, double-blind, randomized, placebo-controlled study. 67 investigative sites in the United States and Canada. A total of 1,052 patients were randomized. Patients were randomized to receive twice a day Placebo (n=353), tramiprosate 100 mg (n=352) and tramiprosate 150 mg (n=347). ADAS-cog assessments were conducted every three months over the 78-week study period. Exploratory analyses were performed by comparing ADAS-cog subscale scores between Placebo and each active treatment arm at each visit. The findings of this analysis revealed statistically significant differences or statistical trends in favour of tramiprosate on six ADAS-cog subscales, namely Following Commands, Language Comprehension, Ideational Praxis, Object Naming, Remembering Test Instructions, and Spoken Language Ability. Differences in favor of Placebo were only observed on the Constructional Praxis subscale. This exploratory analysis suggests that tramiprosate may have some benefit on memory, language and praxis skills in mild to moderate AD individuals. Future clinical studies of tramiprosate should include specialized neuropsychological tests to validate its effects within these cognitive domains.

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.

Public health implications from COGS and potential for risk stratification and screening.

Science.gov (United States)

Burton, Hilary; Chowdhury, Susmita; Dent, Tom; Hall, Alison; Pashayan, Nora; Pharoah, Paul

2013-04-01

The PHG Foundation led a multidisciplinary program, which used results from COGS research identifying genetic variants associated with breast, ovarian and prostate cancers to model risk-stratified prevention for breast and prostate cancers. Implementing such strategies would require attention to the use and storage of genetic information, the development of risk assessment tools, new protocols for consent and programs of professional education and public engagement.

Comparison of the heritability of schizophrenia and endophenotypes in the COGS-1 family study.

Science.gov (United States)

Light, Gregory; Greenwood, Tiffany A; Swerdlow, Neal R; Calkins, Monica E; Freedman, Robert; Green, Michael F; Gur, Raquel E; Gur, Ruben C; Lazzeroni, Laura C; Nuechterlein, Keith H; Olincy, Ann; Radant, Allen D; Seidman, Larry J; Siever, Larry J; Silverman, Jeremy M; Sprock, Joyce; Stone, William S; Sugar, Catherine A; Tsuang, Debby W; Tsuang, Ming T; Turetsky, Bruce I; Braff, David L

2014-11-01

Twin and multiplex family studies have established significant heritability for schizophrenia (SZ), often summarized as 81%. The Consortium on the Genetics of Schizophrenia (COGS-1) family study was designed to deconstruct the genetic architecture of SZ using neurocognitive and neurophysiological endophenotypes, for which heritability estimates ranged from 18% to 50% (mean = 30%). This study assessed the heritability of SZ in these families to determine whether there is a "heritability gap" between the diagnosis and related endophenotypes. Nuclear families (N = 296) with a SZ proband, an unaffected sibling, and both parents (n = 1366 subjects; mean family size = 4.6) underwent comprehensive endophenotype and clinical characterization. The Family Interview for Genetic Studies was administered to all participants and used to obtain convergent psychiatric symptom information for additional first-degree relatives of interviewed subjects (N = 3304 subjects; mean family size = 11.2). Heritability estimates of psychotic disorders were computed for both nuclear and extended families. The heritability of SZ was 31% and 44% for nuclear and extended families. The inclusion of bipolar disorder increased the heritability to 37% for the nuclear families. When major depression was added, heritability estimates dropped to 34% and 20% for nuclear and extended families, respectively. Endophenotypes and psychotic disorders exhibit comparable levels of heritability in the COGS-1 family sample. The ascertainment of families with discordant sibpairs to increase endophenotypic contrast may underestimate diagnostic heritability relative to other studies. However, population-based studies also report significantly lower heritability estimates for SZ. Collectively, these findings support the importance of endophenotype-based strategies and the dimensional view of psychosis. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center 2014.

California Verbal Learning Test-II performance in schizophrenia as a function of ascertainment strategy: Comparing the first and second phases of the Consortium on the Genetics of Schizophrenia (COGS)

OpenAIRE

Stone, WS; Mesholam-Gately, RI; Braff, DL; Calkins, ME; Freedman, R; Green, MF; Greenwood, TA; Gur, RE; Gur, RCC; Lazzeroni, LC; Light, GA; Nuechterlein, KH; Olincy, A; Radant, AD; Siever, LJ

2014-01-01

© 2014. The first phase of the Consortium on the Genetics of Schizophrenia (COGS-1) showed performance deficits in learning and memory on the California Verbal Learning Test, Second Edition (CVLT-II) in individuals with schizophrenia (SZ), compared to healthy comparison subjects (HCS). A question is whether the COGS-1 study, which used a family study design (i.e. studying relatively intact families), yielded “milder“ SZ phenotypes than those acquired subsequently in the COGS-2 case-control de...

California verbal learning test-ii performance in schizophrenia as a function of ascertainment strategy: Comparing the first and second phases of the consortium on the genetics of schizophrenia (COGS)

OpenAIRE

Stone, WS; Mesholam-Gately, RI; Braff, DL; Calkins, ME; Freedman, R; Green, MF; Greenwood, TA; Gur, RE; Gur, RC; Lazzeroni, LC; Light, GA; Nuechterlein, KH; Olincy, A; Radant, AD; Siever, LJ

2015-01-01

© 2014. The first phase of the Consortium on the Genetics of Schizophrenia (COGS-1) showed performance deficits in learning and memory on the California Verbal Learning Test, Second Edition (CVLT-II) in individuals with schizophrenia (SZ), compared to healthy comparison subjects (HCS). A question is whether the COGS-1 study, which used a family study design (i.e. studying relatively intact families), yielded "milder" SZ phenotypes than those acquired subsequently in the COGS-2 case-control de...

A genome-wide association scan (GWAS) for mean telomere length within the COGS project

DEFF Research Database (Denmark)

Pooley, Karen A; Bojesen, Stig E; Weischer, Maren

2013-01-01

Mean telomere length (TL) in blood cells is heritable and has been reported to be associated with risks of several diseases, including cancer. We conducted a meta-analysis of three GWAS for TL (total n=2240) and selected 1629 variants for replication via the "iCOGS" custom genotyping array. All...

GDP-bound and nucleotide-free intermediates of the guanine nucleotide exchange in the Rab5·Vps9 system.

