Processing and turnover of the Hedgehog protein in the endoplasmic reticulum.

Science.gov (United States)

Chen, Xin; Tukachinsky, Hanna; Huang, Chih-Hsiang; Jao, Cindy; Chu, Yue-Ru; Tang, Hsiang-Yun; Mueller, Britta; Schulman, Sol; Rapoport, Tom A; Salic, Adrian

2011-03-07

The Hedgehog (Hh) signaling pathway has important functions during metazoan development. The Hh ligand is generated from a precursor by self-cleavage, which requires a free cysteine in the C-terminal part of the protein and results in the production of the cholesterol-modified ligand and a C-terminal fragment. In this paper, we demonstrate that these reactions occur in the endoplasmic reticulum (ER). The catalytic cysteine needs to form a disulfide bridge with a conserved cysteine, which is subsequently reduced by protein disulfide isomerase. Generation of the C-terminal fragment is followed by its ER-associated degradation (ERAD), providing the first example of an endogenous luminal ERAD substrate that is constitutively degraded. This process requires the ubiquitin ligase Hrd1, its partner Sel1, the cytosolic adenosine triphosphatase p97, and degradation by the proteasome. Processing-defective mutants of Hh are degraded by the same ERAD components. Thus, processing of the Hh precursor competes with its rapid degradation, explaining the impaired Hh signaling of processing-defective mutants, such as those causing human holoprosencephaly.

ER-associated degradation is required for vasopressin prohormone processing and systemic water homeostasis

Science.gov (United States)

Somlo, Diane R.M.; Kim, Geun Hyang; Prescianotto-Baschong, Cristina; Sun, Shengyi; Beuret, Nicole; Long, Qiaoming; Rutishauser, Jonas

2017-01-01

Peptide hormones are crucial regulators of many aspects of human physiology. Mutations that alter these signaling peptides are associated with physiological imbalances that underlie diseases. However, the conformational maturation of peptide hormone precursors (prohormones) in the ER remains largely unexplored. Here, we report that conformational maturation of proAVP, the precursor for the antidiuretic hormone arginine-vasopressin, within the ER requires the ER-associated degradation (ERAD) activity of the Sel1L-Hrd1 protein complex. Serum hyperosmolality induces expression of both ERAD components and proAVP in AVP-producing neurons. Mice with global or AVP neuron–specific ablation of Se1L-Hrd1 ERAD progressively developed polyuria and polydipsia, characteristics of diabetes insipidus. Mechanistically, we found that ERAD deficiency causes marked ER retention and aggregation of a large proportion of all proAVP protein. Further, we show that proAVP is an endogenous substrate of Sel1L-Hrd1 ERAD. The inability to clear misfolded proAVP with highly reactive cysteine thiols in the absence of Sel1L-Hrd1 ERAD causes proAVP to accumulate and participate in inappropriate intermolecular disulfide–bonded aggregates, promoted by the enzymatic activity of protein disulfide isomerase (PDI). This study highlights a pathway linking ERAD to prohormone conformational maturation in neuroendocrine cells, expanding the role of ERAD in providing a conducive ER environment for nascent proteins to reach proper conformation. PMID:28920920

A pro-cathepsin L mutant is a luminal substrate for endoplasmic-reticulum-associated degradation in C. elegans.

Directory of Open Access Journals (Sweden)

Mark T Miedel

Full Text Available Endoplasmic-reticulum associated degradation (ERAD is a major cellular misfolded protein disposal pathway that is well conserved from yeast to mammals. In yeast, a mutant of carboxypeptidase Y (CPY* was found to be a luminal ER substrate and has served as a useful marker to help identify modifiers of the ERAD pathway. Due to its ease of genetic manipulation and the ability to conduct a genome wide screen for modifiers of molecular pathways, C. elegans has become one of the preferred metazoans for studying cell biological processes, such as ERAD. However, a marker of ERAD activity comparable to CPY* has not been developed for this model system. We describe a mutant of pro-cathepsin L fused to YFP that no longer targets to the lysosome, but is efficiently eliminated by the ERAD pathway. Using this mutant pro-cathepsin L, we found that components of the mammalian ERAD system that participate in the degradation of ER luminal substrates were conserved in C. elegans. This transgenic line will facilitate high-throughput genetic or pharmacological screens for ERAD modifiers using widefield epifluorescence microscopy.

The Unfolded Protein Response Is Induced by the Cell Wall Integrity Mitogen-activated Protein Kinase Signaling Cascade and Is Required for Cell Wall Integrity in Saccharomyces cerevisiae

OpenAIRE

Scrimale, Thomas; Didone, Louis; de Mesy Bentley, Karen L.; Krysan, Damian J.

2009-01-01

The yeast cell wall is an extracellular structure that is dependent on secretory and membrane proteins for its construction. We investigated the role of protein quality control mechanisms in cell wall integrity and found that the unfolded protein response (UPR) and, to a lesser extent, endoplasmic reticulum (ER)-associated degradation (ERAD) pathways are required for proper cell wall construction. Null mutation of IRE1, double mutation of ERAD components (hrd1Δ and ubc7Δ) and ire1Δ, or expres...

The C-terminal amino acid of the MHC-I heavy chain is critical for binding to Derlin-1 in human cytomegalovirus US11-induced MHC-I degradation.

Science.gov (United States)

Cho, Sunglim; Kim, Bo Young; Ahn, Kwangseog; Jun, Youngsoo

2013-01-01

Derlin-1 plays a critical role in endoplasmic reticulum-associated protein degradation (ERAD) of a particular subset of proteins. Although it is generally accepted that Derlin-1 mediates the export of ERAD substrates from the ER to the cytosol, little is known about how Derlin-1 interacts with these substrates. Human cytomegalovirus (HCMV) US11 exploits Derlin-1-dependent ERAD to degrade major histocompatibility complex class I (MHC-I) molecules and evade immune surveillance. US11 requires the cytosolic tail of the MHC-I heavy chain to divert MHC-I molecules into the ERAD pathway for degradation; however, the underlying mechanisms remain unknown. Here, we show that the cytosolic tail of the MHC-I heavy chain, although not required for interaction with US11, is required for tight binding to Derlin-1 and thus for US11-induced dislocation of the MHC-I heavy chain to the cytosol for proteasomal degradation. Surprisingly, deletion of a single C-terminal amino acid from the cytosolic tail disrupted the interaction between MHC-I molecules and Derlin-1, rendering mutant MHC-I molecules resistant to US11-induced degradation. Consistently, deleting the C-terminal cytosolic region of Derlin-1 prevented it from binding to MHC-I molecules. Taken together, these results suggest that the cytosolic region of Derlin-1 is involved in ERAD substrate binding and that this interaction is critical for the Derlin-1-mediated dislocation of the MHC-I heavy chain to the cytosol during US11-induced MHC-I degradation.

Endoplasmic Reticulum-Targeted Subunit Toxins Provide a New Approach to Rescue Misfolded Mutant Proteins and Revert Cell Models of Genetic Diseases.

Science.gov (United States)

Adnan, Humaira; Zhang, Zhenbo; Park, Hyun-Joo; Tailor, Chetankumar; Che, Clare; Kamani, Mustafa; Spitalny, George; Binnington, Beth; Lingwood, Clifford

2016-01-01

Many germ line diseases stem from a relatively minor disturbance in mutant protein endoplasmic reticulum (ER) 3D assembly. Chaperones are recruited which, on failure to correct folding, sort the mutant for retrotranslocation and cytosolic proteasomal degradation (ER-associated degradation-ERAD), to initiate/exacerbate deficiency-disease symptoms. Several bacterial (and plant) subunit toxins, retrograde transport to the ER after initial cell surface receptor binding/internalization. The A subunit has evolved to mimic a misfolded protein and hijack the ERAD membrane translocon (dislocon), to effect cytosolic access and cytopathology. We show such toxins compete for ERAD to rescue endogenous misfolded proteins. Cholera toxin or verotoxin (Shiga toxin) containing genetically inactivated (± an N-terminal polyleucine tail) A subunit can, within 2-4 hrs, temporarily increase F508delCFTR protein, the major cystic fibrosis (CF) mutant (5-10x), F508delCFTR Golgi maturation (glucocerobrosidase (GCC) in N370SGCC Gaucher Disease fibroblasts (3x), another ERAD-exacerbated misfiling disease. We identify a new, potentially benign approach to the treatment of certain genetic protein misfolding diseases.

AAA-ATPases in Protein Degradation

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Ravikiran S. Yedidi

2017-06-01

Full Text Available Proteolytic machineries containing multisubunit protease complexes and AAA-ATPases play a key role in protein quality control and the regulation of protein homeostasis. In these protein degradation machineries, the proteolytically active sites are formed by either threonines or serines which are buried inside interior cavities of cylinder-shaped complexes. In eukaryotic cells, the proteasome is the most prominent protease complex harboring AAA-ATPases. To degrade protein substrates, the gates of the axial entry ports of the protease need to be open. Gate opening is accomplished by AAA-ATPases, which form a hexameric ring flanking the entry ports of the protease. Protein substrates with unstructured domains can loop into the entry ports without the assistance of AAA-ATPases. However, folded proteins require the action of AAA-ATPases to unveil an unstructured terminus or domain. Cycles of ATP binding/hydrolysis fuel the unfolding of protein substrates which are gripped by loops lining up the central pore of the AAA-ATPase ring. The AAA-ATPases pull on the unfolded polypeptide chain for translocation into the proteolytic cavity of the protease. Conformational changes within the AAA-ATPase ring and the adjacent protease chamber create a peristaltic movement for substrate degradation. The review focuses on new technologies toward the understanding of the function and structure of AAA-ATPases to achieve substrate recognition, unfolding and translocation into proteasomes in yeast and mammalian cells and into proteasome-equivalent proteases in bacteria and archaea.

AAA-ATPases in Protein Degradation.

Science.gov (United States)

Yedidi, Ravikiran S; Wendler, Petra; Enenkel, Cordula

2017-01-01

Proteolytic machineries containing multisubunit protease complexes and AAA-ATPases play a key role in protein quality control and the regulation of protein homeostasis. In these protein degradation machineries, the proteolytically active sites are formed by either threonines or serines which are buried inside interior cavities of cylinder-shaped complexes. In eukaryotic cells, the proteasome is the most prominent protease complex harboring AAA-ATPases. To degrade protein substrates, the gates of the axial entry ports of the protease need to be open. Gate opening is accomplished by AAA-ATPases, which form a hexameric ring flanking the entry ports of the protease. Protein substrates with unstructured domains can loop into the entry ports without the assistance of AAA-ATPases. However, folded proteins require the action of AAA-ATPases to unveil an unstructured terminus or domain. Cycles of ATP binding/hydrolysis fuel the unfolding of protein substrates which are gripped by loops lining up the central pore of the AAA-ATPase ring. The AAA-ATPases pull on the unfolded polypeptide chain for translocation into the proteolytic cavity of the protease. Conformational changes within the AAA-ATPase ring and the adjacent protease chamber create a peristaltic movement for substrate degradation. The review focuses on new technologies toward the understanding of the function and structure of AAA-ATPases to achieve substrate recognition, unfolding and translocation into proteasomes in yeast and mammalian cells and into proteasome-equivalent proteases in bacteria and archaea.

Sterol homeostasis requires regulated degradation of squalene monooxygenase by the ubiquitin ligase Doa10/Teb4

DEFF Research Database (Denmark)

Foresti, Ombretta; Ruggiano, Annamaria; Hannibal-Bach, Hans K

2013-01-01

Sterol homeostasis is essential for the function of cellular membranes and requires feedback inhibition of HMGR, a rate-limiting enzyme of the mevalonate pathway. As HMGR acts at the beginning of the pathway, its regulation affects the synthesis of sterols and of other essential mevalonate......-derived metabolites, such as ubiquinone or dolichol. Here, we describe a novel, evolutionarily conserved feedback system operating at a sterol-specific step of the mevalonate pathway. This involves the sterol-dependent degradation of squalene monooxygenase mediated by the yeast Doa10 or mammalian Teb4, a ubiquitin...... ligase implicated in a branch of the endoplasmic reticulum (ER)-associated protein degradation (ERAD) pathway. Since the other branch of ERAD is required for HMGR regulation, our results reveal a fundamental role for ERAD in sterol homeostasis, with the two branches of this pathway acting together...

Impact of protein uptake and degradation on recombinant protein secretion in yeast

DEFF Research Database (Denmark)

Tyo, Keith E. J.; Liu, Zihe; Magnusson, Ylva

2014-01-01

Protein titers, a key bioprocessing metric, depend both on the synthesis of protein and the degradation of protein. Secreted recombinant protein production in Saccharomyces cerevisiae is an attractive platform as minimal media can be used for cultivation, thus reducing fermentation costs...... and transcriptomics, we identify metabolic and regulatory markers that are consistent with uptake of whole proteins by endocytosis, followed by intracellular degradation and catabolism of substituent amino acids. Uptake and degradation of recombinant protein products may be common in S. cerevisiae protein secretion...... and simplifying downstream purification, compared to other systems that require complex media. As such, engineering S. cerevisiae to improve titers has been then the subject of significant attention, but the majority of previous efforts have been focused on improving protein synthesis. Here, we characterize...

Model for Stress-induced Protein Degradation in Lemna minor1

Science.gov (United States)

Cooke, Robert J.; Roberts, Keith; Davies, David D.

1980-01-01

Transfer of Lemna minor fronds to adverse or stress conditions produces a large increase in the rate of protein degradation. Cycloheximide partially inhibits stress-induced protein degradation and also partially inhibits the protein degradation which occurs in the absence of stress. The increased protein degradation does not appear to be due to an increase in activity of soluble proteolytic enzymes. Biochemical evidence indicates that stress, perhaps acting via hormones, affects the permeability of certain membranes, particularly the tonoplast. A general model for stress-induced protein degradation is presented in which changes in membrane properties allow vacuolar proteolytic enzymes increased access to cytoplasmic proteins. PMID:16661588

EDEM2 and OS-9 are required for ER-associated degradation of non-glycosylated sonic hedgehog.

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Hsiang-Yun Tang

Full Text Available Misfolded proteins of the endoplasmic reticulum (ER are eliminated by the ER-associated degradation (ERAD in eukaryotes. In S. cerevisiae, ER-resident lectins mediate substrate recognition through bipartite signals consisting of an unfolded local structure and the adjacent glycan. Trimming of the glycan is essential for the directional delivery of the substrates. Whether a similar recognition and delivery mechanism exists in mammalian cells is unknown. In this study, we systematically study the function and substrate specificity of known mammalian ER lectins, including EDEM1/2/3, OS-9 and XTP-3B using the recently identified ERAD substrate sonic hedgehog (SHH, a soluble protein carrying a single N-glycan, as well as its nonglycosylated mutant N278A. Efficient ERAD of N278A requires the core processing complex of HRD1, SEL1L and p97, similar to the glycosylated SHH. While EDEM2 was required for ERAD of both glycosylated and non-glycosylated SHHs, EDEM3 was only necessary for glycosylated SHH and EDEM1 was dispensable for both. Degradation of SHH and N278A also required OS-9, but not the related lectin XTP3-B. Robust interaction of both EDEM2 and OS-9 with a non-glycosylated SHH variant indicates that the misfolded polypeptide backbone, rather than a glycan signature, functions as the predominant signal for recognition for ERAD. Notably, SHH-N278A is the first nonglycosylated substrate to require EDEM2 for recognition and targeting for ERAD. EDEM2 also interacts with calnexin and SEL1L, suggesting a potential avenue by which misfolded glycoproteins may be shunted towards SEL1L and ERAD rather than being released into the secretory pathway. Thus, ER lectins participate in the recognition and delivery of misfolded ER substrates differently in mammals, with an underlying mechanism distinct from that of S. cerevisiae.

Cytosolic protein quality control of the orphan protein Fas2, a novel physiological substrate of the E3 ligase Ubr1

OpenAIRE

Scazzari, Mario

2013-01-01

Cellular protein quality control (PQC) monitors the proper folding of polypeptides, assembly of protein subunits into protein complexes as well as the delivery of terminally misfolded proteins to degradation. The components of PQC known best at the moment are molecular chaperones and the ubiquitin proteasome system. In contrast to the well-described protein quality control system of the endoplasmic reticulum (ERAD), less is known about how misfolded proteins in the cytosol are recognized and ...

Cellular proteostasis: degradation of misfolded proteins by lysosomes

Science.gov (United States)

Jackson, Matthew P.

2016-01-01

Proteostasis refers to the regulation of the cellular concentration, folding, interactions and localization of each of the proteins that comprise the proteome. One essential element of proteostasis is the disposal of misfolded proteins by the cellular pathways of protein degradation. Lysosomes are an important site for the degradation of misfolded proteins, which are trafficked to this organelle by the pathways of macroautophagy, chaperone-mediated autophagy and endocytosis. Conversely, amyloid diseases represent a failure in proteostasis, in which proteins misfold, forming amyloid deposits that are not degraded effectively by cells. Amyloid may then exacerbate this failure by disrupting autophagy and lysosomal proteolysis. However, targeting the pathways that regulate autophagy and the biogenesis of lysosomes may present approaches that can rescue cells from the deleterious effects of amyloidogenic proteins. PMID:27744333

Dissection of membrane protein degradation mechanisms by reversible inhibitors

International Nuclear Information System (INIS)

Hare, J.F.

1988-01-01

The degradation of slowly turning over 125I-lactoperoxidase-labeled plasma membrane polypeptides in response to reversible temperature and lysosomotropic inhibitors was studied in rat hepatoma cultures. Cells were radiolabeled and left for 24 h to allow the removal of rapidly degraded proteins. Remaining trichloroacetic acid-precipitable protein was degraded (t 1/2 = 40-68 h) by an apparent first order process 60-86% sensitive to 10 mM NH4Cl or 5 mM methylamine and greater than 95% inhibited by temperature reduction to 18 degrees C. Thus, membrane proteins are selected for degradation in a time-dependent manner by a system which is sensitive to both 18 degrees C and to lysosomotropic amines. When inhibitory conditions were removed after 40-48 h, degradation of 125I-labeled protein resumed at the same rate as that seen in their absence. Since membrane proteins do not exhibit accelerated degradation after removal of inhibitory conditions, there can be no marking or sorting of those proteins destined for degradation during the 40-h exposure to inhibitory conditions. Exposure to amines or 18 degrees C did not affect the position of two-dimensionally resolved labeled polypeptides. Fractionation of labeled cells on Percoll gradients after 40 h of exposure to low temperature or amines showed that labeled protein remained in the plasma membrane fractions of the gradient although shifted to a slightly lower buoyant density in the presence of amines. These results support the notion that selection of plasma membrane proteins for degradation requires their internalization into acidic vesicles. Lysosomotropic amines and reduced temperature interfere with the selection process by preventing membrane fusion events

Uptake and degradation of circulating proteins by the liver.

NARCIS (Netherlands)

Buys, Carolus Henricus Cornelis Maria

1976-01-01

Circulating proteins, like all proteins in a living animal, are subject to continual replacement or turnover. This process implies both synthesis and degradation, This thesis deals with the degradative part of turnover of circulating proteins. ... Summary

Protein oxidation and degradation caused by particulate matter

Science.gov (United States)

Lai, Ching-Huang; Lee, Chun-Nin; Bai, Kuan-Jen; Yang, You-Lan; Chuang, Kai-Jen; Wu, Sheng-Ming; Chuang, Hsiao-Chi

2016-09-01

Particulate matter (PM) modulates the expression of autophagy; however, the role of selective autophagy by PM remains unclear. The objective of this study was to determine the underlying mechanisms in protein oxidation and degradation caused by PM. Human epithelial A549 cells were exposed to diesel exhaust particles (DEPs), urban dust (UD), and carbon black (CB; control particles). Cell survival and proliferation were significantly reduced by DEPs and UD in A549 cells. First, benzo(a)pyrene diolepoxide (BPDE) protein adduct was caused by DEPs at 150 μg/ml. Methionine oxidation (MetO) of human albumin proteins was induced by DEPs, UD, and CB; however, the protein repair mechanism that converts MetO back to methionine by methionine sulfoxide reductases A (MSRA) and B3 (MSRB3) was activated by DEPs and inhibited by UD, suggesting that oxidized protein was accumulating in cells. As to the degradation of oxidized proteins, proteasome and autophagy activation was induced by CB with ubiquitin accumulation, whereas proteasome and autophagy activation was induced by DEPs without ubiquitin accumulation. The results suggest that CB-induced protein degradation may be via an ubiquitin-dependent autophagy pathway, whereas DEP-induced protein degradation may be via an ubiquitin-independent autophagy pathway. A distinct proteotoxic effect may depend on the physicochemistry of PM.

Tyrosinase degradation is prevented when EDEM1 lacks the intrinsically disordered region.

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Marioara B Marin

Full Text Available EDEM1 is a mannosidase-like protein that recruits misfolded glycoproteins from the calnexin/calreticulin folding cycle to downstream endoplasmic reticulum associated degradation (ERAD pathway. Here, we investigate the role of EDEM1 in the processing of tyrosinase, a tumour antigen overexpressed in melanoma cells. First, we analyzed and modeled EDEM1 major domains. The homology model raised on the crystal structures of human and Saccharomyces cerevisiae ER class I α1,2-mannosidases reveals that the major mannosidase domain located between aminoacids 121-598 fits with high accuracy. We have further identified an N-terminal region located between aminoacids 40-119, predicted to be intrinsically disordered (ID and susceptible to adopt multiple conformations, hence facilitating protein-protein interactions. To investigate these two domains we have constructed an EDEM1 deletion mutant lacking the ID region and a triple mutant disrupting the glycan-binding domain and analyzed their association with tyrosinase. Tyrosinase is a glycoprotein partly degraded endogenously by ERAD and the ubiquitin proteasomal system. We found that the degradation of wild type and misfolded tyrosinase was enhanced when EDEM1 was overexpressed. Glycosylated and non-glycosylated mutants co-immunoprecipitated with EDEM1 even in the absence of its intact mannosidase-like domain, but not when the ID region was deleted. In contrast, calnexin and SEL 1L associated with the deletion mutant. Our data suggest that the ID region identified in the N-terminal end of EDEM1 is involved in the binding of glycosylated and non-glycosylated misfolded proteins. Accelerating tyrosinase degradation by EDEM1 overexpression may lead to an efficient antigen presentation and enhanced elimination of melanoma cells.

The different roles of selective autophagic protein degradation in mammalian cells.

Science.gov (United States)

Wang, Da-wei; Peng, Zhen-ju; Ren, Guang-fang; Wang, Guang-xin

2015-11-10

Autophagy is an intracellular pathway for bulk protein degradation and the removal of damaged organelles by lysosomes. Autophagy was previously thought to be unselective; however, studies have increasingly confirmed that autophagy-mediated protein degradation is highly regulated. Abnormal autophagic protein degradation has been associated with multiple human diseases such as cancer, neurological disability and cardiovascular disease; therefore, further elucidation of protein degradation by autophagy may be beneficial for protein-based clinical therapies. Macroautophagy and chaperone-mediated autophagy (CMA) can both participate in selective protein degradation in mammalian cells, but the process is quite different in each case. Here, we summarize the various types of macroautophagy and CMA involved in determining protein degradation. For this summary, we divide the autophagic protein degradation pathways into four categories: the post-translational modification dependent and independent CMA pathways and the ubiquitin dependent and independent macroautophagy pathways, and describe how some non-canonical pathways and modifications such as phosphorylation, acetylation and arginylation can influence protein degradation by the autophagy lysosome system (ALS). Finally, we comment on why autophagy can serve as either diagnostics or therapeutic targets in different human diseases.

Endoplasmic Reticulum-Targeted Subunit Toxins Provide a New Approach to Rescue Misfolded Mutant Proteins and Revert Cell Models of Genetic Diseases.

Directory of Open Access Journals (Sweden)

Humaira Adnan

Full Text Available Many germ line diseases stem from a relatively minor disturbance in mutant protein endoplasmic reticulum (ER 3D assembly. Chaperones are recruited which, on failure to correct folding, sort the mutant for retrotranslocation and cytosolic proteasomal degradation (ER-associated degradation-ERAD, to initiate/exacerbate deficiency-disease symptoms. Several bacterial (and plant subunit toxins, retrograde transport to the ER after initial cell surface receptor binding/internalization. The A subunit has evolved to mimic a misfolded protein and hijack the ERAD membrane translocon (dislocon, to effect cytosolic access and cytopathology. We show such toxins compete for ERAD to rescue endogenous misfolded proteins. Cholera toxin or verotoxin (Shiga toxin containing genetically inactivated (± an N-terminal polyleucine tail A subunit can, within 2-4 hrs, temporarily increase F508delCFTR protein, the major cystic fibrosis (CF mutant (5-10x, F508delCFTR Golgi maturation (<10x, cell surface expression (20x and chloride transport (2x in F508del CFTR transfected cells and patient-derived F508delCFTR bronchiolar epithelia, without apparent cytopathology. These toxoids also increase glucocerobrosidase (GCC in N370SGCC Gaucher Disease fibroblasts (3x, another ERAD-exacerbated misfiling disease. We identify a new, potentially benign approach to the treatment of certain genetic protein misfolding diseases.

Microbial degradation of dissolved proteins in seawater

International Nuclear Information System (INIS)

Hollibaugh, J.T.; Azam, F.

1983-01-01

An experimental protocol using radiolabeled proteins was developed to investigate the rates and mechanisms whereby dissolved proteins are degraded in natural marine plankton communities. The results of field observations and laboratory experiments indicate that proteins are degraded by a particle-bound, thermolabile system, presumably bacteria-associated enzymes, with an apparent half-saturation constant of ca. 25 μg bovine serum albumin (BSA) per liter. Gel permeation chromatography indicated that peptides of chain length intermediate between BSA and the final products of degradation (MW<700) do not accumulate in the medium. Competition experiments indicate that the system is relatively nonspecific. Turnover rates for the protein pool in samples collected in the Southern California Bight were of the same order of magnitude as the turnover rate of the L-leucine pool and were correlated with primary productivity, chlorophyll a concentrations, bacterial abundance and biomass, and L-leucine turnover rate. These data suggest that amino acids derived from proteins are utilized preferentially and do not completely mix with the amino acids in the bulk phase

Education for the Eradication of Poverty

OpenAIRE

C.I. Oriahi; A.O. Aitufe

2010-01-01

This study examines the possible education for the eradication of poverty in Nigeria. It defines poverty as a state pf shortage or deficiency of meeting basic needs. Majors causes of poverty are overpopulation, illiteracy, unemployment, environmental degradation and government insensitive to the welfare of the people. Effects of poverty include homelessness, malnutrition and starvation, illness, crime, violence and antisocial behaviour like Internet Fraud (Yahoo business) and Advance Fee Frau...

Proteasomal and lysosomal protein degradation and heart disease.

Science.gov (United States)

Wang, Xuejun; Robbins, Jeffrey

2014-06-01

In the cell, the proteasome and lysosomes represent the most important proteolytic machineries, responsible for the protein degradation in the ubiquitin-proteasome system (UPS) and autophagy, respectively. Both the UPS and autophagy are essential to protein quality and quantity control. Alterations in cardiac proteasomal and lysosomal degradation are remarkably associated with most heart disease in humans and are implicated in the pathogenesis of congestive heart failure. Studies carried out in animal models and in cell culture have begun to establish both sufficiency and, in some cases, the necessity of proteasomal functional insufficiency or lysosomal insufficiency as a major pathogenic factor in the heart. This review article highlights some recent advances in the research into proteasome and lysosome protein degradation in relation to cardiac pathology and examines the emerging evidence for enhancing degradative capacities of the proteasome and/or lysosome as a new therapeutic strategy for heart disease. This article is part of a Special Issue entitled "Protein Quality Control, the Ubiquitin Proteasome System, and Autophagy". Copyright © 2013 Elsevier Ltd. All rights reserved.

Light-induced protein degradation in human-derived cells.

Science.gov (United States)

Sun, Wansheng; Zhang, Wenyao; Zhang, Chao; Mao, Miaowei; Zhao, Yuzheng; Chen, Xianjun; Yang, Yi

2017-05-27

Controlling protein degradation can be a valuable tool for posttranslational regulation of protein abundance to study complex biological systems. In the present study, we designed a light-switchable degron consisting of a light oxygen voltage (LOV) domain of Avena sativa phototropin 1 (AsLOV2) and a C-terminal degron. Our results showed that the light-switchable degron could be used for rapid and specific induction of protein degradation in HEK293 cells by light in a proteasome-dependent manner. Further studies showed that the light-switchable degron could also be utilized to mediate the degradation of secreted Gaussia princeps luciferase (GLuc), demonstrating the adaptability of the light-switchable degron in different types of protein. We suggest that the light-switchable degron offers a robust tool to control protein levels and may serves as a new and significant method for gene- and cell-based therapies. Copyright © 2017 Elsevier Inc. All rights reserved.

Degradation of misfolded proteins in neurodegenerative diseases: therapeutic targets and strategies.

Science.gov (United States)

Ciechanover, Aaron; Kwon, Yong Tae

2015-03-13

Mammalian cells remove misfolded proteins using various proteolytic systems, including the ubiquitin (Ub)-proteasome system (UPS), chaperone mediated autophagy (CMA) and macroautophagy. The majority of misfolded proteins are degraded by the UPS, in which Ub-conjugated substrates are deubiquitinated, unfolded and cleaved into small peptides when passing through the narrow chamber of the proteasome. The substrates that expose a specific degradation signal, the KFERQ sequence motif, can be delivered to and degraded in lysosomes via the CMA. Aggregation-prone substrates resistant to both the UPS and the CMA can be degraded by macroautophagy, in which cargoes are segregated into autophagosomes before degradation by lysosomal hydrolases. Although most misfolded and aggregated proteins in the human proteome can be degraded by cellular protein quality control, some native and mutant proteins prone to aggregation into β-sheet-enriched oligomers are resistant to all known proteolytic pathways and can thus grow into inclusion bodies or extracellular plaques. The accumulation of protease-resistant misfolded and aggregated proteins is a common mechanism underlying protein misfolding disorders, including neurodegenerative diseases such as Huntington's disease (HD), Alzheimer's disease (AD), Parkinson's disease (PD), prion diseases and Amyotrophic Lateral Sclerosis (ALS). In this review, we provide an overview of the proteolytic pathways in neurons, with an emphasis on the UPS, CMA and macroautophagy, and discuss the role of protein quality control in the degradation of pathogenic proteins in neurodegenerative diseases. Additionally, we examine existing putative therapeutic strategies to efficiently remove cytotoxic proteins from degenerating neurons.

Knowns and unknowns of plasma membrane protein degradation in plants.

Science.gov (United States)

Liu, Chuanliang; Shen, Wenjin; Yang, Chao; Zeng, Lizhang; Gao, Caiji

2018-07-01

Plasma membrane (PM) not only creates a physical barrier to enclose the intracellular compartments but also mediates the direct communication between plants and the ever-changing environment. A tight control of PM protein homeostasis by selective degradation is thus crucial for proper plant development and plant-environment interactions. Accumulated evidences have shown that a number of plant PM proteins undergo clathrin-dependent or membrane microdomain-associated endocytic routes to vacuole for degradation in a cargo-ubiquitination dependent or independent manner. Besides, several trans-acting determinants involved in the regulation of endocytosis, recycling and multivesicular body-mediated vacuolar sorting have been identified in plants. More interestingly, recent findings have uncovered the participation of selective autophagy in PM protein turnover in plants. Although great progresses have been made to identify the PM proteins that undergo dynamic changes in subcellular localizations and to explore the factors that control the membrane protein trafficking, several questions remain to be answered regarding the molecular mechanisms of PM protein degradation in plants. In this short review article, we briefly summarize recent progress in our understanding of the internalization, sorting and degradation of plant PM proteins. More specifically, we focus on discussing the elusive aspects underlying the pathways of PM protein degradation in plants. Copyright © 2018 Elsevier B.V. All rights reserved.

Sterol homeostasis requires regulated degradation of squalene monooxygenase by the ubiquitin ligase Doa10/Teb4

Science.gov (United States)

Foresti, Ombretta; Ruggiano, Annamaria; Hannibal-Bach, Hans K; Ejsing, Christer S; Carvalho, Pedro

2013-01-01

Sterol homeostasis is essential for the function of cellular membranes and requires feedback inhibition of HMGR, a rate-limiting enzyme of the mevalonate pathway. As HMGR acts at the beginning of the pathway, its regulation affects the synthesis of sterols and of other essential mevalonate-derived metabolites, such as ubiquinone or dolichol. Here, we describe a novel, evolutionarily conserved feedback system operating at a sterol-specific step of the mevalonate pathway. This involves the sterol-dependent degradation of squalene monooxygenase mediated by the yeast Doa10 or mammalian Teb4, a ubiquitin ligase implicated in a branch of the endoplasmic reticulum (ER)-associated protein degradation (ERAD) pathway. Since the other branch of ERAD is required for HMGR regulation, our results reveal a fundamental role for ERAD in sterol homeostasis, with the two branches of this pathway acting together to control sterol biosynthesis at different levels and thereby allowing independent regulation of multiple products of the mevalonate pathway. DOI: http://dx.doi.org/10.7554/eLife.00953.001 PMID:23898401

The relationship between protein synthesis and protein degradation in object recognition memory.

Science.gov (United States)

Furini, Cristiane R G; Myskiw, Jociane de C; Schmidt, Bianca E; Zinn, Carolina G; Peixoto, Patricia B; Pereira, Luiza D; Izquierdo, Ivan

2015-11-01

For decades there has been a consensus that de novo protein synthesis is necessary for long-term memory. A second round of protein synthesis has been described for both extinction and reconsolidation following an unreinforced test session. Recently, it was shown that consolidation and reconsolidation depend not only on protein synthesis but also on protein degradation by the ubiquitin-proteasome system (UPS), a major mechanism responsible for protein turnover. However, the involvement of UPS on consolidation and reconsolidation of object recognition memory remains unknown. Here we investigate in the CA1 region of the dorsal hippocampus the involvement of UPS-mediated protein degradation in consolidation and reconsolidation of object recognition memory. Animals with infusion cannulae stereotaxically implanted in the CA1 region of the dorsal hippocampus, were exposed to an object recognition task. The UPS inhibitor β-Lactacystin did not affect the consolidation and the reconsolidation of object recognition memory at doses known to affect other forms of memory (inhibitory avoidance, spatial learning in a water maze) while the protein synthesis inhibitor anisomycin impaired the consolidation and the reconsolidation of the object recognition memory. However, β-Lactacystin was able to reverse the impairment caused by anisomycin on the reconsolidation process in the CA1 region of the hippocampus. Therefore, it is possible to postulate a direct link between protein degradation and protein synthesis during the reconsolidation of the object recognition memory. Copyright © 2015 Elsevier B.V. All rights reserved.

Proteasomal and Lysosomal Protein Degradation and Heart Disease

OpenAIRE

Wang, Xuejun; Robbins, Jeffrey

2013-01-01

In the cell, the proteasome and lysosomes represent the most important proteolytic machineries, responsible for the protein degradation in the ubiquitin-proteasome system (UPS) and autophagy, respectively. Both the UPS and autophagy are essential to protein quality and quantity control. Alterations in cardiac proteasomal and lysosomal degradation are remarkably associated with most heart disease in humans and are implicated in the pathogenesis of congestive heart failure. Studies carried out ...

Protein degradation pathways in Parkinson's disease: curse or blessing.

Science.gov (United States)

Ebrahimi-Fakhari, Darius; Wahlster, Lara; McLean, Pamela J

2012-08-01

Protein misfolding, aggregation and deposition are common disease mechanisms in many neurodegenerative diseases including Parkinson's disease (PD). Accumulation of damaged or abnormally modified proteins may lead to perturbed cellular function and eventually to cell death. Thus, neurons rely on elaborated pathways of protein quality control and removal to maintain intracellular protein homeostasis. Molecular chaperones, the ubiquitin-proteasome system (UPS) and the autophagy-lysosomal pathway (ALP) are critical pathways that mediate the refolding or removal of abnormal proteins. The successive failure of these protein degradation pathways, as a cause or consequence of early pathological alterations in vulnerable neurons at risk, may present a key step in the pathological cascade that leads to spreading neurodegeneration. A growing number of studies in disease models and patients have implicated dysfunction of the UPS and ALP in the pathogenesis of Parkinson's disease and related disorders. Deciphering the exact mechanism by which the different proteolytic systems contribute to the elimination of pathogenic proteins, like α-synuclein, is therefore of paramount importance. We herein review the role of protein degradation pathways in Parkinson's disease and elaborate on the different contributions of the UPS and the ALP to the clearance of altered proteins. We examine the interplay between different degradation pathways and provide a model for the role of the UPS and ALP in the evolution and progression of α-synuclein pathology. With regards to exciting recent studies we also discuss the putative potential of using protein degradation pathways as novel therapeutic targets in Parkinson's disease.

Accelerated degradation of the D2 protein of photosystem II under ultraviolet radiation

International Nuclear Information System (INIS)

Jansen, M.A.K.; Edelman, M.; Greenberg, B.M.; Gaba, V.

1996-01-01

The D2 protein of photosystem II is relatively stable in vivo under photosynthetic active radiation, but its degradation accelerates under UVB radiation. Little is known about accelerated D2 protein degradation. We characterized wavelength dependence and sensitivity toward photosystem II inhibitors. The in vivo D2 degradation spectrum resembles the pattern for the rapidly turning over D1 protein of photosystem II, with rates being maximal in the UVB region. We propose that D2 degradation, like D1 degradation, is activated by distinct photosensitizers in the UVB and visible regions of the spectrum. In both wavelength regions, photosystem II inhibitors that are known to be targeted to the D1 protein affect D2 degradation. This suggests that degradation of the two proteins is coupled, D2 degradation being influenced by events occurring at the Q B niche on the D1 protein. (Author)

Protein degradation and protection against misfolded or damaged proteins

Science.gov (United States)

Goldberg, Alfred L.

2003-12-01

The ultimate mechanism that cells use to ensure the quality of intracellular proteins is the selective destruction of misfolded or damaged polypeptides. In eukaryotic cells, the large ATP-dependent proteolytic machine, the 26S proteasome, prevents the accumulation of non-functional, potentially toxic proteins. This process is of particular importance in protecting cells against harsh conditions (for example, heat shock or oxidative stress) and in a variety of diseases (for example, cystic fibrosis and the major neurodegenerative diseases). A full understanding of the pathogenesis of the protein-folding diseases will require greater knowledge of how misfolded proteins are recognized and selectively degraded.

Endoplasmic reticulum-associated degradation of the renal potassium channel, ROMK, leads to type II Bartter syndrome.

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O'Donnell, Brighid M; Mackie, Timothy D; Subramanya, Arohan R; Brodsky, Jeffrey L

2017-08-04

Type II Bartter syndrome is caused by mutations in the renal outer medullary potassium (ROMK) channel, but the molecular mechanisms underlying this disease are poorly defined. To rapidly screen for ROMK function, we developed a yeast expression system and discovered that yeast cells lacking endogenous potassium channels could be rescued by WT ROMK but not by ROMK proteins containing any one of four Bartter mutations. We also found that the mutant proteins were significantly less stable than WT ROMK. However, their degradation was slowed in the presence of a proteasome inhibitor or when yeast cells contained mutations in the CDC48 or SSA1 gene, which is required for endoplasmic reticulum (ER)-associated degradation (ERAD). Consistent with these data, sucrose gradient centrifugation and indirect immunofluorescence microscopy indicated that most ROMK protein was ER-localized. To translate these findings to a more relevant cell type, we measured the stabilities of WT ROMK and the ROMK Bartter mutants in HEK293 cells. As in yeast, the Bartter mutant proteins were less stable than the WT protein, and their degradation was slowed in the presence of a proteasome inhibitor. Finally, we discovered that low-temperature incubation increased the steady-state levels of a Bartter mutant, suggesting that the disease-causing mutation traps the protein in a folding-deficient conformation. These findings indicate that the underlying pathology for at least a subset of patients with type II Bartter syndrome is linked to the ERAD pathway and that future therapeutic strategies should focus on correcting deficiencies in ROMK folding. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

In vitro degradation of the 32kDa PS II reaction centre protein

International Nuclear Information System (INIS)

Eckenswiller, L.C.; Greenberg, B.M.

1989-01-01

The 32kDa thylakoid membrane protein is an integral component of the PS II reaction centre. The protein, although stable in the dark, undergoes light dependent turnover. Light from the UV, visible and far-red spectral regions induce 32kDa protein degradation. To better understand 32kDa protein metabolism, an in vitro degradation system is being developed. It consists of isolated thylakoid membranes than contain radiolabelled protein. The 32kDa protein is actively and specifically degraded when the thylakoid preparation is exposed to UV or visible radiation. The protein is stable in the dark. The herbicides (atrazine and DCMU) inhibit degradation in the in vitro system as they do in vivo. Additionally, several methods of isolating thylakoids are being compared to optimize the 32kDa protein degradation reaction. The preparations will be evaluated based on their ability to permit light dependent degradation of the 32kDa protein without affecting the other membrane components

Secretion of intact proteins and peptide fragments by lysosomal pathways of protein degradation

International Nuclear Information System (INIS)

Isenman, L.D.; Dice, J.F.

1989-01-01

We report that degradation of proteins microinjected into human fibroblasts is accompanied by release into the culture medium of peptide fragments and intact proteins as well as single amino acids. For the nine proteins and polypeptides microinjected, acid-precipitable radioactivity, i.e. peptide fragments and/or intact proteins, ranged from 10 to 67% of the total released radioactivity. Peptide fragments and/or intact protein accounted for 60% of the radioactivity released into the medium by cells microinjected with ribonuclease A. Two major radiolabeled peptide fragments were found, and one was of an appropriate size to function as an antigen in antigen-presenting cells. The peptides released from microinjected ribonuclease A were derived from lysosomal pathways of proteolysis based on several lines of evidence. Previous studies have shown that microinjected ribonuclease A is degraded to single amino acids entirely within lysosomes. We show that release of free amino acids and peptide fragments and/or intact protein was equivalently stimulated by serum deprivation and equivalently inhibited by NH4Cl. We also show that lysosomal degradation of endocytosed [3H]ribonuclease A was accompanied by the release of two peptide fragments similar in size and charge to those from microinjected [ 3 H]ribonuclease A. These findings demonstrate that degradation within lysosomes occurs in a manner that spares specific peptides; they also suggest a previously unsuspected pathway by which cells can secrete cytosol-derived polypeptides

Long-term aversive taste memory requires insular and amygdala protein degradation.

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Rodriguez-Ortiz, Carlos J; Balderas, Israela; Saucedo-Alquicira, Fernando; Cruz-Castañeda, Paulina; Bermudez-Rattoni, Federico

2011-03-01

Some reports have shown that the ubiquitin-proteasome system (UPS) is necessary to degrade repressor factors to produce new proteins essential to memory consolidation. Furthermore, recent evidence suggests that memory updating also relies on protein degradation through the UPS. To evaluate whether degradation of proteins is part of the cellular events needed for long-term storage of taste aversion, we injected lactacystin--an UPS inhibitor--into the amygdala and/or insular cortex 30 min before the first or second training trials. The results revealed that degradation of proteins in either the amygdala or insular cortex suffices for long-term stabilization of first-time encounter taste aversion. On the other hand, lactacystin applied in the insula, but not in the amygdala, before the second training prevented long-term storage of updated information. Our results support that degradation of proteins by means of the UPS is required every time taste aversion is to be stored in long-term memory. Copyright © 2010 Elsevier Inc. All rights reserved.

Direct ubiquitin independent recognition and degradation of a folded protein by the eukaryotic proteasomes-origin of intrinsic degradation signals.

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Amit Kumar Singh Gautam

Full Text Available Eukaryotic 26S proteasomes are structurally organized to recognize, unfold and degrade globular proteins. However, all existing model substrates of the 26S proteasome in addition to ubiquitin or adaptor proteins require unstructured regions in the form of fusion tags for efficient degradation. We report for the first time that purified 26S proteasome can directly recognize and degrade apomyoglobin, a globular protein, in the absence of ubiquitin, extrinsic degradation tags or adaptor proteins. Despite a high affinity interaction, absence of a ligand and presence of only helices/loops that follow the degradation signal, apomyoglobin is degraded slowly by the proteasome. A short floppy F-helix exposed upon ligand removal and in conformational equilibrium with a disordered structure is mandatory for recognition and initiation of degradation. Holomyoglobin, in which the helix is buried, is neither recognized nor degraded. Exposure of the floppy F-helix seems to sensitize the proteasome and primes the substrate for degradation. Using peptide panning and competition experiments we speculate that initial encounters through the floppy helix and additional strong interactions with N-terminal helices anchors apomyoglobin to the proteasome. Stabilizing helical structure in the floppy F-helix slows down degradation. Destabilization of adjacent helices accelerates degradation. Unfolding seems to follow the mechanism of helix unraveling rather than global unfolding. Our findings while confirming the requirement for unstructured regions in degradation offers the following new insights: a origin and identification of an intrinsic degradation signal in the substrate, b identification of sequences in the native substrate that are likely to be responsible for direct interactions with the proteasome, and c identification of critical rate limiting steps like exposure of the intrinsic degron and destabilization of an unfolding intermediate that are presumably

Eradication of tephritid fruit fly pest populations: outcomes and prospects.

Science.gov (United States)

Suckling, David Maxwell; Kean, John M; Stringer, Lloyd D; Cáceres-Barrios, Carlos; Hendrichs, Jorge; Reyes-Flores, Jesus; Dominiak, Bernard C

2016-03-01

The number of insect eradication programmes is rising in response to globalisation. A database of arthropod and plant pathogen eradications covers 1050 incursion responses, with 928 eradication programmes on 299 pest and disease taxa in 104 countries (global eradication database b3.net.nz/gerda). A subset of the database was assembled with 211 eradication or response programmes against 17 species of fruit flies (Tephritidae) in 31 countries, in order to investigate factors affecting the outcome. The failure rate for fruit fly eradication programmes was about 7%, with 0% for Ceratitis capitata (n = 85 programmes) and 0% for two Anastrepha species (n = 12 programmes), but 12% for 13 Bactrocera species (n = 108 programmes). A number of intended eradication programmes against long-established populations were not initiated because of cost and other considerations, or evolved during the planning phase into suppression programmes. Cost was dependent on area, ranged from $US 0.1 million to $US 240 million and averaged about $US 12 million (normalised to $US in 2012). In addition to the routine use of surveillance networks, quarantine and fruit destruction, the key tactics used in eradication programmes were male annihilation, protein bait sprays (which can attract both sexes), fruit destruction and the sterile insect technique. Eradication success generally required the combination of several tactics applied on an area-wide basis. Because the likelihood of eradication declines with an increase in the area infested, it pays to invest in effective surveillance networks that allow early detection and delimitation while invading populations are small, thereby greatly favouring eradication success. © 2014 Society of Chemical Industry.

Eradication of tephritid fruit fly pest populations: outcomes and prospects

International Nuclear Information System (INIS)

Suckling, David Maxwell; Kean, John M.; Stringer, Lloyd D.; Cáceres-Barrios, Carlos; Hendrichs, Jorge; Reyes-Flores, Jesus; Dominiak, Bernard C.

2015-01-01

BACKGROUND: The number of insect eradication programmes is rising in response to globalisation. A database of arthropod and plant pathogen eradications covers 1050 incursion responses, with 928 eradication programmes on 299 pest and disease taxa in 104 countries (global eradication database b3.net.nz/gerda). METHODS: A subset of the database was assembled with 211 eradication or response programmes against 17 species of fruit flies (Tephritidae) in 31 countries, in order to investigate factors affecting the outcome. RESULTS: The failure rate for fruit fly eradication programmes was about 7%, with 0% for Ceratitis capitata (n=85 programmes) and 0% for two Anastrepha species (n=12 programmes), but 12% for 13 Bactrocera species (n=108 programmes). A number of intended eradication programmesagainst long-established populations were not initiated because of cost and other considerations, or evolved during the planning phase into suppression programmes. Cost was dependent on area, ranged from $US 0.1 million to $US 240 million and averaged about $US 12 million (normalised to $US in 2012). In addition to the routine use of surveillance networks, quarantine and fruit destruction, the key tactics used in eradication programmes were male annihilation, protein bait sprays (which can attract both sexes), fruit destruction and the sterile insect technique. CONCLUSIONS: Eradication success generally required the combination of several tactics applied on an area-wide basis. Because the likelihood of eradication declines with an increase in the area infested, it pays to invest in effective surveillance networks that allow early detection and delimitation while invading populations are small, thereby greatly favouring eradication success. (author)

Selectivity in protein degradation during sporulation of Bacillus subtilis

International Nuclear Information System (INIS)

Mitani, Takahiko; Kadota, Hajime

1976-01-01

The breakdown of cellular protein was investigated in Bacillus subtilis ATCC 6051 labeled with glycine-2- 3 H or L-phenylalanine-U- 14 C at the different stages of vegetative growth and sporulation. The growth of the culture was determined by measuring optical density at 660 nm. The heat-resistant spores were scored by plating after heating at 80 deg C for 10 minutes. A question whether the turnover of glycine-labeled protein is similar to that of phenylalanine-labeled protein was experimentally studied. The patterns obtained with the glycine-labeled protein were different from those of phenylalanine-labeled protein. This was not multiple turnover. The cellular protein which was labeled with glycine at an early stage of sporulation showed rapid degradation, but the degradation of the protein labeled with glycine at later stages did not occur at all. Another question whether the labeled glycine incorporated into cells at the different stages of growth and sporulation was present in the spore coat fraction of matured spores was studied. Experiment demonstrated that the glycine incorporated into cells at the late sporulation stage was mainly utilized for the biosynthesis of the spore coat protein. These data suggest that the spore coat protein which contains relatively large amount of glycine is rarely subject to further degradation. (Iwakiri, K.)

Synergy between an antiangiogenic integrin αv antagonist and an antibody–cytokine fusion protein eradicates spontaneous tumor metastases

OpenAIRE

Lode, Holger N.; Moehler, Thomas; Xiang, Rong; Jonczyk, Alfred; Gillies, Stephen D.; Cheresh, David A.; Reisfeld, Ralph A.

1999-01-01

The suppression and eradication of primary tumors and distant metastases is a major goal of alternative treatment strategies for cancer, such as inhibition of angiogenesis and targeted immunotherapy. We report here a synergy between two novel monotherapies directed against vascular and tumor compartments, respectively, a tumor vasculature-specific antiangiogenic integrin αv antagonist and tumor-specific antibody–interleukin 2 (IL-2) fusion proteins. Simultaneous an...

Pre-emptive Quality Control Protects the ER from Protein Overload via the Proximity of ERAD Components and SRP

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Hisae Kadowaki

2015-11-01

Full Text Available Cells possess ER quality control systems to adapt to ER stress and maintain their function. ER-stress-induced pre-emptive quality control (ER pQC selectively degrades ER proteins via translocational attenuation during ER stress. However, the molecular mechanism underlying this process remains unclear. Here, we find that most newly synthesized endogenous transthyretin proteins are rerouted to the cytosol without cleavage of the signal peptide, resulting in proteasomal degradation in hepatocytes during ER stress. Derlin family proteins (Derlins, which are ER-associated degradation components, reroute specific ER proteins, but not ER chaperones, from the translocon to the proteasome through interactions with the signal recognition particle (SRP. Moreover, the cytosolic chaperone Bag6 and the AAA-ATPase p97 contribute to the degradation of ER pQC substrates. These findings demonstrate that Derlins-mediated substrate-specific rerouting and Bag6- and p97-mediated effective degradation contribute to the maintenance of ER homeostasis without the need for translocation.

SGTA Recognizes a Noncanonical Ubiquitin-like Domain in the Bag6-Ubl4A-Trc35 Complex to Promote Endoplasmic Reticulum-Associated Degradation

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Yue Xu

2012-12-01

Full Text Available Elimination of aberrantly folded polypeptides from the endoplasmic reticulum (ER by the ER-associated degradation (ERAD system promotes cell survival under stress conditions. This quality control mechanism requires movement of misfolded proteins across the ER membrane for targeting to the cytosolic proteasome, a process facilitated by a “holdase” complex, consisting of Bag6 and the cofactors Ubl4A and Trc35. This multiprotein complex also participates in several other protein quality control processes. Here, we report SGTA as a component of the Bag6 system, which cooperates with Bag6 to channel dislocated ERAD substrates that are prone to aggregation. Using nuclear magnetic resonance spectroscopy and biochemical assays, we demonstrate that SGTA contains a noncanonical ubiquitin-like-binding domain that interacts specifically with an unconventional ubiquitin-like protein/domain in Ubl4A at least in part via electrostatics. This interaction helps recruit SGTA to Bag6, enhances substrate loading to Bag6, and thus prevents the formation of nondegradable protein aggregates in ERAD.

Human sperm degradation of zona pellucida proteins contributes to fertilization.

Science.gov (United States)

Saldívar-Hernández, Analilia; González-González, María E; Sánchez-Tusié, Ana; Maldonado-Rosas, Israel; López, Pablo; Treviño, Claudia L; Larrea, Fernando; Chirinos, Mayel

2015-09-02

The mammalian oocyte extracellular matrix known as the zona pellucida (ZP) acts as a barrier to accomplish sperm fusion with the female gamete. Although penetration of the ZP is a limiting event to achieve fertilization, this is one of the least comprehended stages of gamete interaction. Even though previous studies suggest that proteases of sperm origin contribute to facilitate the passage of sperm through the ZP, in human this process is not yet fully understood. The aim of this study was to determine the ability of human sperm to degrade recombinant human ZP (rhZPs) proteins and to characterize the proteases involved in this process. Purified rhZP2, rhZP3 and rhZP4 proteins were incubated with capacitated sperm and the proteolytic activity was determined by Western blot analysis. To further characterize the proteases involved, parallel incubations were performed in the presence of the protease inhibitors o-phenanthroline, benzamidine and MG-132 meant to block the activity of metalloproteases, serine proteases and the proteasome, respectively. Additionally, protease inhibitors effect on sperm-ZP binding was evaluated by hemizona assay. The results showed that rhZPs were hydrolyzed in the presence of capacitated sperm. O-phenanthroline inhibited the degradation of rhZP3, MG-132 inhibited the degradation of rhZP4 and benzamidine inhibited the degradation of the three proteins under investigation. Moreover, hemizona assays demonstrated that sperm proteasome inhibition impairs sperm interaction with human native ZP. This study suggests that sperm proteasomes could participate in the degradation of ZP, particularly of the ZP4 protein. Besides, metalloproteases may be involved in specific degradation of ZP3 while serine proteases may contribute to unspecific degradation of the ZP. These findings suggest that localized degradation of ZP proteins by sperm is probably involved in ZP penetration and may be of help in understanding the mechanisms of fertilization in humans.

Mass spectrometry analysis of proteome-wide proteolytic post-translational degradation of proteins

OpenAIRE

Shen, Yufeng; Hixson, Kim K.; Tolić, Nikola; Camp, David G.; Purvine, Samuel O.; Moore, Ronald J.; Smith, Richard D.

2008-01-01

Protein proteolytic degradation is an essential component to proper cell function and its life cycle. Here, we study the protein degradation in yeast Saccharomyces cerevisiae cells on a proteome-wide scale by detection of the intermediate peptides produced from the intracellular degradation of proteins using sequencing-based tandem mass spectrometry. By tracing the detected ~1,100 peptides and their ~200 protein substrate origins we obtain evidence for new insights into the proteome-wide prot...

Protein synthesis and degradation during starvation-induced cardiac atrophy in rabbits

International Nuclear Information System (INIS)

Samarel, A.M.; Parmacek, M.S.; Magid, N.M.; Decker, R.S.; Lesch, M.

1987-01-01

To determine the relative importance of protein degradation in the development of starvation-induced cardiac atrophy, in vivo fractional synthetic rates of total cardiac protein, myosin heavy chain, actin, light chain 1, and light chain 2 were measured in fed and fasted rabbits by continuous infusion of [ 3 H] leucine. In addition, the rate of left ventricular protein accumulation and loss were assessed in weight-matched control and fasted rabbits. Rates of total cardiac protein degradation were then estimated as the difference between rates of synthesis and growth. Fasting produced left ventricular atrophy by decreasing the rate of left ventricular protein synthesis (34.8 +/- 1.4, 27.3 +/- 3.0, and 19.3 +/- 1.2 mg/day of left ventricular protein synthesized for 0-, 3-, and 7-day fasted rabbits, respectively). Inhibition of contractile protein synthesis was evident by significant reductions in the fractional synthetic rates of all myofibrillar protein subunits. Although fractional rates of protein degradation increased significantly within 7 days of fasting, actual amounts of left ventricular protein degraded per day were unaffected. Thus, prolonged fasting profoundly inhibits the synthesis of new cardiac protein, including the major protein constituents of the myofibril. Both this inhibition in new protein synthesis as well as a smaller but significant reduction in the average half-lives of cardiac proteins are responsible for atrophy of the heart in response to fasting

RNAi screening for characterisation of ER-associated degradation pathways in mammalian cells

DEFF Research Database (Denmark)

Månsson, Mats David Joakim

in a process termed ER-associated degradation (ERAD). This mechanism proceeds through four steps involving recognition, dislocation, ubiquitination and proteasomal degradation. This report describes a high-throughput screening method for identification of hitherto unknown pathways for degradation. We present...... fluorescence-based RNAi screens in mammalian cells on TCR-α-GFP and HANSκLC, for identification of ERAD pathways. By validating the obtained screening hits we concluded that UBE2J2 is involved in TCR-α-GFP degradation, possibly by ubiquitination of C-terminal serine residues in TCR-α-GFP. Additionally, we also...

Degradation of Akt using protein-catalyzed capture agents.

Science.gov (United States)

Henning, Ryan K; Varghese, Joseph O; Das, Samir; Nag, Arundhati; Tang, Grace; Tang, Kevin; Sutherland, Alexander M; Heath, James R

2016-04-01

Abnormal signaling of the protein kinase Akt has been shown to contribute to human diseases such as diabetes and cancer, but Akt has proven to be a challenging target for drugging. Using iterative in situ click chemistry, we recently developed multiple protein-catalyzed capture (PCC) agents that allosterically modulate Akt enzymatic activity in a protein-based assay. Here, we utilize similar PCCs to exploit endogenous protein degradation pathways. We use the modularity of the anti-Akt PCCs to prepare proteolysis targeting chimeric molecules that are shown to promote the rapid degradation of Akt in live cancer cells. These novel proteolysis targeting chimeric molecules demonstrate that the epitope targeting selectivity of PCCs can be coupled with non-traditional drugging moieties to inhibit challenging targets. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd.

Are animal models predictive for human postmortem muscle protein degradation?

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Ehrenfellner, Bianca; Zissler, Angela; Steinbacher, Peter; Monticelli, Fabio C; Pittner, Stefan

2017-11-01

A most precise determination of the postmortem interval (PMI) is a crucial aspect in forensic casework. Although there are diverse approaches available to date, the high heterogeneity of cases together with the respective postmortal changes often limit the validity and sufficiency of many methods. Recently, a novel approach for time since death estimation by the analysis of postmortal changes of muscle proteins was proposed. It is however necessary to improve the reliability and accuracy, especially by analysis of possible influencing factors on protein degradation. This is ideally investigated on standardized animal models that, however, require legitimization by a comparison of human and animal tissue, and in this specific case of protein degradation profiles. Only if protein degradation events occur in comparable fashion within different species, respective findings can sufficiently be transferred from the animal model to application in humans. Therefor samples from two frequently used animal models (mouse and pig), as well as forensic cases with representative protein profiles of highly differing PMIs were analyzed. Despite physical and physiological differences between species, western blot analysis revealed similar patterns in most of the investigated proteins. Even most degradation events occurred in comparable fashion. In some other aspects, however, human and animal profiles depicted distinct differences. The results of this experimental series clearly indicate the huge importance of comparative studies, whenever animal models are considered. Although animal models could be shown to reflect the basic principles of protein degradation processes in humans, we also gained insight in the difficulties and limitations of the applicability of the developed methodology in different mammalian species regarding protein specificity and methodic functionality.

The effect of Helicobacter pylori eradication on macrophage migration inhibitory factor, C-reactive protein and fetuin-a levels

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Levent Kebapcilar

2010-06-01

Full Text Available OBJECTIVES: To determine the effect of Helicobacter pylori (H. pylori eradication on blood levels of high-sensitivity C-reactive protein (hs-CRP, macrophage migration inhibitory factor and fetuin-A in patients with dyspepsia who are concurrently infected with H. pylori. METHODS: H.pylori infection was diagnosed based on the 14C urea breath test (UBT and histology. Lansoprazole 30 mg twice daily, amoxicillin 1 g twice daily, and clarithromycin 500 mg twice daily were given to all infected patients for 14 days; 14C UBT was then re-measured. In 30 subjects, migration inhibitory factor, fetuin-A and hs-CRP levels were examined before and after the eradication of H. pylori infection and compared to levels in 30 healthy subjects who tested negative for H. pylori infection. RESULTS: Age and sex distribution were comparable between patients and controls. Migration inhibitory factor and hs-CRP levels were higher, and fetuin-A levels were lower, in H. pylori-infected patients (p0.05. CONCLUSION: These findings suggest that H. pylori eradication reduces the levels of pro-inflammatory cytokines such as migration inhibitory factor and hs-CRP and also results in a significant increase in anti-inflammatory markers such as fetuin-A.

Radiation degradation of silk protein

International Nuclear Information System (INIS)

Pewlong, W.; Sudatis, B.; Takeshita, Hidefumi; Yoshii, Fumio; Kume, Tamikazu

2000-01-01

Silk fibroin fiber from the domesticated silkworm Bombyx mori was irradiated using an electron beam accelerator to investigate the application of the radiation degradation technique as a means to solubilize fibroin. The irradiation caused a significant degradation of the fiber. The tensile strength of fibroin fiber irradiated up to 2500 kGy decreased rapidly with increasing dose. The presence of oxygen in the irradiation atmosphere enhanced degradation of the tensile strength. The solubilization of irradiated fibroin fiber was evaluated using the following three kinds of solutions: a calcium chloride solution(CaCl 2 /C 2 H 5 OH/H 2 O=1:2:8 in mole ratio), a hydrochloric acid (0.5 N) and a distilled water. Dissolution of fibroin fiber into these solutions was significantly enhanced by irradiation. Especially, an appreciable amount of water soluble proteins was extracted by a distilled water. (author)

Radiation degradation of silk protein

Energy Technology Data Exchange (ETDEWEB)

Pewlong, W; Sudatis, B [Office of Atomic Energy for Peace, Bangkok (Thailand); Takeshita, Hidefumi; Yoshii, Fumio; Kume, Tamikazu [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

2000-03-01

Silk fibroin fiber from the domesticated silkworm Bombyx mori was irradiated using an electron beam accelerator to investigate the application of the radiation degradation technique as a means to solubilize fibroin. The irradiation caused a significant degradation of the fiber. The tensile strength of fibroin fiber irradiated up to 2500 kGy decreased rapidly with increasing dose. The presence of oxygen in the irradiation atmosphere enhanced degradation of the tensile strength. The solubilization of irradiated fibroin fiber was evaluated using the following three kinds of solutions: a calcium chloride solution(CaCl{sub 2}/C{sub 2}H{sub 5}OH/H{sub 2}O=1:2:8 in mole ratio), a hydrochloric acid (0.5 N) and a distilled water. Dissolution of fibroin fiber into these solutions was significantly enhanced by irradiation. Especially, an appreciable amount of water soluble proteins was extracted by a distilled water. (author)

Glucose Deprivation Triggers Protein Kinase C-dependent β-Catenin Proteasomal Degradation*

Science.gov (United States)

Choi, Seung-Won; Song, Jun-Kyu; Yim, Ye-Seal; Yun, Ho-Geun; Chun, Kyung-Hee

2015-01-01

Autophagy is a conserved process that contributes to cell homeostasis. It is well known that induction mainly occurs in response to nutrient starvation, such as starvation of amino acids and insulin, and its mechanisms have been extensively characterized. However, the mechanisms behind cellular glucose deprivation-induced autophagy are as of now poorly understood. In the present study, we determined a mechanism by which glucose deprivation induced the PKC-dependent proteasomal degradation of β-catenin, leading to autophagy. Glucose deprivation was shown to cause a sub-G1 transition and enhancement of the LC3-II protein levels, whereas β-catenin protein underwent degradation in a proteasome-dependent manner. Moreover, the inhibition of GSK3β was unable to abolish the glucose deprivation-mediated β-catenin degradation or up-regulation of LC3-II protein levels, which suggested GSK3β-independent protein degradation. Intriguingly, the inhibition of PKCα using a pharmacological inhibitor and transfection of siRNA for PKCα was observed to effectively block glucose deprivation-induced β-catenin degradation as well as the increase in LC3-II levels and the accumulation of a sub-G1 population. Together, our results demonstrated a molecular mechanism by which glucose deprivation can induce the GSK3β-independent protein degradation of β-catenin, leading to autophagy. PMID:25691573

Rapid degradation of abnormal proteins in vacuoles from Acer pseudoplatanus L. cells

International Nuclear Information System (INIS)

Canut, H.; Alibert, G.; Carrasco, A.; Boudet, A.M.

1986-01-01

In Acer pseudoplatanus cells, the proteins synthesized in the presence of an amino acid analog ([ 14 C]p-fluorophenylalanine), were degraded more rapidly than normal ones ([ 14 C]phenylalanine as precursor). The degradation of an important part of these abnormal proteins occurred inside the vacuoles. The degradation process was not apparently associated to a specific proteolytic system but was related to a preferential transfer of these aberrant proteins from the cytoplasm to the vacuole

Prion protein degradation by lichens of the genus Cladonia

Science.gov (United States)

Bennett, James P.; Rodriguez, Cynthia M.; Johnson, Christopher J.

2012-01-01

It has recently been discovered that lichens contain a serine protease capable of degrading the pathogenic prion protein, the etiological agent of prion diseases such as sheep scrapie and cervid chronic wasting disease. Limited methods are available to degrade or inactivate prion disease agents, especially in the environment, and lichens or their serine protease could prove important for management of these diseases. Scant information is available regarding the presence or absence of the protease responsible for degrading prion protein (PrP) in lichen species and, in this study, we tested the hypothesis that PrP degradation activity in lichens is phylogenetically-based by testing 44 species of Cladonia lichens, a genus for which a significant portion of the phylogeny is well established. We categorized PrP degradation activity among the 44 species (high, moderate, low or none) and found that activity in Cladonia species did not correspond with phylogenetic position of the species. Degradation of PrP did correspond, however, with three classical taxonomic characters within the genus: species with brown apothecia, no usnic acid, and the presence of a cortex. Of the 44 species studied, 18 (41%) had either high or moderate PrP degradation activity, suggesting the protease may be frequent in this genus of lichens.

Critical lysine residues of Klf4 required for protein stabilization and degradation

Energy Technology Data Exchange (ETDEWEB)

Lim, Key-Hwan; Kim, So-Ra; Ramakrishna, Suresh; Baek, Kwang-Hyun, E-mail: baek@cha.ac.kr

2014-01-24

Highlights: • Klf4 undergoes the 26S proteasomal degradation by ubiquitination on its multiple lysine residues. • Essential Klf4 ubiquitination sites are accumulated between 190–263 amino acids. • A mutation of lysine at 232 on Klf4 elongates protein turnover. • Klf4 mutants dramatically suppress p53 expression both under normal and UV irradiated conditions. - Abstract: The transcription factor, Krüppel-like factor 4 (Klf4) plays a crucial role in generating induced pluripotent stem cells (iPSCs). As the ubiquitination and degradation of the Klf4 protein have been suggested to play an important role in its function, the identification of specific lysine sites that are responsible for protein degradation is of prime interest to improve protein stability and function. However, the molecular mechanism regulating proteasomal degradation of the Klf4 is poorly understood. In this study, both the analysis of Klf4 ubiquitination sites using several Klf4 deletion fragments and bioinformatics predictions showed that the lysine sites which are signaling for Klf4 protein degradation lie in its N-terminal domain (aa 1–296). The results also showed that Lys32, 52, 232, and 252 of Klf4 are responsible for the proteolysis of the Klf4 protein. These results suggest that Klf4 undergoes proteasomal degradation and that these lysine residues are critical for Klf4 ubiquitination.

Proteolysis targeting peptide (PROTAP) strategy for protein ubiquitination and degradation.

Science.gov (United States)

Zheng, Jing; Tan, Chunyan; Xue, Pengcheng; Cao, Jiakun; Liu, Feng; Tan, Ying; Jiang, Yuyang

2016-02-19

Ubiquitination proteasome pathway (UPP) is the most important and selective way to degrade proteins in vivo. Here, a novel proteolysis targeting peptide (PROTAP) strategy, composed of a target protein binding peptide, a linker and a ubiquitin E3 ligase recognition peptide, was designed to recruit both target protein and E3 ligase and then induce polyubiquitination and degradation of the target protein through UPP. In our study, the PROTAP strategy was proved to be a general method with high specificity using Bcl-xL protein as model target in vitro and in cells, which indicates that the strategy has great potential for in vivo application. Copyright © 2016 Elsevier Inc. All rights reserved.

Mutational analysis of PVX TGBp3 links subcellular accumulation and protein turnover

International Nuclear Information System (INIS)

Ju, H.-J.; Ye, C.-M.; Verchot-Lubicz, Jeanmarie

2008-01-01

Potato virus X (PVX) TGBp3 is required for virus cell-to-cell transport, has an N-terminal transmembrane domain, and a C-terminal cytosolic domain. In the absence of virus infection TGBp3:GFP is seen in the cortical and perinuclear ER. In PVX infected cells the TGBp3:GFP fusion is also seen in the nucleoplasm indicating that events during PVX infection trigger entry into the nucleus. Mutational analysis failed to identify a nuclear targeting domain. Mutations inhibiting TGBp3 association with the ER and inhibiting virus movement did not block TGBp3:GFP in the nucleoplasm. A mutation disrupting the N-terminal transmembrane domain of TGBp3 caused the fusion to accumulate in the nucleus indicating that nuclear import is regulated by ER interactions. Tunicamycin, an ER-stress inducing chemical, caused lower levels of GFP and TGBp3:GFP to accumulate in virus infected protoplasts. MG115 and MG132 were used to demonstrate that wild-type and mutant TGBp3:GFP fusions were degraded by the 26S proteasome. These observations are consistent with an ER-associated protein degradation (ERAD) pathway suggesting that PVX TGBp3, similar to aberrant ER proteins, is translocate to the cytoplasm for degradation. Nuclear accumulation of mutant and wild-type TGBp3:GFP is independent of other PVX proteins and may be another feature of an ERAD pathway

Protein degradation during reconsolidation as a mechanism for memory reorganization

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Bong-Kiun Kaang

2011-02-01

Full Text Available Memory is a reference formed from a past experience that is used to respond to present situations. However, the world is dynamic and situations change, so it is important to update the memory with new information each time it is reactivated in order to adjust the response in the future. Recent researches indicate that memory may undergo a dynamic process that could work as an updating mechanism. This process which is called reconsolidation involves destabilization of the memory after it is reactivated, followed by restabilization. Recently, it has been demonstrated that the initial destabilization process of reconsolidation requires protein degradation. Using protein degradation inhibition as a method to block reconsolidation, recent researches suggest that reconsolidation, especially the protein degradation-dependent destabilization process is necessary for memory reorganization.

Radiation degradation of silk protein

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Wachiraporn Pewlong; Boonya Sudatis [Office of Atomic Energy for Peace, Bangkok (Thailand); Takeshita, Hidefumi; Yoshii, Fumio; Kume, Tamikazu [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

2000-09-01

Silk fibroin fiber from the domesticated silkworm Bombyx mori was irradiated in the dose range up to 2500 kGy using an electron beam accelerator to apply the radiation degradation technique as a means to solubilize fibroin. The tensile strength of irradiated fibroin fiber decreased with increasing dose and the presence of oxygen in the irradiation atmosphere enhanced the degradation. The solubilization of irradiated fibroin fiber was evaluated using the following three kinds of solutions: calcium chloride solution (CaCl{sub 2}/C{sub 2}H{sub 5}OH/H{sub 2}O = 1 : 2 : 8 in mole ratio), hydrochloric acid (0.5N) and distilled water. Dissolution of fibroin fiber into these solutions was significantly enhanced by irradiation. Especially, an appreciable amount of water-soluble protein was extracted by distilled water. (author)

Cyclosporine A-sensitive, cyclophilin B-dependent endoplasmic reticulum-associated degradation.

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Riccardo Bernasconi

2010-09-01

Full Text Available Peptidyl-prolyl cis/trans isomerases (PPIs catalyze cis/trans isomerization of peptide bonds preceding proline residues. The involvement of PPI family members in protein refolding has been established in test tube experiments. Surprisingly, however, no data is available on the involvement of endoplasmic reticulum (ER-resident members of the PPI family in protein folding, quality control or disposal in the living cell. Here we report that the immunosuppressive drug cyclosporine A (CsA selectively inhibits the degradation of a subset of misfolded proteins generated in the ER. We identify cyclophilin B (CyPB as the ER-resident target of CsA that catalytically enhances disposal from the ER of ERAD-L(S substrates containing cis proline residues. Our manuscript presents the first evidence for enzymatic involvement of a PPI in protein quality control in the ER of living cells.

Cyclosporine A-Sensitive, Cyclophilin B-Dependent Endoplasmic Reticulum-Associated Degradation

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Luban, Jeremy; Molinari, Maurizio

2010-01-01

Peptidyl-prolyl cis/trans isomerases (PPIs) catalyze cis/trans isomerization of peptide bonds preceding proline residues. The involvement of PPI family members in protein refolding has been established in test tube experiments. Surprisingly, however, no data is available on the involvement of endoplasmic reticulum (ER)-resident members of the PPI family in protein folding, quality control or disposal in the living cell. Here we report that the immunosuppressive drug cyclosporine A (CsA) selectively inhibits the degradation of a subset of misfolded proteins generated in the ER. We identify cyclophilin B (CyPB) as the ER-resident target of CsA that catalytically enhances disposal from the ER of ERAD-LS substrates containing cis proline residues. Our manuscript presents the first evidence for enzymatic involvement of a PPI in protein quality control in the ER of living cells. PMID:20927389

Degradation of structurally characterized proteins injected into HeLa cells. Basic measurements

International Nuclear Information System (INIS)

Rogers, S.W.; Rechsteiner, M.

1988-01-01

Thirty-five proteins of known x-ray structure were labeled by chloramine-T radioiodination or by reaction with 125I-Bolton-Hunter reagent and introduced into HeLa cells using red cell-mediated microinjection. Degradation rates of the injected proteins were then determined over the next 50 h by measuring the release of soluble isotope to the culture medium. Control experiments demonstrated that the measured rates were not compromised by proteolysis within RBCs, the presence of unfused RBCs, or degradation of protein released from RBCs to the medium. Degradation of some injected proteins was faster during the first 12 h after fusion than at later times, apparently a response of HeLa cells to trypsinization. However, all proteins exhibited first-order degradation rates between 24 and 48 h post injection. Except for seven proteins, stabilities measured during this interval were unaffected by the labeling procedure. Reductive methylation was used to choose among the seven discordant values, and half-lives for the 35 proteins ranged from 16 h for lysozyme to 214 h for yeast alcohol dehydrogenase. Since half-lives for six of the injected proteins closely match values obtained by in vivo measurements, we consider our estimates of the metabolic stabilities of the injected proteins to be generally accurate. Therefore, the half-lives obtained by microinjection should prove useful in the search for relationships between protein structure and intracellular stability

Sequence and 3D structure based analysis of TNT degrading proteins in Arabidopsis thaliana.

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Bhattacherjee, Amrita; Mandal, Rahul Shubhra; Das, Santasabuj; Kundu, Sudip

2014-03-01

TNT, accidentally released at several manufacturing sites, contaminates ground water and soil. It has a toxic effect to algae and invertebrate, and chronic exposure to TNT also causes harmful effects to human. On the other hand, many plants including Arabidopsis thaliana have the ability to metabolize TNT either completely or at least to a reduced less toxic form. In A. thaliana, the enzyme UDP glucosyltransferase (UDPGT) can further conjugate the reduced forms 2-HADNT and 4-HADNT (2-hydroxylamino-4, 6- dinitrotoluene and 4-hydroxylamino-2, 6- dinitrotoluene) of TNT. Based on the experimental analysis, existing literature and phylogenetic analysis, it is evident that among 107 UDPGT proteins only six are involved in the TNT degrading process. A total of 13 UDPGT proteins including five of these TNT degrading proteins fall within the same group of phylogeny. Thus, these 13 UDPGT proteins have been classified into two groups, TNT-degrading and TNT-non-degrading proteins. To understand the differences in TNT-degrading capacities; using homology modeling we first predicted two structures, taking one representative sequence from both the groups. Next, we performed molecular docking of the modeled structure and TNT reduced form 2-hydroxylamino-4, 6- dinitrotoluene (2-HADNT). We observed that while the Trp residue located within the active site region of the TNT- degrading protein showed π-Cation interaction; such type of interaction was absent in TNT-non-degrading protein, as the respective Trp residue lay outside of the pocket in this case. We observed the conservation of this π-Cation interaction during MD simulation of TNT-degrading protein. Thus, the position and the orientation of the active site residue Trp could explain the presence and absence of TNT-degrading capacity of the UDPGT proteins.

Prefoldin Promotes Proteasomal Degradation of Cytosolic Proteins with Missense Mutations by Maintaining Substrate Solubility.

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Sophie A Comyn

2016-07-01

Full Text Available Misfolded proteins challenge the ability of cells to maintain protein homeostasis and can accumulate into toxic protein aggregates. As a consequence, cells have adopted a number of protein quality control pathways to prevent protein aggregation, promote protein folding, and target terminally misfolded proteins for degradation. In this study, we employed a thermosensitive allele of the yeast Guk1 guanylate kinase as a model misfolded protein to investigate degradative protein quality control pathways. We performed a flow cytometry based screen to identify factors that promote proteasomal degradation of proteins misfolded as the result of missense mutations. In addition to the E3 ubiquitin ligase Ubr1, we identified the prefoldin chaperone subunit Gim3 as an important quality control factor. Whereas the absence of GIM3 did not impair proteasomal function or the ubiquitination of the model substrate, it led to the accumulation of the poorly soluble model substrate in cellular inclusions that was accompanied by delayed degradation. We found that Gim3 interacted with the Guk1 mutant allele and propose that prefoldin promotes the degradation of the unstable model substrate by maintaining the solubility of the misfolded protein. We also demonstrated that in addition to the Guk1 mutant, prefoldin can stabilize other misfolded cytosolic proteins containing missense mutations.

Iron-Binding Protein Degradation by Cysteine Proteases of Naegleria fowleri

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Moisés Martínez-Castillo

2015-01-01

Full Text Available Naegleria fowleri causes acute and fulminant primary amoebic meningoencephalitis. This microorganism invades its host by penetrating the olfactory mucosa and then traveling up the mesaxonal spaces and crossing the cribriform plate; finally, the trophozoites invade the olfactory bulbs. During its invasion, the protozoan obtains nutrients such as proteins, lipids, carbohydrates, and cationic ions (e.g., iron, calcium, and sodium from the host. However, the mechanism by which these ions are obtained, particularly iron, is poorly understood. In the present study, we evaluated the ability of N. fowleri to degrade iron-binding proteins, including hololactoferrin, transferrin, ferritin, and hemoglobin. Zymography assays were performed for each substrate under physiological conditions (pH 7 at 37°C employing conditioned medium (CM and total crude extracts (TCEs of N. fowleri. Different degradation patterns with CM were observed for hololactoferrin, transferrin, and hemoglobin; however, CM did not cause ferritin degradation. In contrast, the TCEs degraded only hololactoferrin and transferrin. Inhibition assays revealed that cysteine proteases were involved in this process. Based on these results, we suggest that CM and TCEs of N. fowleri degrade iron-binding proteins by employing cysteine proteases, which enables the parasite to obtain iron to survive while invading the central nervous system.

Hypothalamic ER–associated degradation regulates POMC maturation, feeding, and age-associated obesity

Science.gov (United States)

Kim, Geun Hyang; Somlo, Diane R.M.; Haataja, Leena; Song, Soobin; Nillni, Eduardo A.

2018-01-01

Pro-opiomelanocortin (POMC) neurons function as key regulators of metabolism and physiology by releasing prohormone-derived neuropeptides with distinct biological activities. However, our understanding of early events in prohormone maturation in the ER remains incomplete. Highlighting the significance of this gap in knowledge, a single POMC cysteine-to-phenylalanine mutation at position 28 (POMC-C28F) is defective for ER processing and causes early onset obesity in a dominant-negative manner in humans through an unclear mechanism. Here, we report a pathologically important role of Sel1L-Hrd1, the protein complex of ER-associated degradation (ERAD), within POMC neurons. Mice with POMC neuron–specific Sel1L deficiency developed age-associated obesity due, at least in part, to the ER retention of POMC that led to hyperphagia. The Sel1L-Hrd1 complex targets a fraction of nascent POMC molecules for ubiquitination and proteasomal degradation, preventing accumulation of misfolded and aggregated POMC, thereby ensuring that another fraction of POMC can undergo normal posttranslational processing and trafficking for secretion. Moreover, we found that the disease-associated POMC-C28F mutant evades ERAD and becomes aggregated due to the presence of a highly reactive unpaired cysteine thiol at position 50. Thus, this study not only identifies ERAD as an important mechanism regulating POMC maturation within the ER, but also provides insights into the pathogenesis of monogenic obesity associated with defective prohormone folding. PMID:29457782

ESCRT-dependent degradation of ubiquitylated plasma membrane proteins in plants.

Science.gov (United States)

Isono, Erika; Kalinowska, Kamila

2017-12-01

To control the abundance of plasma membrane receptors and transporters is crucial for proper perception and response to extracellular signals from surrounding cells and the environment. Posttranslational modification of plasma membrane proteins, especially ubiquitin conjugation or ubiquitylation, is key for the determination of stability for many transmembrane proteins localized on the cell surface. The targeted degradation is ensured by a complex network of proteins among which the endosomal sorting complex required for transport (ESCRT) plays a central role. This review focuses on progresses made in recent years on the understanding of the function of the ESCRT machinery in the degradation of ubiquitylated plasma membrane proteins in plants. Copyright © 2017 Elsevier Ltd. All rights reserved.

Non-degradative Ubiquitination of Protein Kinases.

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K Aurelia Ball

2016-06-01

Full Text Available Growing evidence supports other regulatory roles for protein ubiquitination in addition to serving as a tag for proteasomal degradation. In contrast to other common post-translational modifications, such as phosphorylation, little is known about how non-degradative ubiquitination modulates protein structure, dynamics, and function. Due to the wealth of knowledge concerning protein kinase structure and regulation, we examined kinase ubiquitination using ubiquitin remnant immunoaffinity enrichment and quantitative mass spectrometry to identify ubiquitinated kinases and the sites of ubiquitination in Jurkat and HEK293 cells. We find that, unlike phosphorylation, ubiquitination most commonly occurs in structured domains, and on the kinase domain, ubiquitination is concentrated in regions known to be important for regulating activity. We hypothesized that ubiquitination, like other post-translational modifications, may alter the conformational equilibrium of the modified protein. We chose one human kinase, ZAP-70, to simulate using molecular dynamics with and without a monoubiquitin modification. In Jurkat cells, ZAP-70 is ubiquitinated at several sites that are not sensitive to proteasome inhibition and thus may have other regulatory roles. Our simulations show that ubiquitination influences the conformational ensemble of ZAP-70 in a site-dependent manner. When monoubiquitinated at K377, near the C-helix, the active conformation of the ZAP-70 C-helix is disrupted. In contrast, when monoubiquitinated at K476, near the kinase hinge region, an active-like ZAP-70 C-helix conformation is stabilized. These results lead to testable hypotheses that ubiquitination directly modulates kinase activity, and that ubiquitination is likely to alter structure, dynamics, and function in other protein classes as well.

Nanobody-Directed Specific Degradation of Proteins by the 26S-Proteasome in Plants

OpenAIRE

Baudisch, Bianca; Pfort, Ingrid; Sorge, Eberhard; Conrad, Udo

2018-01-01

Here, we present data showing the directed degradation of target proteins recognized by a specific nanobody in transgenic plants. Green fluorescent protein was depleted by a chimeric nanobody fused to a distinct F-box domain, which enables protein degradation via the ubiquitin proteasome pathway. This technique could thus be used to knock out other proteins of interest in planta using specific, high-affinity binding proteins.

Nanobody-Directed Specific Degradation of Proteins by the 26S-Proteasome in Plants.

Science.gov (United States)

Baudisch, Bianca; Pfort, Ingrid; Sorge, Eberhard; Conrad, Udo

2018-01-01

Here, we present data showing the directed degradation of target proteins recognized by a specific nanobody in transgenic plants. Green fluorescent protein was depleted by a chimeric nanobody fused to a distinct F-box domain, which enables protein degradation via the ubiquitin proteasome pathway. This technique could thus be used to knock out other proteins of interest in planta using specific, high-affinity binding proteins.

Effects of grain source, grain processing, and protein degradability on rumen kinetics and microbial protein synthesis in Boer kids.

Science.gov (United States)

Brassard, M-E; Chouinard, P Y; Berthiaume, R; Tremblay, G F; Gervais, R; Martineau, R; Cinq-Mars, D

2015-11-01

Microbial protein synthesis in the rumen would be optimized when dietary carbohydrates and proteins have synchronized rates and extent of degradation. The aim of this study was to evaluate the effect of varying ruminal degradation rate of energy and nitrogen sources on intake, nitrogen balance, microbial protein yield, and kinetics of nutrients in the rumen of growing kids. Eight Boer goats (38.2 ± 3.0 kg) were used. The treatments were arranged in a split-plot Latin square design with grain sources (barley or corn) forming the main plots (squares). Grain processing methods and levels of protein degradability formed the subplots in a 2 × 2 factorial arrangement for a total of 8 dietary treatments. The grain processing method was rolling for barley and cracking for corn. Levels of protein degradability were obtained by feeding untreated soybean meal (SBM) or heat-treated soybean meal (HSBM). Each experimental period lasted 21 d, consisting of a 10-d adaptation period, a 7-d digestibility determination period, and a 4-d rumen evacuation and sampling period. Kids fed with corn had higher purine derivatives (PD) excretion when coupled with SBM compared with HSBM and the opposite occurred with barley-fed kids ( ≤ 0.01). Unprocessed grain offered with SBM led to higher PD excretion than with HSBM whereas protein degradability had no effect when processed grain was fed ( ≤ 0.03). Results of the current experiment with high-concentrate diets showed that microbial N synthesis could be maximized in goat kids by combining slowly fermented grains (corn or unprocessed grains) with a highly degradable protein supplement (SBM). With barley, a more rapidly fermented grain, a greater microbial N synthesis was observed when supplementing a low-degradable protein (HSBM).

Polyubiquitin chain assembly and organisation determine the dynamics of protein activation and degradation

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Lan K. Nguyen

2014-01-01

Full Text Available Protein degradation via ubiquitination is a major proteolytic mechanism in cells. Once a protein is destined for degradation, it is tagged by multiple ubiquitin molecules. The synthesised polyubiquitin chains can be recognised by the 26S proteosome where proteins are degraded. These chains form through multiple ubiquitination cycles that are similar to multi-site phosphorylation cycles. As kinases and phosphatases, two opposing enzymes (E3 ligases and deubiquitinases DUBs catalyse (deubiquitination cycles. Although multi-ubiquitination cycles are fundamental mechanisms of controlling protein concentrations within a cell, their dynamics have never been explored. Here, we fill this knowledge gap. We show that under permissive physiological conditions, the formation of polyubiquitin chain of length greater than two and subsequent degradation of the ubiquitinated protein, which is balanced by protein synthesis, can display bistable, switch-like responses. Interestingly, the occurrence of bistability becomes pronounced, as the chain grows, giving rise to all-or-none regulation at the protein levels. We give predictions of protein distributions under bistable regime awaiting experimental verification. Importantly, we show for the first time that sustained oscillations can robustly arise in the process of formation of ubiquitin chain, largely due to the degradation of the target protein. This new feature is opposite to the properties of multi-site phosphorylation cycles, which are incapable of generating oscillation if the total abundance of interconverted protein forms is conserved. We derive structural and kinetic constraints for the emergence of oscillations, indicating that a competition between different substrate forms and the E3 and DUB is critical for oscillation. Our work provides the first detailed elucidation of the dynamical features brought about by different molecular setups of the polyubiquitin chain assembly process responsible for

Monoubiquitination of Tob/BTG family proteins competes with degradation-targeting polyubiquitination

Energy Technology Data Exchange (ETDEWEB)

Suzuki, Toru, E-mail: toru@ims.u-tokyo.ac.jp [Division of Oncology, Institute of Medical Science, University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639 (Japan); Kim, Minsoo [Division of Bacterial Infection, Institute of Medical Science, University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639 (Japan); Kozuka-Hata, Hiroko [Medical Proteomics Laboratory, Institute of Medical Science, University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639 (Japan); Watanabe, Masato [Department of Medical Genome Science, School of Frontier Sciences, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa 277-8562 (Japan); Oyama, Masaaki [Medical Proteomics Laboratory, Institute of Medical Science, University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639 (Japan); Tsumoto, Kouhei [Medical Proteomics Laboratory, Institute of Medical Science, University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639 (Japan); Department of Medical Genome Science, School of Frontier Sciences, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa 277-8562 (Japan); Yamamoto, Tadashi, E-mail: tyamamot@ims.u-tokyo.ac.jp [Division of Oncology, Institute of Medical Science, University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639 (Japan); Cell Signal Unit, Okinawa Institute of Science and Technology, 1919-1 Onna-son, Kunigami, Okinawa 904-0412 (Japan)

2011-05-27

Highlights: {yields} Tob/BTG family proteins are monoubiquitinated in the absence of E3s in vitro. {yields} Monoubiquitination sites of Tob are identified by mass spectrometry. {yields} The monoubiquitination event correlates with lower levels of polyubiquitination. -- Abstract: Tob belongs to the anti-proliferative Tob/BTG protein family. The expression level of Tob family proteins is strictly regulated both transcriptionally and through post-translational modification. Ubiquitin (Ub)/proteosome-dependent degradation of Tob family proteins is critical in controlling cell cycle progression and DNA damage responses. Various Ub ligases (E3s) are responsible for degradation of Tob protein. Here, we show that Tob family proteins undergo monoubiquitination even in the absence of E3s in vitro. Determination of the ubiquitination site(s) in Tob by mass spectrometric analysis revealed that two lysine residues (Lys48 and Lys63) located in Tob/BTG homology domain are ubiquitinated. A mutant Tob, in which both Lys48 and Lys63 are substituted with alanine, is more strongly polyubiquitinated than wild-type Tob in vivo. These data suggest that monoubiquitination of Tob family proteins confers resistance against polyubiquitination, which targets proteins for degradation. The strategy for regulating the stability of Tob family proteins suggests a novel role for monoubiquitination.

Monoubiquitination of Tob/BTG family proteins competes with degradation-targeting polyubiquitination

International Nuclear Information System (INIS)

Suzuki, Toru; Kim, Minsoo; Kozuka-Hata, Hiroko; Watanabe, Masato; Oyama, Masaaki; Tsumoto, Kouhei; Yamamoto, Tadashi

2011-01-01

Highlights: → Tob/BTG family proteins are monoubiquitinated in the absence of E3s in vitro. → Monoubiquitination sites of Tob are identified by mass spectrometry. → The monoubiquitination event correlates with lower levels of polyubiquitination. -- Abstract: Tob belongs to the anti-proliferative Tob/BTG protein family. The expression level of Tob family proteins is strictly regulated both transcriptionally and through post-translational modification. Ubiquitin (Ub)/proteosome-dependent degradation of Tob family proteins is critical in controlling cell cycle progression and DNA damage responses. Various Ub ligases (E3s) are responsible for degradation of Tob protein. Here, we show that Tob family proteins undergo monoubiquitination even in the absence of E3s in vitro. Determination of the ubiquitination site(s) in Tob by mass spectrometric analysis revealed that two lysine residues (Lys48 and Lys63) located in Tob/BTG homology domain are ubiquitinated. A mutant Tob, in which both Lys48 and Lys63 are substituted with alanine, is more strongly polyubiquitinated than wild-type Tob in vivo. These data suggest that monoubiquitination of Tob family proteins confers resistance against polyubiquitination, which targets proteins for degradation. The strategy for regulating the stability of Tob family proteins suggests a novel role for monoubiquitination.

Nanobody-Directed Specific Degradation of Proteins by the 26S-Proteasome in Plants

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Bianca Baudisch

2018-02-01

Full Text Available Here, we present data showing the directed degradation of target proteins recognized by a specific nanobody in transgenic plants. Green fluorescent protein was depleted by a chimeric nanobody fused to a distinct F-box domain, which enables protein degradation via the ubiquitin proteasome pathway. This technique could thus be used to knock out other proteins of interest in planta using specific, high-affinity binding proteins.

Influence of anabolic agents on protein synthesis and degradation in muscle cells grown in culture

Energy Technology Data Exchange (ETDEWEB)

Roeder, R.A.; Thorpe, S.D.; Byers, F.M.; Schelling, G.T.; Gunn, J.M.

Muscle cell culture (L/sub 6/) studies were conducted to determine whether anabolic agents have a direct effect on the muscle cell. The effect of zeranol, testosterone propionate, estradiol benzoate, progesterone, dexamethasone and anabolic agent-dexamethasone combinations on protein synthesis and degradation were measured. Myoblast and myotube cultures were pretreated with 1 ..mu..M compounds for 12, 24 and 48 h before a 6-h synthesis or degradation measuring period. Protein synthesis was determined as cpm of (/sup 3/H) leucine incorporated per mg cell protein. Protein degradation was measured by a pulse-chase procedure using (/sup 3/H) leucine and expressed as the percentage labeled protein degraded in 6 h. Progesterone slightly increased protein synthesis in myoblast cultures. Testosterone propionate had no effect on synthesis. Protein synthesis was decreased by estradiol benzoate in myotube cultures. Protein degradation was not altered appreciably by anabolic agents. Protein synthesis was initially inhibited in myotubes by dexamethasone, but increased in myoblasts and myotubes in the extended incubation time. Dexamethasone also consistently increased protein degradation, but this required several hours to be expressed. Anabolic agents did not interfere with dexamethasone-induced increases in protein synthesis and degradation. The magnitude of response and sensitivity were similar for both the myoblast and the more fully differentiated myotube for all compounds tested. These results indicate that anabolic agents at the 1 ..mu..M level do not have a direct anabolic effect on muscle or alter glucocorticoid-induced catabolic response in muscle.

Influence of anabolic agents on protein synthesis and degradation in muscle cells grown in culture

International Nuclear Information System (INIS)

Roeder, R.A.; Thorpe, S.D.; Byers, F.M.; Schelling, G.T.; Gunn, J.M.

1986-01-01

Muscle cell culture (L 6 ) studies were conducted to determine whether anabolic agents have a direct effect on the muscle cell. The effect of zeranol, testosterone propionate, estradiol benzoate, progesterone, dexamethasone and anabolic agent-dexamethasone combinations on protein synthesis and degradation were measured. Myoblast and myotube cultures were pretreated with 1 μM compounds for 12, 24 and 48 h before a 6-h synthesis or degradation measuring period. Protein synthesis was determined as cpm of [ 3 H] leucine incorporated per mg cell protein. Protein degradation was measured by a pulse-chase procedure using [ 3 H] leucine and expressed as the percentage labeled protein degraded in 6 h. Progesterone slightly increased protein synthesis in myoblast cultures. Testosterone propionate had no effect on synthesis. Protein synthesis was decreased by estradiol benzoate in myotube cultures. Protein degradation was not altered appreciably by anabolic agents. Protein synthesis was initially inhibited in myotubes by dexamethasone, but increased in myoblasts and myotubes in the extended incubation time. Dexamethasone also consistently increased protein degradation, but this required several hours to be expressed. Anabolic agents did not interfere with dexamethasone-induced increases in protein synthesis and degradation. The magnitude of response and sensitivity were similar for both the myoblast and the more fully differentiated myotube for all compounds tested. These results indicate that anabolic agents at the 1 μM level do not have a direct anabolic effect on muscle or alter glucocorticoid-induced catabolic response in muscle

A Critical Appraisal of Quantitative Studies of Protein Degradation in the Framework of Cellular Proteostasis

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Beatriz Alvarez-Castelao

2012-01-01

Full Text Available Protein homeostasis, proteostasis, is essential to understand cell function. Protein degradation is a crucial component of the proteostatic mechanisms of the cell. Experiments on protein degradation are nowadays present in many investigations in the field of molecular and cell biology. In the present paper, we focus on the different experimental approaches to study protein degradation and present a critical appraisal of the results derived from steady-state and kinetic experiments using detection of unlabelled and labelled protein methodologies with a proteostatic perspective. This perspective allows pinpointing the limitations in interpretation of results and the need of further experiments and/or controls to establish “definitive evidence” for the role of protein degradation in the proteostasis of a given protein or the entire proteome. We also provide a spreadsheet for simple calculations of mRNA and protein decays for mimicking different experimental conditions and a checklist for the analysis of experiments dealing with protein degradation studies that may be useful for researchers interested in the area of protein turnover.

Heat Shock Proteins and Autophagy Pathways in Neuroprotection: from Molecular Bases to Pharmacological Interventions

Directory of Open Access Journals (Sweden)

Botond Penke

2018-01-01

Full Text Available Neurodegenerative diseases (NDDs such as Alzheimer’s disease, Parkinson’s disease and Huntington’s disease (HD, amyotrophic lateral sclerosis, and prion diseases are all characterized by the accumulation of protein aggregates (amyloids into inclusions and/or plaques. The ubiquitous presence of amyloids in NDDs suggests the involvement of disturbed protein homeostasis (proteostasis in the underlying pathomechanisms. This review summarizes specific mechanisms that maintain proteostasis, including molecular chaperons, the ubiquitin-proteasome system (UPS, endoplasmic reticulum associated degradation (ERAD, and different autophagic pathways (chaperon mediated-, micro-, and macro-autophagy. The role of heat shock proteins (Hsps in cellular quality control and degradation of pathogenic proteins is reviewed. Finally, putative therapeutic strategies for efficient removal of cytotoxic proteins from neurons and design of new therapeutic targets against the progression of NDDs are discussed.

ORGANIC MATTER AND CRUDE PROTEIN DEGRADATION SYNCHRONY IN DIETS SELECTED BY RANGE GOATS.

Directory of Open Access Journals (Sweden)

Rafael Ramírez Orduña

2010-09-01

Full Text Available The study was carried out with the aim to asses the synchrony of organic matter and crude protein degradation in the rumen of diets selected by range goats through two years. Five esophageal cannulated adult male goats were used to collect extrusa samples during summer (August 9–13 and autumn (November 29 –December 3 of 2006, winter (February 20 – 24, spring (April 29 –May 5, summer (September 10–15 and autumn (December 4–8 of 2007 and winter (February 20 – 25 and spring (May 9 –13 of 2008. Extrusa samples were subjected to chemical analysis to determine organic matter (OM, crude protein (CP in situ and in vitro true digestibility of dry matter. OM and CP intake were estimated by total fecal collection. Effective extent of degradation of the OM and CP was calculated hourly and total 24 hours. From the hourly quantity of OM and CP degraded, a synchrony index of CP to OM was calculated, and from the total 24 hours degradation, degraded organic matter intake and crude protein intake were also estimated. Sampling date was the main effect that determined the variation of diet OM and CP degradation parameters. Degraded crude protein intake as a proportion of degraded OM was affected by sampling date and was correlated to rainfall. During winter of the first year degraded crude protein intake was below the requirements for maintenance or to promote growth for range goats weighing 40 kg. Even though, synchrony index between OM and CP degradation was affected by sampling date goats maintained a high synchrony index throughout the years.

Chemical degradation of proteins in the solid state with a focus on photochemical reactions.

Science.gov (United States)

Mozziconacci, Olivier; Schöneich, Christian

2015-10-01

Protein pharmaceuticals comprise an increasing fraction of marketed products but the limited solution stability of proteins requires considerable research effort to prepare stable formulations. An alternative is solid formulation, as proteins in the solid state are thermodynamically less susceptible to degradation. Nevertheless, within the time of storage a large panel of kinetically controlled degradation reactions can occur such as, e.g., hydrolysis reactions, the formation of diketopiperazine, condensation and aggregation reactions. These mechanisms of degradation in protein solids are relatively well covered by the literature. Considerably less is known about oxidative and photochemical reactions of solid proteins. This review will provide an overview over photolytic and non-photolytic degradation reactions, and specially emphasize mechanistic details on how solid structure may affect the interaction of protein solids with light. Copyright © 2014 Elsevier B.V. All rights reserved.