Science.gov (United States)

Uejima, Tamami; Ihara, Kentaro; Goh, Tatsuaki; Ito, Emi; Sunada, Mariko; Ueda, Takashi; Nakano, Akihiko; Wakatsuki, Soichi

2010-11-19

Many GTPases regulate intracellular transport and signaling in eukaryotes. Guanine nucleotide exchange factors (GEFs) activate GTPases by catalyzing the exchange of their GDP for GTP. Here we present crystallographic and biochemical studies of a GEF reaction with four crystal structures of Arabidopsis thaliana ARA7, a plant homolog of Rab5 GTPase, in complex with its GEF, VPS9a, in the nucleotide-free and GDP-bound forms, as well as a complex with aminophosphonic acid-guanylate ester and ARA7·VPS9a(D185N) with GDP. Upon complex formation with ARA7, VPS9 wedges into the interswitch region of ARA7, inhibiting the coordination of Mg(2+) and decreasing the stability of GDP binding. The aspartate finger of VPS9a recognizes GDP β-phosphate directly and pulls the P-loop lysine of ARA7 away from GDP β-phosphate toward switch II to further destabilize GDP for its release during the transition from the GDP-bound to nucleotide-free intermediates in the nucleotide exchange reaction.

The Ciliopathy Protein CC2D2A Associates with NINL and Functions in RAB8-MICAL3-Regulated Vesicle Trafficking.

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Ruxandra Bachmann-Gagescu

2015-10-01

Full Text Available Ciliopathies are a group of human disorders caused by dysfunction of primary cilia, ubiquitous microtubule-based organelles involved in transduction of extra-cellular signals to the cell. This function requires the concentration of receptors and channels in the ciliary membrane, which is achieved by complex trafficking mechanisms, in part controlled by the small GTPase RAB8, and by sorting at the transition zone located at the entrance of the ciliary compartment. Mutations in the transition zone gene CC2D2A cause the related Joubert and Meckel syndromes, two typical ciliopathies characterized by central nervous system malformations, and result in loss of ciliary localization of multiple proteins in various models. The precise mechanisms by which CC2D2A and other transition zone proteins control protein entrance into the cilium and how they are linked to vesicular trafficking of incoming cargo remain largely unknown. In this work, we identify the centrosomal protein NINL as a physical interaction partner of CC2D2A. NINL partially co-localizes with CC2D2A at the base of cilia and ninl knockdown in zebrafish leads to photoreceptor outer segment loss, mislocalization of opsins and vesicle accumulation, similar to cc2d2a-/- phenotypes. Moreover, partial ninl knockdown in cc2d2a-/- embryos enhances the retinal phenotype of the mutants, indicating a genetic interaction in vivo, for which an illustration is found in patients from a Joubert Syndrome cohort. Similar to zebrafish cc2d2a mutants, ninl morphants display altered Rab8a localization. Further exploration of the NINL-associated interactome identifies MICAL3, a protein known to interact with Rab8 and to play an important role in vesicle docking and fusion. Together, these data support a model where CC2D2A associates with NINL to provide a docking point for cilia-directed cargo vesicles, suggesting a mechanism by which transition zone proteins can control the protein content of the ciliary

Estimation of diagnostic performance of dementia screening tests: Mini-Mental State Examination, Mini-Cog, Clock Drawing test and Ascertain Dementia 8 questionnaire.

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Yang, Li; Yan, Jing; Jin, Xiaoqing; Jin, Yu; Yu, Wei; Xu, Shanhu; Wu, Haibin; Xu, Ying; Liu, Caixia

2017-05-09

Dementia is one of the leading causes of dependence in the elderly. This study was conducted to estimate diagnostic performance of dementia screening tests including Mini-Mental State Examination (MMSE), Mini-Cog, Clock Drawing Test (CDT) and Ascertain Dementia 8 questionnaire (AD8) by Bayesian models. A total of 2015 participants aged 65 years or more in eastern China were enrolled. The four screening tests were administered and scored by specifically trained psychiatrists. The prior information of sensitivity and specificity of every screening test was updated via Bayes' theorem to a posterior distribution. Then the results were compared with the estimation based on National Institute of Aging-Alzheimer's Association criteria (NIA-AA). The diagnostic characteristics of Mini-Cog, including sensitivity, specificity, PPV, NPV, especially the Youden index, performed well, even better than the combinations of several screening tests. The Mini-Cog with excellent screening characteristics, spending less time, could be considered to be used as a screening test to help to screen patients with cognitive impairment or dementia early. And Bayesian method was shown to be a suitable tool for evaluating dementia screening tests. The Mini-Cog with excellent screening characteristics, spending less time, could be considered to be used as a screening test to help to screen patients with cognitive impairment or dementia early. And Bayesian method was shown to be a suitable tool for evaluating dementia screening tests.

Early stages of functional diversification in the Rab GTPase gene family revealed by genomic and localization studies in Paramecium species.

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Bright, Lydia J; Gout, Jean-Francois; Lynch, Michael

2017-04-15

New gene functions arise within existing gene families as a result of gene duplication and subsequent diversification. To gain insight into the steps that led to the functional diversification of paralogues, we tracked duplicate retention patterns, expression-level divergence, and subcellular markers of functional diversification in the Rab GTPase gene family in three Paramecium aurelia species. After whole-genome duplication, Rab GTPase duplicates are more highly retained than other genes in the genome but appear to be diverging more rapidly in expression levels, consistent with early steps in functional diversification. However, by localizing specific Rab proteins in Paramecium cells, we found that paralogues from the two most recent whole-genome duplications had virtually identical localization patterns, and that less closely related paralogues showed evidence of both conservation and diversification. The functionally conserved paralogues appear to target to compartments associated with both endocytic and phagocytic recycling functions, confirming evolutionary and functional links between the two pathways in a divergent eukaryotic lineage. Because the functionally diversifying paralogues are still closely related to and derived from a clade of functionally conserved Rab11 genes, we were able to pinpoint three specific amino acid residues that may be driving the change in the localization and thus the function in these proteins. © 2017 Bright et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

Rivastigmine in Alzheimer's disease and Parkinson's disease dementia: an ADAS-cog factor analysis.

Science.gov (United States)

Weintraub, Daniel; Somogyi, Monique; Meng, Xiangyi

2011-09-01

Rivastigmine treatment is associated with significant improvements on the cognitive subscale of the Alzheimer's Disease Assessment Scale (ADAS-cog) in patients with mild-to-moderate Alzheimer's disease (AD) and Parkinson's disease dementia (PDD). Both AD and PDD are purported to have different profiles of cognitive impairment, which may respond differentially to rivastigmine treatment. This was a retrospective analysis of 3 randomized, double-blind, rivastigmine trial databases (Investigation of transDermal Exelon in ALzheimer's disease [IDEAL; AD], EXelon in PaRkinson's disEaSe dementia Study [EXPRESS; PDD], and Alzheimer's Disease with ENA 713 [ADENA; AD]). Factor analyses of the 11 baseline ADAS-cog items derived the same factors in the 2 diseases, that is, "memory" and "language". Rivastigmine-treated AD and PDD patients showed significant improvements (P < .0001 versus placebo) on both factors. For both AD and PDD, rivastigmine had a numerically greater effect on memory than language. Treatment effect sizes were numerically greater in PDD compared with AD. Rivastigmine treatment is associated with improvement in memory and language in AD and PDD. The numerically greater response in PDD is consistent with greater cholinergic deficits in this disease state.