Does altered protein metabolism interfere with postmortem degradation analysis for PMI estimation?

Science.gov (United States)

Zissler, A; Ehrenfellner, B; Foditsch, E E; Monticelli, F C; Pittner, S

2018-03-02

An accurate estimation of the postmortem interval (PMI) is a central aspect in forensic routine. Recently, a novel approach based on the analysis of postmortem muscle protein degradation has been proposed. However, a number of questions remain to be answered until sensible application of this method to a broad variety of forensic cases is possible. To evaluate whether altered in vivo protein metabolism interferes with postmortem degradation patterns, we conducted a comparative study. We developed a standardized animal degradation model in rats, and collected additional muscle samples from animals recovering from muscle injury and from rats with developed disuse muscle atrophy after induced spinal cord injury. All samples were analyzed by SDS-PAGE and Western blot, labeling well-characterized muscle proteins. Tropomyosin was found to be stable throughout the investigated PMI and no alterations were detected in regenerating and atrophic muscles. In contrast, significant predictable postmortem changes occurred in desmin and vinculin protein band patterns. While no significant deviations from native patterns were detected in at-death samples of disuse muscle atrophy, interestingly, samples of rats recovering from muscle injury revealed additional desmin and vinculin degradation bands that did not occur in this form in any of the examined postmortem samples regardless of PMI. It remains to be investigated whether in vivo-altered metabolism influences postmortem degradation kinetics or if such muscle samples undergo postmortem degradation in a regular fashion.

Eradication of dracunculiasis from Pakistan.

Science.gov (United States)

Hopkins, D R; Azam, M; Ruiz-Tiben, E; Kappus, K D

1995-09-02

In 1986 the World Health Organization targeted dracunculiasis (Guinea-worm disease), which seriously impairs socioeconomic development in 16 African countries, India, Pakistan, and Yemen, to be eradicated globally. The target date for eradication by the end of 1995 was established in 1991. Pakistan eradicated dracunculiasis from the country in October, 1993, after a national campaign which began in 1987 with a nationwide village-by-village search for cases. The infection, which is transmitted by drinking water from ponds containing infected water fleas, was eradicated by using health education, cloth filters, and the cyclopsicide, temephos; and in the later stages, by case containment. Methods pioneered in Pakistan's National Guinea Worm Eradication Program are now being applied in remaining endemic countries.

Degradation of Human PDZ-Proteins by Human Alphapapillomaviruses Represents an Evolutionary Adaptation to a Novel Cellular Niche

Science.gov (United States)

Van Doorslaer, Koenraad; DeSalle, Rob; Einstein, Mark H.; Burk, Robert D.

2015-01-01

In order to complete their life cycle, papillomaviruses have evolved to manipulate a plethora of cellular pathways. The products of the human Alphapapillomavirus E6 proteins specifically interact with and target PDZ containing proteins for degradation. This viral phenotype has been suggested to play a role in viral oncogenesis. To analyze the association of HPV E6 mediated PDZ-protein degradation with cervical oncogenesis, a high-throughput cell culture assay was developed. Degradation of an epitope tagged human MAGI1 isoform was visualized by immunoblot. The correlation between HPV E6-induced degradation of hMAGI1 and epidemiologically determined HPV oncogenicity was evaluated using a Bayesian approach within a phylogenetic context. All tested oncogenic types degraded the PDZ-containing protein hMAGI1d; however, E6 proteins isolated from several related albeit non-oncogenic viral types were equally efficient at degrading hMAGI1. The relationship between both traits (oncogenicity and PDZ degradation potential) is best explained by a model in which the potential to degrade PDZ proteins was acquired prior to the oncogenic phenotype. This analysis provides evidence that the ancestor of both oncogenic and non-oncogenic HPVs acquired the potential to degrade human PDZ-containing proteins. This suggests that HPV E6 directed degradation of PDZ-proteins represents an ancient ecological niche adaptation. Phylogenetic modeling indicates that this phenotype is not specifically correlated with oncogenic risk, but may act as an enabling phenotype. The role of PDZ protein degradation in HPV fitness and oncogenesis needs to be interpreted in the context of Alphapapillomavirus evolution. PMID:26086730

Degradation of Human PDZ-Proteins by Human Alphapapillomaviruses Represents an Evolutionary Adaptation to a Novel Cellular Niche.

Directory of Open Access Journals (Sweden)

Koenraad Van Doorslaer

2015-06-01

Full Text Available In order to complete their life cycle, papillomaviruses have evolved to manipulate a plethora of cellular pathways. The products of the human Alphapapillomavirus E6 proteins specifically interact with and target PDZ containing proteins for degradation. This viral phenotype has been suggested to play a role in viral oncogenesis. To analyze the association of HPV E6 mediated PDZ-protein degradation with cervical oncogenesis, a high-throughput cell culture assay was developed. Degradation of an epitope tagged human MAGI1 isoform was visualized by immunoblot. The correlation between HPV E6-induced degradation of hMAGI1 and epidemiologically determined HPV oncogenicity was evaluated using a Bayesian approach within a phylogenetic context. All tested oncogenic types degraded the PDZ-containing protein hMAGI1d; however, E6 proteins isolated from several related albeit non-oncogenic viral types were equally efficient at degrading hMAGI1. The relationship between both traits (oncogenicity and PDZ degradation potential is best explained by a model in which the potential to degrade PDZ proteins was acquired prior to the oncogenic phenotype. This analysis provides evidence that the ancestor of both oncogenic and non-oncogenic HPVs acquired the potential to degrade human PDZ-containing proteins. This suggests that HPV E6 directed degradation of PDZ-proteins represents an ancient ecological niche adaptation. Phylogenetic modeling indicates that this phenotype is not specifically correlated with oncogenic risk, but may act as an enabling phenotype. The role of PDZ protein degradation in HPV fitness and oncogenesis needs to be interpreted in the context of Alphapapillomavirus evolution.

Degradation of Human PDZ-Proteins by Human Alphapapillomaviruses Represents an Evolutionary Adaptation to a Novel Cellular Niche.

Science.gov (United States)

Van Doorslaer, Koenraad; DeSalle, Rob; Einstein, Mark H; Burk, Robert D

2015-06-01

In order to complete their life cycle, papillomaviruses have evolved to manipulate a plethora of cellular pathways. The products of the human Alphapapillomavirus E6 proteins specifically interact with and target PDZ containing proteins for degradation. This viral phenotype has been suggested to play a role in viral oncogenesis. To analyze the association of HPV E6 mediated PDZ-protein degradation with cervical oncogenesis, a high-throughput cell culture assay was developed. Degradation of an epitope tagged human MAGI1 isoform was visualized by immunoblot. The correlation between HPV E6-induced degradation of hMAGI1 and epidemiologically determined HPV oncogenicity was evaluated using a Bayesian approach within a phylogenetic context. All tested oncogenic types degraded the PDZ-containing protein hMAGI1d; however, E6 proteins isolated from several related albeit non-oncogenic viral types were equally efficient at degrading hMAGI1. The relationship between both traits (oncogenicity and PDZ degradation potential) is best explained by a model in which the potential to degrade PDZ proteins was acquired prior to the oncogenic phenotype. This analysis provides evidence that the ancestor of both oncogenic and non-oncogenic HPVs acquired the potential to degrade human PDZ-containing proteins. This suggests that HPV E6 directed degradation of PDZ-proteins represents an ancient ecological niche adaptation. Phylogenetic modeling indicates that this phenotype is not specifically correlated with oncogenic risk, but may act as an enabling phenotype. The role of PDZ protein degradation in HPV fitness and oncogenesis needs to be interpreted in the context of Alphapapillomavirus evolution.

The Polerovirus silencing suppressor P0 targets ARGONAUTE proteins for degradation.

Science.gov (United States)

Baumberger, Nicolas; Tsai, Ching-Hsui; Lie, Miranda; Havecker, Ericka; Baulcombe, David C

2007-09-18

Plant and animal viruses encode suppressor proteins of an adaptive immunity mechanism in which viral double-stranded RNA is processed into 21-25 nt short interfering (si)RNAs. The siRNAs guide ARGONAUTE (AGO) proteins so that they target viral RNA. Most viral suppressors bind long dsRNA or siRNAs and thereby prevent production of siRNA or binding of siRNA to AGO. The one exception is the 2b suppressor of Cucumoviruses that binds to and inhibits AGO1. Here we describe a novel suppressor mechanism in which a Polerovirus-encoded F box protein (P0) targets the PAZ motif and its adjacent upstream sequence in AGO1 and mediates its degradation. F box proteins are components of E3 ubiquitin ligase complexes that add polyubiquitin tracts on selected lysine residues and thereby mark a protein for proteasome-mediated degradation. With P0, however, the targeted degradation of AGO is insensitive to inhibition of the proteasome, indicating that the proteasome is not involved. We also show that P0 does not block a mobile signal of silencing, indicating that the signal molecule does not have AGO protein components. The ability of P0 to block silencing without affecting signal movement may contribute to the phloem restriction of viruses in the Polerovirus group.

Endoplasmic Reticulum-Targeted Subunit Toxins Provide a New Approach to Rescue Misfolded Mutant Proteins and Revert Cell Models of Genetic Diseases

OpenAIRE

Adnan, Humaira; Zhang, Zhenbo; Park, Hyun-Joo; Tailor, Chetankumar; Che, Clare; Kamani, Mustafa; Spitalny, George; Binnington, Beth; Lingwood, Clifford

2016-01-01

Many germ line diseases stem from a relatively minor disturbance in mutant protein endoplasmic reticulum (ER) 3D assembly. Chaperones are recruited which, on failure to correct folding, sort the mutant for retrotranslocation and cytosolic proteasomal degradation (ER-associated degradation-ERAD), to initiate/exacerbate deficiency-disease symptoms. Several bacterial (and plant) subunit toxins, retrograde transport to the ER after initial cell surface receptor binding/internalization. The A subu...

Protein aggregation and degradation during iodine labeling and its consequences for protein adsorption to biomaterials

DEFF Research Database (Denmark)

Holmberg, Maria; Jensen, Karin Bagger Stibius; Ndoni, Sokol

2007-01-01

Protein adsorption on modified and unmodified polymer surfaces investigated through radiolabeling experiments showed a tendency for higher than expected albumin and immunoglobulin G (IgG) adsorption. Possible enhanced protein aggregation and degradation caused by the iodine labeling method used w...

Biological Feasibility of Measles Eradication

Science.gov (United States)

Strebel, Peter

2011-01-01

Recent progress in reducing global measles mortality has renewed interest in measles eradication. Three biological criteria are deemed important for disease eradication: (1) humans are the sole pathogen reservoir; (2) accurate diagnostic tests exist; and (3) an effective, practical intervention is available at reasonable cost. Interruption of transmission in large geographical areas for prolonged periods further supports the feasibility of eradication. Measles is thought by many experts to meet these criteria: no nonhuman reservoir is known to exist, accurate diagnostic tests are available, and attenuated measles vaccines are effective and immunogenic. Measles has been eliminated in large geographical areas, including the Americas. Measles eradication is biologically feasible. The challenges for measles eradication will be logistical, political, and financial. PMID:21666201

The establishment of a protein degradability data base for dairy ...

African Journals Online (AJOL)

The degradability values ranged from 96,2; 91,9 and 88,7% for ... McDonald, 1979; Kristensen, et ai., 1982; Lindberg,. 1983 ... mass of 570 kg, and average production of 5000 kg ... Dicalcium phosphate'. 0,5. Commercial vitamin and trace mineral premix. 0,3 .... effects on the degradation of most protein supplements.

Endgame for polio eradication? Options for overcoming social and political factors in the progress to eradicating polio.

Science.gov (United States)

Ganapathiraju, Pavan V; Morssink, Christiaan B; Plumb, James

2015-01-01

In 1988, the Global Polio Eradication Initiative (GPEI) was launched with the goal of eradicating polio by the year 2000. After 25 years, several dynamics still challenge this large public health campaign with new cases of polio being reported annually. We examine the roots of this initiative to eradicate polio, its scope, the successes and setbacks during the last 25 years and reflect on the current state of affairs. We examine the social and political factors that are barriers to polio eradication. Options are discussed for solving the current impasse of polio eradication: using force, respecting individual freedoms and gaining support from those vulnerable to fundamentalist 'propaganda'. The travails of the GPEI indicate the need for expanding the Convention on the Rights of the Child to address situations of war and civic strife. Such a cultural and structural reference will provide the basis for global stakeholders to engage belligerent local actors whose local political conflicts are barriers to the eradication of polio. Disregard for these actors will result in stagnation of polio eradication policy, delaying eradication beyond 2018.

Global Polio Eradication - Way Ahead.

Science.gov (United States)

Bahl, Sunil; Bhatnagar, Pankaj; Sutter, Roland W; Roesel, Sigrun; Zaffran, Michel

2018-02-01

In 1988, the World Health Assembly resolved to eradicate poliomyelitis by the year 2000. Although substantial progress was achieved by 2000, global polio eradication proved elusive. In India, the goal was accomplished in 2011, and the entire South-East Asia Region was certified as polio-free in 2014. The year 2016 marks the lowest wild poliovirus type 1 case count ever, the lowest number of polio-endemic countries (Afghanistan, Nigeria and Pakistan), the maintenance of wild poliovirus type 2 eradication, and the continued absence of wild poliovirus type 3 detection since 2012. The year also marks the Global Polio Eradication Initiative (GPEI) moving into the post-cessation of Sabin type 2, after the effort of globally synchronized withdrawal of Sabin type 2 poliovirus in April 2016. Sustained efforts will be needed to ensure polio eradication is accomplished, to overcome the access and security issues, and continue to improve the quality and reach of field operations. After that, surveillance (the "eyes and ears") will move further to the center stage. Sensitive surveillance will monitor the withdrawal of all Sabin polioviruses, and with facility containment, constitute the cornerstones for eventual global certification of wild poliovirus eradication. An emergency response capacity is essential to institute timely control measures should polio still re-emerge. Simultaneously, the public health community needs to determine whether and how to apply the polio-funded infrastructure to other priorities (after the GPEI funding has stopped). Eradication is the primary goal, but securing eradication will require continued efforts, dedicated resources, and a firm commitment by the global public health community.

The F-box Protein FBXO44 Mediates BRCA1 Ubiquitination and Degradation*

Science.gov (United States)

Lu, Yunzhe; Li, Jiezhi; Cheng, Dongmei; Parameswaran, Balaji; Zhang, Shaohua; Jiang, Zefei; Yew, P. Renee; Peng, Junmin; Ye, Qinong; Hu, Yanfen

2012-01-01

BRCA1 mutations account for a significant proportion of familial breast and ovarian cancers. In addition, reduced BRCA1 protein is associated with sporadic cancer cases in these tissues. At the cellular level, BRCA1 plays a critical role in multiple cellular functions such as DNA repair and cell cycle checkpoint control. Its protein level is regulated in a cell cycle-dependent manner. However, regulation of BRCA1 protein stability is not fully understood. Our earlier study showed that the amino terminus of BRCA1 harbors a degron sequence that is sufficient and necessary for conferring BRCA1 degradation. In the current study, we used mass spectrometry to identify Skp1 that regulates BRCA1 protein stability. Small interfering RNA screening that targets all human F-box proteins uncovered FBXO44 as an important protein that influences BRCA1 protein level. The Skp1-Cul1-F-box-protein44 (SCFFBXO44) complex ubiquitinates full-length BRCA1 in vitro. Furthermore, the N terminus of BRCA1 mediates the interaction between BRCA1 and FBXO44. Overexpression of SCFFBXO44 reduces BRCA1 protein level. Taken together, our work strongly suggests that SCFFBXO44 is an E3 ubiquitin ligase responsible for BRCA1 degradation. In addition, FBXO44 expression pattern in breast carcinomas suggests that SCFFBXO44-mediated BRCA1 degradation might contribute to sporadic breast tumor development. PMID:23086937

Estimation of Relationship Between In Situ and In Vitro Rumen Protein Degradability of Extruded Full Fat Soybean

Directory of Open Access Journals (Sweden)

Arzu Erol Tunç

2017-10-01

Full Text Available The objectives of this study were to estimate the protein degradability of extruded full fat soybean (ESB by in situ (nylon bag and in vitro enzymatic method and to develop an equation in order predict in situ degradability from in vitro values. In the study enzymatic technique; hydrolysis after 1 h (INV1 and after 24 h (INV24 by a purified protease extracted from Streptomyces griseus in a borate-phosphate buffer at pH 8 was used as in vitro method. Relationship between in situ effective protein degradability (INSE and in vitro degradability after 1 and 24 hours incubations (INV1 and INV24 were determined. In situ protein degradability was measured at 0, 2, 4, 8, 16, 24, and 48 and at 72 h incubations in the rumen of 3 Holstein cows. In the study INSE, INV1 and INV24 were determined as 58.05, 20.24 and 41.46% respectively. Despite there were differences between in situ and in vitro protein degradability values, correlation coefficients between in situ and in vitro protein degradability of ESB were high and regression equations for estimation of in situ from in vitro were found significant. As conclusion in vitro enzymatic protein degradability (INV1 and INV24 can be used for estimation of in situ effective protein degradability of extruded full fat soybean.

The Arabidopsis CROWDED NUCLEI genes regulate seed germination by modulating degradation of ABI5 protein.

Science.gov (United States)

Zhao, Wenming; Guan, Chunmei; Feng, Jian; Liang, Yan; Zhan, Ni; Zuo, Jianru; Ren, Bo

2016-07-01

In Arabidopsis, the phytohormone abscisic acid (ABA) plays a vital role in inhibiting seed germination and in post-germination seedling establishment. In the ABA signaling pathway, ABI5, a basic Leu zipper transcription factor, has important functions in the regulation of seed germination. ABI5 protein localizes in nuclear bodies, along with AFP, COP1, and SIZ1, and was degraded through the 26S proteasome pathway. However, the mechanisms of ABI5 nuclear body formation and ABI5 protein degradation remain obscure. In this study, we found that the Arabidopsis CROWDED NUCLEI (CRWN) proteins, predicted nuclear matrix proteins essential for maintenance of nuclear morphology, also participate in ABA-controlled seed germination by regulating the degradation of ABI5 protein. During seed germination, the crwn mutants are hypersensitive to ABA and have higher levels of ABI5 protein compared to wild type. Genetic analysis suggested that CRWNs act upstream of ABI5. The observation that CRWN3 colocalizes with ABI5 in nuclear bodies indicates that CRWNs might participate in ABI5 protein degradation in nuclear bodies. Moreover, we revealed that the extreme C-terminal of CRWN3 protein is necessary for its function in the response to ABA in germination. Our results suggested important roles of CRWNs in ABI5 nuclear body organization and ABI5 protein degradation during seed germination. © 2015 Institute of Botany, Chinese Academy of Sciences.

Metabolic consequences of Helicobacter pylori infection and eradication

Science.gov (United States)

Buzás, György Miklós

2014-01-01

Helicobacter pylori (H. pylori) is still the most prevalent infection of the world. Colonization of the stomach by this agent will invariably induce chronic gastritis which is a low-grade inflammatory state leading to local complications (peptic ulcer, gastric cancer, lymphoma) and remote manifestations. While H. pylori does not enter circulation, these extragastric manifestations are probably mediated by the cytokines and acute phase proteins produced by the inflammed mucosa. The epidemiologic link between the H. pylori infection and metabolic changes is inconstant and controversial. Growth delay was described mainly in low-income regions with high prevalence of the infection, where probably other nutritional and social factors contribute to it. The timely eradication of the infection will lead to a more healthy development of the young population, along with preventing peptic ulcers and gastric cancer An increase of total, low density lipoprotein and high density liporotein cholesterol levels in some infected people creates an atherogenic lipid profile which could promote atherosclerosis with its complications, myocardial infarction, stroke and peripheral vascular disease. Well designed and adequately powered long-term studies are required to see whether eradication of the infection will prevent these conditions. In case of glucose metabolism, the most consistent association was found between H. pylori and insulin resistance: again, proof that eradication prevents this common metabolic disturbance is expected. The results of eradication with standard regimens in diabetics are significantly worse than in non-diabetic patients, thus, more active regimens must be found to obtain better results. Successful eradication itself led to an increase of body mass index and cholesterol levels in some populations, while in others no such changes were encountered. Uncertainities of the metabolic consequences of H. pylori infection must be clarified in the future. PMID:24833852

Muscle protein degradation and amino acid metabolism during prolonged knee-extensor exercise in humans

DEFF Research Database (Denmark)

Van Hall, Gerrit; Saltin, B; Wagenmakers, A J

1999-01-01

to a substantial increase in net muscle protein degradation, and that a lowering of the starting muscle glycogen content leads to a further increase. The carbon atoms of the branched-chain amino acids (BCAA), glutamate, aspartate and asparagine, liberated by protein degradation, and the BCAA and glutamate......The aim of this study was to investigate whether prolonged one-leg knee-extensor exercise enhances net protein degradation in muscle with a normal or low glycogen content. Net amino acid production, as a measure of net protein degradation, was estimated from leg exchange and from changes...... in the concentrations of amino acids that are not metabolized in skeletal muscle. Experiments were performed at rest and during one-leg knee-extensor exercise in six subjects having one leg with a normal glycogen content and the other with a low glycogen content. Exercise was performed for 90 min at a workload of 60...

Effects of gamma irradiation on chemical composition and ruminal protein degradation of canola meal

Science.gov (United States)

Shawrang, P.; Nikkhah, A.; Zare-Shahneh, A.; Sadeghi, A. A.; Raisali, G.; Moradi-Shahrebabak, M.

2008-07-01

Gamma irradiation of canola meal (at doses of 25, 50 and 75 kGy) could alter its ruminal protein degradation characteristics by cross-linking of the polypeptide chains. This processing resulted in decrease (linear effect, Pruminal protein degradation and increase (linear effect, Pruminant nutrition.

The F-box protein FBXO44 mediates BRCA1 ubiquitination and degradation.

Science.gov (United States)

Lu, Yunzhe; Li, Jiezhi; Cheng, Dongmei; Parameswaran, Balaji; Zhang, Shaohua; Jiang, Zefei; Yew, P Renee; Peng, Junmin; Ye, Qinong; Hu, Yanfen

2012-11-30

BRCA1 mutations account for a significant proportion of familial breast and ovarian cancers. In addition, reduced BRCA1 protein is associated with sporadic cancer cases in these tissues. At the cellular level, BRCA1 plays a critical role in multiple cellular functions such as DNA repair and cell cycle checkpoint control. Its protein level is regulated in a cell cycle-dependent manner. However, regulation of BRCA1 protein stability is not fully understood. Our earlier study showed that the amino terminus of BRCA1 harbors a degron sequence that is sufficient and necessary for conferring BRCA1 degradation. In the current study, we used mass spectrometry to identify Skp1 that regulates BRCA1 protein stability. Small interfering RNA screening that targets all human F-box proteins uncovered FBXO44 as an important protein that influences BRCA1 protein level. The Skp1-Cul1-F-box-protein44 (SCF(FBXO44)) complex ubiquitinates full-length BRCA1 in vitro. Furthermore, the N terminus of BRCA1 mediates the interaction between BRCA1 and FBXO44. Overexpression of SCF(FBXO44) reduces BRCA1 protein level. Taken together, our work strongly suggests that SCF(FBXO44) is an E3 ubiquitin ligase responsible for BRCA1 degradation. In addition, FBXO44 expression pattern in breast carcinomas suggests that SCF(FBXO44)-mediated BRCA1 degradation might contribute to sporadic breast tumor development.

The establishment of a protein degradability data base for dairy ...

African Journals Online (AJOL)

The establishment of a protein degradability data base for dairy cattle using the nylon bag technique. 1. Protein sources. LJ Erasmus, J Prinsloo, HH Meissner. Abstract. No Abstract. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · AJOL African Journals ...

Effects of gamma irradiation on chemical composition and ruminal protein degradation of canola meal

Energy Technology Data Exchange (ETDEWEB)

Shawrang, P. [Agriculture, Medical and Industrial Research School, Nuclear Science and Technology Research Institute, Atomic Energy Organization of Iran, P.O. Box 31485-498, Karaj (Iran, Islamic Republic of); Department of Animal Science, Faculty of Agriculture, Tehran University P.O. Box 4111, Karaj (Iran, Islamic Republic of)], E-mail: parvinshawrang@yahoo.co.uk; Nikkhah, A.; Zare-Shahneh, A. [Department of Animal Science, Faculty of Agriculture, Tehran University P.O. Box 4111, Karaj (Iran, Islamic Republic of); Sadeghi, A.A. [Department of Animal Science, Faculty of Agriculture, Science and Research Branch, Islamic Azad University, P.O. Box 14515-4933, Tehran (Iran, Islamic Republic of); Raisali, G. [Radiation Applications Research School, Nuclear Science and Technology Research Institute, Atomic Energy Organization of Iran, P.O. Box 11365-3486, Tehran (Iran, Islamic Republic of); Moradi-Shahrebabak, M. [Department of Animal Science, Faculty of Agriculture, Tehran University P.O. Box 4111, Karaj (Iran, Islamic Republic of)

2008-07-15

Gamma irradiation of canola meal (at doses of 25, 50 and 75 kGy) could alter its ruminal protein degradation characteristics by cross-linking of the polypeptide chains. This processing resulted in decrease (linear effect, P<0.001) of ruminal protein degradation and increase (linear effect, P<0.001) of intestinal protein digestibility. The results showed that gamma irradiation at doses higher than 25 kGy can be used as a cross-linking agent to improve protein properties of supplements in ruminant nutrition.

Effects of gamma irradiation on chemical composition and ruminal protein degradation of canola meal

International Nuclear Information System (INIS)

Shawrang, P.; Nikkhah, A.; Zare-Shahneh, A.; Sadeghi, A.A.; Raisali, G.; Moradi-Shahrebabak, M.

2008-01-01

Gamma irradiation of canola meal (at doses of 25, 50 and 75 kGy) could alter its ruminal protein degradation characteristics by cross-linking of the polypeptide chains. This processing resulted in decrease (linear effect, P<0.001) of ruminal protein degradation and increase (linear effect, P<0.001) of intestinal protein digestibility. The results showed that gamma irradiation at doses higher than 25 kGy can be used as a cross-linking agent to improve protein properties of supplements in ruminant nutrition

Reflux esophagitis triggered after Helicobacter pylori eradication: a noteworthy demerit of eradication therapy among the Japanese?

Directory of Open Access Journals (Sweden)

Katsunori eIijima

2015-06-01

Full Text Available In the February 2013 Revision of Insured Medical Treatment, bacterial eradication for all Helicobacter pylori-positive individuals in Japan was covered under the insurance scheme. However, reflux esophagitis is believed to occur in approximately 10% of Japanese patients who undergo eradication therapy. Hence, the risk of reflux esophagitis among such cases should be carefully considered, particularly in the treatment for H. pylori-positive patients who are otherwise healthy. The eradication of Helicobacter pylori in cases of H. pylori-positive gastritis markedly suppresses gastric inflammation, and inhibits gastric mucosal atrophy and its progression to intestinal metaplasia. In a long-term follow-up study (10-20 years, eradication treatment was found to reduce the risk of subsequent gastric cancer. However, the fact that eradication-induced reflux esophagitis could increase the long-term risk of Barrett’s esophagus and esophageal adenocarcinoma should also be considered in the Japanese population. Appropriate treatment with proton pump inhibitors should be taken into consideration for patients undergoing eradication therapy in clinical practice.

Tsetse eradication: Zanzibar

International Nuclear Information System (INIS)

2003-01-01

Tsetse flies (Glossina sp.) continue to make livestock production difficult or impossible throughout a very large part of Africa. One of the most promising techniques for eradicating tsetse from certain locations is the environmentally safe Sterile Insect Technique (SIT). In collaboration with the Tanzanian authorities, the Department of Technical Co-operation is sponsoring a programme, with technical support from the Joint FAO/IAEA Division, to eradicate tsetse from Zanzibar using the SIT. (IAEA)

Fabrication of Flexible, Fully Organic, Degradable Energy Storage Devices Using Silk Proteins.

Science.gov (United States)

Pal, Ramendra K; Kundu, Subhas C; Yadavalli, Vamsi K

2018-03-21

Flexible and thin-film devices are of great interest in epidermal and implantable bioelectronics. The integration of energy storage and delivery devices such as supercapacitors (SCs) with properties such as flexibility, miniaturization, biocompatibility, and degradability are sought for such systems. Reducing e-waste and using sustainable materials and processes are additional desirable qualities. Herein, a silk protein-based biocompatible and degradable thin-film microSC (μSC) is reported. A protein carrier with the conducting polymer poly(3,4-ethylenedioxythiophene) polystyrene sulfonate and reduced graphene oxide dopant is used as a photopatternable biocomposite ink. Active electrodes are fabricated using photolithography under benign conditions, using only water as the solvent. These electrodes are printed on flexible protein sheets to form degradable, organic devices with a benign agarose-NaCl gel electrolyte. High capacitance, power density, cycling stability over 500 cycles, and the ability to power a light-emitting diode are shown. The device is flexible, can sustain cyclic mechanical stresses over 450 cycles, and retain capacitive properties over several days in liquid. Significantly, the μSCs are cytocompatible and completely degraded over the period of ∼1 month. By precise control of the device configuration, these silk protein-based, all-polymer organic devices can be designed to be tunably transient and provide viable alternatives for powering flexible and implantable bioelectronics.

The central domain of yeast transcription factor Rpn4 facilitates degradation of reporter protein in human cells.

Science.gov (United States)

Morozov, A V; Spasskaya, D S; Karpov, D S; Karpov, V L

2014-10-16

Despite high interest in the cellular degradation machinery and protein degradation signals (degrons), few degrons with universal activity along species have been identified. It has been shown that fusion of a target protein with a degradation signal from mammalian ornithine decarboxylase (ODC) induces fast proteasomal degradation of the chimera in both mammalian and yeast cells. However, no degrons from yeast-encoded proteins capable to function in mammalian cells were identified so far. Here, we demonstrate that the yeast transcription factor Rpn4 undergoes fast proteasomal degradation and its central domain can destabilize green fluorescent protein and Alpha-fetoprotein in human HEK 293T cells. Furthermore, we confirm the activity of this degron in yeast. Thus, the Rpn4 central domain is an effective interspecies degradation signal. Copyright © 2014 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

Activity dependent protein degradation is critical for the formation and stability of fear memory in the amygdala.

Directory of Open Access Journals (Sweden)

Timothy J Jarome

Full Text Available Protein degradation through the ubiquitin-proteasome system [UPS] plays a critical role in some forms of synaptic plasticity. However, its role in memory formation in the amygdala, a site critical for the formation of fear memories, currently remains unknown. Here we provide the first evidence that protein degradation through the UPS is critically engaged at amygdala synapses during memory formation and retrieval. Fear conditioning results in NMDA-dependent increases in degradation-specific polyubiquitination in the amygdala, targeting proteins involved in translational control and synaptic structure and blocking the degradation of these proteins significantly impairs long-term memory. Furthermore, retrieval of fear memory results in a second wave of NMDA-dependent polyubiquitination that targets proteins involved in translational silencing and synaptic structure and is critical for memory updating following recall. These results indicate that UPS-mediated protein degradation is a major regulator of synaptic plasticity necessary for the formation and stability of long-term memories at amygdala synapses.

Eradication of poliomyelitis in South Africa

African Journals Online (AJOL)

An international campaign under the leadership of the. World Health Organisation is underway to eradicate polio from the world by the year 2000. South Africa may already be free of polio. However, to ensure eradication we need to move from a polio control programme to a polio eradication programme. This necessitates ...

Degradation of protein translation machinery by amino acid starvation-induced macroautophagy

DEFF Research Database (Denmark)

Gretzmeier, Christine; Eiselein, Sven; Johnson, Gregory R.

2017-01-01

, unbiased approaches relying on quantitative mass spectrometry-based proteomics. Macroautophagy is induced by rapamycin treatment, and by amino acid and glucose starvation in differentially, metabolically labeled cells. Protein dynamics are linked to image-based models of autophagosome turnover. Depending...... on the inducing stimulus, protein as well as organelle turnover differ. Amino acid starvation-induced macroautophagy leads to selective degradation of proteins important for protein translation. Thus, protein dynamics reflect cellular conditions in the respective treatment indicating stimulus-specific pathways...

Ubiquitination is absolutely required for the degradation of hypoxia-inducible factor - 1 alpha protein in hypoxic conditions

International Nuclear Information System (INIS)

Wang, Ronghai; Zhang, Ping; Li, Jinhang; Guan, Hongzai; Shi, Guangjun

2016-01-01

The hypoxia-inducible factor (HIF) is recognized as the master regulator of hypoxia response. HIF-α subunits expression are tightly regulated. In this study, our data show that ts20 cells still expressed detectable E1 protein even at 39.5° C for 12 h, and complete depletion of E1 protein expression at 39.5° C by siRNA enhanced HIF-1α and P53 protein expression. Further inhibition of E1 at 39.5 °C by siRNA, or E1 inhibitor Ube1-41 completely blocked HIF-1α degradation. Moreover, immunoprecipitations of co-transfection of HA-ubiquitin and FLAG–HIF–1α plasmids directly confirmed the involvement of ubiquitin in the hypoxic degradation of HIF-1α. Additionally, hypoxic HIF-1 α degradation is independent of HAF, RACK1, sumoylation or nuclear/cytoplasmic localization. Taken together, our data suggest that constitutive HIF-1α protein degradation in hypoxia is absolutely ubiquitination-dependent, and unidentified E3 ligase may exist for this degradation pathway. - Highlights: • HIF-1α protein is constitutively degraded in hypoxic conditions. • Requirement of ubiquitination for HIF-1α degradation in hypoxia. • Hypoxic HIF-1α degradation is independent of HAF, RACK1, sumoylation or nuclear/cytoplasmic localization.

Ubiquitination is absolutely required for the degradation of hypoxia-inducible factor - 1 alpha protein in hypoxic conditions

Energy Technology Data Exchange (ETDEWEB)

Wang, Ronghai [Department of Urology, Linzi District People' s Hospital, Zibo, 255400 (China); Zhang, Ping, E-mail: zpskx001@163.com [Department of Gynecology, Qingdao Municipal Hospital, Qingdao, 266011 (China); Li, Jinhang [Department of Gynecology, Qingdao Municipal Hospital, Qingdao, 266011 (China); Guan, Hongzai [Laboratory Department, School of Medicine, Qingdao University, Qingdao, 266071 (China); Shi, Guangjun, E-mail: qdmhshigj@yahoo.com [Department of Hepatobiliary Surgery, Qingdao Municipal Hospital, Qingdao, 266071 (China)

2016-01-29

The hypoxia-inducible factor (HIF) is recognized as the master regulator of hypoxia response. HIF-α subunits expression are tightly regulated. In this study, our data show that ts20 cells still expressed detectable E1 protein even at 39.5° C for 12 h, and complete depletion of E1 protein expression at 39.5° C by siRNA enhanced HIF-1α and P53 protein expression. Further inhibition of E1 at 39.5 °C by siRNA, or E1 inhibitor Ube1-41 completely blocked HIF-1α degradation. Moreover, immunoprecipitations of co-transfection of HA-ubiquitin and FLAG–HIF–1α plasmids directly confirmed the involvement of ubiquitin in the hypoxic degradation of HIF-1α. Additionally, hypoxic HIF-1 α degradation is independent of HAF, RACK1, sumoylation or nuclear/cytoplasmic localization. Taken together, our data suggest that constitutive HIF-1α protein degradation in hypoxia is absolutely ubiquitination-dependent, and unidentified E3 ligase may exist for this degradation pathway. - Highlights: • HIF-1α protein is constitutively degraded in hypoxic conditions. • Requirement of ubiquitination for HIF-1α degradation in hypoxia. • Hypoxic HIF-1α degradation is independent of HAF, RACK1, sumoylation or nuclear/cytoplasmic localization.

Biochemistry of cellulose degradation and cellulose utilization for feeds and for protein

Energy Technology Data Exchange (ETDEWEB)

Sadara, J C; Lachke, A H; Shewale, J G

1979-01-01

A review discussing production of single-cell protein, fuel, and glucose from cellulose decomposition; surface or solid fermentations of single-cell protein; production of cellulases; and the biochemistry of cellulose degradation was presented.

The N-end rule pathway catalyzes a major fraction of the protein degradation in skeletal muscle

Science.gov (United States)

Solomon, V.; Lecker, S. H.; Goldberg, A. L.

1998-01-01

In skeletal muscle, overall protein degradation involves the ubiquitin-proteasome system. One property of a protein that leads to rapid ubiquitin-dependent degradation is the presence of a basic, acidic, or bulky hydrophobic residue at its N terminus. However, in normal cells, substrates for this N-end rule pathway, which involves ubiquitin carrier protein (E2) E214k and ubiquitin-protein ligase (E3) E3alpha, have remained unclear. Surprisingly, in soluble extracts of rabbit muscle, we found that competitive inhibitors of E3alpha markedly inhibited the 125I-ubiquitin conjugation and ATP-dependent degradation of endogenous proteins. These inhibitors appear to selectively inhibit E3alpha, since they blocked degradation of 125I-lysozyme, a model N-end rule substrate, but did not affect the degradation of proteins whose ubiquitination involved other E3s. The addition of several E2s or E3alpha to the muscle extracts stimulated overall proteolysis and ubiquitination, but only the stimulation by E3alpha or E214k was sensitive to these inhibitors. A similar general inhibition of ubiquitin conjugation to endogenous proteins was observed with a dominant negative inhibitor of E214k. Certain substrates of the N-end rule pathway are degraded after their tRNA-dependent arginylation. We found that adding RNase A to muscle extracts reduced the ATP-dependent proteolysis of endogenous proteins, and supplying tRNA partially restored this process. Finally, although in muscle extracts the N-end rule pathway catalyzes most ubiquitin conjugation, it makes only a minor contribution to overall protein ubiquitination in HeLa cell extracts.

Protein Degradation in Normal and Beige (Chediak-Higashi) Mice

Science.gov (United States)

Lyons, Robert T.; Pitot, Henry C.

1978-01-01

The beige mouse, C57BL/6 (bg/bg), is an animal model for the Chediak-Higashi syndrome in man, a disease characterized morphologically by giant lysosomes in most cell types. Half-lives for the turnover of [14C]bicarbonate-labeled total soluble liver protein were determined in normal and beige mice. No significant differences were observed between the normal and mutant strain for both rapidly and slowly turning-over classes of proteins. Glucagon treatment during the time-course of protein degradation had similar effects on both normal and mutant strains and led to the conclusion that the rate of turnover of endogenous intracellular protein in the beige mouse liver does not differ from normal. The rates of uptake and degradation of an exogenous protein were determined in normal and beige mice by intravenously injecting 125I-bovine serum albumin and following, in peripheral blood, the loss with time of phosphotungstic acid-insoluble bovine serum albumin and the parallel appearance of phosphotungstic acid-soluble (degraded) material. No significant differences were observed between beige and normal mice in the uptake by liver lysosomes of 125I-bovine serum albumin (t½ = 3.9 and 2.8 h, respectively). However, it was found that lysosomes from livers of beige mice released phosphotungstic acid-soluble radioactivity at a rate significantly slower than normal (t½ = 6.8 and 3.1 h, respectively). This defect in beige mice could be corrected by chronic administration of carbamyl choline (t½ = 3.5 h), a cholinergic agonist which raises intracellular cyclic GMP levels. However, no significant differences between normal and beige mice were observed either in the ability of soluble extracts of liver and kidney to bind [3H]cyclic GMP in vitro or in the basal levels of cyclic AMP in both tissues. The relevance of these observations to the presumed biochemical defect underlying the Chediak-Higashi syndrome is discussed. PMID:202611

Effect of Electron Beam Irradiation on Degradability Coefficients and Ruminalpostruminal Digestibility of Dry Matter and Crude Protein of some Plant Protein Sources

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gasem tahan

2016-06-01

Full Text Available Effect of electron beam irradiation on degradability coefficients and ruminal- postruminal digestibility of dry matter and crude protein of soybean meal, canola meal and Lathyrus sativus seed, irradiated at doses of 50, 100 and 150 kGy was investigated. Ruminal degradability of dry matter and crude protein was determined by in situ method using two cannulated Holstein heifers. Ruminal- postruminal digestibility of dry matter and crude protein was determined by in situ (nylon bag-in vitro (daisy digestor techniques. Data analyzed using SAS software as randomized completely design and the treatment means were compared using Tukey test. The results indicated that irradiation had no effect on dry matter, ether extract and ash content of feeds. In soybean meal, washout fraction and potentially degradable fraction of dry matter and crude protein was higher and lower at dose of 150 kGy irradiation than other treatments, respectively, and degradation rate constant and ruminal effective degradability of dry matter and crude protein was lower at all doses of irradiation than untreated soybean meal. In canola meal, irradiation at doses of 50 and 100 kGy decreased washout fraction and increased potentially degradable fraction of crude protein compared with untreated canola meal. In Lathyrus sativus seed, only potentially degradable fraction of dry matter and crude protein was lower at dose of 150 kGy irradiation than untreated Lathyrus sativus seed. Ruminal digestibility of crude protein decreased in soybean meal at doses of 100 and 150 kGy irradiation and for canola meal at all doses of irradiation than untreated samples. Total tract digestibility of crude protein decreased in soybean meal at dose of 150 kGy irradiation and for canola meal at all doses of irradiation than untreated samples. In Lathyrus sativus seed, ruminal-postruminal digestibility and total tract digestibility of dry matter increased at doses of 100 and 150 kGy irradiation than untreated

Leprosy: eradication or cure?

Science.gov (United States)

Kakar, S

1995-01-01

The National Leprosy Eradication Program (NLEP), launched in 1986, has brought medicine for leprosy to more people than ever before, covering 200 of India's 455 districts. Since 1988, the number of leprosy patients discharged as cured each year has been greater than the number of newly detected, thus moving the country closer to its goal of eradicating leprosy from India. A substantial number of the 3 million people with leprosy in India are likely to come under the coverage of the NLEP. The author, however, argues that the fight against leprosy and the NLEP should be considered in their historical context. Leprosy is therefore used to illustrate how the perhaps interchangeable terms eradication and cure are charged with history and custom. Historically, the focus on eradicating leprosy has had terrible consequences for the patient. In England, perceptions about leprosy are relevant to the situation India, for colonial policy on leprosy was largely derivative. In the 1880s, especially, leprosy excited the public imagination. Asylums adopted segregation and confinement during this period for people with leprosy and the colonial government in India supported that approach from 1882. The author concludes that while the NLEP is laudable, the program must not focus upon eradicating leprosy. It should instead focus upon the leprosy patient, who has for so long been denied and discriminated against. The individual must be placed at the center of any program. Some steps in this direction have been taken.

Effect of protein degradability on milk production of dairy ewes.

Science.gov (United States)

Mikolayunas-Sandrock, C; Armentano, L E; Thomas, D L; Berger, Y M

2009-09-01

The objective of this experiment was to determine the effect of protein degradability of dairy sheep diets on milk yield and protein utilization across 2 levels of milk production. Three diets were formulated to provide similar energy concentrations and varying concentrations of rumen-degradable protein (RDP) and rumen-undegradable protein (RUP): 12% RDP and 4% RUP (12-4) included basal levels of RDP and RUP, 12% RDP and 6% RUP (12-6) included additional RUP, and 14% RDP and 4% RUP (14-4) included additional RDP. Diets were composed of alfalfa-timothy cubes, whole and ground corn, whole oats, dehulled soybean meal, and expeller soybean meal (SoyPlus, West Central, Ralston, IA). Estimates of RDP and RUP were based on the Small Ruminant Nutrition System model (2008) and feed and orts were analyzed for Cornell N fractions. Eighteen multiparous dairy ewes in midlactation were divided by milk yield (low and high) into 2 blocks of 9 ewes each and were randomly assigned within block (low and high) to 3 pens of 3 ewes each. Dietary treatments were arranged in a 3 x 3 Latin square within each block and applied to pens for 14-d periods. We hypothesized that pens consuming high-RUP diets (12-6) would produce more milk and milk protein than the basal diet (12-4) and pens consuming high-RDP diets (14-4) would not produce more milk than the basal diet (12-4). Ewes in the high-milk-yield square consumed more dry matter and produced more milk, milk fat, and milk protein than ewes in the low-milk-yield square. There was no effect of dietary treatment on dry matter intake. Across both levels of milk production, the 12-6 diet increased milk yield by 14%, increased milk fat yield by 14%, and increased milk protein yield by 13% compared with the 14-4 and 12-4 diets. Gross N efficiency (milk protein N/intake protein N) was 11 and 15% greater in the 12-6 and 12-4 diets, respectively, compared with the 14-4 diet. Milk urea N concentration was greater in the 12-6 diet and tended to be

Eradication of Human Hepatic and Pulmonary Melanoma Metastases in SCID Mice by Antibody--Interleukin 2 Fusion Proteins

Science.gov (United States)

Becker, Jurgen C.; Pancook, James D.; Gillies, Stephen D.; Mendelsohn, John; Reisfeld, Ralph A.

1996-04-01

Antibody--cytokine fusion proteins combine the unique targeting ability of antibodies with the multifunctional activity of cytokines. Here, we demonstrate the therapeutic efficacy of such constructs for the treatment of hepatic and pulmonary metastases of different melanoma cell lines. Two antibody--interleukin 2 (IL-2) fusion proteins, ch225-IL2 and ch14.18-IL2, constructed by fusion of a synthetic sequence coding for human IL-2 to the carboxyl end of the Cγ 1 gene of the corresponding antibodies, were tested for their therapeutic efficacy against xenografted human melanoma in vivo. Tumorspecific fusion proteins completely inhibited the growth of hepatic and pulmonary metastases in C.B-17 scid/scid mice previously reconstituted with human lymphokine-activated killer cells, whereas treatment with combinations of the corresponding antibodies plus recombinant IL-2 only reduced the tumor load. Even when treatment with fusion proteins was delayed up to 8 days after inoculation of tumor cells, it still resulted in complete eradication of micrometastases that were established at that time point. Selection of tumor cell lines expressing or lacking the targeted antigen of the administered fusion protein proved the specificity of the observed antitumor effect. Biodistribution analysis demonstrated that the tumorspecific fusion protein accumulated not only in subcutaneous tumors but also in lungs and livers affected with micrometastases. Survival times of animals treated with the fusion protein were more than doubled as compared to those treated with the combination of the corresponding antibody plus IL-2. Our data demonstrate that an immunotherapeutic approach using cytokines targeted by antibodies to tumor sites has potent effects against disseminated human melanoma.

Context Memory Formation Requires Activity-Dependent Protein Degradation in the Hippocampus

Science.gov (United States)

Cullen, Patrick K.; Ferrara, Nicole C.; Pullins, Shane E.; Helmstetter, Fred J.

2017-01-01

Numerous studies have indicated that the consolidation of contextual fear memories supported by an aversive outcome like footshock requires de novo protein synthesis as well as protein degradation mediated by the ubiquitin-proteasome system (UPS). Context memory formed in the absence of an aversive stimulus by simple exposure to a novel…

Lysine-Less Variants of Spinal Muscular Atrophy SMN and SMNΔ7 Proteins Are Degraded by the Proteasome Pathway

Directory of Open Access Journals (Sweden)

Raúl Sánchez-Lanzas

2017-12-01

Full Text Available Spinal muscular atrophy is due to mutations affecting the SMN1 gene coding for the full-length protein (survival motor neuron; SMN and the SMN2 gene that preferentially generates an exon 7-deleted protein (SMNΔ7 by alternative splicing. To study SMN and SMNΔ7 degradation in the cell, we have used tagged versions at the N- (Flag or C-terminus (V5 of both proteins. Transfection of those constructs into HeLa cells and treatment with cycloheximide showed that those protein constructs were degraded. Proteasomal degradation usually requires prior lysine ubiquitylation. Surprisingly, lysine-less variants of both proteins tagged either at N- (Flag or C-terminus (V5 were also degraded. The degradation of the endogenous SMN protein, and the protein constructs mentioned above, was mediated by the proteasome, as it was blocked by lactacystin, a specific and irreversible proteasomal inhibitor. The results obtained allowed us to conclude that SMN and SMNΔ7 proteasomal degradation did not absolutely require internal ubiquitylation nor N-terminal ubiquitylation (prevented by N-terminal tagging. While the above conclusions are firmly supported by the experimental data presented, we discuss and justify the need of deep proteomic techniques for the study of SMN complex components (orphan and bound turn-over to understand the physiological relevant mechanisms of degradation of SMN and SMNΔ7 in the cell.

Poverty eradication in a carbon constrained world

OpenAIRE

Hubacek, Klaus; Baiocchi, Giovanni; Feng, Kuishuang; Patwardhan, Anand

2017-01-01

The UN Framework Convention on Climate Change aims to keep warming below 2 °C while recognizing developing countries’ right to eradicate extreme poverty. Poverty eradication is also the first of the Sustainable Development Goals. This paper investigates potential consequences for climate targets of achieving poverty eradication. We find that eradicating extreme poverty, i.e., moving people to an income above $1.9 purchasing power parity (PPP) a day, does not jeopardize the climate target even...

Degradation of Crude Protein in Groundnut Cake, Guinea Grass ...

African Journals Online (AJOL)

Three West African dwarf rams fitted with rumen cannula, were used in a completely randomized design for degradation of crude protein (CP) of groundnut cake (GNC), Panicum maximum, rumen epithelial scraping (RES), and diets containing increasing levels of RES. Concentrate diets were formulated such that 0% (A), ...

Novel function of the endoplasmic reticulum degradation-enhancing α-mannosidase-like proteins in the human hepatitis B virus life cycle, mediated by the middle envelope protein.

Science.gov (United States)

Lazar, Catalin; Uta, Mihaela; Petrescu, Stefana Maria; Branza-Nichita, Norica

2017-02-01

Cells replicating the human hepatitis B virus (HBV) express high levels of degradation-enhancing α-mannosidase-like proteins (EDEMs), a family of proteins involved in the endoplasmic reticulum associated degradation, one of the pathways activated during the unfolded protein response. Owing to their α-1,2 mannosidase activity, the EDEM1-3 proteins are able to process the N-linked glycans of misfolded or incompletely folded proteins, providing the recognition signal for their subsequent degradation. The HBV small (S), medium (M), and large (L) surface proteins bear an N-linked glycosylation site in the common S domain that is partially occupied in all proteins. The M protein contains an additional site in its preS2 domain, which is always functional. Here, we report that these oligosaccharides are processed by EDEMs, more efficiently by EDEM3, which induces degradation of L and S proteins, accompanied by a reduction of subviral particles production. In striking contrast, M not only is spared from degradation but its trafficking is also accelerated leading to an improved secretion. This unusual behavior of the M protein requires strictly the mannose trimming of the preS2 N-linked glycan. Furthermore, we show that HBV secretion is significantly inhibited under strong endoplasmic reticulum stress conditions when M expression is prevented by mutagenesis of the viral genome. These observations unfold unique properties of the M protein in the HBV life cycle during unfolded protein response and point to alternative mechanisms employed by EDEMs to alleviate this stress in case of necessity by promoting glycoprotein trafficking rather than degradation. © 2016 John Wiley & Sons Ltd.

Calculating the Degradation Rate of Individual Proteins Using Xenopus Extract Systems.

Science.gov (United States)

McDowell, Gary S; Philpott, Anna

2018-05-16

The Xenopus extract system has been used extensively as a simple, quick, and robust method for assessing the stability of proteins against proteasomal degradation. In this protocol, methods are provided for assessing the half-life of in vitro translated radiolabeled proteins using Xenopus egg or embryo extracts. © 2019 Cold Spring Harbor Laboratory Press.

Pathogenic prion protein is degraded by a manganese oxide mineral found in soils

Science.gov (United States)

Russo, F.; Johnson, C.J.; McKenzie, D.; Aiken, Judd M.; Pedersen, J.A.

2009-01-01

Prions, the aetiological agents of transmissible spongiform encephalopathies, exhibit extreme resistance to degradation. Soil can retain prion infectivity in the environment for years. Reactive soil components may, however, contribute to the inactivation of prions in soil. Members of the birnessite family of manganese oxides (MnO2) rank among the strongest natural oxidants in soils. Here, we report the abiotic degradation of pathogenic prion protein (PrPTSE) by a synthetic analogue of naturally occurring birnessite minerals. Aqueous MnO2 suspensions degraded the PrPTSE as evidenced by decreased immunoreactivity and diminished ability to seed protein misfolding cyclic amplification reactions. Birnessite-mediated PrPTSE degradation increased as a solution's pH decreased, consistent with the pH-dependence of the redox potential of MnO2. Exposure to 5.6 mg MnO2 ml-1 (PrPTSE:MnO2=1 : 110) decreased PrPTSE levels by ???4 orders of magnitude. Manganese oxides may contribute to prion degradation in soil environments rich in these minerals. ?? 2009 SGM.

Degradation of the disease-associated prion protein by a serine protease from lichens

Science.gov (United States)

Johnson, C.J.; Bennett, J.P.; Biro, S.M.; Duque-Velasquez, J.C.; Rodriguez, C.M.; Bessen, R.A.; Rocke, T.E.; Bartz, Jason C.

2011-01-01

The disease-associated prion protein (PrP(TSE)), the probable etiological agent of the transmissible spongiform encephalopathies (TSEs), is resistant to degradation and can persist in the environment. Lichens, mutualistic symbioses containing fungi, algae, bacteria and occasionally cyanobacteria, are ubiquitous in the environment and have evolved unique biological activities allowing their survival in challenging ecological niches. We investigated PrP(TSE) inactivation by lichens and found acetone extracts of three lichen species (Parmelia sulcata, Cladonia rangiferina and Lobaria pulmonaria) have the ability to degrade prion protein (PrP) from TSE-infected hamsters, mice and deer. Immunoblots measuring PrP levels and protein misfolding cyclic amplification indicated at least two logs of reductions in PrP(TSE). Degradative activity was not found in closely related lichen species or in algae or a cyanobacterium that inhabit lichens. Degradation was blocked by Pefabloc SC, a serine protease inhibitor, but not inhibitors of other proteases or enzymes. Additionally, we found that PrP levels in PrP(TSE)-enriched preps or infected brain homogenates are also reduced following exposure to freshly-collected P. sulcata or an aqueous extract of the lichen. Our findings indicate that these lichen extracts efficiently degrade PrP(TSE) and suggest that some lichens could have potential to inactivate TSE infectivity on the landscape or be a source for agents to degrade prions. Further work to clone and characterize the protease, assess its effect on TSE infectivity and determine which organism or organisms present in lichens produce or influence the protease activity is warranted.

Molecular chaperones in targeting misfolded proteins for ubiquitin-dependent degradation

DEFF Research Database (Denmark)

Kriegenburg, Franziska; Ellgaard, Lars; Hartmann-Petersen, Rasmus

2012-01-01

The accumulation of misfolded proteins presents a considerable threat to the health of individual cells and has been linked to severe diseases, including neurodegenerative disorders. Considering that, in nature, cells often are exposed to stress conditions that may lead to aberrant protein...... conformational changes, it becomes clear that they must have an efficient quality control apparatus to refold or destroy misfolded proteins. In general, cells rely on molecular chaperones to seize and refold misfolded proteins. If the native state is unattainable, misfolded proteins are targeted for degradation...... via the ubiquitin-proteasome system. The specificity of this proteolysis is generally provided by E3 ubiquitin-protein ligases, hundreds of which are encoded in the human genome. However, rather than binding the misfolded proteins directly, most E3s depend on molecular chaperones to recognize...

[Dental status and efficacy of Helicobacter pylori eradication].

Science.gov (United States)

Namiot, D B; Namiot, Z; Kemona, A; Gołebiewska, M

2001-04-01

Beside stomach Helicobacter pylori can colonize the oral cavity. One may think, therefore, that if H. pylori persists the eradication therapy in the oral cavity, it could infect the stomach again. Since in the oral cavity H. pylori occurs most frequently in a dental plaque gathering on teeth, the aim of the study was to investigate whether the natural teeth status is important for the efficacy of H. pylori eradication. The study was conducted on 45 peptic ulcer patients with natural teeth. They were eradicated with one of two regimens: 1/OAT-omeprazole (2 x 20 mg), amoxicillin (2 x 1000 mg), tinidazole (2 x 500 mg) (14-day course), 2/OAC-omeprazole (2 x 20 mg), amoxicillin (2 x 1000 mg), clarithromycin (2 x 250 mg) (7-day course). Dentistry examination was performed 4-6 weeks after the end of eradication therapy and consisted of determination of the number of teeth, caries index, dental treatment index, plaque index, and periodontal index. It was found that in successfully eradicated patients with OAT regimen, the number of teeth was higher and caries index lower than in those whose eradication therapy was unsuccessful; 24.8 +/- 5.2 vs 15.5 +/- 8.6 (p caries index were not associated with the efficacy of H. pylori eradication in OAC treated group. Irrespectively of the eradication regimen used, OAT or OAC, dental treatment index, plaque index, and periodontal index were not associated with the efficacy of H. pylori eradication. It is concluded that the natural teeth status may have influence on the outcome of H. pylori eradication. One should remember about this prescribing drugs for H. pylori eradication.

Calpain activation by ROS mediates human ether-a-go-go-related gene protein degradation by intermittent hypoxia.

Science.gov (United States)

Wang, N; Kang, H S; Ahmmed, G; Khan, S A; Makarenko, V V; Prabhakar, N R; Nanduri, J

2016-03-01

Human ether-a-go-go-related gene (hERG) channels conduct delayed rectifier K(+) current. However, little information is available on physiological situations affecting hERG channel protein and function. In the present study we examined the effects of intermittent hypoxia (IH), which is a hallmark manifestation of sleep apnea, on hERG channel protein and function. Experiments were performed on SH-SY5Y neuroblastoma cells, which express hERG protein. Cells were exposed to IH consisting of alternating cycles of 30 s of hypoxia (1.5% O2) and 5 min of 20% O2. IH decreased hERG protein expression in a stimulus-dependent manner. A similar reduction in hERG protein was also seen in adrenal medullary chromaffin cells from IH-exposed neonatal rats. The decreased hERG protein was associated with attenuated hERG K(+) current. IH-evoked hERG protein degradation was not due to reduced transcription or increased proteosome/lysomal degradation. Rather it was mediated by calcium-activated calpain proteases. Both COOH- and NH2-terminal sequences of the hERG protein were the targets of calpain-dependent degradation. IH increased reactive oxygen species (ROS) levels, intracellular Ca(2+) concentration ([Ca(2+)]i), calpain enzyme activity, and hERG protein degradation, and all these effects were prevented by manganese-(111)-tetrakis-(1-methyl-4-pyridyl)-porphyrin pentachloride, a membrane-permeable ROS scavenger. These results demonstrate that activation of calpains by ROS-dependent elevation of [Ca(2+)]i mediates hERG protein degradation by IH. Copyright © 2016 the American Physiological Society.

Proteomes and Ubiquitylomes Analysis Reveals the Involvement of Ubiquitination in Protein Degradation in Petunias1

Science.gov (United States)

Liu, Juanxu; Wei, Qian; Wang, Rongmin; Yang, Weiyuan; Ma, Yueyue; Chen, Guoju

2017-01-01

Petal senescence is a complex programmed process. It has been demonstrated previously that treatment with ethylene, a plant hormone involved in senescence, can extensively alter transcriptome and proteome profiles in plants. However, little is known regarding the impact of ethylene on posttranslational modification (PTM) or the association between PTM and the proteome. Protein degradation is one of the hallmarks of senescence, and ubiquitination, a major PTM in eukaryotes, plays important roles in protein degradation. In this study, we first obtained reference petunia (Petunia hybrida) transcriptome data via RNA sequencing. Next, we quantitatively investigated the petunia proteome and ubiquitylome and the association between them in petunia corollas following ethylene treatment. In total, 51,799 unigenes, 3,606 proteins, and 2,270 ubiquitination sites were quantified 16 h after ethylene treatment. Treatment with ethylene resulted in 14,448 down-regulated and 6,303 up-regulated unigenes (absolute log2 fold change > 1 and false discovery rate petunia. Several putative ubiquitin ligases were up-regulated at the protein and transcription levels. Our results showed that the global proteome and ubiquitylome were negatively correlated and that ubiquitination could be involved in the degradation of proteins during ethylene-mediated corolla senescence in petunia. Ethylene regulates hormone signaling transduction pathways at both the protein and ubiquitination levels in petunia corollas. In addition, our results revealed that ethylene increases the ubiquitination levels of proteins involved in endoplasmic reticulum-associated degradation. PMID:27810942

A STRUCTURAL OVERVIEW OF GH61 PROTEINS – FUNGAL CELLULOSE DEGRADING POLYSACCHARIDE MONOOXYGENASES

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Leila Lo Leggio

2012-09-01

Full Text Available Recent years have witnessed a spurt of activities in the elucidation of the molecular function of a class of proteins with great potential in biomass degradation. GH61 proteins are of fungal origin and were originally classified in family 61 of the glycoside hydrolases. From the beginning they were strongly suspected to be involved in cellulose degradation because of their expression profiles, despite very low detectable endoglucanase activities. A major breakthrough came from structure determination of the first members, establishing the presence of a divalent metal binding site and a similarity to bacterial proteins involved in chitin degradation. A second breakthrough came from the identification of cellulase boosting activity dependent on the integrity of the metal binding site. Finally very recently GH61 proteins were demonstrated to oxidatively cleave crystalline cellulose in a Cu and reductant dependant manner. This mini-review in particular focuses on the contribution that structure elucidation has made in the understanding of GH61 molecular function and reviews the currently known structures and the challenges remaining ahead for exploiting this new class of enzymes to the full.

A structural overview of GH61 proteins – fungal cellulose degrading polysaccharide monooxygenases

Directory of Open Access Journals (Sweden)

Leila Lo Leggio

2012-09-01

Full Text Available Recent years have witnessed a spurt of activities in the elucidation of the molecular function of a class of proteins with great potential in biomass degradation. GH61 proteins are of fungal origin and were originally classified in family 61 of the glycoside hydrolases. From the beginning they were strongly suspected to be involved in cellulose degradation because of their expression profiles, despite very low detectable endoglucanase activities. A major breakthrough came from structure determination of the first members, establishing the presence of a divalent metal binding site and a similarity to bacterial proteins involved in chitin degradation. A second breakthrough came from the identification of cellulase boosting activity dependent on the integrity of the metal binding site. Finally very recently GH61 proteins were demonstrated to oxidatively cleave crystalline cellulose in a Cu and reductant dependant manner. This mini-review in particular focuses on the contribution that structure elucidation has made in the understanding of GH61 molecular function and reviews the currently known structures and the challenges remaining ahead for exploiting this new class of enzymes to the full.

Quantifying protein synthesis and degradation in Arabidopsis by dynamic 13CO2 labeling and analysis of enrichment in individual amino acids in their free pools and in protein.

Science.gov (United States)

Ishihara, Hirofumi; Obata, Toshihiro; Sulpice, Ronan; Fernie, Alisdair R; Stitt, Mark

2015-05-01

Protein synthesis and degradation represent substantial costs during plant growth. To obtain a quantitative measure of the rate of protein synthesis and degradation, we supplied (13)CO2 to intact Arabidopsis (Arabidopsis thaliana) Columbia-0 plants and analyzed enrichment in free amino acids and in amino acid residues in protein during a 24-h pulse and 4-d chase. While many free amino acids labeled slowly and incompletely, alanine showed a rapid rise in enrichment in the pulse and a decrease in the chase. Enrichment in free alanine was used to correct enrichment in alanine residues in protein and calculate the rate of protein synthesis. The latter was compared with the relative growth rate to estimate the rate of protein degradation. The relative growth rate was estimated from sequential determination of fresh weight, sequential images of rosette area, and labeling of glucose in the cell wall. In an 8-h photoperiod, protein synthesis and cell wall synthesis were 3-fold faster in the day than at night, protein degradation was slow (3%-4% d(-1)), and flux to growth and degradation resulted in a protein half-life of 3.5 d. In the starchless phosphoglucomutase mutant at night, protein synthesis was further decreased and protein degradation increased, while cell wall synthesis was totally inhibited, quantitatively accounting for the inhibition of growth in this mutant. We also investigated the rates of protein synthesis and degradation during leaf development, during growth at high temperature, and compared synthesis rates of Rubisco large and small subunits of in the light and dark. © 2015 American Society of Plant Biologists. All Rights Reserved.

Endocytosis and intracellular protein degradation in cystic fibrosis fibroblasts

International Nuclear Information System (INIS)

Jessup, W.; Dean, R.T.

1983-01-01

Normal rates of pinocytosis of [ 3 H]sucrose were measured in cystic fibrosis fibroblasts, and were not affected by the addition of cystic fibrosis serum. Bulk protein degradation (a significant proportion of which occurs intralysosomally following autophagy) and its regulation by growth state were apparently identical in normal and cystic fibrosis cultures. (Auth.)

Decomposition of insoluble and hard-to-degrade animal proteins by enzyme E77 and its potential applications.

Science.gov (United States)

Zhao, Hui; Mitsuiki, Shinji; Takasugi, Mikako; Sakai, Masashi; Goto, Masatoshi; Kanouchi, Hiroaki; Oka, Tatsuzo

2012-04-01

Insoluble and hard-to-degrade animal proteins are group of troublesome proteins, such as collagen, elastin, keratin, and prion proteins that are largely generated by the meat industry and ultimately converted to industrial wastes. We analyzed the ability of the abnormal prion protein-degrading enzyme E77 to degrade insoluble and hard-to-degrade animal proteins including keratin, collagen, and elastin. The results indicate that E77 has a much higher keratinolytic activity than proteinase K and subtilisin. Maximal E77 keratinolytic activity was observed at pH 12.0 and 65 °C. E77 was also adsorbed by keratin in a pH-independent manner. E77 showed lower collagenolytic and elastinolytic specificities than proteinase K and subtilisin. Moreover, E77 treatment did not damage collagens in ovine small intestines but did almost completely remove the muscles. We consider that E77 has the potential ability for application in the processing of animal feedstuffs and sausages.

Eradication versus control for poliomyelitis: an economic analysis.

Science.gov (United States)

Thompson, Kimberly M; Tebbens, Radboud J Duintjer

2007-04-21

Worldwide eradication of wild polioviruses is likely to yield substantial health and financial benefits, provided we finish the job. Challenges in the four endemic areas combined with continuing demands for financial resources for eradication have led some to question the goal of eradication and to suggest switching to a policy of control. We developed a dynamic model, based on modelling of the currently endemic areas in India, to show the importance of maintaining and increasing the immunisation intensity to complete eradication and to illustrate how policies based on perception about high short-term costs or cost-effectiveness ratios without consideration of long-term benefits could undermine any eradication effort. An extended model assesses the economic implications and disease burden of a change in policy from eradication to control. Our results suggest that the intensity of immunisation must be increased to achieve eradication, and that even small decreases in intensity could lead to large outbreaks. This finding implies the need to pay even higher short-run costs than are currently being spent, which will further exacerbate concerns about continued investment in interventions with high perceived cost-effectiveness ratios. We show that a wavering commitment leads to a failure to eradicate, greater cumulative costs, and a much larger number of cases. We further show that as long as it is technically achievable, eradication offers both lower cumulative costs and cases than control, even with the costs of achieving eradication exceeding several billion dollars more. A low-cost control policy that relies only on routine immunisation for 20 years with discounted costs of more than $3500 million could lead to roughly 200 000 expected paralytic poliomyelitis cases every year in low-income countries, whereas a low-case control policy that keeps the number of cases at about 1500 per year could cost around $10 000 million discounted over the 20 years. Focusing on the

Memory formation for trace fear conditioning requires ubiquitin-proteasome mediated protein degradation in the prefrontal cortex.

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David S Reis

2013-10-01

Full Text Available The cellular mechanisms supporting plasticity during memory consolidation have been a subject of considerable interest. De novo protein and mRNA synthesis in several brain areas are critical, and more recently protein degradation, mediated by the ubiquitin-proteasome system (UPS, has been shown to be important. Previous work clearly establishes a relationship between protein synthesis and protein degradation in the amygdala, but it is unclear whether cortical mechanisms of memory consolidation are similar to those in the amygdala. Recent work demonstrating a critical role for prefrontal cortex (PFC in the acquisition and consolidation of fear memory allows us to address this question. Here we use a PFC-dependent fear conditioning protocol to determine whether UPS mediated protein degradation is necessary for memory consolidation in PFC. Groups of rats were trained with auditory delay or trace fear conditioning and sacrificed 60 min after training. PFC tissue was then analyzed to quantify the amount of polyubiquinated protein. Other animals were trained with similar procedures but were infused with either a proteasome inhibitor (clasto-lactacystin β-lactone or a translation inhibitor (anisomycin in the PFC immediately after training. Our results show increased UPS-mediated protein degradation in the PFC following trace but not delay fear conditioning. Additionally, post-training proteasome or translation inhibition significantly impaired trace but not delay fear memory when tested the next day. Our results further support the idea that the PFC is critical for trace but not delay fear conditioning highlight the role of UPS-mediated degradation as critical for synaptic plasticity.

Measurement of local cerebral protein synthesis in vivo: influence of recycling of amino acids derived from protein degradation

International Nuclear Information System (INIS)

Smith, C.B.; Deibler, G.E.; Eng, N.; Schmidt, K.; Sokoloff, L.

1988-01-01

A quantitative autoradiographic method for the determination of local rates of protein synthesis in brain in vivo is being developed. The method employs L-[1- 14 C]leucine as the radiolabeled tracer. A comprehensive model has been designed that takes into account intracellular and extracellular spaces, intracellular compartmentation of leucine, and the possibility of recycling of unlabeled leucine derived from steady-state degradation of protein into the precursor pool for protein synthesis. We have evaluated the degree of recycling by measuring the ratio of the steady-state precursor pool distribution space for labeled leucine to that of unlabeled leucine. The values obtained were 0.58 in whole brain and 0.47 in liver. These results indicate that there is significant recycling of unlabeled amino acids derived from steady-state protein degradation in both tissues. Any method for the determination of rates of cerebral protein synthesis in vivo with labeled tracers that depends on estimation of precursor pool specific activity in tissue from measurements in plasma must take this recycling into account

HUWE1 and TRIP12 Collaborate in Degradation of Ubiquitin-Fusion Proteins and Misframed Ubiquitin

DEFF Research Database (Denmark)

Poulsen, Esben G; Steinhauer, Cornelia; Lees, Michael

2012-01-01

In eukaryotic cells an uncleavable ubiquitin moiety conjugated to the N-terminus of a protein signals the degradation of the fusion protein via the proteasome-dependent ubiquitin fusion degradation (UFD) pathway. In yeast the molecular mechanism of the UFD pathway has been well characterized...... in degradation of the UFD substrate Ub(G76V)-YFP. The most significant hits from the screen were the E3 ubiquitin-protein ligase HUWE1, as well as PSMD7 and PSMD14 that encode proteasome subunits. Accordingly, knock down of HUWE1 led to an increase in the steady state level and a retarded degradation of the UFD...... substrate. Knock down of HUWE1 also led to a stabilization of the physiological UFD substrate UBB(+1). Precipitation experiments revealed that HUWE1 is associated with both the Ub(G76V)-YFP substrate and the 26S proteasome, indicating that it functions late in the UFD pathway. Double knock down of HUWE1...

degradable protein sources on performance of high-producing dairy ...

African Journals Online (AJOL)

with high-quality, low·degradable protein sources prOViding47% UDP is advocated for ... saliva and through the rumen wall (Waldo, 1968). Based on this type of ... of the feed industry, but is based on very little solid evidence. (Huber, 1984). Chalupa ...... of rumen fermentation in relation to ammonia concentration. Br. J. Nutr.

Degradation of brown adipocyte purine nucleotides regulates uncoupling protein 1 activity

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Tobias Fromme

2018-02-01

Full Text Available Objective: Non-shivering thermogenesis in mammalian brown adipose tissue depends on thermogenic uncoupling protein 1. Its activity is triggered by free fatty acids while purine nucleotides mediate inhibition. During activation, it is thought that free fatty acids overcome purine-mediated inhibition. We measured the cellular concentration and the release of purine nucleotide metabolites to uncover a possible role of purine nucleotide degradation in uncoupling protein 1 activation. Methods: With mass spectrometry, purine nucleotide metabolites were quantified in cellular homogenates and supernatants of cultured primary brown adipocytes. We also determined oxygen consumption in response to a β-adrenergic agonist. Results: Upon adrenergic activation, brown adipocytes decreased the intracellular concentration of inhibitory nucleotides (ATP, ADP, GTP and GDP and released the respective degradation products. At the same time, an increase in cellular calcium occurred. None of these phenomena occurred in white adipocytes or myotubes. The brown adipocyte expression of enzymes implicated in purine metabolic remodeling is altered upon cold exposure. Pharmacological and genetic interference of purine metabolism altered uncoupling protein 1 mediated uncoupled respiration. Conclusion: Adrenergic stimulation of brown adipocytes lowers the intracellular concentration of purine nucleotides, thereby contributing to uncoupling protein 1 activation. Keywords: Purine nucleotides, Uncoupling protein 1, Brown adipose tissue, Non-shivering thermogenesis, HILIC-MS/MS, Guanosine monophosphate reductase

Protein degradation in preimplantation mouse embryos and the lethality of tritiated amino acids

International Nuclear Information System (INIS)

Wielbold, J.L.

1982-01-01

The role of protein degradation in preimplantation development in the mouse was studied. Proteins of morulae and blastocysts (M and B) cultured in vitro after labeling for 1 hour (h) in 3 H-leucine exhibit a mean half-life (t 1 / 2 ) of 8.1 h. The t 1 / 2 tends to increase (9.5 h) when 10% fetal calf serum is added to the chase medium. This decrease in protein degradation in the presence of serum is associated with an increase in the percentage of B that are hatching (P 3 H-leucine in their proteins than did Day 4 embryos remaining in culture (P<0.02), while Day 4 embryos in a Day 3 uterus retained the same amount of radioactivity as did Day 4 embryos in culture. This differential effect of uterine environment was also seen when Day 4 embryos were transferred to recipients. More fetuses developed to term when the recipient was in Day 3 of PSP (50.8%) than when the recipient was in Day 4 PSP (25.9%, P<0.001), regardless of the age of the recipient. Age of the recipient does affect the percentage of transferred embryos developing to term. Thus, protein degradation may vary with the stage of embryo development and the conditions to which the embryos are exposed. However, even low levels of incorporated tritiated leucine can have lethal effects on the embryos and compromise the validity of the protein half-lives determined

Copper-mediated oxidative degradation of catecholamines and oxidative damage of protein

Energy Technology Data Exchange (ETDEWEB)

Goncalves, P.R.; Harria, M.I.N.; Felix, J.M.; Hoffmann, M.E. [Universidade Estadual de Campinas, SP (Brazil). Inst. de Biologia

1997-12-31

Full text. Degradative oxidation of catecholamines has been a matter of large interest in recent years due to the evidences associating their autoxidation with the etiology of neurotoxic and cardiotoxic processes. In this work we present data on the degradative oxidation of catecholamines of physiological importance: isoproterenol (IP), epinephrine (EP), norepinephrine (NEP), deoxyepinephrine (DEP) and dopamine (DA). The degradative oxidation of the catecholamines was followed by measurement of spectral changes and oxygen consumption by neutral aqueous solutions. The data show that Cu{sup 2+} strongly accelerated the rate of catecholamine oxidation, following the decreasing order; EP>DEP>IP>NEP>DA. The production of superoxide anion radical during catecholamine oxidation was very slow, even in the presence of Cu{sup 2+}. The ability of IP to induce damages on bovine serum albumin (BSA) was determined by measuring the formation of carbonyl-groups in the protein, detected by reduction with tritiated Na BH{sub 4}. The incubation of BSA with IP (50-500{mu}M), in the presence of 100{mu}M Cu{sup 2+} leaded to an increased and dose dependent {sup 3} H-incorporation by the oxidized protein. The production of oxidative damage by IP/Cu{sup 2+} was accompanied by marked BSA fragmentation, detected by SDS-polyacrylamide gel dependent (25-400{mu}M IP) des appearance of the original BSA band and appearance of smaller fragments spread in the gel, when incubation has been done in the presence of 100{mu}M Cu{sup 2+}. These results suggest that copper-catalysed oxidative degradation of proteins induced by catecholamines might be critically involved in the toxic action of these molecules

Ubiquitination is absolutely required for the degradation of hypoxia-inducible factor--1 alpha protein in hypoxic conditions.

Science.gov (United States)

Wang, Ronghai; Zhang, Ping; Li, Jinhang; Guan, Hongzai; Shi, Guangjun

2016-01-29

The hypoxia-inducible factor (HIF) is recognized as the master regulator of hypoxia response. HIF-α subunits expression are tightly regulated. In this study, our data show that ts20 cells still expressed detectable E1 protein even at 39.5° C for 12 h, and complete depletion of E1 protein expression at 39.5° C by siRNA enhanced HIF-1α and P53 protein expression. Further inhibition of E1 at 39.5 °C by siRNA, or E1 inhibitor Ube1-41 completely blocked HIF-1α degradation. Moreover, immunoprecipitations of co-transfection of HA-ubiquitin and FLAG-HIF-1α plasmids directly confirmed the involvement of ubiquitin in the hypoxic degradation of HIF-1α. Additionally, hypoxic HIF-1 α degradation is independent of HAF, RACK1, sumoylation or nuclear/cytoplasmic localization. Taken together, our data suggest that constitutive HIF-1α protein degradation in hypoxia is absolutely ubiquitination-dependent, and unidentified E3 ligase may exist for this degradation pathway. Copyright © 2016 Elsevier Inc. All rights reserved.

Analyzing pepsin degradation assay conditions used for allergenicity assessments to ensure that pepsin susceptible and pepsin resistant dietary proteins are distinguishable.

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Rong Wang

Full Text Available The susceptibility of a dietary protein to proteolytic degradation by digestive enzymes, such as gastric pepsin, provides information on the likelihood of systemic exposure to a structurally intact and biologically active macromolecule, thus informing on the safety of proteins for human and animal consumption. Therefore, the purpose of standardized in vitro degradation studies that are performed during protein safety assessments is to distinguish whether proteins of interest are susceptible or resistant to pepsin degradation via a study design that enables study-to-study comparison. Attempting to assess pepsin degradation under a wide-range of possible physiological conditions poses a problem because of the lack of robust and consistent data collected under a large-range of sub-optimal conditions, which undermines the needs to harmonize in vitro degradation conditions. This report systematically compares the effects of pH, incubation time, and pepsin-to-substrate protein ratio on the relative degradation of five dietary proteins: three pepsin susceptible proteins [ribulose 1,5-bisphosphate carboxylase-oxygenase (Rubisco, horseradish peroxidase (HRP, hemoglobin (Hb], and two pepsin resistant proteins [lipid transfer protein (LTP and soybean trypsin inhibitor (STI]. The results indicate that proteins susceptible to pepsin degradation are readily distinguishable from pepsin-resistant proteins when the reaction conditions are within the well-characterized optima for pepsin. The current standardized in vitro pepsin resistant assay with low pH and high pepsin-to-substrate ratio fits this purpose. Using non-optimal pH and/or pepsin-to-substrate protein ratios resulted in susceptible proteins no longer being reliably degraded by this stomach enzyme, which compromises the ability of this in vitro assay to distinguish between resistant and susceptible proteins and, therefore, no longer providing useful data to an overall weight-of-evidence approach to

Monitoring and eradication of exotic fruit flies in the Asia-Pacific region

International Nuclear Information System (INIS)

Allwood, Allan; Vueti, Ema Tora

2003-01-01

Fruit flies (family Tephritidae) are very mobile and are capable of breaching quarantine barriers, resulting in authorities and horticultural industries having to conduct expensive eradication programs. During the last two decades, with improved air travel and large increases in traveller numbers, the numbers of incursions and outbreaks of exotic pest fruit flies, especially in the Pacific region, have increased, particularly those species belonging to the dorsalis complex. Quarantine surveillance or early warning systems for recording exotic fruit flies include border inspections, passenger profiling, detection trapping, host surveys, and emergency response capacity. Having these systems fully operational improves the prospects of recording new incursions or outbreaks before they have time to expand, but it is still essential to have the capacity to undertake an eradication response as quickly as possible. Eradication programs using protein bait application technique, male annihilation technique, and, in some cases, sterile insect technique have been recently used in Mauritius, Thailand, Philippines, Australia, Nauru, Cook Islands, and French Polynesia against a range of fruit fly species. (author)

Gold nanoparticles enhance the X-ray-induced degradation of human centrin 2 protein

International Nuclear Information System (INIS)

Brun, Emilie; Duchambon, Patricia; Blouquit, Yves; Keller, Gerard; Sanche, Leon; Sicard-Roselli, Cecile

2009-01-01

In the war against cancer, radiotherapy is a prominent tool but counterbalanced by the fact that it also induces damages in healthy tissues. Nanotechnologies could open a new possibility to decrease these side effects. In particular, gold nanoparticles (GNPs) could be used as radio-sensitizers. As the role of proteins in the processes leading to cell death cannot be neglected, their radio-sensitization by GNPs is of great interest. This is particularly true in the case of the human centrin 2 protein, which has been proposed to be involved in DNA repair processes. To investigate this effect, we quantified for the first time the degradation of this protein in a gold colloidal solution when submitted to X-rays. We showed that the X-ray-induced degradation of the human centrin 2 protein is enhanced 1.5-fold in the presence of GNPs, even though no covalent bond exists between protein and GNPs. Among the conditions tested, the maximum enhancement was found with the higher GNP:protein ratio of 2x10 -4 and with the higher X-ray energy of 49 keV

Techniques for characterization and eradication of potato cyst nematode: a review.

Science.gov (United States)

Bairwa, Aarti; Venkatasalam, E P; Sudha, R; Umamaheswari, R; Singh, B P

2017-09-01

Correct identification of species and pathotypes is must for eradication of potato cyst nematodes (PCN). The identification of PCN species after completing the life cycle is very difficult because it is based on morphological and morphometrical characteristics. Genetically different populations of PCN are morphologically same and differentiated based on the host differential study. Later on these traditional techniques have been replaced by biochemical techniques viz, one and two dimensional gel electrophoresis, capillary gel electrophoresis, isozymes, dot blot hybridization and isoelectric focusing etc. to distinguish both the species. One and two dimensional gel electrophoresis has used to examine inter- and intra-specific differences in proteins of Globodera rostochiensis and G. pallida . Now application of PCR and DNA based characterization techniques like RAPD, AFLP and RFLP are the important tools for differentiating inter- and intra specific variation in PCN and has given opportunities to accurate identification of PCN. For managing the PCN, till now we are following integrated pest management (IPM) strategies, however these strategies are not effective to eradicate the PCN. Therefore to eradicate the PCN we need noval management practices like RNAi (RNA interference) or Gene silencing.

Quantifying Protein Synthesis and Degradation in Arabidopsis by Dynamic 13CO2 Labeling and Analysis of Enrichment in Individual Amino Acids in Their Free Pools and in Protein1[OPEN

Science.gov (United States)

Fernie, Alisdair R.; Stitt, Mark

2015-01-01

Protein synthesis and degradation represent substantial costs during plant growth. To obtain a quantitative measure of the rate of protein synthesis and degradation, we supplied 13CO2 to intact Arabidopsis (Arabidopsis thaliana) Columbia-0 plants and analyzed enrichment in free amino acids and in amino acid residues in protein during a 24-h pulse and 4-d chase. While many free amino acids labeled slowly and incompletely, alanine showed a rapid rise in enrichment in the pulse and a decrease in the chase. Enrichment in free alanine was used to correct enrichment in alanine residues in protein and calculate the rate of protein synthesis. The latter was compared with the relative growth rate to estimate the rate of protein degradation. The relative growth rate was estimated from sequential determination of fresh weight, sequential images of rosette area, and labeling of glucose in the cell wall. In an 8-h photoperiod, protein synthesis and cell wall synthesis were 3-fold faster in the day than at night, protein degradation was slow (3%–4% d−1), and flux to growth and degradation resulted in a protein half-life of 3.5 d. In the starchless phosphoglucomutase mutant at night, protein synthesis was further decreased and protein degradation increased, while cell wall synthesis was totally inhibited, quantitatively accounting for the inhibition of growth in this mutant. We also investigated the rates of protein synthesis and degradation during leaf development, during growth at high temperature, and compared synthesis rates of Rubisco large and small subunits of in the light and dark. PMID:25810096

LINGO-1 promotes lysosomal degradation of amyloid-β protein precursor

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Rian de Laat

2015-03-01

Full Text Available Sequential proteolytic cleavages of amyloid-β protein precursor (AβPP by β-secretase and γ-secretase generate amyloid β (Aβ peptides, which are thought to contribute to Alzheimer's disease (AD. Much of this processing occurs in endosomes following endocytosis of AβPP from the plasma membrane. However, this pathogenic mode of processing AβPP may occur in competition with lysosomal degradation of AβPP, a common fate of membrane proteins trafficking through the endosomal system. Following up on published reports that LINGO-1 binds and promotes the amyloidogenic processing of AβPP we have examined the consequences of LINGO-1/AβPP interactions. We report that LINGO-1 and its paralogs, LINGO-2 and LINGO-3, decrease processing of AβPP in the amyloidogenic pathway by promoting lysosomal degradation of AβPP. We also report that LINGO-1 levels are reduced in AD brain, representing a possible pathogenic mechanism stimulating the generation of Aβ peptides in AD.

Effects of Supplementation of Branched-Chain Amino Acids to Reduced-Protein Diet on Skeletal Muscle Protein Synthesis and Degradation in the Fed and Fasted States in a Piglet Model

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Liufeng Zheng

2016-12-01

Full Text Available Supplementation of branched-chain amino acids (BCAA has been demonstrated to promote skeletal muscle mass gain, but the mechanisms underlying this observation are still unknown. Since the regulation of muscle mass depends on a dynamic equilibrium (fasted losses–fed gains in protein turnover, the aim of this study was to investigate the effects of BCAA supplementation on muscle protein synthesis and degradation in fed/fasted states and the related mechanisms. Fourteen 26- (Experiment 1 and 28-day-old (Experiment 2 piglets were fed reduced-protein diets without or with supplemental BCAA. After a four-week acclimation period, skeletal muscle mass and components of anabolic and catabolic signaling in muscle samples after overnight fasting were determined in Experiment 1. Pigs in Experiment 2 were implanted with carotid arterial, jugular venous, femoral arterial and venous catheters, and fed once hourly along with the intravenous infusion of NaH13CO3 for 2 h, followed by a 6-h infusion of [1-13C]leucine. Muscle leucine kinetics were measured using arteriovenous difference technique. The mass of most muscles was increased by BCAA supplementation. During feeding, BCAA supplementation increased leucine uptake, protein synthesis, protein degradation and net transamination. The greater increase in protein synthesis than in protein degradation resulted in elevated protein deposition. Protein synthesis was strongly and positively correlated with the intramuscular net production of α-ketoisocaproate (KIC and protein degradation. Moreover, BCAA supplementation enhanced the fasted-state phosphorylation of protein translation initiation factors and inhibited the protein-degradation signaling of ubiquitin-proteasome and autophagy-lysosome systems. In conclusion, supplementation of BCAA to reduced-protein diet increases fed-state protein synthesis and inhibits fasted-state protein degradation, both of which could contribute to the elevation of skeletal muscle

Application of green fluorescent protein for monitoring phenol-degrading strains

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Ana Milena Valderrama F.

2001-07-01

Full Text Available Several methods have been developed for detecting microorganisms in environmental samples. Some systems for incorporating reporter genes, such as lux or the green fluorescent protein (GFP gene, have been developed recently This study describes gfp gene marking of a phenol degrading strain, its evaluation and monitoring in a bioreactor containing refinery sour water. Tagged strains were obtained having the same physiological and metabolic characteristics as the parent strain. Fluorescent expression was kept stable with no selection for more than 50 consecutive generations and tagged strains were recovered from the bioreactor after forty-five days of phenol-degradation treatment.

Two waves of proteasome-dependent protein degradation in the hippocampus are required for recognition memory consolidation.

Science.gov (United States)

Figueiredo, Luciana S; Dornelles, Arethuza S; Petry, Fernanda S; Falavigna, Lucio; Dargél, Vinicius A; Köbe, Luiza M; Aguzzoli, Cristiano; Roesler, Rafael; Schröder, Nadja

2015-04-01

Healthy neuronal function and synaptic modification require a concert of synthesis and degradation of proteins. Increasing evidence indicates that protein turnover mediated by proteasome activity is involved in long-term synaptic plasticity and memory. However, its role in different phases of memory remains debated, and previous studies have not examined the possible requirement of protein degradation in recognition memory. Here, we show that the proteasome inhibitor, lactacystin (LAC), infused into the CA1 area of the hippocampus at two specific time points during consolidation, impairs 24-retention of memory for object recognition in rats. Administration of LAC after retrieval did not affect retention. These findings provide the first evidence for a requirement of proteasome activity in recognition memory, indicate that protein degradation in the hippocampus is necessary during selective time windows of memory consolidation, and further our understanding of the role of protein turnover in memory formation. Copyright © 2015 Elsevier Inc. All rights reserved.

Harmonization Of Inter-Institutional Authority In Eradicate Corruption

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Agus Salim

2015-08-01

Full Text Available Nowadays the agenda of corruption eradication have been undertaken by various institutions such as the judiciary the police the Corruption Eradication Commission and other bodies related to the corruption eradication. The type of research used in this study is normative-jurisdiction and empirical-jurisdiction. To obtain the necessary data in this study the researcher conducted library research as a reference in some libraries are quite representative. Results shows that the effectiveness of corruption eradication that conducted by regulatory authorities in order to combat corruption has not been implemented maximally because each institution as a subsystem has not carried out an interdependent relationship both vertical and horizontal nature. If we expect the eradication of corruption can be implemented optimally it is recommended that the coordination between law enforcement agencies in the integrated criminal justice system is necessary to build their common vision interpretation and perception in the implementation of the duties for the institution authorized to eradicate corruption.

In situ ruminal degradability of protein feeds with distinct physical ...

African Journals Online (AJOL)

Journal Home > Vol 47, No 1 (2017) > ... of protein feeds with different physical forms (meal versus grain) through a meta-analysis study. ... grains with the meal forms of soybean, peanut, sunflower, cottonseed, and corn gluten. The degradation parameters of dry matter did not differ significantly between meals and grains.

Establishment of a ruminal protein degradation data base for dairy ...

African Journals Online (AJOL)

Establishment of a ruminal protein degradation data base for dairy cattle using the in situ polyester bag technique. 2. Energy sources. LJ Erasmus, J Prinsloo, PM Botha, HH Meissner. Abstract. No Abstract. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT.

Establishment of a ruminal protein degradation data base for dairy ...

African Journals Online (AJOL)

Establishment of a ruminal protein degradation data base for dairy cattle using the in situ polyester bag technique. 3. Roughages. LJ Erasmus, J Prinsloo, PM Botha, HH Meissner. Abstract. No Abstract. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT.

A novel mosquito ubiquitin targets viral envelope protein for degradation and reduces virion production during dengue virus infection.

Science.gov (United States)

Troupin, Andrea; Londono-Renteria, Berlin; Conway, Michael J; Cloherty, Erin; Jameson, Samuel; Higgs, Stephen; Vanlandingham, Dana L; Fikrig, Erol; Colpitts, Tonya M

2016-09-01

Dengue virus (DENV) is a mosquito-borne flavivirus that causes significant human disease and mortality in the tropics and subtropics. By examining the effects of virus infection on gene expression, and interactions between virus and vector, new targets for prevention of infection and novel treatments may be identified in mosquitoes. We previously performed a microarray analysis of the Aedes aegypti transcriptome during infection with DENV and found that mosquito ubiquitin protein Ub3881 (AAEL003881) was specifically and highly down-regulated. Ubiquitin proteins have multiple functions in insects, including marking proteins for proteasomal degradation, regulating apoptosis and mediating innate immune signaling. We used qRT-PCR to quantify gene expression and infection, and RNAi to reduce Ub3881 expression. Mosquitoes were infected with DENV through blood feeding. We transfected DENV protein expression constructs to examine the effect of Ub3881 on protein degradation. We used site-directed mutagenesis and transfection to determine what amino acids are involved in Ub3881-mediated protein degradation. Immunofluorescence, Co-immunoprecipitation and Western blotting were used to examine protein interactions and co-localization. The overexpression of Ub3881, but not related ubiquitin proteins, decreased DENV infection in mosquito cells and live Ae. aegypti. The Ub3881 protein was demonstrated to be involved in DENV envelope protein degradation and reduce the number of infectious virions released. We conclude that Ub3881 has several antiviral functions in the mosquito, including specific viral protein degradation. Our data highlights Ub3881 as a target for future DENV prevention strategies in the mosquito transmission vector. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Pylera for the eradication of Helicobacter pylori infection.

LENUS (Irish Health Repository)

Saleem, Aamir

2012-02-01

An ideal antibiotic regimen for Helicobacter pylori should achieve eradication rates of approximately 90%. Current 7-day triple therapy is successful in about two-thirds of patients. A novel treatment is required to achieve higher eradication with minimal induction of bacterial resistance. The aim of this article is to evaluate the safety and efficacy of a single triple capsule (Pylera) containing bismuth, metronidazole and tetracycline, given with omeprazole for the eradication of H. pylori infection. Extensive literature searches were conducted using PubMed data from 1982 to 2007. This search included headings of H. pylori, bismuth and eradication therapy. The triple capsule Pylera, when given with omeprazole, achieved eradication rates ranging between 84 and 97%. Eradication rates were similar for clarithromycin- and metronidazole-resistant strains. Eradication rates with an omeprazole, bismuth, metronidazole and tetracycline regimen appeared comparable for metronidazole-resistant and -sensitive strains. This effect is not seen with the use of triple therapy in cases of clarithromycin resistance. Clinical trials did not report any serious side effects from bismuth-based regimens and compliance was similar to standard triple therapy. Bismuth-based triple therapy using Pylera is a simplified, effective and well-tolerated regimen achieving cure rates of above 90%.

Non-technical constraints to eradication: the Italian experience.

Science.gov (United States)

Moda, Giuliana

2006-02-25

Although technical constraints to eradication of bovine tuberculosis are well-recognised, non-technical constraints can also delay progress towards eradication, leading to inefficiency and increased programme costs. This paper seeks to analyse the main non-technical constraints that can interfere with the successful implementation of tuberculosis eradication plans, based on experiences from an area of high tuberculosis prevalence in Regione Piemonte, Italy. The main social and economic constraints faced in the past 20 years are reviewed, including a social reluctance to recognise the importance of seeking eradication as the goal of disease control, effective communication of technical issues, the training and the organization of veterinary services, the relationship between the regional authority and farmers and their representatives, and data management and epidemiological reporting. The paper analyses and discusses the solutions that were applied in Regione Piemonte and the benefits that were obtained. Tuberculosis eradication plans are one of the most difficult tasks of the Veterinary Animal Health Services, and non-technical constraints must be considered when progress towards eradication is less than expected. Organizational and managerial resources can help to overcome social or economic obstacles, provided the veterinary profession is willing to address technical, but also non-technical, constraints to eradication.

Methods for the visualization and analysis of extracellular matrix protein structure and degradation.

Science.gov (United States)

Leonard, Annemarie K; Loughran, Elizabeth A; Klymenko, Yuliya; Liu, Yueying; Kim, Oleg; Asem, Marwa; McAbee, Kevin; Ravosa, Matthew J; Stack, M Sharon

2018-01-01

This chapter highlights methods for visualization and analysis of extracellular matrix (ECM) proteins, with particular emphasis on collagen type I, the most abundant protein in mammals. Protocols described range from advanced imaging of complex in vivo matrices to simple biochemical analysis of individual ECM proteins. The first section of this chapter describes common methods to image ECM components and includes protocols for second harmonic generation, scanning electron microscopy, and several histological methods of ECM localization and degradation analysis, including immunohistochemistry, Trichrome staining, and in situ zymography. The second section of this chapter details both a common transwell invasion assay and a novel live imaging method to investigate cellular behavior with respect to collagen and other ECM proteins of interest. The final section consists of common electrophoresis-based biochemical methods that are used in analysis of ECM proteins. Use of the methods described herein will enable researchers to gain a greater understanding of the role of ECM structure and degradation in development and matrix-related diseases such as cancer and connective tissue disorders. © 2018 Elsevier Inc. All rights reserved.

Nck adaptor proteins link Tks5 to invadopodia actin regulation and ECM degradation.

Science.gov (United States)

Stylli, Stanley S; Stacey, T T I; Verhagen, Anne M; Xu, San San; Pass, Ian; Courtneidge, Sara A; Lock, Peter

2009-08-01

Invadopodia are actin-based projections enriched with proteases, which invasive cancer cells use to degrade the extracellular matrix (ECM). The Phox homology (PX)-Src homology (SH)3 domain adaptor protein Tks5 (also known as SH3PXD2A) cooperates with Src tyrosine kinase to promote invadopodia formation but the underlying pathway is not clear. Here we show that Src phosphorylates Tks5 at Y557, inducing it to associate directly with the SH3-SH2 domain adaptor proteins Nck1 and Nck2 in invadopodia. Tks5 mutants unable to bind Nck show reduced matrix degradation-promoting activity and recruit actin to invadopodia inefficiently. Conversely, Src- and Tks5-driven matrix proteolysis and actin assembly in invadopodia are enhanced by Nck1 or Nck2 overexpression and inhibited by Nck1 depletion. We show that clustering at the plasma membrane of the Tks5 inter-SH3 region containing Y557 triggers phosphorylation at this site, facilitating Nck recruitment and F-actin assembly. These results identify a Src-Tks5-Nck pathway in ECM-degrading invadopodia that shows parallels with pathways linking several mammalian and pathogen-derived proteins to local actin regulation.

ERAD defects and the HFE-H63D variant are associated with increased risk of liver damages in Alpha 1-Antitrypsin Deficiency

Science.gov (United States)

Di Martino, Julie; Ruiz, Mathias; Garin, Roman; Restier, Lioara; Belmalih, Abdelouahed; Marchal, Christelle; Cullin, Christophe; Arveiler, Benoit; Fergelot, Patricia; Gitler, Aaron D.; Lachaux, Alain; Couthouis, Julien

2017-01-01

Background The most common and severe disease causing allele of Alpha 1-Antitrypsin Deficiency (1ATD) is Z-1AT. This protein aggregates in the endoplasmic reticulum, which is the main cause of liver disease in childhood. Based on recent evidences and on the frequency of liver disease occurrence in Z-1AT patients, it seems that liver disease progression is linked to still unknown genetic factors. Methods We used an innovative approach combining yeast genetic screens with next generation exome sequencing to identify and functionally characterize the genes involved in 1ATD associated liver disease. Results Using yeast genetic screens, we identified HRD1, an Endoplasmic Reticulum Associated Degradation (ERAD) associated protein, as an inducer of Z-mediated toxicity. Whole exome sequencing of 1ATD patients resulted in the identification of two variants associated with liver damages in Z-1AT homozygous cases: HFE H63D and HERPUD1 R50H. Functional characterization in Z-1AT model cell lines demonstrated that impairment of the ERAD machinery combined with the HFE H63D variant expression decreased both cell proliferation and cell viability, while Unfolded Protein Response (UPR)-mediated cell death was hyperstimulated. Conclusion This powerful experimental pipeline allowed us to identify and functionally validate two genes involved in Z-1AT-mediated severe liver toxicity. This pilot study moves forward our understanding on genetic modifiers involved in 1ATD and highlights the UPR pathway as a target for the treatment of liver diseases associated with 1ATD. Finally, these findings support a larger scale screening for HERPUD1 R50H and HFE H63D variants in the sub-group of 1ATD patients developing significant chronic hepatic injuries (hepatomegaly, chronic cholestasis, elevated liver enzymes) and at risk developing liver cirrhosis. PMID:28617828

Gold nanoparticles enhance the X-ray-induced degradation of human centrin 2 protein

Energy Technology Data Exchange (ETDEWEB)

Brun, Emilie [Laboratoire de Chimie Physique, CNRS UMR 8000, Universite Paris-Sud 11, Bat. 350, 91405 Orsay Cedex (France); Duchambon, Patricia; Blouquit, Yves [INSERM U759, Imagerie Integrative, Campus Universitaire d' Orsay, Bat. 112, Institut Curie, Centre de Recherche, Laboratoire R. Latarjet, Campus Universitaire d' Orsay, 91405 Orsay Cedex (France); Keller, Gerard [UMR CNRS 8612, Physico-Chimie-Pharmacotechnie-Biopharmacie, Universite Paris 11, Faculte de Pharmacie, 5 rue Jean-Baptiste Clement, 92296 Chatenay-Malabry (France); Sanche, Leon [Groupe en Sciences des Radiations, Departement de Medecine Nucleaire et Radiobiologie, Faculte de Medecine, Universite de Sherbrooke, Sherbrooke, Quebec, Canada J1H 5N4 (Canada); Sicard-Roselli, Cecile [Laboratoire de Chimie Physique, CNRS UMR 8000, Universite Paris-Sud 11, Bat. 350, 91405 Orsay Cedex (France)], E-mail: cecile.sicard@u-psud.fr

2009-03-15

In the war against cancer, radiotherapy is a prominent tool but counterbalanced by the fact that it also induces damages in healthy tissues. Nanotechnologies could open a new possibility to decrease these side effects. In particular, gold nanoparticles (GNPs) could be used as radio-sensitizers. As the role of proteins in the processes leading to cell death cannot be neglected, their radio-sensitization by GNPs is of great interest. This is particularly true in the case of the human centrin 2 protein, which has been proposed to be involved in DNA repair processes. To investigate this effect, we quantified for the first time the degradation of this protein in a gold colloidal solution when submitted to X-rays. We showed that the X-ray-induced degradation of the human centrin 2 protein is enhanced 1.5-fold in the presence of GNPs, even though no covalent bond exists between protein and GNPs. Among the conditions tested, the maximum enhancement was found with the higher GNP:protein ratio of 2x10{sup -4} and with the higher X-ray energy of 49 keV.