Effects of memantine on cognition in patients with moderate to severe Alzheimer's disease: post-hoc analyses of ADAS-cog and SIB total and single-item scores from six randomized, double-blind, placebo-controlled studies.

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Mecocci, Patrizia; Bladström, Anna; Stender, Karina

2009-05-01

The post-hoc analyses reported here evaluate the specific effects of memantine treatment on ADAS-cog single-items or SIB subscales for patients with moderate to severe AD. Data from six multicentre, randomised, placebo-controlled, parallel-group, double-blind, 6-month studies were used as the basis for these post-hoc analyses. All patients with a Mini-Mental State Examination (MMSE) score of less than 20 were included. Analyses of patients with moderate AD (MMSE: 10-19), evaluated with the Alzheimer's disease Assessment Scale (ADAS-cog) and analyses of patients with moderate to severe AD (MMSE: 3-14), evaluated using the Severe Impairment Battery (SIB), were performed separately. The mean change from baseline showed a significant benefit of memantine treatment on both the ADAS-cog (p ADAS-cog single-item analyses showed significant benefits of memantine treatment, compared to placebo, for mean change from baseline for commands (p < 0.001), ideational praxis (p < 0.05), orientation (p < 0.01), comprehension (p < 0.05), and remembering test instructions (p < 0.05) for observed cases (OC). The SIB subscale analyses showed significant benefits of memantine, compared to placebo, for mean change from baseline for language (p < 0.05), memory (p < 0.05), orientation (p < 0.01), praxis (p < 0.001), and visuospatial ability (p < 0.01) for OC. Memantine shows significant benefits on overall cognitive abilities as well as on specific key cognitive domains for patients with moderate to severe AD. (c) 2009 John Wiley & Sons, Ltd.

Identification of 23 new prostate cancer susceptibility loci using the iCOGS custom genotyping array

DEFF Research Database (Denmark)

Eeles, Rosalind A; Olama, Ali Amin Al; Benlloch, Sara

2013-01-01

Prostate cancer is the most frequently diagnosed cancer in males in developed countries. To identify common prostate cancer susceptibility alleles, we genotyped 211,155 SNPs on a custom Illumina array (iCOGS) in blood DNA from 25,074 prostate cancer cases and 24,272 controls from the internationa...

Kinesin-73 is a processive motor that localizes to Rab5-containing organelles.

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Huckaba, Thomas M; Gennerich, Arne; Wilhelm, James E; Chishti, Athar H; Vale, Ronald D

2011-03-04

Drosophila Kinesin-73 (Khc-73), which plays a role in mitotic spindle polarity in neuroblasts, is a metazoan-specific member of the Kinesin-3 family of motors, which includes mammalian KIF1A and Caenorhabditis elegans Unc-104. The mechanism of Kinesin-3 motors has been controversial because some studies have reported that they transport cargo as monomers whereas other studies have suggested a dimer mechanism. Here, we have performed single-molecule motility and cell biological studies of Khc-73. We find that constructs containing the motor and the conserved short stretches of putative coiled-coil-forming regions are predominantly monomeric in vitro, but that dimerization allows for fast, processive movement and high force production (7 piconewtons). In Drosophila cell lines, we present evidence that Khc-73 can dimerize in vivo. We also show that Khc-73 is recruited specifically to Rab5-containing endosomes through its "tail" domain. Our results suggest that the N-terminal half of Khc-73 can undergo a monomer-dimer transition to produce a fast processive motor and that its C-terminal half possesses a specific Rab5-vesicle binding domain.

The Influence of Technological Conditions of the Process of Cogging in Flat Dies on the Quality of Two-Phase Titanium Alloys

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Dyja Н.

2016-06-01

Full Text Available To create a rational technology of cogging process and to determinate the optimal values of the angles of tilt and single reduction the stress-strain state (SSS of the blank during cogging in the flat dies was analyzed. By using the finite element method and program MSC.SuperForge quantitative data are obtained and the basic patterns of distribution of SSS, the temperature during the simulation of tilting in flat dies with different angles of tilting and the amount of reduction were established. Sustainable experimental-industrial technology of forging of two-phase titanium alloys was developed and tested.

Cogging Torque Reduction in Brushless DC Motors Using Slot-Opening Shift

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SAIED, S. A.

2009-02-01

Full Text Available In this paper, two new methods for the stator skew are introduced. In contrary with the conventional stator skew, this paper is concentrate on the slot-opening skew. The simula-tion result by finite element shows a considerable reduction in the cogging torque of the motors, the new methods are applied to. Moreover the simulations justify that the back-EMF shape remains trapezoidal for various skew angles in contrary with that in the conventional skew, this fact makes the method highly applicable in BLDC motors.

Complexities in human herpesvirus-6A and -6B binding to host cells

International Nuclear Information System (INIS)

Pedersen, Simon Metz; Hoellsberg, Per

2006-01-01

Human herpesvirus-6A and -6B uses the cellular receptor CD46 for fusion and infection of the host cell. The viral glycoprotein complex gH-gL from HHV-6A binds to the short consensus repeat 2 and 3 in CD46. Although all the major isoforms of CD46 bind the virus, certain isoforms may have higher affinity than others for the virus. Within recent years, elucidation of the viral complex has identified additional HHV-6A and -6B specific glycoproteins. Thus, gH-gL associates with a gQ1-gQ2 dimer to form a heterotetrameric complex. In addition, a novel complex consisting of gH-gL-gO has been described that does not bind CD46. Accumulating evidence suggests that an additional HHV-6A and -6B receptor exists. The previous simple picture of HHV-6A/B-host cell contact therefore includes more layers of complexities on both the viral and the host cell side of the interaction

Updated clusters of orthologous genes for Archaea: a complex ancestor of the Archaea and the byways of horizontal gene transfer