Poverty Relief or Poverty Eradication? | Kritzinger | Acta Theologica

African Journals Online (AJOL)

The author challenges the reader to make two mindshifts: from a focus on poverty relief to an emphasis on poverty eradication; and from viewing the poor as the objects of poverty alleviation to accepting them as the subjects of poverty eradication. The case is argued and a practical approach towards poverty eradication is ...

Poverty eradication in a carbon constrained world.

Science.gov (United States)

Hubacek, Klaus; Baiocchi, Giovanni; Feng, Kuishuang; Patwardhan, Anand

2017-10-24

The UN Framework Convention on Climate Change aims to keep warming below 2 °C while recognizing developing countries' right to eradicate extreme poverty. Poverty eradication is also the first of the Sustainable Development Goals. This paper investigates potential consequences for climate targets of achieving poverty eradication. We find that eradicating extreme poverty, i.e., moving people to an income above $1.9 purchasing power parity (PPP) a day, does not jeopardize the climate target even in the absence of climate policies and with current technologies. On the other hand, bringing everybody to a still modest expenditure level of at least $2.97 PPP would have long-term consequences on achieving emission targets. Compared to the reference mitigation pathway, eradicating extreme poverty increases the effort by 2.8% whereas bringing everybody to at least $2.97 PPP would increase the required mitigation rate by 27%. Given that the top 10% global income earners are responsible for 36% of the current carbon footprint of households; the discourse should address income distribution and the carbon intensity of lifestyles.

The Challenge of Global Poliomyelitis Eradication.

Science.gov (United States)

Garon, Julie R; Cochi, Stephen L; Orenstein, Walter A

2015-12-01

In the United States during the 1950's, polio was on the forefront of every provider and caregiver's mind. Today, most providers in the United States have never seen a case. The Global Polio Eradication Initiative (GPEI), which began in 1988 has reduced the number of cases by over 99%. The world is closer to achieving global eradication of polio than ever before but as long as poliovirus circulates anywhere in the world, every country is vulnerable. The global community can support the polio eradication effort through continued vaccination, surveillance, enforcing travel regulations and contributing financial support, partnerships and advocacy. Copyright © 2015 Elsevier Inc. All rights reserved.

Rate and extent of ruminal degradation of crude protein from ...

African Journals Online (AJOL)

Predicted crude protein degradation was calculated at rate constants for outflow of 0.04 and 0.06/h respect- ively. ... as buffers, an ionophore and an antibiotic according to general .... the non-bird resistant ('sweet') varieties. Ruminal .... have been affected by both the particle type and the math- ematical model we used.

The effect of H. pylori eradication on meal-associated changes in plasma ghrelin and leptin

Directory of Open Access Journals (Sweden)

Chhada Aditi

2011-04-01

Full Text Available Abstract Background Appetite and energy expenditure are regulated in part by ghrelin and leptin produced in the gastric mucosa, which may be modified by H. pylori colonization. We prospectively evaluated the effect of H. pylori eradication on meal-associated changes in serum ghrelin and leptin levels, and body weight. Methods Veterans referred for upper GI endoscopy were evaluated at baseline and ≥8 weeks after endoscopy, and H. pylori status and body weight were ascertained. During the first visit in all subjects, and during subsequent visits in the initially H. pylori-positive subjects and controls, blood was collected after an overnight fast and 1 h after a standard high protein meal, and levels of eight hormones determined. Results Of 92 enrolled subjects, 38 were H. pylori-negative, 44 H. pylori-positive, and 10 were indeterminate. Among 23 H. pylori-positive subjects who completed evaluation after treatment, 21 were eradicated, and 2 failed eradication. After a median of seven months following eradication, six hormones related to energy homeostasis showed no significant differences, but post-prandial acylated ghrelin levels were nearly six-fold higher than pre-eradication (p = 0.005, and median integrated leptin levels also increased (20% significantly (p H. pylori-positive individuals, but was not significantly changed in those who were H. pylori-negative or indeterminant at baseline. Conclusions Circulating meal-associated leptin and ghrelin levels and BMI changed significantly after H. pylori eradication, providing direct evidence that H. pylori colonization is involved in ghrelin and leptin regulation, with consequent effects on body morphometry.

Role of Proteasome-Dependent Protein Degradation in Long-Term Operant Memory in "Aplysia"

Science.gov (United States)

Lyons, Lisa C.; Gardner, Jacob S.; Gandour, Catherine E.; Krishnan, Harini C.

2017-01-01

We investigated the in vivo role of protein degradation during intermediate (ITM) and long-term memory (LTM) in "Aplysia" using an operant learning paradigm. The proteasome inhibitor MG-132 inhibited the induction and molecular consolidation of LTM with no effect on ITM. Remarkably, maintenance of steady-state protein levels through…

Toscana virus NSs protein promotes degradation of double-stranded RNA-dependent protein kinase.

Science.gov (United States)

Kalveram, Birte; Ikegami, Tetsuro

2013-04-01

Toscana virus (TOSV), which is transmitted by Phlebotomus spp. sandflies, is a major etiologic agent of aseptic meningitis and encephalitis in the Mediterranean. Like other members of the genus Phlebovirus of the family Bunyaviridae, TOSV encodes a nonstructural protein (NSs) in its small RNA segment. Although the NSs of Rift Valley fever virus (RVFV) has been identified as an important virulence factor, which suppresses host general transcription, inhibits transcription from the beta interferon promoter, and promotes the proteasomal degradation of double-stranded RNA-dependent protein kinase (PKR), little is known about the functions of NSs proteins encoded by less-pathogenic members of this genus. In this study we report that TOSV is able to downregulate PKR with similar efficiency as RVFV, while infection with the other phleboviruses-i.e., Punta Toro virus, sandfly fever Sicilian virus, or Frijoles virus-has no effect on cellular PKR levels. In contrast to RVFV, however, cellular transcription remains unaffected during TOSV infection. TOSV NSs protein promotes the proteasome-dependent downregulation of PKR and is able to interact with kinase-inactive PKR in infected cells.

Effect of Rapid Chilling on Beef Quality and Cytoskeletal Protein Degradation in of Chinese Yellow Crossbred Bulls

Directory of Open Access Journals (Sweden)

Yanwei Mao

2012-08-01

Full Text Available The objective of this study was to investigate the effect of rapid chilling (RC on beef quality and the degradation of cytoskeletal proteins. Twenty Chinese Yellow crossbred bulls were selected and randomly divided into two groups. RC and conventional chilling (CC were applied to left and right sides of the carcasses respectively after slaughtering. To determine whether electrical stimulation (ES treatment can alleviate the potential hazard of RC on meat quality, ES was applied to one group. The effects of RC and ES were determined by meat color, shear force and cytoskeletal protein degradation postmortem (PM. The results showed that RC decreased beef tenderness at 1 d and 3 d postmortem, but had no detrimental effect on meat color. Western blotting showed that RC decreased the degradation rate of desmin and troponin-T, but the effects weakened gradually as postmortem aging extended. Degradation rates of both desmin and troponin-T were accelerated by ES. The combination of RC and ES could improve beef color, accelerate degradation rate of cytoskeletal protein and improve beef tenderness.

HECTD3 Mediates an HSP90-Dependent Degradation Pathway for Protein Kinase Clients

Directory of Open Access Journals (Sweden)

Zhaobo Li

2017-06-01

Full Text Available Inhibition of the ATPase cycle of the HSP90 chaperone promotes ubiquitylation and proteasomal degradation of its client proteins, which include many oncogenic protein kinases. This provides the rationale for HSP90 inhibitors as cancer therapeutics. However, the mechanism by which HSP90 ATPase inhibition triggers ubiquitylation is not understood, and the E3 ubiquitin ligases involved are largely unknown. Using a siRNA screen, we have identified components of two independent degradation pathways for the HSP90 client kinase CRAF. The first requires CUL5, Elongin B, and Elongin C, while the second requires the E3 ligase HECTD3, which is also involved in the degradation of MASTL and LKB1. HECTD3 associates with HSP90 and CRAF in cells via its N-terminal DOC domain, which is mutationally disrupted in tumor cells with activated MAP kinase signaling. Our data implicate HECTD3 as a tumor suppressor modulating the activity of this important oncogenic signaling pathway.

Malaria eradication: the economic, financial and institutional challenge.

Science.gov (United States)

Mills, Anne; Lubell, Yoel; Hanson, Kara

2008-12-11

Malaria eradication raises many economic, financial and institutional challenges. This paper reviews these challenges, drawing on evidence from previous efforts to eradicate malaria, with a special focus on resource-poor settings; summarizes more recent evidence on the challenges, drawing on the literature on the difficulties of scaling-up malaria control and strengthening health systems more broadly; and explores the implications of these bodies of evidence for the current call for elimination and intensified control. Economic analyses dating from the eradication era, and more recent analyses, suggest that, in general, the benefits of malaria control outweigh the costs, though few studies have looked at the relative returns to eradication versus long-term control. Estimates of financial costs are scanty and difficult to compare. In the 1960s, the consolidation phase appeared to cost less than $1 per capita and, in 1988, was estimated to be $2.31 per capita (both in 2006 prices). More recent estimates for high coverage of control measures suggest a per capita cost of several dollars. Institutional challenges faced by malaria eradication included limits to the rule of law (a major problem where malaria was concentrated in border areas with movement of people associated with illegal activities), the existence and performance of local implementing structures, and political sustainability at national and global levels. Recent analyses of the constraints to scaling-up malaria control, together with the historical evidence, are used to discuss the economic, financial and institutional challenges that face the renewed call for eradication and intensified control. The paper concludes by identifying a research agenda covering: issues of the allocative efficiency of malaria eradication, especially using macro-economic modelling to estimate the benefits and costs of malaria eradication and intensified control, and studies of the links between malaria control and economic

Malaria eradication: the economic, financial and institutional challenge

Directory of Open Access Journals (Sweden)

Hanson Kara

2008-12-01

Full Text Available Abstract Malaria eradication raises many economic, financial and institutional challenges. This paper reviews these challenges, drawing on evidence from previous efforts to eradicate malaria, with a special focus on resource-poor settings; summarizes more recent evidence on the challenges, drawing on the literature on the difficulties of scaling-up malaria control and strengthening health systems more broadly; and explores the implications of these bodies of evidence for the current call for elimination and intensified control. Economic analyses dating from the eradication era, and more recent analyses, suggest that, in general, the benefits of malaria control outweigh the costs, though few studies have looked at the relative returns to eradication versus long-term control. Estimates of financial costs are scanty and difficult to compare. In the 1960s, the consolidation phase appeared to cost less than $1 per capita and, in 1988, was estimated to be $2.31 per capita (both in 2006 prices. More recent estimates for high coverage of control measures suggest a per capita cost of several dollars. Institutional challenges faced by malaria eradication included limits to the rule of law (a major problem where malaria was concentrated in border areas with movement of people associated with illegal activities, the existence and performance of local implementing structures, and political sustainability at national and global levels. Recent analyses of the constraints to scaling-up malaria control, together with the historical evidence, are used to discuss the economic, financial and institutional challenges that face the renewed call for eradication and intensified control. The paper concludes by identifying a research agenda covering: ∘ issues of the allocative efficiency of malaria eradication, especially using macro-economic modelling to estimate the benefits and costs of malaria eradication and intensified control, and studies of the links between

New strategy for renal fibrosis: Targeting Smad3 proteins for ubiquitination and degradation.

Science.gov (United States)

Wang, Xin; Feng, Shaozhen; Fan, Jinjin; Li, Xiaoyan; Wen, Qiong; Luo, Ning

2016-09-15

Smad3 is a critical signaling protein in renal fibrosis. Proteolysis targeting chimeric molecules (PROTACs) are small molecules designed to degrade target proteins via ubiquitination. They have three components: (1) a recognition motif for E3 ligase; (2) a linker; and (3) a ligand for the target protein. We aimed to design a new PROTAC to prevent renal fibrosis by targeting Smad3 proteins and using hydroxylated pentapeptide of hypoxia-inducible factor-1α as the recognition motif for von Hippel-Lindau (VHL) ubiquitin ligase (E3). Computer-aided drug design was used to find a specific ligand targeting Smad3. Surface plasmon resonance (SPR) was used to verify and optimize screening results. Synthesized PROTAC was validated by two-stage mass spectrometry. The PROTAC's specificity for VHL (E3 ligase) was proved with two human renal carcinoma cell lines, 786-0 (VHL(-)) and ACHN (VHL(+)), and its anti-fibrosis effect was tested in renal fibrosis cell models. Thirteen small molecular compounds (SMCs) were obtained from the Enamine library using GLIDE molecular docking program. SPR results showed that #8 SMC (EN300-72284) combined best with Smad3 (KD=4.547×10(-5)M). Mass spectrometry showed that synthesized PROTAC had the correct peptide molecular weights. Western blot showed Smad3 was degraded by PROTAC with whole-cell lysate of ACHN but not 786-0. Degradation, but not ubiquitination, of Smad3 was inhibited by proteasome inhibitor MG132. The upregulation of fibronectin and Collagen I induced by TGF-β1 in both renal fibroblast and mesangial cells were inhibited by PROTAC. The new PROTAC might prevent renal fibrosis by targeting Smad3 for ubiquitination and degradation. Copyright © 2016 Elsevier Inc. All rights reserved.

Boll weevil eradication: a model for sea lamprey control?

Science.gov (United States)

Smith, James W.; Swink, William D.

2003-01-01

Invasions of boll weevil (Anthonomus grandis) into the United States and sea lamprey (Petromyzon marinus) into the Great Lakes were similar in many ways. Important species (American cotton, Gossypium hirsutum, and lake trout, Salvelinus namaycush) and the industries they supported were negatively affected. Initial control efforts were unsuccessful until pesticides and application technologies were developed. For boll weevils, controls relying on pesticides evolved into an integrated program that included recommended farming practices and poisoned baits. However, the discovery of a boll weevil sex pheromone in 1964 allowed adoption of an ongoing program of eradication. Despite opposition over concept and cost, insecticides, pheromone traps, poisoned baits, and approved farming practices were used to eradicate boll weevils from Virginia, North Carolina, South Carolina, Georgia, Florida, and Alabama by 1999. Using the working back approach along the path of the original invasion, eradication was nearly completed by 2002 in Mississippi and eradication programs were underway in Arkansas, Tennessee, Oklahoma, Louisiana, and parts of Texas. Insecticide use for cotton production decreased 50 to 90%, and cotton yields and farm income increased an average of 78 kg/ha and $190 U.S./ha in areas where boll weevils were eradicated. For sea lampreys, integrated management uses lampricides, barriers to migration, trapping, and release of sterilized males. Although sea lamprey eradication is not currently feasible, recent research on larval and sex pheromones might provide the tools to make it possible. A successful eradication program for sea lampreys starting in Lake Superior and expanding to the lower Great Lakes would ultimately provide huge ecological and economic benefits by eliminating lampricide applications, removing barriers that block teleost fishes, and facilitating the recovery of lake trout. Should the opportunity arise, the concept of sea lamprey eradication should

Unique nonstructural proteins of Pneumonia Virus of Mice (PVM) promote degradation of interferon (IFN) pathway components and IFN-stimulated gene proteins.

Science.gov (United States)

Dhar, Jayeeta; Barik, Sailen

2016-12-01

Pneumonia Virus of Mice (PVM) is the only virus that shares the Pneumovirus genus of the Paramyxoviridae family with Respiratory Syncytial Virus (RSV). A deadly mouse pathogen, PVM has the potential to serve as a robust animal model of RSV infection, since human RSV does not fully replicate the human pathology in mice. Like RSV, PVM also encodes two nonstructural proteins that have been implicated to suppress the IFN pathway, but surprisingly, they exhibit no sequence similarity with their RSV equivalents. The molecular mechanism of PVM NS function, therefore, remains unknown. Here, we show that recombinant PVM NS proteins degrade the mouse counterparts of the IFN pathway components. Proteasomal degradation appears to be mediated by ubiquitination promoted by PVM NS proteins. Interestingly, NS proteins of PVM lowered the levels of several ISG (IFN-stimulated gene) proteins as well. These results provide a molecular foundation for the mechanisms by which PVM efficiently subverts the IFN response of the murine cell. They also reveal that in spite of their high sequence dissimilarity, the two pneumoviral NS proteins are functionally and mechanistically similar.

The final stages of the global eradication of poliomyelitis

OpenAIRE

Grassly, Nicholas C.

2013-01-01

The global incidence of poliomyelitis has dropped by more than 99 per cent since the governments of the world committed to eradication in 1988. One of the three serotypes of wild poliovirus has been eradicated and the remaining two serotypes are limited to just a small number of endemic regions. However, the Global Polio Eradication Initiative (GPEI) has faced a number of challenges in eradicating the last 1 per cent of wild-virus transmission. The polio endgame has also been complicated by t...

Eradication of common mynas Acridotheres tristis from Denis Island, Seychelles.

Science.gov (United States)

Feare, Chris J; van der Woude, Jildou; Greenwell, Phill; Edwards, Hannah A; Taylor, Jenni A; Larose, Christine S; Ahlen, Per-Arne; West, Jack; Chadwick, Will; Pandey, Smita; Raines, Katherine; Garcia, Fernando; Komdeur, Jan; de Groene, Arjan

2017-02-01

In Seychelles, the common myna has been shown to have a negative impact on endangered endemic birds on Denis Island, interfering with breeding attempts and attacking adult endemic birds at their nests. This stimulated an attempt to eradicate the island's mynas. The eradication was undertaken in three phases, overall killing 1186 mynas and lasting 5 years. Decoy trapping was the most effective method for catching mynas, but the last birds were shot. Decoy trapping was compromised by catches of non-target species. Data collection from killed birds indicated that trapping did not favour either sex, and that most breeding occurred during the wetter season, November to March. Eradication of mynas from small tropical islands is feasible. The Denis Island eradication was prolonged by difficulties in management and staffing. Using volunteers, the cost of the eradication was similar to that of eradicating rodents from the island. In future eradication attempts in Seychelles, possible food stress during the drier season (May to September) might facilitate trapping at this time. Habitat management, especially the removal of short mown grass, could enhance eradication progress. Continued monitoring is needed to confirm eradication and detect any immigration, and also to record responses in the endemic birds. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Life and death of proteins after protease cleavage: protein degradation by the N-end rule pathway.

Science.gov (United States)

Dissmeyer, Nico; Rivas, Susana; Graciet, Emmanuelle

2018-05-01

Contents Summary 929 I. conservation and diversity of N-end rule pathways 929 II. Defensive functions of the N-end rule pathway in plants 930 III. Proteases and degradation by the N-end rule pathway 930 IV. New proteomics approaches for the identification of N-end rule substrates 932 V. Concluding remarks 932 Acknowledgements 934 References 934 SUMMARY: The N-end rule relates the stability of a protein to the identity of its N-terminal residue and some of its modifications. Since its discovery in the 1980s, the repertoire of N-terminal degradation signals has expanded, leading to a diversity of N-end rule pathways. Although some of these newly discovered N-end rule pathways remain largely unexplored in plants, recent discoveries have highlighted roles of N-end rule-mediated protein degradation in plant defense against pathogens and in cell proliferation during organ growth. Despite this progress, a bottleneck remains the proteome-wide identification of N-end rule substrates due to the prerequisite for endoproteolytic cleavage and technical limitations. Here, we discuss the recent diversification of N-end rule pathways and their newly discovered functions in plant defenses, stressing the role of proteases. We expect that novel proteomics techniques (N-terminomics) will be essential for substrate identification. We review these methods, their limitations and future developments. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

Polio eradication initiative in India: deconstructing the GPEI.

Science.gov (United States)

Sathyamala, C; Mittal, Onkar; Dasgupta, Rajib; Priya, Ritu

2005-01-01

The Global Polio Eradication Initiative (GPEI) promised eradication of polio by the year 2000 and certification of eradication by 2005. The first deadline is already a matter of history. With the reporting of polio cases in 2004, the new deadline for polio eradication by 2004 is postponed further. This article seeks to argue that the scientific and technical bodies spear-heading the GPEI, including the WHO, UNICEF, and the U.S. Centers for Disease Control, have formulated a conceptually flawed strategy and that it is not weak political will that is the central obstacle in this final push for global eradication. The validity of the claims of "near success" by the proponents of the GPEI is also examined in detail. By taking India as a case study, the authors examine the achievements of the GPEI in nine years of intense effort since 1995. They conclude that the GPEI is yet another exercise in mismanaging the health priorities and programs in developing countries in the era of globalization.

The effect of H. pylori eradication on meal-associated changes in plasma ghrelin and leptin.

Science.gov (United States)

Francois, Fritz; Roper, Jatin; Joseph, Neal; Pei, Zhiheng; Chhada, Aditi; Shak, Joshua R; de Perez, Asalia Z Olivares; Perez-Perez, Guillermo I; Blaser, Martin J

2011-04-14

Appetite and energy expenditure are regulated in part by ghrelin and leptin produced in the gastric mucosa, which may be modified by H. pylori colonization. We prospectively evaluated the effect of H. pylori eradication on meal-associated changes in serum ghrelin and leptin levels, and body weight. Veterans referred for upper GI endoscopy were evaluated at baseline and ≥8 weeks after endoscopy, and H. pylori status and body weight were ascertained. During the first visit in all subjects, and during subsequent visits in the initially H. pylori-positive subjects and controls, blood was collected after an overnight fast and 1 h after a standard high protein meal, and levels of eight hormones determined. Of 92 enrolled subjects, 38 were H. pylori-negative, 44 H. pylori-positive, and 10 were indeterminate. Among 23 H. pylori-positive subjects who completed evaluation after treatment, 21 were eradicated, and 2 failed eradication. After a median of seven months following eradication, six hormones related to energy homeostasis showed no significant differences, but post-prandial acylated ghrelin levels were nearly six-fold higher than pre-eradication (p=0.005), and median integrated leptin levels also increased (20%) significantly (p<0.001). BMI significantly increased (5 ± 2%; p=0.008) over 18 months in the initially H. pylori-positive individuals, but was not significantly changed in those who were H. pylori-negative or indeterminant at baseline. Circulating meal-associated leptin and ghrelin levels and BMI changed significantly after H. pylori eradication, providing direct evidence that H. pylori colonization is involved in ghrelin and leptin regulation, with consequent effects on body morphometry. © 2011 Francois et al; licensee BioMed Central Ltd.

Neuroprotective mechanism of Kai Xin San: upregulation of hippocampal insulin-degrading enzyme protein expression and acceleration of amyloid-beta degradation

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Na Wang

2017-01-01

Full Text Available Kai Xin San is a Chinese herbal formula composed of Radix Ginseng , Poria , Radix Polygalae and Acorus Tatarinowii Rhizome . It has been used in China for many years for treating amnesia. Kai Xin San ameliorates amyloid-β (Aβ-induced cognitive dysfunction and is neuroprotective in vivo , but its precise mechanism remains unclear. Expression of insulin-degrading enzyme (IDE, which degrades Aβ, is strongly correlated with cognitive function. Here, we injected rats with exogenous Aβ42 (200 μM, 5 μL into the hippocampus and subsequently administered Kai Xin San (0.54 or 1.08 g/kg/d intragastrically for 21 consecutive days. Hematoxylin-eosin and Nissl staining revealed that Kai Xin San protected neurons against Aβ-induced damage. Furthermore, enzyme-linked immunosorbent assay, western blot and polymerase chain reaction results showed that Kai Xin San decreased Aβ42 protein levels and increased expression of IDE protein, but not mRNA, in the hippocampus. Our findings reveal that Kai Xin San facilitates hippocampal Aβ degradation and increases IDE expression, which leads, at least in part, to the alleviation of hippocampal neuron injury in rats.

CNPY2 inhibits MYLIP-mediated AR protein degradation in prostate cancer cells.

Science.gov (United States)

Ito, Saya; Ueno, Akihisa; Ueda, Takashi; Nakagawa, Hideo; Taniguchi, Hidefumi; Kayukawa, Naruhiro; Fujihara-Iwata, Atsuko; Hongo, Fumiya; Okihara, Koji; Ukimura, Osamu

2018-04-03

The androgen receptor (AR) is a ligand-dependent transcription factor that promotes prostate cancer (PC) cell growth through control of target gene expression. This report suggests that Canopy FGF signaling regulator 2 (CNPY2) controls AR protein levels in PC cells. We found that AR was ubiquitinated by an E3 ubiquitin ligase, myosin regulatory light chain interacting protein (MYLIP) and then degraded through the ubiquitin-proteasome pathway. CNPY2 decreased the ubiquitination activity of MYLIP by inhibition of interaction between MYLIP and UBE2D1, an E2 ubiquitin ligase. CNPY2 up-regulated gene expression of AR target genes such as KLK3 gene which encodes the prostate specific antigen (PSA) and promoted cell growth of PC cells. The cell growth inhibition by CNPY2 knockdown was rescued by AR overexpression. Furthermore, positive correlation of expression levels between CNPY2 and AR/AR target genes was observed in tissue samples from human prostate cancer patients. Together, these results suggested that CNPY2 promoted cell growth of PC cells by inhibition of AR protein degradation through MYLIP-mediated AR ubiquitination.

Cellular Cholesterol Regulates Ubiquitination and Degradation of the Cholesterol Export Proteins ABCA1 and ABCG1*

Science.gov (United States)

Hsieh, Victar; Kim, Mi-Jurng; Gelissen, Ingrid C.; Brown, Andrew J.; Sandoval, Cecilia; Hallab, Jeannette C.; Kockx, Maaike; Traini, Mathew; Jessup, Wendy; Kritharides, Leonard

2014-01-01

The objective of this study was to examine the influence of cholesterol in post-translational control of ABCA1 and ABCG1 protein expression. Using CHO cell lines stably expressing human ABCA1 or ABCG1, we observed that the abundance of these proteins is increased by cell cholesterol loading. The response to increased cholesterol is rapid, is independent of transcription, and appears to be specific for these membrane proteins. The effect is mediated through cholesterol-dependent inhibition of transporter protein degradation. Cell cholesterol loading similarly regulates degradation of endogenously expressed ABCA1 and ABCG1 in human THP-1 macrophages. Turnover of ABCA1 and ABCG1 is strongly inhibited by proteasomal inhibitors and is unresponsive to inhibitors of lysosomal proteolysis. Furthermore, cell cholesterol loading inhibits ubiquitination of ABCA1 and ABCG1. Our findings provide evidence for a rapid, cholesterol-dependent, post-translational control of ABCA1 and ABCG1 protein levels, mediated through a specific and sterol-sensitive mechanism for suppression of transporter protein ubiquitination, which in turn decreases proteasomal degradation. This provides a mechanism for acute fine-tuning of cholesterol transporter activity in response to fluctuations in cell cholesterol levels, in addition to the longer term cholesterol-dependent transcriptional regulation of these genes. PMID:24500716

Reduced synaptic vesicle protein degradation at lysosomes curbs TBC1D24/sky-induced neurodegeneration.

Science.gov (United States)

Fernandes, Ana Clara; Uytterhoeven, Valerie; Kuenen, Sabine; Wang, Yu-Chun; Slabbaert, Jan R; Swerts, Jef; Kasprowicz, Jaroslaw; Aerts, Stein; Verstreken, Patrik

2014-11-24

Synaptic demise and accumulation of dysfunctional proteins are thought of as common features in neurodegeneration. However, the mechanisms by which synaptic proteins turn over remain elusive. In this paper, we study Drosophila melanogaster lacking active TBC1D24/Skywalker (Sky), a protein that in humans causes severe neurodegeneration, epilepsy, and DOOR (deafness, onychdystrophy, osteodystrophy, and mental retardation) syndrome, and identify endosome-to-lysosome trafficking as a mechanism for degradation of synaptic vesicle-associated proteins. In fly sky mutants, synaptic vesicles traveled excessively to endosomes. Using chimeric fluorescent timers, we show that synaptic vesicle-associated proteins were younger on average, suggesting that older proteins are more efficiently degraded. Using a genetic screen, we find that reducing endosomal-to-lysosomal trafficking, controlled by the homotypic fusion and vacuole protein sorting (HOPS) complex, rescued the neurotransmission and neurodegeneration defects in sky mutants. Consistently, synaptic vesicle proteins were older in HOPS complex mutants, and these mutants also showed reduced neurotransmission. Our findings define a mechanism in which synaptic transmission is facilitated by efficient protein turnover at lysosomes and identify a potential strategy to suppress defects arising from TBC1D24 mutations in humans. © 2014 Fernandes et al.

HUWE1 and TRIP12 collaborate in degradation of ubiquitin-fusion proteins and misframed ubiquitin.

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Esben G Poulsen

Full Text Available In eukaryotic cells an uncleavable ubiquitin moiety conjugated to the N-terminus of a protein signals the degradation of the fusion protein via the proteasome-dependent ubiquitin fusion degradation (UFD pathway. In yeast the molecular mechanism of the UFD pathway has been well characterized. Recently the human E3 ubiquitin-protein ligase TRIP12 was connected with the UFD pathway, but little is otherwise known about this system in mammalian cells. In the present work, we utilized high-throughput imaging on cells transfected with a targeted siRNA library to identify components involved in degradation of the UFD substrate Ub(G76V-YFP. The most significant hits from the screen were the E3 ubiquitin-protein ligase HUWE1, as well as PSMD7 and PSMD14 that encode proteasome subunits. Accordingly, knock down of HUWE1 led to an increase in the steady state level and a retarded degradation of the UFD substrate. Knock down of HUWE1 also led to a stabilization of the physiological UFD substrate UBB(+1. Precipitation experiments revealed that HUWE1 is associated with both the Ub(G76V-YFP substrate and the 26S proteasome, indicating that it functions late in the UFD pathway. Double knock down of HUWE1 and TRIP12 resulted in an additive stabilization of the substrate, suggesting that HUWE1 and TRIP12 function in parallel during UFD. However, even when both HUWE1 and TRIP12 are downregulated, ubiquitylation of the UFD substrate was still apparent, revealing functional redundancy between HUWE1, TRIP12 and yet other ubiquitin-protein ligases.

Eradication of poliomyelitis in South Africa | Blecher | South African ...

African Journals Online (AJOL)

An international campaign under the leadership of the World Health Organisation is underway to eradicate polio from the world by the year 2000. South Africa may already be free of polio. However, to ensure eradication we need to move from a polio control programme to a polio eradication programme. This necessitates ...

Effect of conventional and extrusion pelleting on in situ ruminal degradability of starch, protein, and fibre in cattle

DEFF Research Database (Denmark)

Razzaghi, Ali; Larsen, Mogens; Lund, Peter

2016-01-01

+50% sugar beet pulp (SBP), or 50% maize+50% SBP. Meals were pelleted by either conventional pelleting, or by cooking extrusion using two distinct settings giving pellets with either high density (HD) or low density (LD). Ruminal degradation of starch, crude protein (CP) and NDF, and intestinal...... affected ruminal degradability of starch, protein, and NDF differently depending on both type of cereal and composition of the concentrate mixture.......>Pelleting>Meal). In contradiction, ESD for pure wheat and wheat mixtures was reduced, though differences were minor. Conventional pelleting reduced the effective protein degradability (EPD) for pure wheat, but extrusion did not further affect the EPD. In contrast, the most intense processing with extrusion LD increased EPD...

In vitro estimation of rumen protein degradability using 35S to label the bacterial mass

International Nuclear Information System (INIS)

Khristov, A.; Aleksandrov, S.; Aleksiev, I.

1994-01-01

An experiment was carried out in order to simplify a previously developed 15 N-method for in vitro estimation of rumen protein degradability. Casein (Cas), whole soybeans (Sb) heated at 120 o C for 20 min (SbTherm) and sunflower (Sfl) were incubated at 39 o C for 4 hours in a water bathshaker with the following media: McDougall's buffer, strained and enriched with particle associated bacteria rumen fluid (2:1), rapidly (maltose, sucrose, glucose) and more slowly (pectin, soluble starch) degradable carbohydrates with final concentration of 815 mg/100 ml and 21.7 μCi/100 ml of 35 S (from Na 2 35 SO 4 ). After the incubation had been ceased, a bacterial fraction was isolated through differential centrifugation and specific activity of bacterial (Bac) and high speed total solids (TS) nitrogen was measured. The ratio was used to calculate bacterial mass in TS and through the Kjeldahl nitrogen concentration in TS - the net bacterial growth (against control vessels without protein). The level of ammonia-N in the supernate after blank correction was used to find the ammonia-N released from protein degradation. The data showed that the rate (and extend) of degradation for the Cas (as a standard protein) was lower compared to those obtained through the 15 N-method but it was higher than the rate derived through another in vitro method. The Cas equivalent of the Sb was higher than the figure we found in a previous experiment with solvent extracted soybean meal suggesting that the 35 S-method underestimated the degradability of the Cas. After being tested on a wider range of foodstuffs, the proposed 35 S-method might be considered as an alternative procedure which is less laborous than the 15 N-method. (author)

Degradation and de novo synthesis of D1 protein and psbA ...

Indian Academy of Sciences (India)

This shows that synthesis of D1 protein is not the only component involved in the recovery process. Our events, which ... transcript levels in the green alga Chlamydomonas reinhardtii in ..... and Gaba V 1996 Accelerated degradation of the D2 ...

WHO Polio Eradication Program: Problems and Solutions

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S. M. Kharit

2016-01-01

Full Text Available In 2013 WHO re-evaluated its main goals of the polio eradication program. A modernization program was accepted with regard to the National vaccination calendars worldwide which includes a step-by-step refusal from the living polio vaccine (OPV and a total transition to the inactivated polio vaccine (IPV starting in 2019. Because of the total eradication of the polio type 2 virus, as an intermediate step the 3-valence OPV was substituted with the 2-valence OPV, which does not contain the type 2 polio virus, in April 2016. The aim of the article is to present the history of polio prevention and to state the reasons for the adoption of 3rd edition of the Global Polio Eradication Initiative. The new approaches were defined for eradication of wild polio virus type 1 and vaccine related strains. A new strategy for global switch to inactivated polio vaccine by 2019 was suggested.

Eradication of poliomyelitis in countries affected by conflict.

Science.gov (United States)

Tangermann, R H; Hull, H F; Jafari, H; Nkowane, B; Everts, H; Aylward, R B

2000-01-01

The global initiative to eradicate poliomyelitis is focusing on a small number of countries in Africa (Angola, Democratic Republic of the Congo, Liberia, Sierra Leone, Somalia, Sudan) and Asia (Afghanistan, Tajikistan), where progress has been hindered by armed conflict. In these countries the disintegration of health systems and difficulties of access are major obstacles to the immunization and surveillance strategies necessary for polio eradication. In such circumstances, eradication requires special endeavours, such as the negotiation of ceasefires and truces and the winning of increased direct involvement by communities. Transmission of poliovirus was interrupted during conflicts in Cambodia, Colombia, El Salvador, Peru, the Philippines, and Sri Lanka. Efforts to achieve eradication in areas of conflict have led to extra health benefits: equity in access to immunization, brought about because every child has to be reached; the revitalization and strengthening of routine immunization services through additional externally provided resources; and the establishment of disease surveillance systems. The goal of polio eradication by the end of 2000 remains attainable if supplementary immunization and surveillance can be accelerated in countries affected by conflict.

Separate photosensitizers mediate degradation of the 32-kDa photosystem II reaction center protein in the visible and UV spectral regions

International Nuclear Information System (INIS)

Greenberg, B.M.; Gaba, V.; Canaani, O.; Malkin, S.; Mattoo, A.K.; Edelman, M.

1989-01-01

A component of the photosystem II reaction center, the 32-kDa protein, is rapidly turned over in the light. The mechanism of its light-dependent metabolism is largely unknown. We quantified the rate of 32-kDa protein degradation over a broad spectral range (UV, visible, and far red). The quantum yield for degradation was highest in the UVB (280-320 nm) region. Spectral evidence demonstrates two distinctly different photosensitizers for 32-kDa protein degradation. The data implicate the bulk photosynthetic pigments (primarily chlorophyll) in the visible and far red regions, and plastoquinone (in one or more of its redox states) in the UV region. A significant portion of 32-kDa protein degradation in sunlight is attributed to UVB irradiance

A Role of Protein Degradation in Memory Consolidation after Initial Learning and Extinction Learning in the Honeybee ("Apis mellifera")

Science.gov (United States)

Felsenberg, Johannes; Dombrowski, Vincent; Eisenhardt, Dorothea

2012-01-01

Protein degradation is known to affect memory formation after extinction learning. We demonstrate here that an inhibitor of protein degradation, MG132, interferes with memory formation after extinction learning in a classical appetitive conditioning paradigm. In addition, we find an enhancement of memory formation when the same inhibitor is…

The Brucellosis Eradication Program in Texas

Science.gov (United States)

1983-09-01

area he represents. There are three major lawsuits that had impact on the Texas Brucel - losis Program b6cause of questionable constitutional authority...I.- 20 3. Surveillance Prugram The surveillance program element has been a part of the brucel - losis eradication program since it originated in 1959...infected herds selected to participate in the survey. The survey questions were designed to determine if the brucel - losis eradication prugram

Ubiquitination and degradation of the hominoid-specific oncoprotein TBC1D3 is regulated by protein palmitoylation

Energy Technology Data Exchange (ETDEWEB)

Kong, Chen; Lange, Jeffrey J.; Samovski, Dmitri [Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO 63110 (United States); Su, Xiong [Department of Internal Medicine, Center for Human Nutrition Washington University School of Medicine, St. Louis, MO 63110 (United States); Liu, Jialiu [Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO 63110 (United States); Sundaresan, Sinju [Department of Internal Medicine, Center for Human Nutrition Washington University School of Medicine, St. Louis, MO 63110 (United States); Stahl, Philip D., E-mail: pstahl@wustl.edu [Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO 63110 (United States)

2013-05-03

Highlights: •Hominoid-specific oncogene TBC1D3 is targeted to plasma membrane by palmitoylation. •TBC1D3 is palmitoylated on two cysteine residues: 318 and 325. •TBC1D3 palmitoylation governs growth factors-induced TBC1D3 degradation. •Post-translational modifications may regulate oncogenic properties of TBC1D3. -- Abstract: Expression of the hominoid-specific oncoprotein TBC1D3 promotes enhanced cell growth and proliferation by increased activation of signal transduction through several growth factors. Recently we documented the role of CUL7 E3 ligase in growth factors-induced ubiquitination and degradation of TBC1D3. Here we expanded our study to discover additional molecular mechanisms that control TBC1D3 protein turnover. We report that TBC1D3 is palmitoylated on two cysteine residues: 318 and 325. The expression of double palmitoylation mutant TBC1D3:C318/325S resulted in protein mislocalization and enhanced growth factors-induced TBC1D3 degradation. Moreover, ubiquitination of TBC1D3 via CUL7 E3 ligase complex was increased by mutating the palmitoylation sites, suggesting that depalmitoylation of TBC1D3 makes the protein more available for ubiquitination and degradation. The results reported here provide novel insights into the molecular mechanisms that govern TBC1D3 protein degradation. Dysregulation of these mechanisms in vivo could potentially result in aberrant TBC1D3 expression and promote oncogenesis.

The Starch Granule-Associated Protein EARLY STARVATION1 Is Required for the Control of Starch Degradation in Arabidopsis thaliana Leaves[OPEN

Science.gov (United States)

Feike, Doreen; Seung, David; Graf, Alexander; Bischof, Sylvain; Ellick, Tamaryn; Coiro, Mario; Soyk, Sebastian; Eicke, Simona; Mettler-Altmann, Tabea; Lu, Kuan Jen; Trick, Martin; Zeeman, Samuel C.

2016-01-01

To uncover components of the mechanism that adjusts the rate of leaf starch degradation to the length of the night, we devised a screen for mutant Arabidopsis thaliana plants in which starch reserves are prematurely exhausted. The mutation in one such mutant, named early starvation1 (esv1), eliminates a previously uncharacterized protein. Starch in mutant leaves is degraded rapidly and in a nonlinear fashion, so that reserves are exhausted 2 h prior to dawn. The ESV1 protein and a similar uncharacterized Arabidopsis protein (named Like ESV1 [LESV]) are located in the chloroplast stroma and are also bound into starch granules. The region of highest similarity between the two proteins contains a series of near-repeated motifs rich in tryptophan. Both proteins are conserved throughout starch-synthesizing organisms, from angiosperms and monocots to green algae. Analysis of transgenic plants lacking or overexpressing ESV1 or LESV, and of double mutants lacking ESV1 and another protein necessary for starch degradation, leads us to propose that these proteins function in the organization of the starch granule matrix. We argue that their misexpression affects starch degradation indirectly, by altering matrix organization and, thus, accessibility of starch polymers to starch-degrading enzymes. PMID:27207856

Ubiquitin ligase RNF123 mediates degradation of heterochromatin protein 1α and β in lamin A/C knock-down cells.

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Pankaj Chaturvedi

Full Text Available The nuclear lamina is a key determinant of nuclear architecture, integrity and functionality in metazoan nuclei. Mutations in the human lamin A gene lead to highly debilitating genetic diseases termed as laminopathies. Expression of lamin A mutations or reduction in levels of endogenous A-type lamins leads to nuclear defects such as abnormal nuclear morphology and disorganization of heterochromatin. This is accompanied by increased proteasomal degradation of certain nuclear proteins such as emerin, nesprin-1α, retinoblastoma protein and heterochromatin protein 1 (HP1. However, the pathways of proteasomal degradation have not been well characterized.To investigate the mechanisms underlying the degradation of HP1 proteins upon lamin misexpression, we analyzed the effects of shRNA-mediated knock-down of lamins A and C in HeLa cells. Cells with reduced levels of expression of lamins A and C exhibited proteasomal degradation of HP1α and HP1β but not HP1γ. Since specific ubiquitin ligases are upregulated in lamin A/C knock-down cells, further studies were carried out with one of these ligases, RNF123, which has a putative HP1-binding motif. Ectopic expression of GFP-tagged RNF123 directly resulted in degradation of HP1α and HP1β. Mutational analysis showed that the canonical HP1-binding pentapeptide motif PXVXL in the N-terminus of RNF123 was required for binding to HP1 proteins and targeting them for degradation. The role of endogenous RNF123 in the degradation of HP1 isoforms was confirmed by RNF123 RNAi experiments. Furthermore, FRAP analysis suggested that HP1β was displaced from chromatin in laminopathic cells.Our data support a role for RNF123 ubiquitin ligase in the degradation of HP1α and HP1β upon lamin A/C knock-down. Hence lamin misexpression can cause degradation of mislocalized proteins involved in key nuclear processes by induction of specific components of the ubiquitin-proteasome system.

An assessment of differences in the ruminal degradability and intestinal digestibility of crude protein in brewer’s grains and maize draff

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Vladimír Majer

2012-01-01

Full Text Available The submitted thesis aims to assess the differences between the ruminal degradability and intestinal digestibility of crude protein contained in brewer’s grains (BG and maize draff (AMG. The effectiveness of ruminal degradability was tested using the “in sacco” method on 3 dry Holstain cows fitted with rumen cannulas. The dynamics of ruminal degradability of crude protein (CP was detected after 0, 4, 8, 16, and 24 hours of samples incubation in the rumen. The intestinal digestibility of crude protein undegradable in the rumen was determined using the “mobile bag” method on 3 dry Holstain cows fitted with duodenal cannulas. The crude protein degradability of BG was detected in the above-mentioned hours (%: 4.06; 18.16; 32.40; 38.56, and 50.70; crude protein degradability of AMG: 42.04; 63.56; 84.47; 85.16, and 87.19. The effectiveness of rumen degradability of BG crude protein at the rate of passage of rumen content 6 % per hour was calculated at 35.33 % and that of AMG, at 76.29 %. Intestinal digestibility of BG crude protein and dry matter at the rate of passage of intestinal content 6 % per hour was calculated at 79.41 % and 22.84 %, respectively, and that of AMG, at 57.01 % and 11.33 %, respectively. The differences between the indicators of both feedstuffs were significant (P < 0.05. The results show that BG are mostly a source of crude protein with higher intestinal digestibility than AMG.

Rumen Degradability and Post-ruminal Digestion of Dry Matter, Nitrogen and Amino Acids of Three Protein Supplements.

Science.gov (United States)

Gao, Wei; Chen, Aodong; Zhang, Bowen; Kong, Ping; Liu, Chenli; Zhao, Jie

2015-04-01

This study evaluated the in situ ruminal degradability, and subsequent small intestinal digestibility (SID) of dry matter, crude protein (CP), and amino acids (AA) of cottonseed meal (CSM), sunflower seed meal (SFSM) and distillers dried grains with solubles (DDGS) by using the modified three-step in vitro procedure. The ruminal degradability and subsequent SID of AA in rumen-undegradable protein (RUP-AA) varied among three protein supplements. The result show that the effective degradability of DM for SFSM, CSM, and DDGS was 60.8%, 56.4%, and 41.0% and their ruminal fermentable organic matter was 60.0%, 55.9%, and 39.9%, respectively. The ruminal degradable protein (RDP) content in CP for SFSM, CSM, and DDGS was 68.3%, 39.0%, and 32.9%, respectively, at the ruminal solid passage rate of 1.84%/h. The SFSM is a good source of RDP for rumen micro-organisms; however, the SID of RUP of SFSM was lower. The DDGS and CSM are good sources of RUP for lambs to digest in the small intestine to complement ruminal microbial AA of growing lambs. Individual RUP-AA from each protein source was selectively removed by the rumen micro-organisms, especially for Trp, Arg, His, and Lys (p<0.01). The SID of individual RUP-AA was different within specific RUP origin (p<0.01). Limiting amino acid was Leu for RUP of CSM and Lys for both RUP of SFSM and DDGS, respectively. Therefore, different protein supplements with specific limitations should be selected and combined carefully in growing lambs ration to optimize AA balance.

[Possible method of eradication of poliomyelitis as an infection].

Science.gov (United States)

Seĭbil', V B; Malyshkina, L P

2012-01-01

Problem of poliomyelitis eradication is examined in the review. After the eradication of wild poliovirus, vaccine poliomyelitis virus continues to circulate in the human population. In rare cases it can cause the development of the disease. The authors describe disadvantages of the use of oral and inactivated poliomyelitis vaccines and note that by using oral poliomyelitis vaccine and eradication only of wild poliovirus, eradication of poliomyelitis as an infection will not succeed. As one of the approaches to reach this goal the authors propose the use of various enterovirus interference. Use of live enterovirus vaccine is described and its advantages and disadvantages are examined.

Human Adenovirus Infection Causes Cellular E3 Ubiquitin Ligase MKRN1 Degradation Involving the Viral Core Protein pVII.

Science.gov (United States)

Inturi, Raviteja; Mun, Kwangchol; Singethan, Katrin; Schreiner, Sabrina; Punga, Tanel

2018-02-01

Human adenoviruses (HAdVs) are common human pathogens encoding a highly abundant histone-like core protein, VII, which is involved in nuclear delivery and protection of viral DNA as well as in sequestering immune danger signals in infected cells. The molecular details of how protein VII acts as a multifunctional protein have remained to a large extent enigmatic. Here we report the identification of several cellular proteins interacting with the precursor pVII protein. We show that the cellular E3 ubiquitin ligase MKRN1 is a novel precursor pVII-interacting protein in HAdV-C5-infected cells. Surprisingly, the endogenous MKRN1 protein underwent proteasomal degradation during the late phase of HAdV-C5 infection in various human cell lines. MKRN1 protein degradation occurred independently of the HAdV E1B55K and E4orf6 proteins. We provide experimental evidence that the precursor pVII protein binding enhances MKRN1 self-ubiquitination, whereas the processed mature VII protein is deficient in this function. Based on these data, we propose that the pVII protein binding promotes MKRN1 self-ubiquitination, followed by proteasomal degradation of the MKRN1 protein, in HAdV-C5-infected cells. In addition, we show that measles virus and vesicular stomatitis virus infections reduce the MKRN1 protein accumulation in the recipient cells. Taken together, our results expand the functional repertoire of the HAdV-C5 precursor pVII protein in lytic virus infection and highlight MKRN1 as a potential common target during different virus infections. IMPORTANCE Human adenoviruses (HAdVs) are common pathogens causing a wide range of diseases. To achieve pathogenicity, HAdVs have to counteract a variety of host cell antiviral defense systems, which would otherwise hamper virus replication. In this study, we show that the HAdV-C5 histone-like core protein pVII binds to and promotes self-ubiquitination of a cellular E3 ubiquitin ligase named MKRN1. This mutual interaction between the pVII and

Reticulophagy and Ribophagy: Regulated Degradation of Protein Production Factories

Directory of Open Access Journals (Sweden)

Eduardo Cebollero

2012-01-01

Full Text Available During autophagy, cytosol, protein aggregates, and organelles are sequestered into double-membrane vesicles called autophagosomes and delivered to the lysosome/vacuole for breakdown and recycling of their basic components. In all eukaryotes this pathway is important for adaptation to stress conditions such as nutrient deprivation, as well as to regulate intracellular homeostasis by adjusting organelle number and clearing damaged structures. For a long time, starvation-induced autophagy has been viewed as a nonselective transport pathway; however, recent studies have revealed that autophagy is able to selectively engulf specific structures, ranging from proteins to entire organelles. In this paper, we discuss recent findings on the mechanisms and physiological implications of two selective types of autophagy: ribophagy, the specific degradation of ribosomes, and reticulophagy, the selective elimination of portions of the ER.

Degradation kinetics of fisetin and quercetin in solutions affected by medium pH, temperature and co-existed proteins

Directory of Open Access Journals (Sweden)

Wang Jing

2016-01-01

Full Text Available Impacts of medium pH, temperature and coexisted proteins on the degradation of two flavonoids fisetin and quercetin were assessed by spectroscopic method in the present study. Based on the measured degradation rate constants (k, fisetin was more stable than quercetin in all cases. Increasing medium pH from 6.0 to 7.5 at 37°C enhanced respective k values of fisetin and quercetin from 8.30x10−3 and 2.81x10−2 to 0.202 and 0.375 h-1 (P<0.05. In comparison with their degradation at 37°C, fisetin and quercetin showed larger k values at higher temperature (0.124 and 0.245 h−1 at 50°C, or 0.490 and 1.42 h−1 at 65°C. Four protein products in medium could stabilize the two flavonoids (P<0.05, as these proteins at 0.10 g L-1 decreased respective k values of fisetin and quercetin to 2.28x10−2-2.98x10−2 and 4.37´10−2-5.97x10−2 h−1. Hydrophobic interaction between the proteins and the two flavonoids was evidenced responsible for the stabilization, as sodium dodecyl sulfate could destroy the stabilization significantly (P<0.05. Casein and soybean protein provided greater stabilization than whey protein isolate. It is thus concluded that higher temperature and alkaline pH can enhance flavonoid loss, whereas coexisted proteins as flavonoid stabilizers can inhibit flavonoid degradation.

[The effect of Helicobacter pylori eradication on chronic gastritis].

Science.gov (United States)

Kodama, Masaaki; Murakami, Kazunari; Okimoto, Tadayoshi; Fujioka, Toshio

2013-08-01

Helicobacter pylori (H. pylori) is a major pathogen of chronic atrophic gastritis, intestinal metaplasia, and gastric cancer. Atrophic gastritis and intestinal metaplasia are recognized as precancerous lesion of gastric cancer. Many studies reported that H. pylori eradication had the preventive effect of gastric cancer. Moreover many studies mentioned the improvement of gastric atrophy and/or intestinal metaplasia. Two meta-analysis indicated the improvement of atrophic gastritis but not of intestinal metaplasia. In our study, intestinal metaplasia improved at lesser curvature of the corpus six years after eradication. H. pylori eradication has benefit for gastric cancer prevention provably due to improvement of the precancerous lesion such as atrophic gastritis and intestinal metaplasia. Especially, H. pylori eradication before the appearance of atrophy and intestinal metaplasia has been considered to be effective in inhibiting the development of gastric cancer. Therefore, improvement or elimination of chronic gastritis with H. pylori eradication might have possibility of gastric cancer inhibition.

Poliovirus Studies during the Endgame of the Polio Eradication Program.

Science.gov (United States)

Arita, Minetaro

2017-01-24

Since the beginning of Global Polio Eradication Initiative in 1988, poliomyelitis cases caused by wild poliovirus (PV) have been drastically reduced, with only 74 cases reported in 2 endemic countries in 2015. The current limited PV transmission suggests that we are in the endgame of the polio eradication program. However, specific challenges have emerged in the endgame, including tight budget, switching of the vaccines, and changes in biorisk management of PV. To overcome these challenges, several PV studies have been implemented in the eradication program. Some of the responses to the emerging challenges in the polio endgame might be valuable in other infectious diseases eradication programs. Here, I will review challenges that confront the polio eradication program and current research to address these challenges.

Potential of Environmental DNA to Evaluate Northern Pike (Esox lucius) Eradication Efforts: An Experimental Test and Case Study.

Science.gov (United States)

Dunker, Kristine J; Sepulveda, Adam J; Massengill, Robert L; Olsen, Jeffrey B; Russ, Ora L; Wenburg, John K; Antonovich, Anton

2016-01-01

Determining the success of invasive species eradication efforts is challenging because populations at very low abundance are difficult to detect. Environmental DNA (eDNA) sampling has recently emerged as a powerful tool for detecting rare aquatic animals; however, detectable fragments of DNA can persist over time despite absence of the targeted taxa and can therefore complicate eDNA sampling after an eradication event. This complication is a large concern for fish eradication efforts in lakes since killed fish can sink to the bottom and slowly decay. DNA released from these carcasses may remain detectable for long periods. Here, we evaluated the efficacy of eDNA sampling to detect invasive Northern pike (Esox lucius) following piscicide eradication efforts in southcentral Alaskan lakes. We used field observations and experiments to test the sensitivity of our Northern pike eDNA assay and to evaluate the persistence of detectable DNA emitted from Northern pike carcasses. We then used eDNA sampling and traditional sampling (i.e., gillnets) to test for presence of Northern pike in four lakes subjected to a piscicide-treatment designed to eradicate this species. We found that our assay could detect an abundant, free-roaming population of Northern pike and could also detect low-densities of Northern pike held in cages. For these caged Northern pike, probability of detection decreased with distance from the cage. We then stocked three lakes with Northern pike carcasses and collected eDNA samples 7, 35 and 70 days post-stocking. We detected DNA at 7 and 35 days, but not at 70 days. Finally, we collected eDNA samples ~ 230 days after four lakes were subjected to piscicide-treatments and detected Northern pike DNA in 3 of 179 samples, with a single detection at each of three lakes, though we did not catch any Northern pike in gillnets. Taken together, we found that eDNA can help to inform eradication efforts if used in conjunction with multiple lines of inquiry and sampling

Potential of Environmental DNA to Evaluate Northern Pike (Esox lucius Eradication Efforts: An Experimental Test and Case Study.

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Kristine J Dunker

Full Text Available Determining the success of invasive species eradication efforts is challenging because populations at very low abundance are difficult to detect. Environmental DNA (eDNA sampling has recently emerged as a powerful tool for detecting rare aquatic animals; however, detectable fragments of DNA can persist over time despite absence of the targeted taxa and can therefore complicate eDNA sampling after an eradication event. This complication is a large concern for fish eradication efforts in lakes since killed fish can sink to the bottom and slowly decay. DNA released from these carcasses may remain detectable for long periods. Here, we evaluated the efficacy of eDNA sampling to detect invasive Northern pike (Esox lucius following piscicide eradication efforts in southcentral Alaskan lakes. We used field observations and experiments to test the sensitivity of our Northern pike eDNA assay and to evaluate the persistence of detectable DNA emitted from Northern pike carcasses. We then used eDNA sampling and traditional sampling (i.e., gillnets to test for presence of Northern pike in four lakes subjected to a piscicide-treatment designed to eradicate this species. We found that our assay could detect an abundant, free-roaming population of Northern pike and could also detect low-densities of Northern pike held in cages. For these caged Northern pike, probability of detection decreased with distance from the cage. We then stocked three lakes with Northern pike carcasses and collected eDNA samples 7, 35 and 70 days post-stocking. We detected DNA at 7 and 35 days, but not at 70 days. Finally, we collected eDNA samples ~ 230 days after four lakes were subjected to piscicide-treatments and detected Northern pike DNA in 3 of 179 samples, with a single detection at each of three lakes, though we did not catch any Northern pike in gillnets. Taken together, we found that eDNA can help to inform eradication efforts if used in conjunction with multiple lines of

Potential of environmental DNA to evaluate Northern pike (Esox lucius) eradication efforts: An experimental test and case study

Science.gov (United States)

Dunker, Kristine J.; Sepulveda, Adam; Massengill, Robert L.; Olsen, Jeffrey B.; Russ, Ora L.; Wenburg, John K.; Antonovich, Anton

2016-01-01

Determining the success of invasive species eradication efforts is challenging because populations at very low abundance are difficult to detect. Environmental DNA (eDNA) sampling has recently emerged as a powerful tool for detecting rare aquatic animals; however, detectable fragments of DNA can persist over time despite absence of the targeted taxa and can therefore complicate eDNA sampling after an eradication event. This complication is a large concern for fish eradication efforts in lakes since killed fish can sink to the bottom and slowly decay. DNA released from these carcasses may remain detectable for long periods. Here, we evaluated the efficacy of eDNA sampling to detect invasive Northern pike (Esox lucius) following piscicide eradication efforts in southcentral Alaskan lakes. We used field observations and experiments to test the sensitivity of our Northern pike eDNA assay and to evaluate the persistence of detectable DNA emitted from Northern pike carcasses. We then used eDNA sampling and traditional sampling (i.e., gillnets) to test for presence of Northern pike in four lakes subjected to a piscicide-treatment designed to eradicate this species. We found that our assay could detect an abundant, free-roaming population of Northern pike and could also detect low-densities of Northern pike held in cages. For these caged Northern pike, probability of detection decreased with distance from the cage. We then stocked three lakes with Northern pike carcasses and collected eDNA samples 7, 35 and 70 days post-stocking. We detected DNA at 7 and 35 days, but not at 70 days. Finally, we collected eDNA samples ~ 230 days after four lakes were subjected to piscicide-treatments and detected Northern pike DNA in 3 of 179 samples, with a single detection at each of three lakes, though we did not catch any Northern pike in gillnets. Taken together, we found that eDNA can help to inform eradication efforts if used in conjunction with multiple lines of inquiry and sampling

Prolyl hydroxylation regulates protein degradation, synthesis, and splicing in human induced pluripotent stem cell-derived cardiomyocytes.

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Stoehr, Andrea; Yang, Yanqin; Patel, Sajni; Evangelista, Alicia M; Aponte, Angel; Wang, Guanghui; Liu, Poching; Boylston, Jennifer; Kloner, Philip H; Lin, Yongshun; Gucek, Marjan; Zhu, Jun; Murphy, Elizabeth

2016-06-01

Protein hydroxylases are oxygen- and α-ketoglutarate-dependent enzymes that catalyse hydroxylation of amino acids such as proline, thus linking oxygen and metabolism to enzymatic activity. Prolyl hydroxylation is a dynamic post-translational modification that regulates protein stability and protein-protein interactions; however, the extent of this modification is largely uncharacterized. The goals of this study are to investigate the biological consequences of prolyl hydroxylation and to identify new targets that undergo prolyl hydroxylation in human cardiomyocytes. We used human induced pluripotent stem cell-derived cardiomyocytes in combination with pulse-chase amino acid labelling and proteomics to analyse the effects of prolyl hydroxylation on protein degradation and synthesis. We identified 167 proteins that exhibit differences in degradation with inhibition of prolyl hydroxylation by dimethyloxalylglycine (DMOG); 164 were stabilized. Proteins involved in RNA splicing such as serine/arginine-rich splicing factor 2 (SRSF2) and splicing factor and proline- and glutamine-rich (SFPQ) were stabilized with DMOG. DMOG also decreased protein translation of cytoskeletal and sarcomeric proteins such as α-cardiac actin. We searched the mass spectrometry data for proline hydroxylation and identified 134 high confidence peptides mapping to 78 unique proteins. We identified SRSF2, SFPQ, α-cardiac actin, and cardiac titin as prolyl hydroxylated. We identified 29 prolyl hydroxylated proteins that showed a significant difference in either protein degradation or synthesis. Additionally, we performed next-generation RNA sequencing and showed that the observed decrease in protein synthesis was not due to changes in mRNA levels. Because RNA splicing factors were prolyl hydroxylated, we investigated splicing ± inhibition of prolyl hydroxylation and detected 369 alternative splicing events, with a preponderance of exon skipping. This study provides the first extensive

Generation of Oxygen Free Radicals by Proflavine: Implication in Protein Degradation

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Mansour K.M. Gatasheh

2017-07-01

Full Text Available Proflavine, an acridine dye, is a known DNA intercalating agent. In the present study, we show that proflavine alone on photoillumination can generate reactive oxygen species (ROS. These proflavine-derived ROS cause damage to proteins, and this effect is enhanced when the divalent metal ion Cu (II is included in the reaction. Bathocuproine, a specific Cu (I sequestering agent, when present in the reaction mixture containing Cu (II, was found to inhibit the protein degradation, showing that Cu (I is an essential intermediate in the reaction. The effect of several scavengers of ROS such as superoxide dismutase, sodium azide, potassium iodide, and thiourea were examined on the protein damaging reaction. Potassium iodide was found to be the most effective in inhibiting protein damage followed by sodium azide and thiourea. Our results indicate the involvement of superoxide, singlet oxygen, triplet oxygen, and hydroxyl radicals in proflavine-induced damage to proteins.

Monitoring protein turnover during phosphate starvation-dependent autophagic degradation using a photoconvertible fluorescent protein aggregate in tobacco BY-2 cells.

Science.gov (United States)

Tasaki, Maiko; Asatsuma, Satoru; Matsuoka, Ken

2014-01-01

We have developed a system for quantitative monitoring of autophagic degradation in transformed tobacco BY-2 cells using an aggregate-prone protein comprised of cytochrome b5 (Cyt b5) and a tetrameric red fluorescent protein (RFP). Unfortunately, this system is of limited use for monitoring the kinetics of autophagic degradation because the proteins synthesized before and after induction of autophagy cannot be distinguished. To overcome this problem, we developed a system using kikume green-red (KikGR), a photoconvertible and tetrameric fluorescent protein that changes its fluorescence from green to red upon irradiation with purple light. Using the fusion protein of Cyt b5 and KikGR together with a method for the bulk conversion of KikGR, which we had previously used to convert the Golgi-localized monomeric KikGR fusion protein, we were able to monitor both the growth and de novo formation of aggregates. Using this system, we found that tobacco cells do not cease protein synthesis under conditions of phosphate (Pi)-starvation. Induction of autophagy under Pi-starvation, but not under sugar- or nitrogen-starvation, was specifically inhibited by phosphite, which is an analog of Pi with a different oxidation number. Therefore, the mechanism by which BY-2 cells can sense Pi-starvation and induce autophagy does not involve sensing a general decrease in energy supply and a specific Pi sensor might be involved in the induction of autophagy under Pi-starvation.

The final stages of the global eradication of poliomyelitis.

Science.gov (United States)

Grassly, Nicholas C

2013-08-05

The global incidence of poliomyelitis has dropped by more than 99 per cent since the governments of the world committed to eradication in 1988. One of the three serotypes of wild poliovirus has been eradicated and the remaining two serotypes are limited to just a small number of endemic regions. However, the Global Polio Eradication Initiative (GPEI) has faced a number of challenges in eradicating the last 1 per cent of wild-virus transmission. The polio endgame has also been complicated by the recognition that vaccination with the oral poliovirus vaccine (OPV) must eventually cease because of the risk of outbreaks of vaccine-derived polioviruses. I describe the major challenges to wild poliovirus eradication, focusing on the poor immunogenicity of OPV in lower-income countries, the inherent limitations to the sensitivity and specificity of surveillance, the international spread of poliovirus and resulting outbreaks, and the potential significance of waning intestinal immunity induced by OPV. I then focus on the challenges to eradicating all polioviruses, the problem of vaccine-derived polioviruses and the risk of wild-type or vaccine-derived poliovirus re-emergence after the cessation of oral vaccination. I document the role of research in the GPEI's response to these challenges and ultimately the feasibility of achieving a world without poliomyelitis.

Identifiability study of the proteins degradation model, based on ADM1, using simultaneous batch experiments

DEFF Research Database (Denmark)

Flotats, X.; Palatsi, J.; Ahring, Birgitte Kiær

2006-01-01

are not inhibiting the hydrolysis process. The ADM1 model adequately expressed the consecutive steps of hydrolysis and acidogenesis, with estimated kinetic values corresponding to a fast acidogenesis and slower hydrolysis. The hydrolysis was found to be the rate limiting step of anaerobic degradation. Estimation...... of yield coefficients based on the relative initial slopes of VFA profiles obtained in a simple batch experiment produced satisfactory results. From the identification study, it was concluded that it is possible to determine univocally the related kinetic parameter values for protein degradation...... if the evolution of amino acids is measured in simultaneous batch experiments, with different initial protein and amino acids concentrations....

Rumen Degradability and Post-ruminal Digestion of Dry Matter, Nitrogen and Amino Acids of Three Protein Supplements

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Wei Gao

2015-04-01

Full Text Available This study evaluated the in situ ruminal degradability, and subsequent small intestinal digestibility (SID of dry matter, crude protein (CP, and amino acids (AA of cottonseed meal (CSM, sunflower seed meal (SFSM and distillers dried grains with solubles (DDGS by using the modified three-step in vitro procedure. The ruminal degradability and subsequent SID of AA in rumen-undegradable protein (RUP-AA varied among three protein supplements. The result show that the effective degradability of DM for SFSM, CSM, and DDGS was 60.8%, 56.4%, and 41.0% and their ruminal fermentable organic matter was 60.0%, 55.9%, and 39.9%, respectively. The ruminal degradable protein (RDP content in CP for SFSM, CSM, and DDGS was 68.3%, 39.0%, and 32.9%, respectively, at the ruminal solid passage rate of 1.84%/h. The SFSM is a good source of RDP for rumen micro-organisms; however, the SID of RUP of SFSM was lower. The DDGS and CSM are good sources of RUP for lambs to digest in the small intestine to complement ruminal microbial AA of growing lambs. Individual RUP-AA from each protein source was selectively removed by the rumen micro-organisms, especially for Trp, Arg, His, and Lys (p<0.01. The SID of individual RUP-AA was different within specific RUP origin (p<0.01. Limiting amino acid was Leu for RUP of CSM and Lys for both RUP of SFSM and DDGS, respectively. Therefore, different protein supplements with specific limitations should be selected and combined carefully in growing lambs ration to optimize AA balance.

GCK-MODY diabetes associated with protein misfolding, cellular self-association and degradation.

Science.gov (United States)

Negahdar, Maria; Aukrust, Ingvild; Johansson, Bente B; Molnes, Janne; Molven, Anders; Matschinsky, Franz M; Søvik, Oddmund; Kulkarni, Rohit N; Flatmark, Torgeir; Njølstad, Pål Rasmus; Bjørkhaug, Lise

2012-11-01

GCK-MODY, dominantly inherited mild fasting hyperglycemia, has been associated with >600 different mutations in the glucokinase (GK)-encoding gene (GCK). When expressed as recombinant pancreatic proteins, some mutations result in enzymes with normal/near-normal catalytic properties. The molecular mechanism(s) of GCK-MODY due to these mutations has remained elusive. Here, we aimed to explore the molecular mechanisms for two such catalytically 'normal' GCK mutations (S263P and G264S) in the F260-L270 loop of GK. When stably overexpressed in HEK293 cells and MIN6 β-cells, the S263P- and G264S-encoded mutations generated misfolded proteins with an increased rate of degradation (S263P>G264S) by the protein quality control machinery, and a propensity to self-associate (G264S>S263P) and form dimers (SDS resistant) and aggregates (partly Triton X-100 insoluble), as determined by pulse-chase experiments and subcellular fractionation. Thus, the GCK-MODY mutations S263P and G264S lead to protein misfolding causing destabilization, cellular dimerization/aggregation and enhanced rate of degradation. In silico predicted conformational changes of the F260-L270 loop structure are considered to mediate the dimerization of both mutant proteins by a domain swapping mechanism. Thus, similar properties may represent the molecular mechanisms for additional unexplained GCK-MODY mutations, and may also contribute to the disease mechanism in other previously characterized GCK-MODY inactivating mutations. Copyright © 2012 Elsevier B.V. All rights reserved.

Severe gastritis decreases success rate of Helicobacter pylori eradication.

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Kalkan, Ismail Hakki; Sapmaz, Ferdane; Güliter, Sefa; Atasoy, Pınar

2016-05-01

In several studies, different risk factors other than antibiotic resistance have been documented with Helicobacter pylori eradication failure. We aimed in this study to investigate the relationship of gastric density of H. pylori, the occurrence/degree of gastric atrophy, and intestinal metaplasia (IM) with success rate of H. pylori eradication. Two hundred consecutive treatment naive patients who received bismuth containing standart quadruple treatment due to H. pylori infection documented by histopathological examination of two antral or two corpal biopsies entered this retrospective study. The updated Sydney system was used to grade the activity of gastritis, density of H. pylori colonization, atrophy, and IM. Stages III and IV of operative link for gastritis assessment (OLGA) or the operative link on gastric intestinal metaplasia assessment (OLGIM) stages was considered as severe gastritis. H. pylori eradication was determined via stool H. pylori antigen test performed 4 weeks after the end of therapy. The presence of gastric atrophy and IM was significantly higher in patients with eradication failure (p = 0.001 and 0.01, respectively). Severe gastritis (OLGA III-IV and OLGIM III-IV) rates were higher in eradication failure group. A multiple linear regression analysis showed that OLGA and OLGIM stages were to be independent risk factors for eradication failure (p = 0.03 and 0.01, respectively). Our results suggested that histopathologically severe gastritis may cause H. pylori eradication failure. In addition, we found that H. pylori density was not a risk factor for treatment failure in patients who receive quadruple treatment.

Six challenges in the eradication of infectious diseases

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Petra Klepac

2015-03-01

Full Text Available Eradication and elimination are increasingly a part of the global health agenda. Once control measures have driven infection to low levels, the ecology of disease may change posing challenges for eradication efforts. These challenges vary from identifying pockets of susceptibles, improving monitoring during and after the endgame, to quantifying the economics of disease eradication versus sustained control, all of which are shaped and influenced by processes of loss of immunity, susceptible build-up, emergence of resistance, population heterogeneities and non-compliance with control measures. Here we discuss how modelling can be used to address these challenges.

The use of a tannin crude extract from Cistus ladanifer L. to protect soya-bean protein from degradation in the rumen.

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Dentinho, M T P; Moreira, O C; Pereira, M S; Bessa, R J B

2007-06-01

Cistus ladanifer L. (CL) is a perennial shrub abundant in dry woods and dry land of Mediterranean zone, with high level of tannins. Tannins bind to protein, preventing its degradation in the digestive compartments. This tannin/protein complex may be advantageous when partially protecting good-quality feed protein from excessive rumen protein degradation. The objective of this trial was to use a CL phenol crude extract to prevent excessive rumen degradation of soya-bean meal protein. The phenolic compounds were extracted using an acetone/water solution (70:30, v/v). Soya-bean meal was then treated with this crude CL extract, containing 640 g of total phenols (TP) per kg of dry matter (DM), in order to obtain mixtures with 0, 12.5, 25, 50, 100 and 150 g of TP per kg DM. Three rumen-cannulated rams were used to assess in sacco rumen degradability of DM and nitrogen (N). The three-step in vitro procedure was used to determine intestinal digestibility. Increasing extract concentrations quadratically decreased the N-soluble fraction a (R2 = 0.96, P = 0.0001) and increased the non-soluble degradable fraction b (R2 = 0.92, P = 0.005). The rate of degradation c linearly decreased with CL extract doses (R2 = 0.44, P = 0.0065). For the effective rumen degradability of N, a linear reduction (R2 = 0.94, P < 0.0001) was observed. The in vitro intestinal digestibility of protein (ivID) quadratically decreased (R2 = 0.99, P < 0.0001) with TP inclusion and the rumen undegradable protein (RUP) showed a quadratic increase (R2 = 0.94, P = 0.0417). Total intestinal protein availability, computed from the RUP and ivID, linearly decreased with TP inclusion level (R2 = 0.45, P = 0.0033).

Ruminal degradation and intestinal digestibility of protein and amino acids in high-protein feedstuffs commonly used in dairy diets.

Science.gov (United States)

Paz, H A; Klopfenstein, T J; Hostetler, D; Fernando, S C; Castillo-Lopez, E; Kononoff, P J

2014-10-01

A study was conducted to determine the rumen degradation and intestinal digestibility of crude protein (CP) and AA, and AA composition of the rumen-undegradable protein (RUP) from 3 sources of blood meal (BM1, BM2, and BM3), canola meal (CM), low-fat distillers dried grains with solubles (LFDG), soybean meal (SBM), and expeller soybean meal (ESBM). Two Holstein cows fitted with ruminal and proximal duodenal cannulas were used for in situ incubation of 16h and for the mobile bag technique. To correct for bacterial contamination of the RUP, 2 methods were used: purines and DNA as bacterial markers. Ruminal degradations of CP were 85.3, 29.8, 40.7, 75.7, 76.9, 68.8, and 37.0 ± 3.93% for BM1, BM2, BM3, CM, LFDG, SBM, and ESBM, respectively. Ruminal degradation of both total essential AA and nonessential AA followed a similar pattern to that of CP across feedstuffs. Based on the ratio of AA concentration in the RUP to AA concentration in the original feedstuff, ruminal incubation decreased (ratio 1) the concentrations of Ile and Met across feedstuffs. Compared with purines, the use of DNA as bacterial marker resulted in a higher estimate of bacterial CP contamination for CM and lower estimates for LFDG and ESBM. Intestinal digestibility of RUP could not be estimated for BM1, BM3, and SBM due to insufficient recovery of residue. For the remaining feedstuffs, intestinal digestibility of RUP was highest for ESBM, followed by BM2 and LFDG, and lowest for CM: 98.8, 87.9, 89.7, and 72.4 ± 1.40%, respectively. Intestinal absorbable dietary protein was higher for BM2 compared with CM and LFDG, at 61.7, 17.9, and 20.7 ± 2.73% CP, respectively. As prices fluctuate, intestinal absorbable protein or AA may be used as a tool to aid in the selection among feedstuffs with different protein quality. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

National Leprosy Eradication Programme (NLEP

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Shetty Sushant

1997-01-01

Full Text Available This article traces the history of the growth and development of our National Leprosy Eradication Programme (NLEP. The aims, strategy, means of eradication, the organizational structure have been discussed. Since the beginning of this programme, the prevalence rate and disability rate have shown a sharp decline. The number of cases detected and under treatment have also increased. The achievement made has been possible due to an excellent organization of leprosy relief work under NLEP with the active cooperation of the non- governmental organizations. Now that leprosy is on the decline, the need of education and rehabilitation of patients assumes a greater importance.

Effect of Helicobacter pylori Eradication on Functional Dyspepsia

Science.gov (United States)

Kim, Sung Eun; Park, Young Soo; Kim, Min Soo; Jo, Hyun Jin; Shin, Cheol Min; Lee, Sang Hyub; Hwang, Jin-Hyeok; Kim, Jin-Wook; Jeong, Sook-Hyang; Lee, Dong Ho; Jung, Hyun Chae

2013-01-01

Background/Aims This study evaluated the effect of Helicobacter pylori eradication on functional dyspepsia (FD), and the relationship between the changes of histological gastritis and FD symptom responses. Methods A total of 213 FD patients diagnosed by Rome III criteria were consecutively enrolled. H. pylori tests and gastritis grade by the Sydney system were performed before and 1 year after the proton pump based-eradication therapy for 7 days. Serum levels of pepsinogen, and genetic polymorphisms IL-6, IL-8 and IL-10 were investigated. Results Total of 91 patients completed the 1 year follow-up. When the response rate of dyspepsia was compared at 1 year between the non-eradicated group (n = 24) and eradicated group (n = 67), each group showed complete response of 62.5% and 62.7%; satisfactory response (≥ 50%) of 0.0% and 19.4%; partial response (gastritis at 1 year, suggesting that inflammation mediates FD. PMID:23667755

Interferon-stimulated gene of 20 kDa protein (ISG20) degrades RNA of hepatitis B virus to impede the replication of HBV in vitro and in vivo

Science.gov (United States)

Oshiumi, Hiroyuki; Mengao, Deng; Takaki, Hiromi; Matsumoto, Misako; Aly, Hussein H.; Watashi, Koichi; Chayama, Kazuaki; Seya, Tsukasa

2016-01-01

Hepatitis B virus (HBV) barely induces host interferon (IFN)-stimulated genes (ISGs), which allows efficient HBV replication in the immortalized mouse hepatocytes as per human hepatocytes. Here we found that transfection of Isg20 plasmid robustly inhibits the HBV replication in HBV-infected hepatocytes irrespective of IRF3 or IFN promoter activation. Transfection of Isg20 is thus effective to eradicate HBV in the infected hepatocytes. Transfection of HBV genome or ε-stem of HBV pgRNA (active pgRNA moiety) failed to induce Isg20 in the hepatocytes, while control polyI:C (a viral dsRNA analogue mimic) activated MAVS pathway leading to production of type I IFN and then ISGsg20 via the IFN-α/β receptor (IFNAR). Consistently, addition of IFN-α induced Isg20 and partially suppressed HBV replication in hepatocytes. Chasing HBV RNA, DNA and proteins by blotting indicated that ISG20 expression decreased HBV RNA and replicative DNA in HBV-transfected cells, which resulted in low HBs antigen production and virus titer. The exonuclease domains of ISG20 mainly participated in HBV-RNA decay. In vivo hydrodynamic injection, ISG20 was crucial for suppressing HBV replication without degrading host RNA in the liver. Taken together, ISG20 acts as an innate anti-HBV effector that selectively degrades HBV RNA and blocks replication of infectious HBV particles. ISG20 would be a critical effector for ameliorating chronic HBV infection in the IFN therapy. PMID:27626689

Targeting HIV latency: pharmacologic strategies toward eradication

Science.gov (United States)

Xing, Sifei; Siliciano, Robert F.

2013-01-01

The latent reservoir for HIV-1 in resting CD4+ T cells remains a major barrier to HIV-1 eradication, even though highly active antiretroviral therapy (HAART) can successfully reduce plasma HIV-1 levels to below the detection limit of clinical assays and reverse disease progression. Proposed eradication strategies involve reactivation of this latent reservoir. Multiple mechanisms are believed to be involved in maintaining HIV-1 latency, mostly through suppression of transcription. These include cytoplasmic sequestration of host transcription factors and epigenetic modifications such as histone deacetylation, histone methylation and DNA methylation. Therefore, strategies targeting these mechanisms have been explored for reactivation of the latent reservoir. In this review, we discuss current pharmacological approaches toward eradication, focusing on small molecule latency-reversing agents, their mechanisms, advantages and limitations. PMID:23270785

Eradicating hepatitis C virus ameliorates insulin resistance without change in adipose depots.

Science.gov (United States)

Milner, K-L; Jenkins, A B; Trenell, M; Tid-Ang, J; Samocha-Bonet, D; Weltman, M; Xu, A; George, J; Chisholm, D J

2014-05-01

Chronic hepatitis C (CHC) is associated with lipid-related changes and insulin resistance; the latter predicts response to antiviral therapy, liver disease progression and the risk of diabetes. We sought to determine whether insulin sensitivity improves following CHC viral eradication after antiviral therapy and whether this is accompanied by changes in fat depots or adipokine levels. We compared 8 normoglycaemic men with CHC (genotype 1 or 3) before and at least 6 months post viral eradication and 15 hepatitis C antibody negative controls using an intravenous glucose tolerance test and two-step hyperinsulinaemic-euglycaemic clamp with [6,6-(2) H2 ] glucose to assess peripheral and hepatic insulin sensitivity. Magnetic resonance imaging and spectroscopy quantified abdominal fat compartments, liver and intramyocellular lipid. Peripheral insulin sensitivity improved (glucose infusion rate during high-dose insulin increased from 10.1 ± 1.6 to 12 ± 2.1 mg/kg/min/, P = 0.025), with no change in hepatic insulin response following successful viral eradication, without any accompanying change in muscle, liver or abdominal fat depots. There was corresponding improvement in incremental glycaemic response to intravenous glucose (pretreatment: 62.1 ± 8.3 vs post-treatment: 56.1 ± 8.5 mm, P = 0.008). Insulin sensitivity after viral clearance was comparable to matched controls without CHC. Post therapy, liver enzyme levels decreased but, interestingly, levels of glucagon, fatty acid-binding protein and lipocalin-2 remained elevated. Eradication of the hepatitis C virus improves insulin sensitivity without alteration in fat depots, adipokine or glucagon levels, consistent with a direct link of the virus with insulin resistance. © 2013 John Wiley & Sons Ltd.

Comparison of protein degradation, protein oxidation, and μ-calpain activation between pale, soft, and exudative and red, firm, and nonexudative pork during postmortem aging.

Science.gov (United States)

Yin, Y; Zhang, W G; Zhou, G H; Guo, B

2014-08-01

The objective of this study was to investigate the differences in protein modifications between pale, soft, and exudative (PSE) and red, firm, and nonexudative (RFN) pork during postmortem (PM) aging. Longissimus dorsi (LD) including 8 PSE and 8 RFN muscles were individually removed from 16 carcasses. These 16 LD muscles were vacuum packaged at 24 h after slaughter and stored at 4°C for 1, 3, and 5 d. The centrifugation loss, drip loss, color, protein solubility, protein oxidation, protein degradation including desmin, troponin T, and integrin, and μ-calpain activation were determined. The pH of PSE samples was significantly lower than that of RFN samples at both 1 and 24 h PM (P 0.05). In addition, PSE pork presented a lower solubility of sarcoplasmic protein, myofibrillar protein, and total protein than RFN pork except the solubility of myofibrillar protein at d 1 (P firm, and nonexudative pork presented lower intensity of intact 80 kDa calpain and greater intensity of autolyzed 76 kDa product compared to PSE pork (P < 0.01). The results indicate that the degree of μ-calpain activation, the extent of protein degradation including desmin and integrin, and the level of protein solubility in PSE pork could contribute to its low water holding capacity during PM storage.

Printing education and poverty eradication in Nigeria | Afolabi ...

African Journals Online (AJOL)

One of the key goals of the Millennium Development Goals (MDGs) is the eradication of extreme poverty and hunger. In the Nigerian context, unemployment is a major cause of poverty which can be eradicated through empowerment and wealth creation. Printing technology, a technical based course offers benefits in this ...

Studies to Prevent Degradation of Recombinant Fc-Fusion Protein Expressed in Mammalian Cell Line and Protein Characterization

Directory of Open Access Journals (Sweden)

Sanjukta Chakrabarti

2016-06-01

Full Text Available Clipping of recombinant proteins is a major issue in animal cell cultures. A recombinant Fc-fusion protein, VEGFR1(D1–D3-Fc expressed in CHOK1SV GS-KO cells was observed to be undergoing clippings in lab scale cultures. Partial cleaving of expressed protein initiated early on in cell culture and was observed to increase over time in culture and also on storage. In this study, a few parameters were explored in a bid to inhibit clipping in the fusion protein The effects of culture temperature, duration of culture, the addition of an anti-clumping agent, ferric citrate and use of protease inhibitor cocktail on inhibition of proteolysis of the Fc fusion were studied. Lowering of culture temperature from 37 to 30 °C alone appears to be the best solution for reducing protein degradation from the quality, cost and regulatory points of view. The obtained Fc protein was characterized and found to be in its stable folded state, exhibiting a high affinity for its ligand and also biological and functional activities.

Tumour eradication using synchronous thermal ablation and Hsp90 chemotherapy with protein engineered triblock biopolymer-geldanamycin conjugates.

Science.gov (United States)

Chen, Yizhe; Youn, Pilju; Pysher, Theodore J; Scaife, Courtney L; Furgeson, Darin Y

2014-12-01

Hepatocellular carcinoma (HCC) suffers high tumour recurrence rate after thermal ablation. Heat shock protein 90 (Hsp90) induced post-ablation is critical for tumour survival and progression. A combination therapy of thermal ablation and polymer conjugated Hsp90 chemotherapy was designed and evaluated for complete tumour eradication of HCC. A thermo-responsive, elastin-like polypeptide (ELP)-based tri-block biopolymer was developed and conjugated with a potent Hsp90 inhibitor, geldanamycin (GA). The anti-cancer efficacy of conjugates was evaluated in HCC cell cultures with and without hyperthermia (43 °C). The conjugates were also administered twice weekly in a murine HCC model as a single treatment or in combination with single electrocautery as the ablation method. ELP-GA conjugates displayed enhanced cytotoxicity in vitro and effective heat shock inhibition under hyperthermia. The conjugates alone significantly slowed the tumour growth without systemic toxicity. Four doses of thermo-responsive ELP-GA conjugates with concomitant simple electrocautery accomplished significant Hsp90 inhibition and sustained tumour suppression. Hsp90 inhibition plays a key role in preventing the recurrence of HCC, and the combination of ablation with targeted therapy holds great potential to improve prognosis and survival of HCC patients.

HIV-1 accessory proteins VPR and Vif modulate antiviral response by targeting IRF-3 for degradation

International Nuclear Information System (INIS)

Okumura, Atsushi; Alce, Tim; Lubyova, Barbora; Ezelle, Heather; Strebel, Klaus; Pitha, Paula M.

2008-01-01

The activation of IRF-3 during the early stages of viral infection is critical for the initiation of the antiviral response; however the activation of IRF-3 in HIV-1 infected cells has not yet been characterized. We demonstrate that the early steps of HIV-1 infection do not lead to the activation and nuclear translocation of IRF-3; instead, the relative levels of IRF-3 protein are decreased due to the ubiquitin-associated proteosome degradation. Addressing the molecular mechanism of this effect we show that the degradation is independent of HIV-1 replication and that virion-associated accessory proteins Vif and Vpr can independently degrade IRF-3. The null mutation of these two genes reduced the capacity of the HIV-1 virus to down modulate IRF-3 levels. The degradation was associated with Vif- and Vpr-mediated ubiquitination of IRF-3 and was independent of the activation of IRF-3. N-terminal lysine residues were shown to play a critical role in the Vif- and Vpr-mediated degradation of IRF-3. These data implicate Vif and Vpr in the disruption of the initial antiviral response and point to the need of HIV-1 to circumvent the antiviral response during the very early phase of replication

Autoantibodies to myelin basic protein catalyze site-specific degradation of their antigen.

Science.gov (United States)

Ponomarenko, Natalia A; Durova, Oxana M; Vorobiev, Ivan I; Belogurov, Alexey A; Kurkova, Inna N; Petrenko, Alexander G; Telegin, Georgy B; Suchkov, Sergey V; Kiselev, Sergey L; Lagarkova, Maria A; Govorun, Vadim M; Serebryakova, Marina V; Avalle, Bérangère; Tornatore, Pete; Karavanov, Alexander; Morse, Herbert C; Thomas, Daniel; Friboulet, Alain; Gabibov, Alexander G

2006-01-10

Autoantibody-mediated tissue destruction is among the main features of organ-specific autoimmunity. This report describes "an antibody enzyme" (abzyme) contribution to the site-specific degradation of a neural antigen. We detected proteolytic activity toward myelin basic protein (MBP) in the fraction of antibodies purified from the sera of humans with multiple sclerosis (MS) and mice with induced experimental allergic encephalomyelitis. Chromatography and zymography data demonstrated that the proteolytic activity of this preparation was exclusively associated with the antibodies. No activity was found in the IgG fraction of healthy donors. The human and murine abzymes efficiently cleaved MBP but not other protein substrates tested. The sites of MBP cleavage determined by mass spectrometry were localized within immunodominant regions of MBP. The abzymes could also cleave recombinant substrates containing encephalytogenic MBP(85-101) peptide. An established MS therapeutic Copaxone appeared to be a specific abzyme inhibitor. Thus, the discovered epitope-specific antibody-mediated degradation of MBP suggests a mechanistic explanation of the slow development of neurodegeneration associated with MS.

Strengthening the partnership between routine immunization and the global polio eradication initiative to achieve eradication and assure sustainability.

Science.gov (United States)

Abdelwahab, Jalaa; Dietz, Vance; Eggers, Rudolf; Maher, Christopher; Olaniran, Marianne; Sandhu, Hardeep; Vandelaer, Jos

2014-11-01

Since the launch of the Global Polio Eradication Initiative (GPEI) in 1988, the number of polio endemic countries has declined from 125 to 3 in 2013. Despite this remarkable achievement, ongoing circulation of wild poliovirus in polio-endemic countries and the increase in the number of circulating vaccine-derived poliovirus cases, especially those caused by type 2, is a cause for concern. The Polio Eradication and Endgame Strategic Plan 2013-2018 (PEESP) was developed and includes 4 objectives: detection and interruption of poliovirus transmission, containment and certification, legacy planning, and a renewed emphasis on strengthening routine immunization (RI) programs. This is critical for the phased withdrawal of oral poliovirus vaccine, beginning with the type 2 component, and the introduction of a single dose of inactivated polio vaccine into RI programs. This objective has inspired renewed consideration of how the GPEI and RI programs can mutually benefit one another, how the infrastructure from the GPEI can be used to strengthen RI, and how a strengthened RI can facilitate polio eradication. The PEESP is the first GPEI strategic plan that places strong and clear emphasis on the necessity of improving RI to achieve and sustain global polio eradication. Published by Oxford University Press on behalf of the Infectious Diseases Society of America 2014. This work is written by (a) US Government employee(s) and is in the public domain in the US.

Pu-Erh Tea Extract Induces the Degradation of FET Family Proteins Involved in the Pathogenesis of Amyotrophic Lateral Sclerosis

Directory of Open Access Journals (Sweden)

Yang Yu

2014-01-01

Full Text Available FET family proteins consist of fused in sarcoma/translocated in liposarcoma (FUS/TLS, Ewing's sarcoma (EWS, and TATA-binding protein-associated factor 15 (TAF15. Mutations in the copper/zinc superoxide dismutase (SOD1, TAR DNA-binding protein 43 (TDP-43, and FET family proteins are associated with the development of amyotrophic lateral sclerosis (ALS, a fatal neurodegenerative disease. There is currently no cure for this disease and few effective treatments are available. Epidemiological studies indicate that the consumption of tea is associated with a reduced risk of developing neurodegenerative diseases. The results of this study revealed that components of a pu-erh tea extract (PTE interacted with FET family proteins but not with TDP-43 or SOD1. PTE induced the degradation of FET family proteins but had no effects on TDP-43 or SOD1. The most frequently occurring ALS-linked FUS/TLS mutant protein, R521C FUS/TLS, was also degraded in the presence of PTE. Furthermore, ammonium chloride, a lysosome inhibitor, but not lactacystin, a proteasome inhibitor, reduced the degradation of FUS/TLS protein by PTE. PTE significantly reduced the incorporation of R521C FUS/TLS into stress granules under stress conditions. These findings suggest that PTE may have beneficial health effects, including preventing the onset of FET family protein-associated neurodegenerative diseases and delaying the progression of ALS by inhibiting the cytoplasmic aggregation of FET family proteins.

Phosphorylation-dependent signaling controls degradation of DNA mismatch repair protein PMS2.

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Hinrichsen, Inga; Weßbecher, Isabel M; Huhn, Meik; Passmann, Sandra; Zeuzem, Stefan; Plotz, Guido; Biondi, Ricardo M; Brieger, Angela

2017-12-01

MutLα, a heterodimer consisting of MLH1 and PMS2, plays an important role in DNA mismatch repair and has been shown to be additionally involved in several other important cellular mechanisms. Previous work indicated that AKT could modulate PMS2 stability by phosphorylation. Still, the mechanisms of regulation of MutLα remain unclear. The stability of MutLα subunits was investigated by transiently overexpression of wild type and mutant forms of MLH1 and PMS2 using immunoblotting for measuring the protein levels after treatment. We found that treatment with the cell-permeable serine/threonine phosphatase inhibitor, Calyculin, leads to degradation of PMS2 when MLH1 or its C-terminal domain is missing or if amino acids of MLH1 essential for PMS2 interaction are mutated. In addition, we discovered that the C-terminal tail of PMS2 is relevant for this Calyculin-dependent degradation. A direct involvement of AKT, which was previously described to be responsible for PMS2 degradation, could not be detected. The multi-kinase inhibitor Sorafenib, in contrast, was able to avoid the degradation of PMS2 which postulates that cellular phosphorylation is involved in this process. Together, we show that pharmacologically induced phosphorylation by Calyculin can induce the selective proteasome-dependent degradation of PMS2 but not of MLH1 and that the PMS2 degradation could be blocked by Sorafenib treatment. Curiously, the C-terminal Lynch Syndrome-variants MLH1 L749P and MLH1 Y750X make PMS2 prone to Calyculin induced degradation. Therefore, we conclude that the specific degradation of PMS2 may represent a new mechanism to regulate MutLα. © 2017 Wiley Periodicals, Inc.

Proteolytic degradation of regulator of G protein signaling 2 facilitates temporal regulation of Gq/11 signaling and vascular contraction.

Science.gov (United States)

Kanai, Stanley M; Edwards, Alethia J; Rurik, Joel G; Osei-Owusu, Patrick; Blumer, Kendall J

2017-11-24

Regulator of G protein signaling 2 (RGS2) controls signaling by receptors coupled to the G q/11 class heterotrimeric G proteins. RGS2 deficiency causes several phenotypes in mice and occurs in several diseases, including hypertension in which a proteolytically unstable RGS2 mutant has been reported. However, the mechanisms and functions of RGS2 proteolysis remain poorly understood. Here we addressed these questions by identifying degradation signals in RGS2, and studying dynamic regulation of G q/11 -evoked Ca 2+ signaling and vascular contraction. We identified a novel bipartite degradation signal in the N-terminal domain of RGS2. Mutations disrupting this signal blunted proteolytic degradation downstream of E3 ubiquitin ligase binding to RGS2. Analysis of RGS2 mutants proteolyzed at various rates and the effects of proteasome inhibition indicated that proteolytic degradation controls agonist efficacy by setting RGS2 protein expression levels, and affecting the rate at which cells regain agonist responsiveness as synthesis of RGS2 stops. Analyzing contraction of mesenteric resistance arteries supported the biological relevance of this mechanism. Because RGS2 mRNA expression often is strikingly and transiently up-regulated and then down-regulated upon cell stimulation, our findings indicate that proteolytic degradation tightly couples RGS2 transcription, protein levels, and function. Together these mechanisms provide tight temporal control of G q/11 -coupled receptor signaling in the cardiovascular, immune, and nervous systems. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Interplay between Molecular Chaperones and the Ubiquitin-Proteasome System in Targeting of Misfolded Proteins for Degradation

DEFF Research Database (Denmark)

Poulsen, Esben Guldahl

interacting with purified 26S proteasomes, and the subsequent characterization of two novel proteasome interacting proteins. The third study was aimed at analyzing the chaperone-assisted pathway leading to degradation of misfolded kinetochore proteins in S. pombe. In this study chaperones, E2s, E3s and DUBs...

WJBF TV tower meteorological database for the ERAD Code-1993

International Nuclear Information System (INIS)

Weber, A.H.

1996-07-01

The Explosive Release Atmospheric Dispersion (ERAD) model (Boughton and DeLaurentis 1992) is a three-dimensional numerical model for simulating atmospheric transport and dispersion. The ERAD code is particularly adept at handling explosive releases into the atmosphere and is being used by the Materials and Accountability Department at the Savannah River Site (SRS) to provide risk estimates. The Environmental Technology Section (ETS) was asked to provide meteorological data to be used for applying ERAD to some site facilities. The ERAD model requires a vertical profile of meteorological measurements. The 1993 data from the WJBF-TV tower has been processed and provided for this purpose. This document describes the steps taken to prepare and format the database

Human cytomegalovirus gH stability and trafficking are regulated by ER-associated degradation and transmembrane architecture.

Science.gov (United States)

Gardner, Thomas J; Hernandez, Rosmel E; Noriega, Vanessa M; Tortorella, Domenico

2016-03-30

The prototypic betaherpesvirus human cytomegalovirus (CMV) establishes life-long persistence within its human host. While benign in healthy individuals, CMV poses a significant threat to the immune compromised, including transplant recipients and neonates. The CMV glycoprotein complex gH/gL/gO mediates infection of fibroblasts, and together with the gH/gL/UL128/130/131 a pentameric complex permits infection of epithelial, endothethial, and myeloid cells. Given the central role of the gH/gL complex during infection, we were interested in studying cellular trafficking of the gH/gL complex through generation of human cells that stably express gH and gL. When expressed alone, CMV gH and gL were degraded through the ER-associated degradation (ERAD) pathway. However, co-expression of these proteins stabilized the polypeptides and enhanced their cell-surface expression. To further define regulatory factors involved in gH/gL trafficking, a CMV gH chimera in which the gH transmembrane and cytoplasmic tail were replaced with that of human CD4 protein permitted cell surface gH expression in absence of gL. We thus demonstrate the ability of distinct cellular processes to regulate the trafficking of viral glycoproteins. Collectively, the data provide insight into the processing and trafficking requirements of CMV envelope protein complexes and provide an example of the co-opting of cellular processes by CMV.

Dma1-dependent degradation of SIN proteins during meiosis in Schizosaccharomyces pombe.

Science.gov (United States)

Krapp, Andrea; Simanis, Viesturs

2014-07-15

The Schizosaccharomyces pombe septation initiation network (SIN) is required for cytokinesis during vegetative growth and for spore formation during meiosis. Regulation of the SIN during mitosis has been studied extensively, but less is known about its meiotic regulation. Here, we show that several aspects of SIN regulation differ between mitosis and meiosis. First, the presence of GTP-bound Spg1p is not the main determinant of the timing of Cdc7p and Sid1p association with the spindle pole body (SPB) during meiosis. Second, the localisation dependencies of SIN proteins differ from those in mitotic cells, suggesting a modified functional organisation of the SIN during meiosis. Third, there is stage-specific degradation of SIN components in meiosis; Byr4p is degraded after meiosis I, whereas the degradation of Cdc7p, Cdc11p and Sid4p occurs after the second meiotic division and depends upon the ubiquitin ligase Dma1p. Finally, Dma1p-dependent degradation is not restricted to the SIN, as we show that Dma1p is needed for the degradation of Mcp6p (also known as Hrs1p) during meiosis I. Taken together, these data suggest that stage-specific targeted proteolysis plays an important role in regulating meiotic progression. © 2014. Published by The Company of Biologists Ltd.

Archipelago-wide island restoration in the Galápagos Islands: reducing costs of invasive mammal eradication programs and reinvasion risk.