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Wolf Yuri I

2012-12-01

Full Text Available Abstract Background Collections of Clusters of Orthologous Genes (COGs provide indispensable tools for comparative genomic analysis, evolutionary reconstruction and functional annotation of new genomes. Initially, COGs were made for all complete genomes of cellular life forms that were available at the time. However, with the accumulation of thousands of complete genomes, construction of a comprehensive COG set has become extremely computationally demanding and prone to error propagation, necessitating the switch to taxon-specific COG collections. Previously, we reported the collection of COGs for 41 genomes of Archaea (arCOGs. Here we present a major update of the arCOGs and describe evolutionary reconstructions to reveal general trends in the evolution of Archaea. Results The updated version of the arCOG database incorporates 91% of the pangenome of 120 archaea (251,032 protein-coding genes altogether into 10,335 arCOGs. Using this new set of arCOGs, we performed maximum likelihood reconstruction of the genome content of archaeal ancestral forms and gene gain and loss events in archaeal evolution. This reconstruction shows that the last Common Ancestor of the extant Archaea was an organism of greater complexity than most of the extant archaea, probably with over 2,500 protein-coding genes. The subsequent evolution of almost all archaeal lineages was apparently dominated by gene loss resulting in genome streamlining. Overall, in the evolution of Archaea as well as a representative set of bacteria that was similarly analyzed for comparison, gene losses are estimated to outnumber gene gains at least 4 to 1. Analysis of specific patterns of gene gain in Archaea shows that, although some groups, in particular Halobacteria, acquire substantially more genes than others, on the whole, gene exchange between major groups of Archaea appears to be largely random, with no major ‘highways’ of horizontal gene transfer. Conclusions The updated collection

Rab11-dependent Recycling of the Human Ether-a-go-go-related Gene (hERG) Channel*

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Chen, Jeffery; Guo, Jun; Yang, Tonghua; Li, Wentao; Lamothe, Shawn M.; Kang, Yudi; Szendrey, John A.; Zhang, Shetuan

2015-01-01

The human ether-a-go-go-related gene (hERG) encodes the pore-forming subunit of the rapidly activating delayed rectifier potassium channel (IKr). A reduction in the hERG current causes long QT syndrome, which predisposes affected individuals to ventricular arrhythmias and sudden death. We reported previously that hERG channels in the plasma membrane undergo vigorous internalization under low K+ conditions. In the present study, we addressed whether hERG internalization occurs under normal K+ conditions and whether/how internalized channels are recycled back to the plasma membrane. Using patch clamp, Western blot, and confocal imaging analyses, we demonstrated that internalized hERG channels can effectively recycle back to the plasma membrane. Low K+-enhanced hERG internalization is accompanied by an increased rate of hERG recovery in the plasma membrane upon reculture following proteinase K-mediated clearance of cell-surface proteins. The increased recovery rate is not due to enhanced protein synthesis, as hERG mRNA expression was not altered by low K+ exposure, and the increased recovery was observed in the presence of the protein biosynthesis inhibitor cycloheximide. GTPase Rab11, but not Rab4, is involved in the recycling of hERG channels. Interfering with Rab11 function not only delayed hERG recovery in cells after exposure to low K+ medium but also decreased hERG expression and function in cells under normal culture conditions. We concluded that the recycling pathway plays an important role in the homeostasis of plasma membrane-bound hERG channels. PMID:26152716

A RAB3GAP1 SINE Insertion in Alaskan Huskies with Polyneuropathy, Ocular Abnormalities, and Neuronal Vacuolation (POANV Resembling Human Warburg Micro Syndrome 1 (WARBM1

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Michaela Wiedmer

2016-02-01

Full Text Available We observed a hereditary phenotype in Alaskan Huskies that was characterized by polyneuropathy with ocular abnormalities and neuronal vacuolation (POANV. The affected dogs developed a progressive severe ataxia, which led to euthanasia between 8 and 16 months of age. The pedigrees were consistent with a monogenic autosomal recessive inheritance. We localized the causative genetic defect to a 4 Mb interval on chromosome 19 by a combined linkage and homozygosity mapping approach. Whole genome sequencing of one affected dog, an obligate carrier, and an unrelated control revealed a 218-bp SINE insertion into exon 7 of the RAB3GAP1 gene. The SINE insertion was perfectly associated with the disease phenotype in a cohort of 43 Alaskan Huskies, and it was absent from 541 control dogs of diverse other breeds. The SINE insertion induced aberrant splicing and led to a transcript with a greatly altered exon 7. RAB3GAP1 loss-of-function variants in humans cause Warburg Micro Syndrome 1 (WARBM1, which is characterized by additional developmental defects compared to canine POANV, whereas Rab3gap1-deficient mice have a much milder phenotype than either humans or dogs. Thus, the RAB3GAP1 mutant Alaskan Huskies provide an interesting intermediate phenotype that may help to better understand the function of RAB3GAP1 in development. Furthermore, the identification of the presumed causative genetic variant will enable genetic testing to avoid the nonintentional breeding of affected dogs.

Host cell virus entry mediated by Australian bat lyssavirus G envelope glycoprotein occurs through a clathrin-mediated endocytic pathway that requires actin and Rab5.

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Weir, Dawn L; Laing, Eric D; Smith, Ina L; Wang, Lin-Fa; Broder, Christopher C

2014-02-27

Australian bat lyssavirus (ABLV), a rhabdovirus of the genus Lyssavirus which circulates in both pteropid fruit bats and insectivorous bats in mainland Australia, has caused three fatal human infections, the most recent in February 2013, manifested as acute neurological disease indistinguishable from clinical rabies. Rhabdoviruses infect host cells through receptor-mediated endocytosis and subsequent pH-dependent fusion mediated by their single envelope glycoprotein (G), but the specific host factors and pathways involved in ABLV entry have not been determined. ABLV internalization into HEK293T cells was examined using maxGFP-encoding recombinant vesicular stomatitis viruses (rVSV) that express ABLV G glycoproteins. A combination of chemical and molecular approaches was used to investigate the contribution of different endocytic pathways to ABLV entry. Dominant negative Rab GTPases were used to identify the endosomal compartment utilized by ABLV to gain entry into the host cell cytosol. Here we show that ABLV G-mediated entry into HEK293T cells was significantly inhibited by the dynamin-specific inhibitor dynasore, chlorpromazine, a drug that blocks clathrin-mediated endocytosis, and the actin depolymerizing drug latrunculin B. Over expression of dominant negative mutants of Eps15 and Rab5 also significantly reduced ABLV G-mediated entry into HEK293T cells. Chemical inhibitors of caveolae-dependent endocytosis and macropinocytosis and dominant negative mutants of Rab7 and Rab11 had no effect on ABLV entry. The predominant pathway utilized by ABLV for internalization into HEK293T cells is clathrin-and actin-dependent. The requirement of Rab5 for productive infection indicates that ABLV G-mediated fusion occurs within the early endosome compartment.