Directory of Open Access Journals (Sweden)

Victor Carrion

Full Text Available Invasive alien mammals are the major driver of biodiversity loss and ecosystem degradation on islands. Over the past three decades, invasive mammal eradication from islands has become one of society's most powerful tools for preventing extinction of insular endemics and restoring insular ecosystems. As practitioners tackle larger islands for restoration, three factors will heavily influence success and outcomes: the degree of local support, the ability to mitigate for non-target impacts, and the ability to eradicate non-native species more cost-effectively. Investments in removing invasive species, however, must be weighed against the risk of reintroduction. One way to reduce reintroduction risks is to eradicate the target invasive species from an entire archipelago, and thus eliminate readily available sources. We illustrate the costs and benefits of this approach with the efforts to remove invasive goats from the Galápagos Islands. Project Isabela, the world's largest island restoration effort to date, removed >140,000 goats from >500,000 ha for a cost of US$10.5 million. Leveraging the capacity built during Project Isabela, and given that goat reintroductions have been common over the past decade, we implemented an archipelago-wide goat eradication strategy. Feral goats remain on three islands in the archipelago, and removal efforts are underway. Efforts on the Galápagos Islands demonstrate that for some species, island size is no longer the limiting factor with respect to eradication. Rather, bureaucratic processes, financing, political will, and stakeholder approval appear to be the new challenges. Eradication efforts have delivered a suite of biodiversity benefits that are in the process of revealing themselves. The costs of rectifying intentional reintroductions are high in terms of financial and human resources. Reducing the archipelago-wide goat density to low levels is a technical approach to reducing reintroduction risk in the short

Archipelago-wide island restoration in the Galápagos Islands: reducing costs of invasive mammal eradication programs and reinvasion risk.

Science.gov (United States)

Carrion, Victor; Donlan, C Josh; Campbell, Karl J; Lavoie, Christian; Cruz, Felipe

2011-05-11

Invasive alien mammals are the major driver of biodiversity loss and ecosystem degradation on islands. Over the past three decades, invasive mammal eradication from islands has become one of society's most powerful tools for preventing extinction of insular endemics and restoring insular ecosystems. As practitioners tackle larger islands for restoration, three factors will heavily influence success and outcomes: the degree of local support, the ability to mitigate for non-target impacts, and the ability to eradicate non-native species more cost-effectively. Investments in removing invasive species, however, must be weighed against the risk of reintroduction. One way to reduce reintroduction risks is to eradicate the target invasive species from an entire archipelago, and thus eliminate readily available sources. We illustrate the costs and benefits of this approach with the efforts to remove invasive goats from the Galápagos Islands. Project Isabela, the world's largest island restoration effort to date, removed >140,000 goats from >500,000 ha for a cost of US$10.5 million. Leveraging the capacity built during Project Isabela, and given that goat reintroductions have been common over the past decade, we implemented an archipelago-wide goat eradication strategy. Feral goats remain on three islands in the archipelago, and removal efforts are underway. Efforts on the Galápagos Islands demonstrate that for some species, island size is no longer the limiting factor with respect to eradication. Rather, bureaucratic processes, financing, political will, and stakeholder approval appear to be the new challenges. Eradication efforts have delivered a suite of biodiversity benefits that are in the process of revealing themselves. The costs of rectifying intentional reintroductions are high in terms of financial and human resources. Reducing the archipelago-wide goat density to low levels is a technical approach to reducing reintroduction risk in the short-term, and is being

Combining the auxin-inducible degradation system with CRISPR/Cas9-based genome editing for the conditional depletion of endogenous Drosophila melanogaster proteins.

Science.gov (United States)

Bence, Melinda; Jankovics, Ferenc; Lukácsovich, Tamás; Erdélyi, Miklós

2017-04-01

Inducible protein degradation techniques have considerable advantages over classical genetic approaches, which generate loss-of-function phenotypes at the gene or mRNA level. The plant-derived auxin-inducible degradation system (AID) is a promising technique which enables the degradation of target proteins tagged with the AID motif in nonplant cells. Here, we present a detailed characterization of this method employed during the adult oogenesis of Drosophila. Furthermore, with the help of CRISPR/Cas9-based genome editing, we improve the utility of the AID system in the conditional elimination of endogenously expressed proteins. We demonstrate that the AID system induces efficient and reversible protein depletion of maternally provided proteins both in the ovary and the early embryo. Moreover, the AID system provides a fine spatiotemporal control of protein degradation and allows for the generation of different levels of protein knockdown in a well-regulated manner. These features of the AID system enable the unraveling of the discrete phenotypes of genes with highly complex functions. We utilized this system to generate a conditional loss-of-function allele which allows for the specific degradation of the Vasa protein without affecting its alternative splice variant (solo) and the vasa intronic gene (vig). With the help of this special allele, we demonstrate that dramatic decrease of Vasa protein in the vitellarium does not influence the completion of oogenesis as well as the establishment of proper anteroposterior and dorsoventral polarity in the developing oocyte. Our study suggests that both the localization and the translation of gurken mRNA in the vitellarium is independent from Vasa. © 2017 Federation of European Biochemical Societies.

Protection of a protein against irradiation-induced degradation by additives in the solid state

International Nuclear Information System (INIS)

Shalaev, E.; Reddy, R.; Kimball, R.N.; Weinschenk, M.F.; Guinn, M.; Margulis, L.

2003-01-01

The impact of ionizing radiation on a globular protein (porcine somatotropin, pST) in the solid state was studied using rate of dissolution, high-performance liquid chromatography, and Electron spin resonance (ESR) in the presence of different additives. o-Vanillin stabilized pST against irradiation-induced degradation whereas effects of trolox and isopropyl alcohol were less significant. Stabilization effect of o-vanillin has been related to the energy transfer from pST molecules to the additive which was facilitated by formation of covalent bonds between o-vanillin and pST molecules. Anticorrelation between the level of free radicals and chemical degradation (i.e. degradation increased with decrease in a free radical level) was observed in the presence of o-vanillin

Proteasome-mediated degradation of integral inner nuclear membrane protein emerin in fibroblasts lacking A-type lamins

International Nuclear Information System (INIS)

Muchir, Antoine; Massart, Catherine; Engelen, Baziel G. van; Lammens, Martin; Bonne, Gisele; Worman, Howard J.

2006-01-01

We previously identified and characterized a homozygous LMNA nonsense mutation leading to the absence of A-type lamins in a premature neonate who died at birth. We show here that the absence of A-type lamins is due to degradation of the aberrant mRNA transcript with a premature termination codon. In cultured fibroblasts from the subject with the homozygous LMNA nonsense mutation, there was a decreased steady-state expression of the integral inner nuclear membrane proteins emerin and nesprin-1α associated with their mislocalization to the bulk endoplasmic reticulum and a hyperphosphorylation of emerin. To determine if decreased emerin expression occurred post-translationally, we treated cells with a selective proteasome inhibitor and observed an increase in expression. Our results show that mislocalization of integral inner nuclear membrane proteins to the endoplasmic reticulum in human cells lacking A-type lamins leads to their degradation and provides the first evidence that their degradation is mediated by the proteasome

Thermolysin damages animal life through degradation of plasma proteins enhanced by rapid cleavage of serpins and activation of proteases.

Science.gov (United States)

Kong, Lulu; Lu, Anrui; Guan, Jingmin; Yang, Bing; Li, Muwang; Hillyer, Julián F; Ramarao, Nalini; Söderhäll, Kenneth; Liu, Chaoliang; Ling, Erjun

2015-01-01

Thermolysin, a metallopeptidase secreted by pathogenic microbes, is concluded as an important virulence factor due to cleaving purified host proteins in vitro. Using the silkworm Bombyx mori as a model system, we found that thermolysin injection into larvae induces the destruction of the coagulation response and the activation of hemolymph melanization, which results in larval death. Thermolysin triggers the rapid degradation of insect and mammalian plasma proteins at a level that is considerably greater than expected in vitro and/or in vivo. To more specifically explore the mechanism, thermolysin-induced changes to key proteins belonging to the insect melanization pathway were assessed as a window for observing plasma protein cleavage. The application of thermolysin induced the rapid cleavage of the melanization negative regulator serpin-3, but did not directly activate the melanization rate-limiting enzyme prophenoloxidase (PPO) or the terminal serine proteases responsible for PPO activation. Terminal serine proteases of melanization are activated indirectly after thermolysin exposure. We hypothesize that thermolysin induces the rapid degradation of serpins and the activation of proteases directly or indirectly, boosting uncontrolled plasma protein degradation in insects and mammalians. © 2014 Wiley Periodicals, Inc.

The polio eradication campaign: time to shift the goal.

Science.gov (United States)

Baron, Emmanuel; Magone, Claire

2014-03-01

The social rejection of the polio eradication campaign in endemic countries challenges an assumption underlying the goal itself: the full compliance of an entire population to a public health programme. The polio campaign, which has been an extraordinary public health enterprise, is at risk of becoming irremediably unpopular if the eradication goal is pursued at all costs. The Global Polio Eradication Initiative (GPEI) should not be driven by the fear of failure, because the greatest benefit of the polio campaign is that it has demonstrated how simple, community-wide actions can contribute to a dramatic decrease in the incidence of a disease.

Helicobacter pylori eradication therapy: A review of current trends.

Science.gov (United States)

Olokoba, A B; Obateru, O A; Bojuwoye, M O

2013-01-01

Helicobacter pylori has been implicated in the formation of chronic gastritis, peptic ulcer disease, mucosa-associated lymphoid tissue lymphoma and gastric cancer. Eradication of H. Pylori has been recommended as treatment and prevention for these complications. This review is based on a search of Medline, the Cochrane Database of Systemic Reviews, and citation lists of relevant publications. Subject heading and key words used include H. Pylori, current treatment and emerging therapy. Only articles in English were included. There has been a substantial decline in the H. pylori eradication rates over the years, despite the use of proton pump inhibitor and bismuth salts for triple and quadruple therapies respectively. The reasons for eradication failure are diverse, among them, antibiotic resistance is an important factor in the treatment failure. Primary resistance to clarithromycin or metronidazole significantly affects the efficacy of eradication therapy. This has led to the introduction of second line, third line "rescue," and sequential therapies for resistant cases. Subsequently, new antibiotic combinations with proton-pump inhibitors and bismuth salts are being studied in the last decade, to find out the antibiotics that are capable of increasing the eradication rates. Some of these antibiotics include Levofloxacin, Doxycycline, Rifaximin, Rifampicin, Furazolidone based therapies. Studies are ongoing to determine the efficacy of Lactoferrin based therapy.

Differential expression in Phanerochaete chrysosporium of membrane- associated proteins relevant to lignin degradation

Science.gov (United States)

Semarjit Shary; Alexander N. Kapich; Ellen A. Panisko; Jon K. Magnuson; Daniel Cullen; Kenneth E. Hammel

2008-01-01

Fungal lignin-degrading systems likely include membrane-associated proteins that participate in diverse processes such as uptake and oxidation of lignin fragments, production of ligninolytic secondary metabolites, and defense of the mycelium against ligninolytic oxidants. Little is known about the nature or regulation of these membrane-associated components. We grew...

Suppression of type I interferon production by porcine epidemic diarrhea virus and degradation of CREB-binding protein by nsp1

Energy Technology Data Exchange (ETDEWEB)

Zhang, Qingzhan; Shi, Kaichuang; Yoo, Dongwan, E-mail: dyoo@illinois.edu

2016-02-15

Type I interferons (IFN-α/β) are the major components of the innate immune response of hosts, and in turn many viruses have evolved to modulate the host response during infection. We found that the IFN-β production was significantly suppressed during PEDV infection in cells. To identify viral IFN antagonists and to study their suppressive function, viral coding sequences for the entire structural and nonstructural proteins were cloned and expressed. Of 16 PEDV nonstructural proteins (nsps), nsp1, nsp3, nsp7, nsp14, nsp15 and nsp16 were found to inhibit the IFN-β and IRF3 promoter activities. The sole accessory protein ORF3, structure protein envelope (E), membrane (M), and nucleocapsid (N) protein were also shown to inhibit such activities. PEDV nsp1 did not interfere the IRF3 phosphorylation and nuclear translocation but interrupted the enhanceosome assembly of IRF3 and CREB-binding protein (CBP) by degrading CBP. A further study showed that the CBP degradation by nsp1 was proteasome-dependent. Our data demonstrate that PEDV modulates the host innate immune responses by degrading CBP and suppressing ISGs expression. - Highlights: • PEDV modulates the host innate immune system by suppressing the type I interferon production and ISGs expression. • Ten viral proteins were identified as IFN antagonists, and nsp1 was the most potent viral IFN antagonist. • PEDV nsp1 did not interfere the IRF3 phosphorylation and nuclear translocation but interrupted the enhanceosome assembly of IRF3 and CREB-binding protein (CBP). • PEDV nsp1 caused the CBP degradation in the nucleus, which may be the key mechanism for PEDV-mediated IFN downregulation.

Induced oligomerization targets Golgi proteins for degradation in lysosomes.

Science.gov (United States)

Tewari, Ritika; Bachert, Collin; Linstedt, Adam D

2015-12-01

Manganese protects cells against forms of Shiga toxin by down-regulating the cycling Golgi protein GPP130. Down-regulation occurs when Mn binding causes GPP130 to oligomerize and traffic to lysosomes. To determine how GPP130 is redirected to lysosomes, we tested the role of GGA1 and clathrin, which mediate sorting in the canonical Golgi-to-lysosome pathway. GPP130 oligomerization was induced using either Mn or a self-interacting version of the FKBP domain. Inhibition of GGA1 or clathrin specifically blocked GPP130 redistribution, suggesting recognition of the aggregated GPP130 by the GGA1/clathrin-sorting complex. Unexpectedly, however, GPP130's cytoplasmic domain was not required, and redistribution also occurred after removal of GPP130 sequences needed for its normal cycling. Therefore, to test whether aggregate recognition might be a general phenomenon rather than one involving a specific GPP130 determinant, we induced homo-oligomerization of two unrelated Golgi-targeted constructs using the FKBP strategy. These were targeted to the cis- and trans-Golgi, respectively, using domains from mannosidase-1 and galactosyltransferase. Significantly, upon oligomerization, each redistributed to peripheral punctae and was degraded. This occurred in the absence of detectable UPR activation. These findings suggest the unexpected presence of quality control in the Golgi that recognizes aggregated Golgi proteins and targets them for degradation in lysosomes. © 2015 Tewari 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).

Novel Phosphorylation and Ubiquitination Sites Regulate Reactive Oxygen Species-dependent Degradation of Anti-apoptotic c-FLIP Protein*

Science.gov (United States)

Wilkie-Grantham, Rachel P.; Matsuzawa, Shu-Ichi; Reed, John C.

2013-01-01

The cytosolic protein c-FLIP (cellular Fas-associated death domain-like interleukin 1β-converting enzyme inhibitory protein) is an inhibitor of death receptor-mediated apoptosis that is up-regulated in a variety of cancers, contributing to apoptosis resistance. Several compounds found to restore sensitivity of cancer cells to TRAIL, a TNF family death ligand with promising therapeutic potential, act by targeting c-FLIP ubiquitination and degradation by the proteasome. The generation of reactive oxygen species (ROS) has been implicated in c-FLIP protein degradation. However, the mechanism by which ROS post-transcriptionally regulate c-FLIP protein levels is not well understood. We show here that treatment of prostate cancer PPC-1 cells with the superoxide generators menadione, paraquat, or buthionine sulfoximine down-regulates c-FLIP long (c-FLIPL) protein levels, which is prevented by the proteasome inhibitor MG132. Furthermore, pretreatment of PPC-1 cells with a ROS scavenger prevented ubiquitination and loss of c-FLIPL protein induced by menadione or paraquat. We identified lysine 167 as a novel ubiquitination site of c-FLIPL important for ROS-dependent degradation. We also identified threonine 166 as a novel phosphorylation site and demonstrate that Thr-166 phosphorylation is required for ROS-induced Lys-167 ubiquitination. The mutation of either Thr-166 or Lys-167 was sufficient to stabilize c-FLIP protein levels in PPC-1, HEK293T, and HeLa cancer cells treated with menadione or paraquat. Accordingly, expression of c-FLIP T166A or K167R mutants protected cells from ROS-mediated sensitization to TRAIL-induced cell death. Our findings reveal novel ROS-dependent post-translational modifications of the c-FLIP protein that regulate its stability, thus impacting sensitivity of cancer cells to TRAIL. PMID:23519470

The effective eradication and control strategies for tsetse and ...

African Journals Online (AJOL)

I conducted an extensive literature review on the effective tsetse and trypanosomiasis eradication method strategies in Africa in 2010 as i embarked on my research that coincided with the formulation of the Tsetse and Trypanosomiasis Eradication Strategy for Kenya spearheaded by Pan African Tsetse and Trypanosomiasis ...

Redefining the Viral Reservoirs That Prevent HIV-1 Eradication

Science.gov (United States)

Eisele, Evelyn; Siliciano, Robert F.

2014-01-01

Summary This review proposes definitions for key terms in the field of HIV-1 latency and eradication. In the context of eradication, a reservoir is a cell type that allows persistence of replication-competent HIV-1 on a time scale of years in patients on optimal antiretroviral therapy. Reservoirs act as a barrier to eradication in the patient population in whom cure attempts will likely be made. Halting viral replication is essential to eradication, and definitions and criteria for assessing whether this goal has been achieved are proposed. The cell types that may serve as reservoirs for HIV-1 are discussed. Currently, only latently infected resting CD4+ T cells fit the proposed definition of a reservoir, and more evidence is necessary to demonstrate that other cell types including hematopoietic stem cells and macrophages fit this definition. Further research is urgently required on potential reservoirs in the gut-associated lymphoid tissue and the central nervous system. PMID:22999944

Association of helicobacter pylori dupA with the failure of primary eradication.

Science.gov (United States)

Shiota, Seiji; Nguyen, Lam Tung; Murakami, Kazunari; Kuroda, Akiko; Mizukami, Kazuhiro; Okimoto, Tadayoshi; Kodama, Masaaki; Fujioka, Toshio; Yamaoka, Yoshio

2012-04-01

To determine whether the presence of dupA Helicobacter pylori (H. pylori) influences the cure rate of primary eradication therapy. Several virulence factors of H. pylori have been reported to affect the efficacy of the eradication rate. However, no study has investigated whether the presence of dupA affects eradication failure. The presence of dupA was evaluated in 142 H. pylori strains isolated from 142 patients with gastrointestinal diseases. Of these patients, 104 received primary eradication therapy for 1 week. The risk factors for eradication failure were determined using univariate and multivariate analyses. Among 142 strains, 44 (31.0%) were dupA positive. There was no association between dupA status and gastroduodenal diseases (P>0.05). The clarithromycin (CLR) resistance rate was generally lower in the dupA-positive than in the dupA-negative group (20.4% vs. 35.7%, P=0.06). However, dupA prevalence was higher in the eradication failure group than in the success group (36.3% vs. 21.9%). Among the CLR-resistant H. pylori infected group, the successful eradication rate was significantly lower in patients infected with dupA-positive H. pylori than dupA-negative H. pylori (P=0.04). In multivariate analysis adjusted for age, sex, and type of disease, not only CLR resistance but also dupA presence was independent risk factors for eradication failure (adjusted odds ratio=3.71; 95% confidence interval,1.07-12.83). Although CLR resistant was more reliable predictor, the presence of dupA may also be an independent risk factor for eradication failure.

Natural and experimental Helicobacter mustelae reinfection following successful antimicrobial eradication in ferrets.

Science.gov (United States)

Batchelder, M; Fox, J G; Hayward, A; Yan, L; Shames, B; Murphy, J C; Palley, L

1996-03-01

Recrudescence or reinfection may occur after eradication of Helicobacter pylori in humans. We used the ferret Helicobacter mustelae model to investigate the effect of prior infection and eradication on reinfection by experimental and natural routes. Two groups of ferrets with naturally acquired H. mustelae infection were treated with an eradication protocol using amoxicillin, metronidazole, and bismuth subsalicylate. The ferrets were monitored for recrudescence by repeated cultures of endoscopic gastric mucosal biopsies. The ferrets were challenged at 17 months (group I) and 6 months (group II) after eradication with a strain of H. mustelae having a distinctive restriction endonuclease analysis pattern. The eradication protocol was repeated to eliminate the infection produced by experimental challenge. The ferrets were then cohoused intermittently with naturally infected ferrets. The original H. mustelae infection was successfully eliminated by the eradication protocol. No recrudescence was observed in group I for 12 months nor for 3 months in group II after eradication. All ferrets became persistently reinfected with the challenge strain. The infection from the challenge strain was eradicated successfully. No ferrets in group I and all ferrets in group II became infected through cohousing. These results suggest that though prior infection with H. mustelae may confer some protection against reinfection, such protection is not universal in all circumstances; that susceptibility to reinfection by contact with infected animals varies between individuals; and that age may be a factor in this individual variability. These results are applicable to studies of reinfection after eradication of H. pylori in humans.

The tissue-specific Rep8/UBXD6 tethers p97 to the endoplasmic reticulum membrane for degradation of misfolded proteins.

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Louise Madsen

Full Text Available The protein known as p97 or VCP in mammals and Cdc48 in yeast is a versatile ATPase complex involved in several biological functions including membrane fusion, protein folding, and activation of membrane-bound transcription factors. In addition, p97 plays a central role in degradation of misfolded secretory proteins via the ER-associated degradation pathway. This functional diversity of p97 depends on its association with various cofactors, and to further our understanding of p97 function it is important that these cofactors are identified and analyzed. Here, we isolate and characterize the human protein named Rep8 or Ubxd6 as a new cofactor of p97. Mouse Rep8 is highly tissue-specific and abundant in gonads. In testes, Rep8 is expressed in post-meiotic round spermatids, whereas in ovaries Rep8 is expressed in granulosa cells. Rep8 associates directly with p97 via its UBX domain. We show that Rep8 is a transmembrane protein that localizes to the ER membrane with its UBX domain facing the cytoplasm. Knock-down of Rep8 expression in human cells leads to a decreased association of p97 with the ER membrane and concomitantly a retarded degradation of misfolded ER-derived proteasome substrates. Thus, Rep8 tethers p97 to the ER membrane for efficient ER-associated degradation.

Ruminal and intestinal protein degradability of various seaweed species measured in situ in dairy cows

DEFF Research Database (Denmark)

Tayyab, Usama; Novoa-Garrido, Margarita; Roleda, Michael Y.

2016-01-01

The use of seaweeds in animal diets is not new. However, little is known about the feed value of seaweed, both in terms of chemical composition and protein digestibility, and regarding variation between species and season. In this study, eight seaweed species of the genus Acrosiphonia, Alaria......, Laminaria, Mastocarpus, Palmaria, Pelvetia, Porphyra, and Ulva were sampled in spring (March) and autumn (October and November) 2014 at the coast of Bodø in Northern Norway, and were analysed for chemical composition, in situ rumen degradability and total tract crude protein (CP) digestibility. Ash content...... for Pelvetia (90 g/kg DM). Spring samples were higher in CP than autumn samples. The effective degradability estimated at 5% rumen passage rate (ED5) of CP varied between species (P Ulva (240 g...

Polio Eradication Initiative (PEl) Emergency Plan: A Panacea for ...

African Journals Online (AJOL)

Methods A review of related and available literature was conducted on the subject matter using the Google search engine, Google Scholar, and PubMed using the key words polio; eradication; Nigeria; and Global Polio Eradication Initiative. Result Much progress has been made towards achieving the required coverage ...

Organic matter degradation in Chilean sediments - following nature's own degradation experiment

DEFF Research Database (Denmark)

Langerhuus, Alice Thoft; Niggemann, Jutta; Lomstein, Bente Aagaard

ORGANIC MATTER DEGRADATION IN CHILEAN SEDIMENTS – FOLLOWING NATURE’S OWN DEGRADATION EXPERIMENT Degradation of sedimentary organic matter was studied at two stations from the shelf of the Chilean upwelling region. Sediment cores were taken at 1200 m and 800 m water depth and were 4.5 m and 7.5 m...... in length, respectively. The objective of this study was to assess the degradability of the organic matter from the sediment surface to the deep sediments. This was done by analysing amino acids (both L- and D-isomers) and amino sugars in the sediment cores, covering a timescale of 15.000 years. Diagenetic...... indicators (percentage of carbon and nitrogen present as amino acid carbon and nitrogen, the ratio between a protein precursor and its non-protein degradation product and the percentage of D-amino acids) revealed ongoing degradation in these sediments, indicating that microorganisms were still active in 15...

Rift Valley fever virus NSs inhibits host transcription independently of the degradation of dsRNA-dependent protein kinase PKR.

Science.gov (United States)

Kalveram, Birte; Lihoradova, Olga; Indran, Sabarish V; Lokugamage, Nandadeva; Head, Jennifer A; Ikegami, Tetsuro

2013-01-20

Rift Valley fever virus (RVFV) encodes one major virulence factor, the NSs protein. NSs suppresses host general transcription, including interferon (IFN)-β mRNA synthesis, and promotes degradation of the dsRNA-dependent protein kinase (PKR). We generated a novel RVFV mutant (rMP12-NSsR173A) specifically lacking the function to promote PKR degradation. rMP12-NSsR173A infection induces early phosphorylation of eIF2α through PKR activation, while retaining the function to inhibit host general transcription including IFN-β gene inhibition. MP-12 NSs but not R173A NSs binds to wt PKR. R173A NSs formed filamentous structure in nucleus in a mosaic pattern, which was distinct from MP-12 NSs filament pattern. Due to early phosphorylation of eIF2α, rMP12-NSsR173A could not efficiently accumulate viral proteins. Our results suggest that NSs-mediated host general transcription suppression occurs independently of PKR degradation, while the PKR degradation is important to inhibit the phosphorylation of eIF2α in infected cells undergoing host general transcription suppression. Copyright © 2012 Elsevier Inc. All rights reserved.

Polio Eradication Initiative (PEl) Emergency Plan: A Panacea for ...

African Journals Online (AJOL)

TNHJOURNALPH

and surmount the intractable problem of sub- optimal vaccine coverage which has remained a critical bottleneck in the successful eradication of the polio virus in Nigeria. It becomes pertinent therefore, to appraise this latest effort to avoid a recurrence of failure in subsequent polio eradication programs. METHODS. A review ...

Eradication therapy for peptic ulcer disease in Helicobacter pylori-positive people.

Science.gov (United States)

Ford, Alexander C; Gurusamy, Kurinchi Selvan; Delaney, Brendan; Forman, David; Moayyedi, Paul

2016-04-19

Peptic ulcer disease is the cause of dyspepsia in about 10% of people. Ninety-five percent of duodenal and 70% of gastric ulcers are associated with Helicobacter pylori. Eradication of H. pylori reduces the relapse rate of ulcers but the magnitude of this effect is uncertain. This is an update of Ford AC, Delaney B, Forman D, Moayyedi P. Eradication therapy for peptic ulcer disease in Helicobacter pylori-positive patients. Cochrane Database of Systematic Reviews 2006, Issue 2. Art. No.: CD003840. DOI: 10.1002/14651858.CD003840.pub4. To assess the proportion of peptic ulcers healed and the proportion of participants who remained free from relapse with eradication therapy against placebo or other pharmacological therapies in H. pylori-positive people.To assess the proportion of participants that achieved complete relief of symptoms and improvement in quality of life scores.To compare the incidence of adverse effects/drop-outs (total number for each drug) associated with the different treatments.To assess the proportion of participants in whom successful eradication was achieved. In this update, we identified trials by searching the Cochrane Central Register of Controlled Trials (CENTRAL), Ovid MEDLINE (1950 to March 2016) and Ovid EMBASE (1980 to March 2016). To identify further relevant trials, we handsearched reference lists from trials selected by electronic searching, and published abstracts from conference proceedings from the United European Gastroenterology Week (published in Gut) and Digestive Disease Week (published in Gastroenterology). The search was last updated in March 2016. We contacted members of Cochrane Upper GI and Pancreatic Diseases, and experts in the field and asked them to provide details of outstanding clinical trials and any relevant unpublished materials. We analysed randomised controlled trials of short- and long-term treatment of peptic ulcer disease in H. pylori-positive adults. Participants received at least one week of H. pylori

Isolation and characterization of a tomato non-specific lipid transfer protein involved in polygalacturonase-mediated pectin degradation.

Science.gov (United States)

Tomassen, Monic M M; Barrett, Diane M; van der Valk, Henry C P M; Woltering, Ernst J

2007-01-01

An important aspect of the ripening process of tomato fruit is softening. Softening is accompanied by hydrolysis of the pectin in the cell wall by pectinases, causing loss of cell adhesion in the middle lamella. One of the most significant pectin-degrading enzymes is polygalacturonase (PG). Previous reports have shown that PG in tomato may exist in different forms (PG1, PG2a, PG2b, and PGx) commonly referred to as PG isoenzymes. The gene product PG2 is differentially glycosylated and is thought to associate with other proteins to form PG1 and PGx. This association is thought to modulate its pectin-degrading activity in planta. An 8 kDa protein that is part of the tomato PG1 multiprotein complex has been isolated, purified, and functionally characterized. This protein, designated 'activator' (ACT), belongs to the class of non-specific lipid transfer proteins (nsLTPs). ACT is capable of 'converting' the gene product PG2 into a more active and heat-stable form, which increases PG-mediated pectin degradation in vitro and stimulates PG-mediated tissue breakdown in planta. This finding suggests a new, not previously identified, function for nsLTPs in the modification of hydrolytic enzyme activity. It is proposed that ACT plays a role in the modulation of PG activity during tomato fruit softening.

Postmortem muscle protein degradation in humans as a tool for PMI delimitation.

Science.gov (United States)

Pittner, Stefan; Ehrenfellner, Bianca; Monticelli, Fabio C; Zissler, Angela; Sänger, Alexandra M; Stoiber, Walter; Steinbacher, Peter

2016-11-01

Forensic estimation of time since death relies on diverse approaches, including measurement and comparison of environmental and body core temperature and analysis of insect colonization on a dead body. However, most of the applied methods have practical limitations or provide insufficient results under certain circumstances. Thus, new methods that can easily be implemented into forensic routine work are required to deliver more and discrete information about the postmortem interval (PMI). Following a previous work on skeletal muscle degradation in the porcine model, we analyzed human postmortem skeletal muscle samples of 40 forensic cases by Western blotting and casein zymography. Our results demonstrate predictable protein degradation processes in human muscle that are distinctly associated with temperature and the PMI. We provide information on promising degradation markers for certain periods of time postmortem, which can be useful tools for time since death delimitation. In addition, we discuss external influencing factors such as age, body mass index, sex, and cause of death that need to be considered in future routine application of the method in humans.

Eradication of New World Screwworm from Jamaica

International Nuclear Information System (INIS)

2003-01-01

The New World Screwworm (NWS) is an insect pest affecting warm-blooded animals and also humans. It causes widespread economic losses in livestock production as well as pain and suffering to animals and to those people unfortunate enough to become infected. Although it is endemic in Jamaica, the screwworm can be eradicated from the island using the well proven and successful Sterile Insect Technique. In collaboration with the Jamaican authorities, the Department of Technical Co-operation of the IAEA is planning to sponsor a Model Project to eradicate screwworm from Jamaica. (IAEA)

APC/C-mediated degradation of dsRNA-binding protein 4 (DRB4 involved in RNA silencing.

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Katia Marrocco

Full Text Available Selective protein degradation via the ubiquitin-26S proteasome is a major mechanism underlying DNA replication and cell division in all Eukaryotes. In particular, the APC/C (Anaphase Promoting Complex or Cyclosome is a master ubiquitin protein ligase (E3 that targets regulatory proteins for degradation allowing sister chromatid separation and exit from mitosis. Interestingly, recent work also indicates that the APC/C remains active in differentiated animal and plant cells. However, its role in post-mitotic cells remains elusive and only a few substrates have been characterized.In order to identify novel APC/C substrates, we performed a yeast two-hybrid screen using as the bait Arabidopsis APC10/DOC1, one core subunit of the APC/C, which is required for substrate recruitment. This screen identified DRB4, a double-stranded RNA binding protein involved in the biogenesis of different classes of small RNA (sRNA. This protein interaction was further confirmed in vitro and in plant cells. Moreover, APC10 interacts with DRB4 through the second dsRNA binding motif (dsRBD2 of DRB4, which is also required for its homodimerization and binding to its Dicer partner DCL4. We further showed that DRB4 protein accumulates when the proteasome is inactivated and, most importantly, we found that DRB4 stability depends on APC/C activity. Hence, depletion of Arabidopsis APC/C activity by RNAi leads to a strong accumulation of endogenous DRB4, far beyond its normal level of accumulation. However, we could not detect any defects in sRNA production in lines where DRB4 was overexpressed.Our work identified a first plant substrate of the APC/C, which is not a regulator of the cell cycle. Though we cannot exclude that APC/C-dependent degradation of DRB4 has some regulatory roles under specific growth conditions, our work rather points to a housekeeping function of APC/C in maintaining precise cellular-protein concentrations and homeostasis of DRB4.

Transition Planning For After Polio Eradication.

Science.gov (United States)

Rutter, Paul D; Hinman, Alan R; Hegg, Lea; King, Dennis; Sosler, Stephen; Swezy, Virginia; Hussey, Ann-Lee; Cochi, Stephen L

2017-07-01

The Global Polio Eradication Initiative (GPEI) has been in operation since 1988, now spends $1 billion annually, and operates through thousands of staff and millions of volunteers in dozens of countries. It has brought polio to the brink of eradication. After eradication is achieved, what should happen to the substantial assets, capabilities, and lessons of the GPEI? To answer this question, an extensive process of transition planning is underway. There is an absolute need to maintain and mainstream some of the functions, to keep the world polio-free. There is also considerable risk-and, if seized, substantial opportunity-for other health programs and priorities. And critical lessons have been learned that can be used to address other health priorities. Planning has started in the 16 countries where GPEI's footprint is the greatest and in the program's 5 core agencies. Even though poliovirus transmission has not yet been stopped globally, this planning process is gaining momentum, and some plans are taking early shape. This is a complex area of work-with difficult technical, financial, and political elements. There is no significant precedent. There is forward motion and a willingness on many sides to understand and address the risks and to explore the opportunities. Very substantial investments have been made, over 30 years, to eradicate a human pathogen from the world for the second time ever. Transition planning represents a serious intent to responsibly bring the world's largest global health effort to a close and to protect and build upon the investment in this effort, where appropriate, to benefit other national and global priorities. Further detailed technical work is now needed, supported by broad and engaged debate, for this undertaking to achieve its full potential. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America.

Experiences with smallpox eradication in Ethiopia.

Science.gov (United States)

de Quadros, Ciro A

2011-12-30

The smallpox eradication campaign operated in Ethiopia from 1970 until 1977. During this time Ethiopia had only 84 hospitals, 64 health centres and fewer than 400 physicians in a country of 25 million people. In 1970 smallpox vaccination was relatively unknown in the country, and the government actually contested the fact that smallpox was present in the country. Most of the resources of the Ministry of Health were used for malaria eradication. Initial pessimism from the Ministry of Health and others was eventually overcome as the smallpox eradication campaign continued to pick up steam but many remained unenthusiastic. Ethiopia was the first country in the world to start its smallpox eradication campaign from day one with the strategy of "Surveillance and Containment". Establishing a surveillance system in a country with a limited health infrastructure was a daunting challenge. At the end of the first year of the programme in 1971, 26,000 cases of smallpox had been registered through the growing surveillance system. Throughout revolution of 1974 the smallpox campaign was the only UN program to operate in the country; in fact it expanded with the hire of many locals leading to a "nationalized" program. This development ushered in the most successful final phase of the program. As the program progressed cases were diminishing in most regions, however transmission continued in the Ogaden desert. Over the course of the campaign approximately 14.3 million US dollars was spent. Working conditions were extremely challenging and a variety of chiefs, guerrillas, landowners and governments had to be appeased. The programme was successful due to the dedicated national and international staff on the ground and by having the full support of the WHO HQ in Geneva. Copyright © 2011 Elsevier Ltd. All rights reserved.

pH-responsive and enzymatically-responsive hydrogel microparticles for the oral delivery of therapeutic proteins: Effects of protein size, crosslinking density, and hydrogel degradation on protein delivery.

Science.gov (United States)

Koetting, Michael Clinton; Guido, Joseph Frank; Gupta, Malvika; Zhang, Annie; Peppas, Nicholas A

2016-01-10

Two potential platform technologies for the oral delivery of protein therapeutics were synthesized and tested. pH-responsive poly(itaconic acid-co-N-vinyl-2-pyrrolidone) (P(IA-co-NVP)) hydrogel microparticles were tested in vitro with model proteins salmon calcitonin, urokinase, and rituximab to determine the effects of particle size, protein size, and crosslinking density on oral delivery capability. Particle size showed no significant effect on overall delivery potential but did improve percent release of encapsulated protein over the micro-scale particle size range studied. Protein size was shown to have a significant impact on the delivery capability of the P(IA-co-NVP) hydrogel. We show that when using P(IA-co-NVP) hydrogel microparticles with 3 mol% tetra(ethylene glycol) dimethacrylate crosslinker, a small polypeptide (salmon calcitonin) loads and releases up to 45 μg/mg hydrogel while the mid-sized protein urokinase and large monoclonal antibody rituximab load and release only 19 and 24 μg/mg hydrogel, respectively. We further demonstrate that crosslinking density offers a simple method for tuning hydrogel properties to variously sized proteins. Using 5 mol% TEGDMA crosslinker offers optimal performance for the small peptide, salmon calcitonin, whereas lower crosslinking density of 1 mol% offers optimal performance for the much larger protein rituximab. Finally, an enzymatically-degradable hydrogels of P(MAA-co-NVP) crosslinked with the peptide sequence MMRRRKK were synthesized and tested in simulated gastric and intestinal conditions. These hydrogels offer ideal loading and release behavior, showing no degradative release of encapsulated salmon calcitonin in gastric conditions while yielding rapid and complete release of encapsulated protein within 1h in intestinal conditions. Copyright © 2015 Elsevier B.V. All rights reserved.

Helicobacter pylori eradication: A randomised comparative trial of 7 ...

African Journals Online (AJOL)

Compliance and side-effects were assessed 2 weeks after the start of therapy and H. pylori eradication was assessed by stool antigen tests 4 weeks after treatment. Results. Both the intention-to-treat (ITT; N=120) and per protocol (PP; N=97) analyses showed no significant differences between the eradication rates of EAC 7 ...

Rift Valley fever virus NSs inhibits host transcription independently of the degradation of dsRNA-dependent Protein Kinase PKR

OpenAIRE

Kalveram, Birte; Lihoradova, Olga; Indran, Sabarish V.; Lokugamage, Nandadeva; Head, Jennifer A.; Ikegami, Tetsuro

2012-01-01

Rift Valley fever virus (RVFV) encodes one major virulence factor, the NSs protein. NSs suppresses host general transcription, including interferon (IFN)-β mRNA synthesis, and promotes degradation of the dsRNA-dependent protein kinase (PKR). We generated a novel RVFV mutant (rMP12-NSsR173A) specifically lacking the function to promote PKR degradation. rMP12-NSsR173A infection induces early phosphorylation of eIF2α through PKR activation, while retaining the function to inhibit host general tr...

An Assessment of Poverty Eradication Programme (NAPEP in Nigeria

Directory of Open Access Journals (Sweden)

Adam Adem ANYEBE

2015-06-01

Full Text Available Poverty situation in Nigeria has become so serious that in 2013 there were as many as 112 million or 70.0% of the country’s population was living below poverty line. It has realized that poverty anywhere is a threat to peace, security and prosperity everywhere hence the conscious efforts by successive administrations in Nigeria to eradicate all forms of extreme poverty and hunger in a country. In spite of these efforts to eradicate absolute poverty in the country, poverty incidence has been on the rise. This study, therefore, attempted to assess NAPEP as a programme to eradicate extreme poverty in the country. Personal interviews and documents were employed in data collection. The data were analyzed using tables, simple percentages and spearman rank correlation. The study showed among others, that NAPEP as a programme targeted at eradicating extreme poverty has not been effective leading to a mixed bag of limited success and continuing challenges. It was therefore, recommended that the programme should be re-examined and possibly re-designed for effective performance instead of scrapping it.

Cyclin A degradation by primate cytomegalovirus protein pUL21a counters its innate restriction of virus replication.

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Nicolas Caffarelli

Full Text Available Cyclin A is critical for cellular DNA synthesis and S phase progression of the cell cycle. Human cytomegalovirus (HCMV can reduce cyclin A levels and block cellular DNA synthesis, and cyclin A overexpression can repress HCMV replication. This interaction has only been previously observed in HCMV as murine CMV does not downregulate cyclin A, and the responsible viral factor has not been identified. We previously reported that the HCMV protein pUL21a disrupted the anaphase-promoting complex (APC, but a point mutant abrogating this activity did not phenocopy a UL21a-deficient virus, suggesting that pUL21a has an additional function. Here we identified a conserved arginine-x-leucine (RxL cyclin-binding domain within pUL21a, which allowed pUL21a to interact with cyclin A and target it for proteasome degradation. Homologous pUL21a proteins from both chimpanzee and rhesus CMVs also contained the RxL domain and similarly degraded cyclin A, indicating that this function is conserved in primate CMVs. The RxL point mutation disabled the virus' ability to block cellular DNA synthesis and resulted in a growth defect similar to pUL21a-deficient virus. Importantly, knockdown of cyclin A rescued growth of UL21a-deficient virus. Together, these data show that during evolution, the pUL21a family proteins of primate CMVs have acquired a cyclin-binding domain that targets cyclin A for degradation, thus neutralizing its restriction on virus replication. Finally, the combined proteasome-dependent degradation of pUL21a and its cellular targets suggests that pUL21a may act as a novel suicide protein, targeting its protein cargos for destruction.

The Effect of Helicobacter pylori Eradication on the Levels of Essential Trace Elements

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Meng-Chieh Wu

2014-01-01

Full Text Available Objective. This study was designed to compare the effect of Helicobacter pylori (H. pylori infection treatment on serum zinc, copper, and selenium levels. Patients and Methods. We measured the serum zinc, copper, and selenium levels in H. pylori-positive and H. pylori-negative patients. We also evaluated the serum levels of these trace elements after H. pylori eradication. These serum copper, zinc, and selenium levels were determined by inductively coupled plasma mass spectrometry. Results. Sixty-three H. pylori-positive patients and thirty H. pylori-negative patients were studied. Serum copper, zinc, and selenium levels had no significant difference between H. pylori-positive and H. pylori-negative groups. There were 49 patients with successful H. pylori eradication. The serum selenium levels were lower after successful H. pylori eradication, but not significantly (P=0.06. There were 14 patients with failed H. pylori eradication. In this failed group, the serum selenium level after H. pylori eradication therapy was significantly lower than that before H. pylori eradication therapy (P<0.05. The serum zinc and copper levels had no significant difference between before and after H. pylori eradication therapies. Conclusion. H pylori eradication regimen appears to influence the serum selenium concentration (IRB number: KMUH-IRB-20120327.

Use of 'eradication' in HIV cure-related research: a public health debate.

Science.gov (United States)

Dubé, Karine; Luter, Stuart; Lesnar, Breanne; Newton, Luke; Galea, Jerome; Brown, Brandon; Gianella, Sara

2018-02-13

The landscape of Human Immunodeficiency Virus (HIV) research has changed drastically over the past three decades. With the remarkable success of antiretroviral treatment (ART) in decreasing AIDS-related mortality, some researchers have shifted their HIV research focus from treatment to cure research. The HIV cure research community often uses the term eradication to describe the science, and talks about eradicating the virus from the body. In public discourse, the term eradication could be conflated with disease eradication at the population level. In this paper, we call for a reframing of HIV cure research as control, as it is a more accurate descriptor and achievable goal in the foreseeable future. The properties of HIV are discordant with eradicability standards at both the individual level (as a clinical concept), and at the population level (as a public health concept). At the individual level, true eradication would necessitate absolute elimination of all latent HIV reservoirs from the body. Current HIV cure-related research strategies have proven unsuccessful at accurately quantifying, let alone eliminating these reservoirs. At the population level, eradication implies the permanent global reduction of HIV to zero new cases and to zero risk for future cases. Given the absence of an efficacious HIV vaccine and the impracticality and unethicality of eliminating animal reservoirs, global eradication of HIV is highly implausible. From a public health perspective, HIV eradication remains an elusive goal. The term 'eradication' is a misleading description of current HIV cure-related research. Instead, we call for the use of more realistic expressions such as 'sustained virologic HIV suppression (or control)' or 'management of HIV persistence' to describe HIV cure-related research. Using these terms reorients what HIV cure science can potentially achieve in the near future and avoids creating unrealistic expectations, particularly among the millions of people

Comparison of vonoprazan and proton pump inhibitors for eradication of Helicobacter pylori

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Satoshi Shinozaki

2016-05-01

Full Text Available Alternative eradication therapies for Helicobacter pylori infection are needed because of an increasing failure rate over the past decade. The aim of this study was to determine if vonoprazan, a new potassium-competitive acid blocker, showed superiority to existing proton pump inhibitors for primary eradication of H. pylori in routine clinical practice. Data for 573 patients who underwent primary H. pylori eradication therapy were retrospectively reviewed. Regimens included clarithromycin 200 mg, amoxicillin 750 mg, and an acid-suppressing drug [lansoprazole 30 mg (LAC, rabeprazole 10 mg (RAC, esomeprazole 20 mg (EAC, or vonoprazan 20 mg (VAC] twice daily for 1 week. Eradication was successful in 73% (419/573 of patients using intention-to-treat (ITT analysis and 76% (419/549 of patients in per-protocol (PP analysis. The VAC group had a significantly superior eradication rate compared with the LAC and RAC groups in ITT (VAC 83%, LAC 66% and RAC 67%, p  80% eradication rate regardless of the degree of atrophy.

A Plastid Protein That Evolved from Ubiquitin and Is Required for Apicoplast Protein Import in Toxoplasma gondii

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Justin D. Fellows

2017-06-01

Full Text Available Apicomplexan parasites cause a variety of important infectious diseases, including malaria, toxoplasma encephalitis, and severe diarrhea due to Cryptosporidium. Most apicomplexans depend on an organelle called the apicoplast which is derived from a red algal endosymbiont. The apicoplast is essential for the parasite as the compartment of fatty acid, heme, and isoprenoid biosynthesis. The majority of the approximate 500 apicoplast proteins are nucleus encoded and have to be imported across the four membranes that surround the apicoplast. Import across the second outermost membrane of the apicoplast, the periplastid membrane, depends on an apicoplast-specific endoplasmic reticulum-associated protein degradation (ERAD complex and on enzymes of the associated ubiquitination cascade. However, identification of an apicoplast ubiquitin associated with this machinery has long been elusive. Here we identify a plastid ubiquitin-like protein (PUBL, an apicoplast protein that is derived from a ubiquitin ancestor but that has significantly changed in its primary sequence. PUBL is distinct from known ubiquitin-like proteins, and phylogenomic analyses suggest a clade specific to apicomplexans. We demonstrate that PUBL and the AAA ATPase CDC48AP both act to translocate apicoplast proteins across the periplastid membrane during protein import. Conditional null mutants and genetic complementation show that both proteins are critical for this process and for parasite survival. PUBL residues homologous to those that are required for ubiquitin conjugation onto target proteins are essential for this function, while those required for polyubiquitination and preprotein processing are dispensable. Our experiments provide a mechanistic understanding of the molecular machinery that drives protein import across the membranes of the apicoplast.

Cheliensisin A (Chel A) induces apoptosis in human bladder cancer cells by promoting PHLPP2 protein degradation.

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Zhang, Ruowen; Che, Xun; Zhang, Jingjie; Li, Yang; Li, Jingxia; Deng, Xu; Zhu, Junlan; Jin, Honglei; Zhao, Qinshi; Huang, Chuanshu

2016-10-11

Cheliensisin A (Chel A), a styryl-lactone compound extracted from Goniothalamus cheliensis, is reported to have significant anti-cancer effects in various cancer cells. Here we demonstrated that Chel A treatment resulted in apoptosis and an inhibition of anchorage-independent growth in human bladder cancer T24, T24T and U5637 cells. Mechanistic studies showed that such effect is mediated by PH domain and Leucine rich repeat Protein Phosphatases (PHLPP2) protein. Chel A treatment led to PHLPP2 degradation and subsequently increased in c-Jun phosphorylation. Moreover PHLPP2 degradation could be attenuated by inhibition of autophagy, which was mediated by Beclin 1. Collectively, we discover that Chel A treatment induces Beclin-dependent autophagy, consequently mediates PHLPP2 degradation and JNK/C-Jun phosphorylation and activation, further in turn contributing to apoptosis in human bladder cancer cells. Current studies provide a significant insight into understanding of anticancer effect of Chel A in treatment of human bladder cancer.

The Type II Hsp40 Sis1 cooperates with Hsp70 and the E3 ligase Ubr1 to promote degradation of terminally misfolded cytosolic protein.

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Daniel W Summers

Full Text Available Mechanisms for cooperation between the cytosolic Hsp70 system and the ubiquitin proteasome system during protein triage are not clear. Herein, we identify new mechanisms for selection of misfolded cytosolic proteins for degradation via defining functional interactions between specific cytosolic Hsp70/Hsp40 pairs and quality control ubiquitin ligases. These studies revolved around the use of S. cerevisiae to elucidate the degradation pathway of a terminally misfolded reporter protein, short-lived GFP (slGFP. The Type I Hsp40 Ydj1 acts with Hsp70 to suppress slGFP aggregation. In contrast, the Type II Hsp40 Sis1 is required for proteasomal degradation of slGFP. Sis1 and Hsp70 operate sequentially with the quality control E3 ubiquitin ligase Ubr1 to target slGFP for degradation. Compromise of Sis1 or Ubr1 function leads slGFP to accumulate in a Triton X-100-soluble state with slGFP degradation intermediates being concentrated into perinuclear and peripheral puncta. Interestingly, when Sis1 activity is low the slGFP that is concentrated into puncta can be liberated from puncta and subsequently degraded. Conversely, in the absence of Ubr1, slGFP and the puncta that contain slGFP are relatively stable. Ubr1 mediates proteasomal degradation of slGFP that is released from cytosolic protein handling centers. Pathways for proteasomal degradation of misfolded cytosolic proteins involve functional interplay between Type II Hsp40/Hsp70 chaperone pairs, PQC E3 ligases, and storage depots for misfolded proteins.

Attempted eradication of Porphyrio porphyrio Linnaeus in the Florida Everglades

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Dave EGGEMAN

2011-01-01

Full Text Available Porphyrio porphyrio (Fulica porphyrio Linnaeus was reported to the South Florida Water Management District in a Water Conservation Area and in constructed wetlands in the Everglades in 2006. A rapid assessment, including casual observations and surveys of land managers, indicated a limited number of P. porphyrio (~300 birds was present, and an eradication attempt was initiated. From 2006 – 2008, more than 3100 P. porphyrio were killed by shotgun from airboats during 73 hunts, suggesting the initial population assessment was severely underestimated. After removing nearly 1500 P. porphyrio in 2008, we concluded that eradication was not possible. Failure of this eradication attempt is attributed to P. porphyrio’s affinity with dense emergent vegetation, which greatly limited shooting effectiveness. Further, the failed eradication underscores the importance of a reporting network to improve early detection and the chance to eliminate naturalized or feral populations of non‐native species.