Characterization of the human GARP (Golgi associated retrograde protein) complex

International Nuclear Information System (INIS)

Liewen, Heike; Meinhold-Heerlein, Ivo; Oliveira, Vasco; Schwarzenbacher, Robert; Luo Guorong; Wadle, Andreas; Jung, Martin; Pfreundschuh, Michael; Stenner-Liewen, Frank

2005-01-01

The Golgi associated retrograde protein complex (GARP) or Vps fifty-three (VFT) complex is part of cellular inter-compartmental transport systems. Here we report the identification of the VFT tethering factor complex and its interactions in mammalian cells. Subcellular fractionation shows that human Vps proteins are found in the smooth membrane/Golgi fraction but not in the cytosol. Immunostaining of human Vps proteins displays a vesicular distribution most concentrated at the perinuclear envelope. Co-staining experiments with endosomal markers imply an endosomal origin of these vesicles. Significant accumulation of VFT complex positive endosomes is found in the vicinity of the Trans Golgi Network area. This is in accordance with a putative role in Golgi associated transport processes. In Saccharomyces cerevisiae, GARP is the main effector of the small GTPase Ypt6p and interacts with the SNARE Tlg1p to facilitate membrane fusion. Accordingly, the human homologue of Ypt6p, Rab6, specifically binds hVps52. In human cells, the 'orphan' SNARE Syntaxin 10 is the genuine binding partner of GARP mediated by hVps52. This reveals a previously unknown function of human Syntaxin 10 in membrane docking and fusion events at the Golgi. Taken together, GARP shows significant conservation between various species but diversification and specialization result in important differences in human cells

Smart I’rab: Smart Aplicasion for Arabic Grammar Learning

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Syd. Ali Zein Farmadi

2013-12-01

Full Text Available Arabic grammar, known as nahwu, is necessary to comprehend the Holy Qur’an that is completely written in Arabic. However, many people get trouble to study this skill because there are various kinds of word formation and sentences that may be created from a single verb, noun, adjective, subject, predicate, object, adverb or another formation. This research proposes a new approach to identify the position and word function in Arabic sentence. The approach creates smart process that employs Natural Language Processing (NLP and expert system with modeling based on knowledge and inference engine in determining the word position. The knowledge base determines the part of speech while the inference engine shows the word function in the sentence. On processing, the system uses 82 templates consisting of 34 verb templates, 34 subject pronouns, 14 pronouns for object or possessive word. All the templates are in the form of char array for harakat (vowel and letters which become the comparators for determining the part of speech from input word sentence. Output from the system is an i’rab (the explanation of word function in sentence written in Arabic. The system has been tested for 159 times to examine word and sentence. The examination for word that is done 117 times has not made any error except for the word that is really like another word. While the detection for word function in sentence that is done 42 times experiment, there is no error too. An error happens when the part of speech from the word being examined is not included in the system yet, influencing the following word function detection. Keywords: I’rab, Arabic grammar, NLP, expert system, knowledge base, inference engine

The EARP Complex and Its Interactor EIPR-1 Are Required for Cargo Sorting to Dense-Core Vesicles.

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Irini Topalidou

2016-05-01

Full Text Available The dense-core vesicle is a secretory organelle that mediates the regulated release of peptide hormones, growth factors, and biogenic amines. Dense-core vesicles originate from the trans-Golgi of neurons and neuroendocrine cells, but it is unclear how this specialized organelle is formed and acquires its specific cargos. To identify proteins that act in dense-core vesicle biogenesis, we performed a forward genetic screen in Caenorhabditis elegans for mutants defective in dense-core vesicle function. We previously reported the identification of two conserved proteins that interact with the small GTPase RAB-2 to control normal dense-core vesicle cargo-sorting. Here we identify several additional conserved factors important for dense-core vesicle cargo sorting: the WD40 domain protein EIPR-1 and the endosome-associated recycling protein (EARP complex. By assaying behavior and the trafficking of dense-core vesicle cargos, we show that mutants that lack EIPR-1 or EARP have defects in dense-core vesicle cargo-sorting similar to those of mutants in the RAB-2 pathway. Genetic epistasis data indicate that RAB-2, EIPR-1 and EARP function in a common pathway. In addition, using a proteomic approach in rat insulinoma cells, we show that EIPR-1 physically interacts with the EARP complex. Our data suggest that EIPR-1 is a new interactor of the EARP complex and that dense-core vesicle cargo sorting depends on the EARP-dependent trafficking of cargo through an endosomal sorting compartment.

Membranes linked by trans-SNARE complexes require lipids prone to non-bilayer structure for progression to fusion.

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Zick, Michael; Stroupe, Christopher; Orr, Amy; Douville, Deborah; Wickner, William T

2014-01-01

Like other intracellular fusion events, the homotypic fusion of yeast vacuoles requires a Rab GTPase, a large Rab effector complex, SNARE proteins which can form a 4-helical bundle, and the SNARE disassembly chaperones Sec17p and Sec18p. In addition to these proteins, specific vacuole lipids are required for efficient fusion in vivo and with the purified organelle. Reconstitution of vacuole fusion with all purified components reveals that high SNARE levels can mask the requirement for a complex mixture of vacuole lipids. At lower, more physiological SNARE levels, neutral lipids with small headgroups that tend to form non-bilayer structures (phosphatidylethanolamine, diacylglycerol, and ergosterol) are essential. Membranes without these three lipids can dock and complete trans-SNARE pairing but cannot rearrange their lipids for fusion. DOI: http://dx.doi.org/10.7554/eLife.01879.001.

Influence of UV and blue-light sun radiation to developing of age-related macular degeneration on Croatian Island Rab

International Nuclear Information System (INIS)

Vojnikovic, Bozo; Coklo, Miran; Ranogajec-Komor, Maria

2008-01-01

Full text: Croatian island Rab has one of the highest solar radiation in geographical area of Europe. The aim of this clinical trial was to estimate correlation between incidence of age-related macular degeneration (AMD) and the exposure to sunlight in different population on island Rab. In the first group agriculturists and fishermen were collected, in the second group members of the urban population were involved. 1753 individuals were investigated. The age in this population was between 40 and 73 years. The incidence of AMD in the first group was 19% while in the urban population only 2% showed AMD. It can be concluded that a very significant incidence exists between chronic exposure to sunlight and appearance of age-related macular degeneration. (author)

Respiration-dependent proton translocation in alkalophilic Bacillus firmus RAB and its non-alkalophilic mutant derivative.

Science.gov (United States)

Lewis, R J; Krulwich, T A; Reynafarje, B; Lehninger, A L

1983-02-25

Obligately alkalophilic Bacillus firmus RAB had a higher molar growth yield on L-malate (Ymal = 38 mg, dry weight/mmol of L-malate) than its non-alkalophilic mutant derivative, strain RABN (Ymal = 12 mg, dry weight/mmol of L-malate). Measurements of respiration dependent proton translocation by the two strains in the presence of K+ and valinomycin showed that the alkalophile also has much higher H+/O stoichiometries (at pH 9.0) than does the mutant (at pH 7.0). H+/O ratios for B. firmus RAB at pH 9.0 were as high as 13, with a frequently observed value of 9. These high values were observed in the first phase of a set of biphasic curves for both oxygen consumption and proton ejection. At pH 7.0, both the wild type and the mutant exhibited H+/O ratios near 4 in a single phase of oxygen consumption and proton ejection. The results are consistent with suggestions that the alkalophilic respiratory chain is especially well adapted for effective energy transduction at alkaline but not neutral pH.

The Rab-GTPase-activating protein TBC1D1 regulates skeletal muscle glucose metabolism

DEFF Research Database (Denmark)

Szekeres, Ferenc; Chadt, Alexandra; Tom, Robby Z

2012-01-01

The Rab-GTPase-activating protein TBC1D1 has emerged as a novel candidate involved in metabolic regulation. Our aim was to determine whether TBC1D1 is involved in insulin as well as energy-sensing signals controlling skeletal muscle metabolism. TBC1D1-deficient congenic B6.SJL-Nob1.10 (Nob1.10(SJL...... be explained partly by a 50% reduction in GLUT4 protein, since proximal signaling at the level of Akt, AMPK, and acetyl-CoA carboxylase (ACC) was unaltered. Paradoxically, in vivo insulin-stimulated 2-deoxyglucose uptake was increased in EDL and tibialis anterior muscle from TBC1D1-deficient mice......)) and wild-type littermates were studied. Glucose and insulin tolerance, glucose utilization, hepatic glucose production, and tissue-specific insulin-mediated glucose uptake were determined. The effect of insulin, AICAR, or contraction on glucose transport was studied in isolated skeletal muscle. Glucose...

A Small Ras-like protein Ray/Rab1c modulates the p53-regulating activity of PRPK

International Nuclear Information System (INIS)

Abe, Yasuhito; Takeuchi, Takashi; Imai, Yoshinori; Murase, Ryuichi; Kamei, Yoshiaki; Fujibuchi, Taketsugu; Matsumoto, Suguru; Ueda, Norifumi; Ogasawara, Masahito; Shigemoto, Kazuhiro; Kito, Katsumi

2006-01-01

PRPK phosphorylates serine-15 residue of p53 and enhances transcriptional activity. PRPK possesses a bipartite nuclear localization signal and localizes in nucleus when over-expressed in cells. However, intrinsic PRPK localizes mainly in the cytosol in situ. While studying the mechanisms in the distribution of intrinsic PRPK, we identified a PRPK binding protein, an ubiquitously expressed Small Ras-like GTPase, Rab1c, also named Ray or Rab35. The over-expressed Ray was distributed in the nucleus, cytosol, and cell membrane. Both Ray wild type and GTP-restrictively binding mutant Ray-Q67L, but not guanine nucleotide unstable binding mutant Ray-N120I, partially distributed the over-expressed PRPK to the cytosol and also suppressed the PRPK-induced p53-transcriptional activity profoundly. A Small Ras-like GTPase protein Ray was thus indicated to modulate p53 transcriptional activity of PRPK

Crystal structures of bis- and hexakis[(6,6′-dihydroxybipyridinecopper(II] nitrate coordination complexes

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Deidra L. Gerlach

2015-12-01

Full Text Available Two multinuclear complexes synthesized from Cu(NO32 and 6,6′-dihydroxybipyridine (dhbp exhibit bridging nitrate and hydroxide ligands. The dinuclear complex (6,6′-dihydroxybipyridine-2κ2N,N′[μ-6-(6-hydroxypyridin-2-ylpyridin-2-olato-1:2κ3N,N′:O2](μ-hydroxido-1:2κ2O:O′(μ-nitrato-1:2κ2O:O′(nitrato-1κOdicopper(II, [Cu2(C10H7N2O2(OH(NO32(C10H8N2O2] or [Cu(6-OH-6′-O-bpy(NO3(μ-OH(μ-NO3Cu(6,6′-dhbp], (I, with a 2:1 ratio of nitrate to hydroxide anions and one partially deprotonated dhbp ligand, forms from a water–ethanol mixture at neutral pH. The hexanuclear complex bis(μ3-bipyridine-2,2′-diolato-κ3O:N,N′:O′tetrakis(6,6′-dihydroxybipyridine-κ2N,N′tetrakis(μ-hydroxido-κ2O:O′bis(methanol-κOtetrakis(μ-nitrato-κ2O:O′hexacopper(II, [Cu6(C10H6N2O22(CH4O2(OH4(NO34(C10H8N2O24] or [Cu(6,6′-dhbp(μ-NO32(μ-OHCu(6,6′-O-bpy(μ-OHCu(6,6′dhbp(CH3OH]2, (II, with a 1:1 NO3–OH ratio and two fully protonated and fully deprotonated dhbp ligands, was obtained by methanol recrystallization of material obtained at pH 3. Complex (II lies across an inversion center. Complexes (I and (II both display intramolecular O—H...O hydrogen bonding. Intermolecular O—H...O hydrogen bonding links symmetry-related molecules forming chains along [100] for complex (I with π-stacking along [010] and [001]. Complex (II forms intermolecular O—H...O hydrogen-bonded chains along [010] with π-stacking along [100] and [001].

A genome-wide association scan (GWAS) for mean telomere length within the COGS project: identified loci show little association with hormone-related cancer risk

OpenAIRE

Pooley, K. A.; Bojesen, S. E.; Weischer, M.; Nielsen, S. F.; Thompson, D.; Amin Al Olama, A.; Michailidou, K.; Tyrer, J. P.; Benlloch, S.; Brown, J.; Audley, T.; Luben, R.; Khaw, K.-T.; Neal, D. E.; Hamdy, F. C.

2013-01-01

Mean telomere length (TL) in blood cells is heritable and has been reported to be associated with risks of several diseases, including cancer. We conducted a meta-analysis of three GWAS for TL (total n=2240) and selected 1629 variants for replication via the ?iCOGS? custom genotyping array. All ?200 000 iCOGS variants were analysed with TL, and those displaying associations in healthy controls (n = 15 065) were further tested in breast cancer cases (n = 11 024). We found a novel TL associatio...

HIV-1 Nef binds with human GCC185 protein and regulates mannose 6 phosphate receptor recycling

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Kumar, Manjeet; Kaur, Supinder; Nazir, Aamir; Tripathi, Raj Kamal, E-mail: rajkamalcdri@gmail.com

2016-05-20

HIV-1 Nef modulates cellular function that enhances viral replication in vivo which culminate into AIDS pathogenesis. With no enzymatic activity, Nef regulates cellular function through host protein interaction. Interestingly, trans-cellular introduction of recombinant Nef protein in Caenorhabditis elegans results in AIDS like pathogenesis which might share common pathophysiology because the gene sequence of C. elegans and humans share considerable homology. Therefore employing C. elegans based initial screen complemented with sequence based homology search we identified GCC185 as novel host protein interacting with HIV-1 Nef. The detailed molecular characterization revealed N-terminal EEEE{sub 65} acidic domain of Nef as key region for interaction. GCC185 is a tethering protein that binds with Rab9 transport vesicles. Our results show that Nef-GCC185 interaction disrupts Rab9 interaction resulting in delocalization of CI-MPR (cation independent Mannose 6 phosphate receptor) resulting in elevated secretion of hexosaminidase. In agreement with this, our studies identified novel host GCC185 protein that interacts with Nef EEEE65 acidic domain interfering GCC185-Rab9 vesicle membrane fusion responsible for retrograde vesicular transport of CI-MPR from late endosomes to TGN. In light of existing report suggesting critical role of Nef-GCC185 interaction reveals valuable mechanistic insights affecting specific protein transport pathway in docking of late endosome derived Rab9 bearing transport vesicle at TGN elucidating role of Nef during viral pathogenesis. -- Highlights: •Nef, an accessory protein of HIV-1 interacts with host factor and culminates into AIDS pathogenesis. •Using Caenorhabditis elegans based screen system, novel Nef interacting cellular protein GCC185 was identified. •Molecular characterization of Nef and human protein GCC185 revealed Nef EEEE{sub 65} key region interacted with full length GCC185. •Nef impeded the GCC185-Rab 9 interaction and

Screening for Dementia in Older Adults: Comparison of Mini-Mental State Examination, Mini-Cog, Clock Drawing Test and AD8.

Science.gov (United States)

Yang, Li; Yan, Jing; Jin, Xiaoqing; Jin, Yu; Yu, Wei; Xu, Shanhu; Wu, Haibin

2016-01-01

This study was conducted to estimate screening performance of dementia screening tools including Mini-Mental State Examination (MMSE), Mini-Cog, Clock Drawing Test (CDT) and Ascertain Dementia 8 questionnaire (AD8) for older adults. 2015 participants aged 65 years or more in eastern China were enrolled. 4 screening tests were administered and scored by specifically trained psychiatrists. We used data from two-by-two tables to calculate the sensitivity, specificity, and positive and negative predictive values (PPV/NPV). Our study showed that dementia was highly prevalent among elderly in Zhejiang province. The Mini-Cog, with excellent screening characteristics and spending less time, could be considered to be used as a screening tool among communities to help to diagnose dementia early.

The N-terminal domains of Vps3 and Vps8 are critical for localization and function of the CORVET tethering complex on endosomes.

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Nadine Epp

Full Text Available Endosomal biogenesis depends on multiple fusion and fission events. For fusion, the heterohexameric CORVET complex as an effector of the endosomal Rab5/Vps21 GTPase has a central function in the initial tethering event. Here, we show that the CORVET-specific Vps3 and Vps8 subunits, which interact with Rab5/Vps21, require their N-terminal domains for localization and function. Surprisingly, CORVET may lack either one of the two N-terminal domains, but not both, to promote protein sorting via the endosome. The dually truncated complex mislocalizes to the cytosol and is impaired in endocytic protein sorting, but not in assembly. Furthermore, the endosomal localization can be rescued by overexpression of Vps21 or one of the truncated CORVET subunits, even though CORVET assembly is not impaired by loss of the N-terminal domains or in strains lacking all endosomal Rab5s and Ypt7. We thus conclude that CORVET requires only its C-terminal domains for assembly and has beyond its putative β-propeller domains additional binding sites for endosomes, which could be important to bind Vps21 and other endosome-specific factors for efficient endosome tethering.

Rab9-dependent autophagy is required for the IGF-IIR triggering mitophagy to eliminate damaged mitochondria.

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Huang, Chih-Yang; Kuo, Wei-Wen; Ho, Tsung-Jung; Chiang, Shu-Fen; Pai, Pei-Ying; Lin, Jing-Ying; Lin, Ding-Yu; Kuo, Chia-Hua; Huang, Chih-Yang

2018-03-25

Mitochondria dysfunction is the major characteristic of mitophagy, which is essential in mitochondrial quality control. However, excessive mitophagy contributes to cell death in a number of diseases, including ischemic stroke and hepatotoxicity. Insulin-like growth factor II (IGF-II) and its receptor (IGF-IIR) play vital roles in the development of heart failure during hypertension. We found that IGF-II triggers IGF-IIR receptor activation, causing mitochondria dysfunction, resulting in mitophagy, and cardiomyocyte cell death. These results indicated that IGF-IIR activation triggers mitochondria fragmentation, leading to autophagosome formation, and loss of mitochondria content. These results are associated with Parkin-dependent mitophagy. Additionally, autophagic proteins Atg5, and Atg7 deficiency did not suppress IGF-IIR-induced mitophagy. However, Rab9 knockdown reduced mitophagy and maintained mitochondrial function. These constitutive mitophagies through IGF-IIR activation trigger mitochondria loss and mitochondrial ROS accumulation for cardiomyocyte viability decrease. Together, our results indicate that IGF-IIR predominantly induces mitophagy through the Rab9-dependent alternative autophagy. © 2018 Wiley Periodicals, Inc.

Commentary on "identification of 23 new prostate cancer susceptibility loci using the iCOGS custom genotyping array." COGS-Cancer Research UK GWAS-ELLIPSE (part of GAME-ON) Initiative; Australian Prostate Cancer Bioresource; UK Genetic Prostate Cancer Study Collaborators/British Association

DEFF Research Database (Denmark)

Olumi, Aria F; Nordestgaard, Børge G.

2014-01-01

Prostate cancer is the most frequently diagnosed cancer in males in developed countries. To identify common prostate cancer susceptibility alleles, we genotyped 211,155 SNPs on a custom Illumina array (iCOGS) in blood DNA from 25,074 prostate cancer cases and 24,272 controls from the internationa...

Incremental Criterion Validity of the WJ-III COG Clinical Clusters: Marginal Predictive Effects beyond the General Factor

Science.gov (United States)

McGill, Ryan J.

2015-01-01

The current study examined the incremental validity of the clinical clusters from the Woodcock-Johnson III Tests of Cognitive Abilities (WJ-III COG) for predicting scores on the Woodcock-Johnson III Tests of Achievement (WJ-III ACH). All participants were children and adolescents (N = 4,722) drawn from the nationally representative WJ-III…

The RabGAP TBC1D1 plays a central role in exercise-regulated glucose metabolism in skeletal muscle

DEFF Research Database (Denmark)

Stöckli, Jacqueline; Meoli, Christopher C; Hoffman, Nolan J

2015-01-01

Insulin and exercise stimulate glucose uptake into skeletal muscle via different pathways. Both stimuli converge on the translocation of the glucose transporter GLUT4 from intracellular vesicles to the cell surface. Two Rab guanosine triphosphatases-activating proteins (GAPs) have been implicated...... weight, insulin action, and exercise. TBC1D1(-/-) mice showed normal glucose and insulin tolerance, with no difference in body weight compared with wild-type littermates. GLUT4 protein levels were reduced by ∼40% in white TBC1D1(-/-) muscle, and TBC1D1(-/-) mice showed impaired exercise endurance...... together with impaired exercise-mediated 2-deoxyglucose uptake into white but not red muscles. These findings indicate that the RabGAP TBC1D1 plays a key role in regulating GLUT4 protein levels and in exercise-mediated glucose uptake in nonoxidative muscle fibers....

The archaeal COG1901/DUF358 SPOUT-methyltransferase members, together with pseudouridine synthase Pus10, catalyze the formation of 1-methylpseudouridine at position 54 of tRNA

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Chatterjee, Kunal; Blaby, Ian K.; Thiaville, Patrick C.; Majumder, Mrinmoyee; Grosjean, Henri; Yuan, Y. Adam; Gupta, Ramesh; de Crécy-Lagard, Valérie

2012-01-01

The methylation of pseudouridine (Ψ) at position 54 of tRNA, producing m1Ψ, is a hallmark of many archaeal species, but the specific methylase involved in the formation of this modification had yet to be characterized. A comparative genomics analysis had previously identified COG1901 (DUF358), part of the SPOUT superfamily, as a candidate for this missing methylase family. To test this prediction, the COG1901 encoding gene, HVO_1989, was deleted from the Haloferax volcanii genome. Analyses of modified base contents indicated that while m1Ψ was present in tRNA extracted from the wild-type strain, it was absent from tRNA extracted from the mutant strain. Expression of the gene encoding COG1901 from Halobacterium sp. NRC-1, VNG1980C, complemented the m1Ψ minus phenotype of the ΔHVO_1989 strain. This in vivo validation was extended with in vitro tests. Using the COG1901 recombinant enzyme from Methanocaldococcus jannaschii (Mj1640), purified enzyme Pus10 from M. jannaschii and full-size tRNA transcripts or TΨ-arm (17-mer) fragments as substrates, the sequential pathway of m1Ψ54 formation in Archaea was reconstituted. The methylation reaction is AdoMet dependent. The efficiency of the methylase reaction depended on the identity of the residue at position 55 of the TΨ-loop. The presence of Ψ55 allowed the efficient conversion of Ψ54 to m1Ψ54, whereas in the presence of C55, the reaction was rather inefficient and no methylation reaction occurred if a purine was present at this position. These results led to renaming the Archaeal COG1901 members as TrmY proteins. PMID:22274953

Non-Rhabdomyosarcoma Soft Tissue Sarcomas in Children: A Surveillance, Epidemiology, and End Results Analysis Validating COG Risk Stratifications

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Waxweiler, Timothy V., E-mail: timothy.waxweiler@ucdenver.edu [Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, Colorado (United States); Rusthoven, Chad G. [Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, Colorado (United States); Proper, Michelle S. [Department of Radiation Oncology, Billings Clinic, Billings, Montana (United States); Cost, Carrye R. [Division of Hematology and Oncology, Department of Pediatrics, University of Colorado Denver School of Medicine, Aurora, Colorado (United States); Cost, Nicholas G. [Division of Urology, Department of Surgery, University of Colorado Denver School of Medicine, Aurora, Colorado (United States); Donaldson, Nathan [Department of Orthopedics, University of Colorado Denver School of Medicine, Aurora, Colorado (United States); Garrington, Timothy; Greffe, Brian S. [Division of Hematology and Oncology, Department of Pediatrics, University of Colorado Denver School of Medicine, Aurora, Colorado (United States); Heare, Travis [Department of Orthopedics, University of Colorado Denver School of Medicine, Aurora, Colorado (United States); Macy, Margaret E. [Division of Hematology and Oncology, Department of Pediatrics, University of Colorado Denver School of Medicine, Aurora, Colorado (United States); Liu, Arthur K. [Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, Colorado (United States)

2015-06-01

Purpose: Non-rhabdomyosarcoma soft tissue sarcomas (NRSTS) are a heterogeneous group of sarcomas that encompass over 35 histologies. With an incidence of ∼500 cases per year in the United States in those <20 years of age, NRSTS are rare and therefore difficult to study in pediatric populations. We used the large Surveillance, Epidemiology, and End Results (SEER) database to validate the prognostic ability of the Children's Oncology Group (COG) risk classification system and to define patient, tumor, and treatment characteristics. Methods and Materials: From SEER data from 1988 to 2007, we identified patients ≤18 years of age with NRSTS. Data for age, sex, year of diagnosis, race, registry, histology, grade, primary size, primary site, stage, radiation therapy, and survival outcomes were analyzed. Patients with nonmetastatic grossly resected low-grade tumors of any size or high-grade tumors ≤5 cm were considered low risk. Cases of nonmetastatic tumors that were high grade, >5 cm, or unresectable were considered intermediate risk. Patients with nodal or distant metastases were considered high risk. Results: A total of 941 patients met the review criteria. On univariate analysis, black race, malignant peripheral nerve sheath (MPNST) histology, tumors >5 cm, nonextremity primary, lymph node involvement, radiation therapy, and higher risk group were associated with significantly worse overall survival (OS) and cancer-specific survival (CSS). On multivariate analysis, MPNST histology, chemotherapy-resistant histology, and higher risk group were significantly poor prognostic factors for OS and CSS. Compared to low-risk patients, intermediate patients showed poorer OS (hazard ratio [HR]: 6.08, 95% confidence interval [CI]: 3.53-10.47, P<.001) and CSS (HR: 6.27; 95% CI: 3.44-11.43, P<.001), and high-risk patients had the worst OS (HR: 13.35, 95% CI: 8.18-21.76, P<.001) and CSS (HR: 14.65, 95% CI: 8.49-25.28, P<.001). Conclusions: The current COG risk group

Should Community College Be Free? Forum. "Education Next" Talks with Sara Goldrick-Rab and Andrew P. Kelly

Science.gov (United States)

Goldrick-Rab, Sara; Kelly, Andrew P.

2016-01-01

In this article, "Education Next" talks with Sara Goldrick-Rab and Andrew Kelly. President Obama's proposal for tuition-free community college, seems to have laid down a marker for the Democratic Party. Vermont senator Bernie Sanders is touting his plan for free four-year public college on the primary trail; Massachusetts senator…