Leucine supplementation stimulates protein synthesis and reduces degradation signal activation in muscle of newborn pigs during acute endotoxemia

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Sepsis disrupts skeletal muscle proteostasis and mitigates the anabolic response to leucine (Leu) in muscle of mature animals. We have shown that Leu stimulates muscle protein synthesis (PS) in healthy neonatal piglets. To determine if supplemental Leu can stimulate PS and reduce protein degradation...

Patients with established gastro-esophageal reflux disease might benefit from Helicobacter pylori eradication.

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Moschos, John M; Kouklakis, George; Vradelis, Stergios; Zezos, Petros; Pitiakoudis, Michael; Chatzopoulos, Dimitrios; Zavos, Christos; Kountouras, Jannis

2014-01-01

The aim of this study was to investigate the effect of Helicobacter pylori ( H. pylori ) eradication in selected H. pylori -positive patients with a primary diagnosis of gastro-esophageal reflux disease (GERD) by using the 3-h postprandial esophageal pH monitoring. We recruited patients with erosive esophagitis at endoscopy and H. pylori infection at histology, successfully cured following eradication therapy; the selected H. pylori -positive patients had weekly reflux symptoms for at least six months and endoscopically established Grade A or B esophagitis. Twenty-nine eligible patients were initially subjected to esophageal manometry and ambulatory 3-h postprandial esophageal pH monitoring. All patients received H. pylori triple eradication therapy accompanied by successful H. pylori eradication. After successful eradication of H. pylori (confirmed by 13 C urea breath test), a second manometry and 3-h postprandial esophageal pH monitoring were introduced to assess the results of eradication therapy, after a 3-month post-treatment period. All 29 selected H. pylori -positive patients became negative due to successful H. pylori eradication, evaluated by 13 C urea breath test after a 4-week post-treatment period. Post-eradication, 62.1% patients showed similar manometric pattern at baseline; 17.2% showed improvement; 17.2% normalization; and 3.4% deterioration of the manometric patterns. The DeMeester symptom scoring in the 3-h postprandial ambulatory esophageal pH monitoring was improved after eradication of H. pylori (median 47.47 vs. 22.00, Wilcoxon's singed rank; P=0.016). On comparing the pH monitoring studies for each patient at baseline and post-eradication period, 82.8% patients showed improvement and 17.2% deterioration of the DeMeester score. By using 3-h postprandial esophageal pH monitoring, this study showed, for the first time, that H. pylori eradication may positively influence GERD symptoms. Large-scale controlled relative studies are warranted to

Activated ClpP kills persisters and eradicates a chronic biofilm infection.

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Conlon, Brian P.; Nakayasu, Ernesto S.; Fleck, Laura E.; LaFleur, Michael D.; Isabella, Vincent M.; Coleman, K.; Leonard, Steve N.; Smith, Richard D.; Adkins, Joshua N.; Lewis, Kim

2013-11-21

The current antibiotic crisis stems from two distinct phenomena-drug resistance, and drug tolerance. Resistance mechanisms such as drug efflux or modification prevent antibiotics from binding to their targets 1, allowing pathogens to grow. Antibiotic tolerance is the property of persister cells, phenotypic variants of regular bacteria 2. Antibiotics kill by corrupting targets, but these are inactive in dormant persisters, leading to tolerance. Persisters were first identified by Joseph Bigger in 1944, when he discovered a surviving sub-population of Staphylococcus following treatment with penicillin3. Persisters are largely responsible for recalcitrance of chronic diseases such as tuberculosis, and various infections associated with biofilms - endocarditis, osteomyelitis, infections of catheters and indwelling devices, and deep-seated infections of soft tissues 4. There are a number of redundant pathways involved in persister formation5,6 precluding development of drugs inhibiting their formation. The acyldepsipeptide antibiotic (ADEP 4) has been shown to activate the ClpP protease resulting in death of growing cells 7. Here we show that ADEP4 activated ClpP becomes a fairly non-specific protease and kills persister cells by degradation of over 400 intracellular targets. clpP mutants are resistant to ADEP4 7, but we find that they display increased susceptibility to killing by a range of conventional antibiotics. Combining ADEP4 with rifampicin leads to eradication of persisters, stationary and biofilm populations of Staphylococcus aureus in vitro and in a deep-seated murine infection. Target corruption/activation provides an approach to killing persisters and eradicating chronic infections.

Economic analysis of the global polio eradication initiative.

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Duintjer Tebbens, Radboud J; Pallansch, Mark A; Cochi, Stephen L; Wassilak, Steven G F; Linkins, Jennifer; Sutter, Roland W; Aylward, R Bruce; Thompson, Kimberly M

2010-12-16

The global polio eradication initiative (GPEI), which started in 1988, represents the single largest, internationally coordinated public health project to date. Completion remains within reach, with type 2 wild polioviruses apparently eradicated since 1999 and fewer than 2000 annual paralytic poliomyelitis cases of wild types 1 and 3 reported since then. This economic analysis of the GPEI reflects the status of the program as of February 2010, including full consideration of post-eradication policies. For the GPEI intervention, we consider the actual pre-eradication experience to date followed by two distinct potential future post-eradication vaccination policies. We estimate GPEI costs based on actual and projected expenditures and poliomyelitis incidence using reported numbers corrected for underreporting and model projections. For the comparator, which assumes only routine vaccination for polio historically and into the future (i.e., no GPEI), we estimate poliomyelitis incidence using a dynamic infection transmission model and costs based on numbers of vaccinated children. Cost-effectiveness ratios for the GPEI vs. only routine vaccination qualify as highly cost-effective based on standard criteria. We estimate incremental net benefits of the GPEI between 1988 and 2035 of approximately 40-50 billion dollars (2008 US dollars; 1988 net present values). Despite the high costs of achieving eradication in low-income countries, low-income countries account for approximately 85% of the total net benefits generated by the GPEI in the base case analysis. The total economic costs saved per prevented paralytic poliomyelitis case drive the incremental net benefits, which become positive even if we estimate the loss in productivity as a result of disability as below the recommended value of one year in average per-capita gross national income per disability-adjusted life year saved. Sensitivity analysis suggests that the finding of positive net benefits of the GPEI remains

Particulate matter air pollution disrupts endothelial cell barrier via calpain-mediated tight junction protein degradation

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Wang Ting

2012-08-01

Full Text Available Abstract Background Exposure to particulate matter (PM is a significant risk factor for increased cardiopulmonary morbidity and mortality. The mechanism of PM-mediated pathophysiology remains unknown. However, PM is proinflammatory to the endothelium and increases vascular permeability in vitro and in vivo via ROS generation. Objectives We explored the role of tight junction proteins as targets for PM-induced loss of lung endothelial cell (EC barrier integrity and enhanced cardiopulmonary dysfunction. Methods Changes in human lung EC monolayer permeability were assessed by Transendothelial Electrical Resistance (TER in response to PM challenge (collected from Ft. McHenry Tunnel, Baltimore, MD, particle size >0.1 μm. Biochemical assessment of ROS generation and Ca2+ mobilization were also measured. Results PM exposure induced tight junction protein Zona occludens-1 (ZO-1 relocation from the cell periphery, which was accompanied by significant reductions in ZO-1 protein levels but not in adherens junction proteins (VE-cadherin and β-catenin. N-acetyl-cysteine (NAC, 5 mM reduced PM-induced ROS generation in ECs, which further prevented TER decreases and atteneuated ZO-1 degradation. PM also mediated intracellular calcium mobilization via the transient receptor potential cation channel M2 (TRPM2, in a ROS-dependent manner with subsequent activation of the Ca2+-dependent protease calpain. PM-activated calpain is responsible for ZO-1 degradation and EC barrier disruption. Overexpression of ZO-1 attenuated PM-induced endothelial barrier disruption and vascular hyperpermeability in vivo and in vitro. Conclusions These results demonstrate that PM induces marked increases in vascular permeability via ROS-mediated calcium leakage via activated TRPM2, and via ZO-1 degradation by activated calpain. These findings support a novel mechanism for PM-induced lung damage and adverse cardiovascular outcomes.

Eradication of common mynas Acridotheres tristis from Denis Island, Seychelles

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Feare, Chris J.; van der woude, Jildou; Greenwell, Phill; Edwards, Hannah A.; Taylor, Jenni A.; Larose, Christine S.; Ahlen, Per-Arne; West, Jack; Chadwick, Will; Pandey, Smita; Raines, Katherine; Garcia, Fernando; Komdeur, Jan; de Groene, Arjan

BACKGROUND: In Seychelles, the common myna has been shown to have a negative impact on endangered endemic birds on Denis Island, interfering with breeding attempts and attacking adult endemic birds at their nests. This stimulated an attempt to eradicate the island's mynas. RESULTS: The eradication

Can Economic Analysis Contribute to Disease Elimination and Eradication? A Systematic Review.

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Sicuri, Elisa; Evans, David B; Tediosi, Fabrizio

2015-01-01

Infectious diseases elimination and eradication have become important areas of focus for global health and countries. Due to the substantial up-front investments required to eliminate and eradicate, and the overall shortage of resources for health, economic analysis can inform decision making on whether elimination/eradication makes economic sense and on the costs and benefits of alternative strategies. In order to draw lessons for current and future initiatives, we review the economic literature that has addressed questions related to the elimination and eradication of infectious diseases focusing on: why, how and for whom? A systematic review was performed by searching economic literature (cost-benefit, cost-effectiveness and economic impact analyses) on elimination/eradication of infectious diseases published from 1980 to 2013 from three large bibliographic databases: one general (SCOPUS), one bio-medical (MEDLINE/PUBMED) and one economic (IDEAS/REPEC). A total of 690 non-duplicate papers were identified from which only 43 met the inclusion criteria. In addition, only one paper focusing on equity issues, the "for whom?" question, was found. The literature relating to "why?" is the largest, much of it focusing on how much it would cost. A more limited literature estimates the benefits in terms of impact on economic growth with mixed results. The question of how to eradicate or eliminate was informed by an economic literature highlighting that there will be opportunities for individuals and countries to free-ride and that forms of incentives and/or disincentives will be needed. This requires government involvement at country level and global coordination. While there is little doubt that eliminating infectious diseases will eventually improve equity, it will only happen if active steps to promote equity are followed on the path to elimination and eradication. The largest part of the literature has focused on costs and economic benefits of elimination/eradication

Trends in the eradication rates of Helicobacter pylori infection for eleven years

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Yoon, Jai Hoon; Baik, Gwang Ho; Sohn, Kyoung Min; Kim, Dae Yong; Kim, Yeon Soo; Suk, Ki Tae; Kim, Jin Bong; Kim, Dong Joon; Kim, Jin Bae; Shin, Woon Geon; Kim, Hak Yang; Baik, Il Hyun; Jang, Hyun Joo

2012-01-01

AIM: To evaluate the trends in the eradication rate of Helicobacter pylori (H. pylori) over the past 11 years in a single center. METHODS: This retrospective study covered the period from January 2000 to December 2010. We evaluated 5746 patients diagnosed with gastric ulcers (GU), duodenal ulcers (DU), GU + DU, or nonpeptic ulcers associated with an H. pylori infection. We treated them annually with the 2 wk standard first-line triple regimen, proton pump inhibitor (PPI) + amoxicilin + clarithromycin (PAC; PPI, clarithromycin 500 mg, and amoxicillin 1 g, all twice a day). The follow-up test was performed at least 4 wk after the completion of the 2 wk standard H. pylori eradication using the PAC regimen. We also assessed the eradication rates of 1 wk second-line therapy with a quadruple standard regimen (PPI b.i.d., tripotassium dicitrate bismuthate 300 mg q.i.d., metronidazole 500 mg t.i.d., and tetracycline 500 mg q.i.d.) after the failure of the first-line therapy. Statistical analysis was performed with 95%CI for the differences in the annual eradication rates. RESULTS: A total of 5746 patients [2333 males (58.8%), 1636 females (41.2%); mean age of males vs females 51.31 ± 13.1 years vs 52.76 ± 13.6 years, P < 0.05, total mean age 51.9 ± 13.3 years (mean ± SD)] were investigated. Among these patients, 1674 patients were excluded: 35 patients refused treatment; 18 patients ceased H. pylori eradication due to side effects; 1211 patients had inappropriate indications for H. pylori eradication, having undergone stomach cancer operation or chemotherapy; and 410 patients did not undergo the follow-up. We also excluded 103 patients who wanted to stop eradication treatment after only 1 wk due to poor compliance or the side effects mentioned above. Finally, we evaluated the annual eradication success rates in a total of 3969 patients who received 2 wk first-line PAC therapy. The endoscopic and clinical findings in patients who received the 2 wk PAC were as follows

Chemical biology based on target-selective degradation of proteins and carbohydrates using light-activatable organic molecules.

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Toshima, Kazunobu

2013-05-01

Proteins and carbohydrates play crucial roles in a wide range of biological processes, including serious diseases. The development of novel and innovative methods for selective control of specific proteins and carbohydrates functions has attracted much attention in the field of chemical biology. In this account article, the development of novel chemical tools, which can degrade target proteins and carbohydrates by irradiation with a specific wavelength of light under mild conditions without any additives, is introduced. This novel class of photochemical agents promise bright prospects for finding not only molecular-targeted bioprobes for understanding of the structure-activity relationships of proteins and carbohydrates but also novel therapeutic drugs targeting proteins and carbohydrates.

Degradation and detection of transgenic Bacillus thuringiensis DNA and proteins in flour of three genetically modified rice events submitted to a set of thermal processes.

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Wang, Xiaofu; Chen, Xiaoyun; Xu, Junfeng; Dai, Chen; Shen, Wenbiao

2015-10-01

This study aimed to investigate the degradation of three transgenic Bacillus thuringiensis (Bt) genes (Cry1Ab, Cry1Ac, and Cry1Ab/Ac) and the corresponding encoded Bt proteins in KMD1, KF6, and TT51-1 rice powder, respectively, following autoclaving, cooking, baking, or microwaving. Exogenous Bt genes were more stable than the endogenous sucrose phosphate synthase (SPS) gene, and short DNA fragments were detected more frequently than long DNA fragments in both the Bt and SPS genes. Autoclaving, cooking (boiling in water, 30 min), and baking (200 °C, 30 min) induced the most severe Bt protein degradation effects, and Cry1Ab protein was more stable than Cry1Ac and Cry1Ab/Ac protein, which was further confirmed by baking samples at 180 °C for different periods of time. Microwaving induced mild degradation of the Bt and SPS genes, and Bt proteins, whereas baking (180 °C, 15 min), cooking and autoclaving led to further degradation, and baking (200 °C, 30 min) induced the most severe degradation. The findings of the study indicated that degradation of the Bt genes and proteins somewhat correlated with the treatment intensity. Polymerase chain reaction, enzyme-linked immunosorbent assay, and lateral flow tests were used to detect the corresponding transgenic components. Strategies for detecting transgenic ingredients in highly processed foods are discussed. Copyright © 2015 Elsevier Ltd. All rights reserved.

Altered methylation and expression of ER-associated degradation factors in long-term alcohol and constitutive ER stress-induced murine hepatic tumors

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Hui eHan

2013-10-01

Full Text Available Mortality from liver cancer in humans is increasingly attributable to heavy or long-term alcohol consumption. The mechanisms by which alcohol exerts its carcinogenic effect are not well understood. In this study, the role of alcohol-induced endoplasmic reticulum (ER stress response in liver cancer development was investigated using an animal model with a liver knockout of the chaperone BiP and under constitutive hepatic ER stress. Long-term alcohol and high fat diet (HFD feeding resulted in higher levels of serum alanine aminotransferase (ALT, impaired ER stress response, and higher incidence of liver tumor in older (aged 16 months knockout females than in either middle-aged (6 months knockouts or older (aged 16 months wild type females. In the older knockout females, stronger effects of the alcohol on methylation of CpG islands at promoter regions of genes involved in the ER associated degradation (ERAD were also detected. Altered expression of ERAD factors including derlin 3, Creld2 (cysteine-rich with EGF-like domains 2, Herpud1 (ubiquitin-like domain member, Wfs1 (wolfram syndrome gene, and Yod1 (deubiquinating enzyme 1 was co-present with decreased proteasome activities, increased estrogen receptor alpha variant (ERa36, and enhanced phosphorylations of ERK1/2 (extracellular signal-regulated protein kinases 1 and 2 and STAT3 (the signal transducers and activators of transcription in the older knockout female fed alcohol. Our results suggest that long-term alcohol consumption and ageing may promote liver tumorigenesis in females through interfering with DNA methylation and expression of genes involved in the ER associated degradation.

Protein degradation in skeletal muscle during experimental hyperthyroidism in rats and the effect of beta-blocking agents.

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Angerås, U; Hasselgren, P O

1987-04-01

beta-Blocking agents are increasingly used in the management of hyperthyroid patients. The effect of this treatment on increased muscle protein breakdown in the hyperthyroid state is not known. In the present study, experimental hyperthyroidism was induced in rats by daily ip injections of T3 (100 micrograms/100 g BW) during a 10-day period. Control animals received corresponding volumes of solvent. In groups of rats the selective beta-1-blocking agent metoprolol or the nonselective beta-blocker propranolol was infused by miniosmotic pumps implanted sc on the backs of the animals. Protein degradation was measured in incubated intact soleus and extensor digitorum longus muscles by determining tyrosine release into the incubation medium. The protein degradation rate in incubated extensor digitorum longus and soleus muscles was increased by 50-60% during T3 treatment. Metoprolol or propranolol did not influence muscle protein breakdown in either T3-treated or control animals. The results suggest that T3-induced increased muscle proteolysis is not mediated by beta-receptors, and muscle weakness and wasting in hyperthyroidism might not be affected by beta-blockers.

The structural determinants responsible for c-Fos protein proteasomal degradation differ according to the conditions of expression.

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Ferrara, Patrizia; Andermarcher, Elisabetta; Bossis, Guillaume; Acquaviva, Claire; Brockly, Frédérique; Jariel-Encontre, Isabelle; Piechaczyk, Marc

2003-03-13

c-fos gene is expressed constitutively in a number of tissues as well as in certain tumor cells and is inducible, in general rapidly and transiently, in virtually all other cell types by a variety of stimuli. Its protein product, c-Fos, is a short-lived transcription factor that heterodimerizes with various protein partners within the AP-1 transcription complex via leucine zipper/leucine zipper interactions for binding to specific DNA sequences. It is mostly, if not exclusively, degraded by the proteasome. To localize the determinant(s) responsible for its instability, we have conducted a genetic analysis in which the half-lives of c-Fos mutants and chimeras made with the stable EGFP reporter protein were compared under two experimental conditions taken as example of continous and inducible expression. Those were constitutive expression in asynchronously growing Balb/C 3T3 mouse embryo fibroblasts and transient induction in the same cells undergoing the G0/G1 phase transition upon stimulation by serum. Our work shows that c-Fos is degraded faster in synchronous- than in asynchronous cells. This difference in turnover is primarily accounted for by several mechanisms. First, in asynchronous cells, a unique C-terminal destabilizer is active whereas, in serum-stimulated cells two destabilizers located at both extremities of the protein are functional. Second, heterodimerization and/or binding to DNA accelerates protein degradation only during the G0/G1 phase transition. Adding another level of complexity to turnover control, phosphorylation at serines 362 and 374, which are c-Fos phosphorylation sites largely modified during the G0/G1 phase transition, stabilizes c-Fos much more efficiently in asynchronous than in serum-stimulated cells. In both cases, the reduced degradation rate is due to inhibition of the activity of the C-terminal destabilizer. However, in serum-stimulated cells, this effect is partially masked by the activation of the N-terminal destabilizer and

Influence of vitamin C and E supplementation on the eradication rates of triple and quadruple eradication regimens for Helicobacter pylori infection.

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Demirci, Hakan; Uygun İlikhan, Sevil; Öztürk, Kadir; Üstündağ, Yücel; Kurt, Ömer; Bilici, Muammer; Köktürk, Furuzan; Uygun, Ahmet

2015-11-01

In our study, we aimed to assess the effect of vitamin E and C supplementation to triple and quadruple Helicobacter pylori eradication regimens. Four hundred patients with H. pylori infection were classified into four groups. Patients in group A (n=100) received amoxicillin, clarithromycin, and lansoprazole for 2 weeks. In group B, patients (n=100) received vitamins C and E for a month, in addition to amoxicillin, clarithromycin, and lansoprazole for 2 weeks. Patients in group C (n=100) received amoxicillin, clarithromycin, lansoprazole, and bismuth subcitrate for 2 weeks, whereas those in group D (n=100) received vitamins C and E for a month, in addition to amoxicillin, clarithromycin, lansoprazole, and bismuth subcitrate for 2 weeks. H. pylori eradication was assessed with the C14 urea breath test 2 months after the end of the therapy. The eradication rate was assessed using per-protocol (PP) and intention-to-treat (ITT) analyses. Three hundred forty-eight patients finished the study. The eradication of H. pylori was achieved in 63 of 84 patients (75%) by PP and 63 of 100 (63%) by ITT analysis in group A, 60 of 84 (71.4%) by PP and 60 of 100 (60%) by ITT analysis in group B, 72 of 89 (80.9 %) by PP and 72 of 100 (72%) by ITT analysis in group C, and 76 of 91 (83.5%) by PP and 76 of 100 (76%) by ITT analysis in group D. There was no remarkable change between groups A and B (p>0.05). Similar results were also found between groups D and C (p>0.05). This study revealed that supplementing vitamins C and E to either the triple or quadruple therapies did not provide an additional advantage for achieving significantly higher eradication rates for H. pylori.

Effect of prolonged intravenous glucose and essential amino acid infusion on nitrogen balance, muscle protein degradation and ubiquitin-conjugating enzyme gene expression in calves

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Scaife Jes R

2008-02-01

Full Text Available Abstract Background Intravenous infusions of glucose and amino acids increase both nitrogen balance and muscle accretion. We hypothesised that co-infusion of glucose (to stimulate insulin and essential amino acids (EAA would act additively to improve nitrogen balance by decreasing muscle protein degradation in association with alterations in muscle expression of components of the ubiquitin-proteasome proteolytic pathway. Methods We examined the effect of a 5 day intravenous infusions of saline, glucose, EAA and glucose + EAA, on urinary nitrogen excretion and muscle protein degradation. We carried out the study in 6 restrained calves since ruminants offer the advantage that muscle protein degradation can be assessed by excretion of 3 methyl-histidine and multiple muscle biopsies can be taken from the same animal. On the final day of infusion blood samples were taken for hormone and metabolite measurement and muscle biopsies for expression of ubiquitin, the 14-kDa E2 ubiquitin conjugating enzyme, and proteasome sub-units C2 and C8. Results On day 5 of glucose infusion, plasma glucose, insulin and IGF-1 concentrations were increased while urea nitrogen excretion and myofibrillar protein degradation was decreased. Co-infusion of glucose + EAA prevented the loss of urinary nitrogen observed with EAA infusions alone and enhanced the increase in plasma IGF-1 concentration but there was no synergistic effect of glucose + EAA on the decrease in myofibrillar protein degradation. Muscle mRNA expression of the ubiquitin conjugating enzyme, 14-kDa E2 and proteasome sub-unit C2 were significantly decreased, after glucose but not amino acid infusions, and there was no further response to the combined infusions of glucose + EAA. Conclusion Prolonged glucose infusion decreases myofibrillar protein degradation, prevents the excretion of infused EAA, and acts additively with EAA to increase plasma IGF-1 and improve net nitrogen balance. There was no evidence of

A dynamic study of protein secretion and aggregation in the secretory pathway.

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Mossuto, Maria Francesca; Sannino, Sara; Mazza, Davide; Fagioli, Claudio; Vitale, Milena; Yoboue, Edgar Djaha; Sitia, Roberto; Anelli, Tiziana

2014-01-01

Precise coordination of protein biogenesis, traffic and homeostasis within the early secretory compartment (ESC) is key for cell physiology. As a consequence, disturbances in these processes underlie many genetic and chronic diseases. Dynamic imaging methods are needed to follow the fate of cargo proteins and their interactions with resident enzymes and folding assistants. Here we applied the Halotag labelling system to study the behavior of proteins with different fates and roles in ESC: a chaperone, an ERAD substrate and an aggregation-prone molecule. Exploiting the Halo property of binding covalently ligands labelled with different fluorochromes, we developed and performed non-radioactive pulse and chase assays to follow sequential waves of proteins in ESC, discriminating between young and old molecules at the single cell level. In this way, we could monitor secretion and degradation of ER proteins in living cells. We can also follow the biogenesis, growth, accumulation and movements of protein aggregates in the ESC. Our data show that protein deposits within ESC grow by sequential apposition of molecules up to a given size, after which novel seeds are detected. The possibility of using ligands with distinct optical and physical properties offers a novel possibility to dynamically follow the fate of proteins in the ESC.

A dynamic study of protein secretion and aggregation in the secretory pathway.

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Maria Francesca Mossuto

Full Text Available Precise coordination of protein biogenesis, traffic and homeostasis within the early secretory compartment (ESC is key for cell physiology. As a consequence, disturbances in these processes underlie many genetic and chronic diseases. Dynamic imaging methods are needed to follow the fate of cargo proteins and their interactions with resident enzymes and folding assistants. Here we applied the Halotag labelling system to study the behavior of proteins with different fates and roles in ESC: a chaperone, an ERAD substrate and an aggregation-prone molecule. Exploiting the Halo property of binding covalently ligands labelled with different fluorochromes, we developed and performed non-radioactive pulse and chase assays to follow sequential waves of proteins in ESC, discriminating between young and old molecules at the single cell level. In this way, we could monitor secretion and degradation of ER proteins in living cells. We can also follow the biogenesis, growth, accumulation and movements of protein aggregates in the ESC. Our data show that protein deposits within ESC grow by sequential apposition of molecules up to a given size, after which novel seeds are detected. The possibility of using ligands with distinct optical and physical properties offers a novel possibility to dynamically follow the fate of proteins in the ESC.

The putative Agrobacterium transcriptional activator-like virulence protein VirD5 may target T-complex to prevent the degradation of coat proteins in the plant cell nucleus.

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Wang, Yafei; Peng, Wei; Zhou, Xu; Huang, Fei; Shao, Lingyun; Luo, Meizhong

2014-09-01

Agrobacterium exports at least five virulence proteins (VirE2, VirE3, VirF, VirD2, VirD5) into host cells and hijacks some host plant factors to facilitate its transformation process. Random DNA binding selection assays (RDSAs), electrophoretic mobility shift assays (EMSAs) and yeast one-hybrid systems were used to identify protein-bound DNA elements. Bimolecular fluorescence complementation, glutathione S-transferase pull-down and yeast two-hybrid assays were used to detect protein interactions. Protoplast transformation, coprecipitation, competitive binding and cell-free degradation assays were used to analyze the relationships among proteins. We found that Agrobacterium VirD5 exhibits transcriptional activation activity in yeast, is located in the plant cell nucleus, and forms homodimers. A specific VirD5-bound DNA element designated D5RE (VirD5 response element) was identified. VirD5 interacted directly with Arabidopsis VirE2 Interacting Protein 1 (AtVIP1). However, the ternary complex of VirD5-AtVIP1-VirE2 could be detected, whereas that of VirD5-AtVIP1-VBF (AtVIP1 Binding F-box protein) could not. We demonstrated that VirD5 competes with VBF for binding to AtVIP1 and stabilizes AtVIP1 and VirE2 in the cell-free degradation system. Our results indicated that VirD5 may act as both a transcriptional activator-like effector to regulate host gene expression and a protector preventing the coat proteins of the T-complex from being quickly degraded by the host's ubiquitin proteasome system (UPS). © 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.

Delaying aging and the aging-associated decline in protein homeostasis by inhibition of tryptophan degradation

NARCIS (Netherlands)

van der Goot, Annemieke T.; Zhu, Wentao; Vazquez-Manrique, Rafael P.; Seinstra, Renee I.; Dettmer, Katja; Michels, Helen; Farina, Francesca; Krijnen, Jasper; Melki, Ronald; Buijsman, Rogier C.; Silva, Mariana Ruiz; Thijssen, Karen L.; Kema, Ido P.; Neri, Christian; Oefner, Peter J.; Nollen, Ellen A. A.

2012-01-01

Toxicity of aggregation-prone proteins is thought to play an important role in aging and age-related neurological diseases like Parkinson and Alzheimer's diseases. Here, we identify tryptophan 2,3-dioxygenase (tdo-2), the first enzyme in the kynurenine pathway of tryptophan degradation, as a

Protein oxidation and degradation during proliferative senescence of human MRC-5 fibroblasts.

Science.gov (United States)

Sitte, N; Merker, K; von Zglinicki, T; Grune, T

2000-03-01

One of the highlights of age-related changes of cellular metabolism is the accumulation of oxidized proteins. The aging process on a cellular level can be treated either as the ongoing proliferation until a certain number of cell divisions is reached (the Hayflick limit) or as the aging of nondividing cells, that is, the age-related changes in cells without proliferation. The present investigation was undertaken to reveal the changes in protein turnover, proteasome activity, and protein oxidation status during proliferative senescence. We were able to demonstrate that the activity of the cytosolic proteasomal system declines dramatically during the proliferative senescence of human MRC-5 fibroblasts. Regardless of the loss in activity, it could be demonstrated that there are no changes in the transcription and translation of proteasomal subunits. This decline in proteasome activity was accompanied by an increased concentration of oxidized proteins. Cells at higher proliferation stages were no longer able to respond with increased degradation of endogenous [(35)S]-Met-radiolabeled proteins after hydrogen peroxide- or quinone-induced oxidative stress. It could be demonstrated that oxidized proteins in senescent human MRC-5 fibroblasts are not as quickly removed as they are in young cells. Therefore, our study demonstrates that the accumulation of oxidized proteins and decline in protein turnover and activity of the proteasomal system are not only a process of postmitotic aging but also occur during proliferative senescence and result in an increased half-life of oxidized proteins.

Anti-nutritional Factors and Ruminal Dry Matter and Crude Protein Degradability of Gamma and Microwave Irradiated Native Rapeseed

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sayyed roohollah ebrahimimahmoudabad

2016-08-01

Full Text Available Introduction Native rapeseed (NRS is planted in some parts of Iran because of climatic condition. The consumption of NRS in animal nutrition is limited by anti-nutritional such as phytic acid and glucosinolate. Moreover, the protein of NRS is highly degraded by rumen microorganisms. Several processing methods have been used to enhance the nutritive value of whole oilseeds, including extrusion, roasting, toasting and Jet-Sploding. However, most heat processing methods adversely affect protein digestibility in the small intestine. Recently, other processing methods such as processing by gamma and microwave irradiation have been noticed. Therefore, this research was carried out to evaluate the effects of gamma irradiation (15, 30 and 45 kGy and microwave irradiation (800 W for 2, 4 and 6 min on ruminal dry matter (DM and crude protein (CP degradability, in vitro CP digestibility, anti-nutritional factors (glucosinolate and phytic acid and chemical composition of NRS. Materials and Methods Chemical composition (DM, CP, EE and Ash of untreated and irradiated NRS was determined by AOAC methods. Then, sufficient water was added to the sample to increase the moisture content to 250 g/kg. Gamma irradiation was completed by using a cobalt-60 irradiator at 20 ºC. The dose rate determined by Fricke dosimetry was 0.36 Gy/s. Another three samples (500 g each were subjected to microwave irradiation at a power of 800 W for 2, 4 and 6 min. Phytic acid and glucosinolate contents of untreated and irradiated samples were determined by standard methods. Degradation kinetics of DM or CP were determined according to in situ procedure. Six grams of untreated or irradiated NRS were incubated in the rumen of three ruminally fistulated Taleshi bulls for 0, 2, 4, 8, 16, 24 and 48 h. Bags were placed in the rumen just before the bulls were offered their first meal. After retrieval from the rumen, bags were thoroughly washed with tap water until the rinsing water was clear

The Mexican Fruit Fly Eradication Programme

Energy Technology Data Exchange (ETDEWEB)

Reyes F, Jesus; Santiago M, Guillermo; Hernandez M, Porfirio [Comision Nacional de Sanidad Agropecuaria (Mexico)

2000-07-01

The goal of the Mexican Fruit Fly Eradication Programme is to control, suppress or eradicate from Mexico four species of fruit flies of economic and quarantine importance (Anastrepha ludens Loew, A. obliqua Macquart, A. serpentina Wied. and A. striata Schiner). These pests cause damage amounting to US$710 million per year. In addition to this cost, there are other expenses from pest control actions and the loss of international markets, because fruit importing countries have established stringent quarantine measures to restrict the entry of these pests. For purposes of the programme's implementation, Mexico was divided into three working zones, defined by agro-ecological characteristics, the number of fruit fly species present and the size of fruit growing regions. In addition, a cost:benefit analysis was carried out which indicated that the rate of return, in a 12-year time frame, might be as much as 33:1 in Northern Mexico, and 17:1 in the rest of the country, for an area over 100,000 hectares. Eradication technology involves: 1) surveys of pest populations by trapping and host fruit harvesting to monitor the presence and density of fruit flies, 2) reduction of pest populations applying cultural practices and using selective bait sprays, 3) mass release of sterile flies and augmentative release of parasitoids to eliminate populations and, 4) enforcement of quarantine measures to protect fruit fly free areas.

The Mexican Fruit Fly Eradication Programme

International Nuclear Information System (INIS)

Reyes F, Jesus; Santiago M, Guillermo; Hernandez M, Porfirio

2000-01-01

The goal of the Mexican Fruit Fly Eradication Programme is to control, suppress or eradicate from Mexico four species of fruit flies of economic and quarantine importance (Anastrepha ludens Loew, A. obliqua Macquart, A. serpentina Wied. and A. striata Schiner). These pests cause damage amounting to US$710 million per year. In addition to this cost, there are other expenses from pest control actions and the loss of international markets, because fruit importing countries have established stringent quarantine measures to restrict the entry of these pests. For purposes of the programme's implementation, Mexico was divided into three working zones, defined by agro-ecological characteristics, the number of fruit fly species present and the size of fruit growing regions. In addition, a cost:benefit analysis was carried out which indicated that the rate of return, in a 12-year time frame, might be as much as 33:1 in Northern Mexico, and 17:1 in the rest of the country, for an area over 100,000 hectares. Eradication technology involves: 1) surveys of pest populations by trapping and host fruit harvesting to monitor the presence and density of fruit flies, 2) reduction of pest populations applying cultural practices and using selective bait sprays, 3) mass release of sterile flies and augmentative release of parasitoids to eliminate populations and, 4) enforcement of quarantine measures to protect fruit fly free areas

Saturated fatty acid palmitate negatively regulates autophagy by promoting ATG5 protein degradation in meniscus cells.

Science.gov (United States)

Mallik, Aritra; Yammani, Raghunatha R

2018-07-20

Obesity and associated metabolic factors are major risk factors for the development of osteoarthritis. Previously, we have shown that the free fatty acid palmitate induces endoplasmic reticulum (ER) stress and induces apoptosis in meniscus cells. However, the molecular mechanisms involved in these effects are not clearly understood. In our current study, we found that palmitate inhibits autophagy by modulating the protein levels of autophagy-related genes-5 (ATG5) that is associated with decreased lipidation of LC3 and increased activation of cleaved caspase 3. Pretreatment of meniscus cells with 4-phenyl butyric acid, a small molecule chemical chaperone that alleviates ER stress, or with MG-132, a proteasome inhibitor, restored normal levels of ATG5 and autophagosome formation, and decreased expression of cleaved caspase 3. Thus, our data suggest that palmitate downregulates autophagy in meniscus cells by degrading ATG5 protein via ER-associated protein degradation, and thus promotes apoptosis. This is the first study to demonstrate that palmitate-induced endoplasmic reticulum stress negatively regulates autophagy. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Effective rumen degradation of dry matter, crude protein and neutral detergent fibre in forage determined by near infrared reflectance spectroscopy

DEFF Research Database (Denmark)

Ohlsson, C; Houmøller, L P; Weisbjerg, Martin Riis

2007-01-01

The objective of the present study was to examine if near infrared reflectance spectroscopy (NIRS) could be used to predict degradation parameters and effective degradation from scans of original forage samples. Degradability of dry matter (DM), crude protein (CP) and neutral detergent fibre (NDF......) of 61 samples of perennial ryegrass (Lolium perenne L.) and orchardgrass (Dactylis glomerata L.) was tested by using the in situ technique. The grass samples were harvested at three different stages, early vegetative growth, early reproductive growth and late reproductive growth. Degradability...

Polio eradication is just over the horizon: the challenges of global resource mobilization.

Science.gov (United States)

Pirio, Gregory Alonso; Kaufmann, Judith

2010-01-01

This study draws lessons from the resource mobilization experiences of the Global Polio Eradication Initiative (GPEI). As the GPEI launched its eradication effort in 1988, it underestimated both the difficulty and the costs of the campaign. Advocacy for resource mobilization came as an afterthought in the late 1990s, when achieving eradication by the target date of 2000 began to look doubtful. The reality of funding shortfalls undercutting eradication leads to the conclusion that advocacy for resource mobilization is as central to operations as are scientific and technical factors.

Degradation of p53 by human Alphapapillomavirus E6 proteins shows a stronger correlation with phylogeny than oncogenicity.

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Leiping Fu

2010-09-01

Full Text Available Human Papillomavirus (HPV E6 induced p53 degradation is thought to be an essential activity by which high-risk human Alphapapillomaviruses (alpha-HPVs contribute to cervical cancer development. However, most of our understanding is derived from the comparison of HPV16 and HPV11. These two viruses are relatively distinct viruses, making the extrapolation of these results difficult. In the present study, we expand the tested strains (types to include members of all known HPV species groups within the Alphapapillomavirus genus.We report the biochemical activity of E6 proteins from 27 HPV types representing all alpha-HPV species groups to degrade p53 in human cells. Expression of E6 from all HPV types epidemiologically classified as group 1 carcinogens significantly reduced p53 levels. However, several types not associated with cancer (e.g., HPV53, HPV70 and HPV71 were equally active in degrading p53. HPV types within species groups alpha 5, 6, 7, 9 and 11 share a most recent common ancestor (MRCA and all contain E6 ORFs that degrade p53. A unique exception, HPV71 E6 ORF that degraded p53 was outside this clade and is one of the most prevalent HPV types infecting the cervix in a population-based study of 10,000 women. Alignment of E6 ORFs identified an amino acid site that was highly correlated with the biochemical ability to degrade p53. Alteration of this amino acid in HPV71 E6 abrogated its ability to degrade p53, while alteration of this site in HPV71-related HPV90 and HPV106 E6s enhanced their capacity to degrade p53.These data suggest that the alpha-HPV E6 proteins' ability to degrade p53 is an evolved phenotype inherited from a most recent common ancestor of the high-risk species that does not always segregate with carcinogenicity. In addition, we identified an amino-acid residue strongly correlated with viral p53 degrading potential.

Effect on Helicobacter pylori eradication therapy against gastric cancer in Japan.

Science.gov (United States)

Tsuda, Momoko; Asaka, Masahiro; Kato, Mototsugu; Matsushima, Rumiko; Fujimori, Kenji; Akino, Kozo; Kikuchi, Shogo; Lin, Yingsong; Sakamoto, Naoya

2017-10-01

In Japan, there have been approximately 50 000 deaths from gastric cancer annually for over 40 years with little variation. It has been reported that most gastric cancers in Japan are caused by Helicobacter pylori infection. H. pylori eradication therapy was approved for patients with chronic gastritis by the Japanese national health insurance scheme in February 2013 for patients with an endoscopic diagnosis of chronic gastritis is positive for H. pylori. We examined the effect on gastric cancer death rate 4 years after expansion of health insurance coverage. We conducted an epidemiological study and analyzed trends in prescription for H. pylori eradication therapy. We used the electronic medical claims database from Hokkaido, Japan to evaluate the impact of expansion of national health insurance coverage for H. pylori eradication therapy on deaths from gastric cancer. Data on deaths from gastric cancer were obtained from the Japanese Ministry of Health, Labour and Welfare and the Cancer Statistics in Japan (2015). Analysis of electronic claims records was performed using the National Database, mainly focusing on Hokkaido. Prescriptions for H. pylori eradication therapy and the number of patients treated for gastric cancer were also extracted from the Hokkaido database. Approximately 1.5 million prescriptions for H. pylori eradication therapy were written annually. Gastric cancer deaths fell each year: 48 427 in 2013, 47 903 in 2014, 46 659 in 2015, and 45 509 in 2016, showing a significant decrease after expansion of insurance coverage for H. pylori eradication therapy (Ppylori eradication therapy increased markedly after approval of the gastritis indication by the national health insurance scheme and was associated with a significant decrease in gastric cancer deaths. © 2017 The Authors. Helicobacter Published by John Wiley & Sons Ltd.

Protein degradation systems in the skeletal muscles of parr and smolt Atlantic salmon Salmo salar L. and brown trout Salmo trutta L.

Science.gov (United States)

Kantserova, Nadezda P; Lysenko, Liudmila A; Veselov, Alexey E; Nemova, Nina N

2017-08-01

Although protein degradation limits the rate of muscle growth in fish, the role of proteolytic systems responsible for degrading myofibrillar proteins in skeletal muscle is not well defined. The study herein aims to evaluate the role of calpains (calcium-activated proteases) and proteasomes (ATP-dependent proteases) in mediating muscle protein turnover at different life stages in wild salmonids. Protease activities were estimated in Atlantic salmon (Salmo salar L.) and brown trout (Salmo trutta L.) parr and smolts from the Indera River (Kola Peninsula, Russia). Calpain and proteasome activities in Atlantic salmon skeletal muscles were lower in smolts as compared with parr. Reduced muscle protein degradation accompanying Atlantic salmon parr-smolt transformation appeared to provide intense muscle growth essential for a minimum threshold size achievement that is required for smoltification. Calpain and proteasome activities in brown trout parr and smolts at age 3+ did not significantly differ. However, calpain activity was higher in smolts brown trout 4+ as compared with parr, while proteasome activity was lower. Results suggest that brown trout smoltification does not correspond with intense muscle growth and is more facultative and plastic in comparison with Atlantic salmon smoltification. Obtained data on muscle protein degradation capacity as well as length-weight parameters of fish reflect differences between salmon and trout in growth and smoltification strategies.

Modulation of type I interferon induction by porcine reproductive and respiratory syndrome virus and degradation of CREB-binding protein by non-structural protein 1 in MARC-145 and HeLa cells

International Nuclear Information System (INIS)

Kim, Oekyung; Sun Yan; Lai, Frances W.; Song Cheng; Yoo, Dongwan

2010-01-01

Porcine reproductive and respiratory syndrome (PRRS) is an emerged disease of swine characterized by negligible response of type I IFNs and viral persistence. We show that the PRRSV non-structural protein 1 (Nsp1) is the viral component responsible for modulation of IFN response. Nsp1 blocked dsRNA-induced IRF3 and IFN promoter activities. Nsp1 did not block phosphorylation and nuclear translocation of IRF3 but inhibited IRF3 association with CREB-binding protein (CBP) in the nucleus. While IRF3 was stable, CBP was degraded, and CBP degradation was proteasome-dependent, suggesting that CBP degradation is not due to the protease activity of Nsp1 but an intermediary is involved. Our data suggest that the Nsp1-mediated CBP degradation inhibits the recruitment of CBP for enhanceosome assembly, leading to the block of IFN response. CBP degradation is a novel strategy for viral evasion from the host response, and Nsp1 may form a new class of viral antagonists for IFN modulation.

In situ ruminal crude protein degradability of by-products from cereals, oilseeds and animal origin

NARCIS (Netherlands)

Habib, G.; Khan, N.A.; Ali, M.; Bezabih, M.

2013-01-01

The aim of this study was to establish a database on in situ ruminal crude protein (CP) degradability characteristics of by-products from cereal grains, oilseeds and animal origin commonly fed to ruminants in Pakistan and South Asian Countries. The oilseed by-products were soybean meal, sunflower

Artemisinin disrupts androgen responsiveness of human prostate cancer cells by stimulating the 26S proteasome-mediated degradation of the androgen receptor protein.

Science.gov (United States)

Steely, Andrea M; Willoughby, Jamin A; Sundar, Shyam N; Aivaliotis, Vasiliki I; Firestone, Gary L

2017-10-01

Androgen receptor (AR) expression and activity is highly linked to the development and progression of prostate cancer and is a target of therapeutic strategies for this disease. We investigated whether the antimalarial drug artemisinin, which is a sesquiterpene lactone isolated from the sweet wormwood plant Artemisia annua, could alter AR expression and responsiveness in cultured human prostate cancer cell lines. Artemisinin treatment induced the 26S proteasome-mediated degradation of the receptor protein, without altering AR transcript levels, in androgen-responsive LNCaP prostate cancer cells or PC-3 prostate cancer cells expressing exogenous wild-type AR. Furthermore, artemisinin stimulated AR ubiquitination and AR receptor interactions with the E3 ubiquitin ligase MDM2 in LNCaP cells. The artemisinin-induced loss of AR protein prevented androgen-responsive cell proliferation and ablated total AR transcriptional activity. The serine/threonine protein kinase AKT-1 was shown to be highly associated with artemisinin-induced proteasome-mediated degradation of AR protein. Artemisinin treatment activated AKT-1 enzymatic activity, enhanced receptor association with AKT-1, and induced AR serine phosphorylation. Treatment of LNCaP cells with the PI3-kinase inhibitor LY294002, which inhibits the PI3-kinase-dependent activation of AKT-1, prevented the artemisinin-induced AR degradation. Furthermore, in transfected receptor-negative PC-3 cells, artemisinin failed to stimulate the degradation of an altered receptor protein (S215A/S792A) with mutations in its two consensus AKT-1 serine phosphorylation sites. Taken together, our results indicate that artemisinin induces the degradation of AR protein and disrupts androgen responsiveness of human prostate cancer cells, suggesting that this natural compound represents a new potential therapeutic molecule that selectively targets AR levels.

Hydrothermal degradation of cellulosic matter to sugars and their fermentative conversion to protein

International Nuclear Information System (INIS)

Bobleter, O.; Niesner, R.; Roehr, M.

1976-01-01

For the hydrothermal degradation of cellulosic matter, an apparatus was developed in which water is used as extraction medium. Samples, 0.15 g each, of pure cellulose (filter paper), natural straw, and 14 C-labeled straw were treated at temperatures of between 200 and 275 0 C. Of the inserted cellulose, 65.7 percent was recovered at the optimum temperature as sugars and hydroxymethylfurfural. It was possible to degrade the straw selectively: at lower temperatures, the hemicellulose part of the plant matter was converted to xylose and arabinose; and then at higher temperatures, the cellulose was converted to glucose and cellobiose. At the same time, a certain amount of the sugars was transformed to furfural compounds. The growth behavior of the yeast Candida utilis (strain Weissenbach) was analyzed, using cellobiose, xylose, and glucose (standard) as carbon sources. The growth curves applying cellobiose were nearly identical to those of glucose. Xylose showed lower productivity than the hexoses. The main products of the hydrothermal degradation can, therefore, be used favorably as nutritive substances for this protein-producing yeast

Trafficking and degradation pathways in pathogenic conversion of prions and prion-like proteins in neurodegenerative diseases.

Science.gov (United States)

Victoria, Guiliana Soraya; Zurzolo, Chiara

2015-09-02

Several neurodegenerative diseases such as transmissible spongiform encephalopathies, Alzheimer's and Parkinson's diseases are caused by the conversion of cellular proteins to a pathogenic conformer. Despite differences in the primary structure and subcellular localization of these proteins, which include the prion protein, α-synuclein and amyloid precursor protein (APP), striking similarity has been observed in their ability to seed and convert naïve protein molecules as well as transfer between cells. This review aims to cover what is known about the intracellular trafficking of these proteins as well as their degradation mechanisms and highlight similarities in their movement through the endocytic pathway that could contribute to the pathogenic conversion and seeding of these proteins which underlies the basis of these diseases. Copyright © 2015 Elsevier B.V. All rights reserved.

Chemical composition and ruminal degradation kinetics of crude protein and amino acids, and intestinal digestibility of amino acids from tropical forages

Directory of Open Access Journals (Sweden)

Lidia Ferreira Miranda

2012-03-01

Full Text Available The objective of this research was to determine the chemical composition and ruminal degradation of the crude protein (CP, total and individual amino acids of leaves from tropical forages: perennial soybean (Neonotonia wightii, cassava (Manihot esculenta, leucaena (Leucaena leucocephala and ramie (Boehmeria nivea, and to estimate the intestinal digestibility of the rumen undegradable protein (RUDP and individual amino acids of leaves from the tropical forages above cited, but including pigeon pea (Cajanus cajan. Three nonlactating Holstein cows were used to determine the in situ ruminal degradability of protein and amino acids from leaves (6, 18 and 48 hours of ruminal incubation. For determination of the intestinal digestibility of RUDP, the residue from ruminal incubation of the materials was used for 18 hours. A larger concentration of total amino acids for ramie and smaller for perennial soybean were observed; however, they were very similar in leucaena and cassava. Leucine was the essential amino acid of greater concentration, with the exception of cassava, which exhibited a leucine concentration 40.45% smaller. Ramie showed 14.35 and 22.31% more lysine and methionine, respectively. The intestinal digestibility of RUDP varied from 23.56; 47.87; 23.48; 25.69 and 10.86% for leucaena, perennial soybean, cassava, ramie and pigeon pea, respectively. The individual amino acids of tropical forage disappeared in different extensions in the rumen. For the correct evaluation of those forages, one should consider their composition of amino acids, degradations and intestinal digestibility, once the amino acid composition of the forage does not reflect the amino acid profiles that arrived in the small intestine. Differences between the degradation curves of CP and amino acids indicate that degradation of amino acids cannot be estimated through the degradation curve of CP, and that amino acids are not degraded in a similar degradation profile.

Helicobacter pylori eradication and reflux disease onset: did gastric acid get "crazy"?

Science.gov (United States)

Zullo, Angelo; Hassan, Cesare; Repici, Alessandro; Bruzzese, Vincenzo

2013-02-14

Gastroesophageal reflux disease (GORD) is highly prevalent in the general population. In the last decade, a potential relationship between Helicobacter pylori (H. pylori) eradication and GORD onset has been claimed. The main putative mechanism is the gastric acid hypersecretion that develops after bacterial cure in those patients with corpus-predominant gastritis. We performed a critical reappraisal of the intricate pathogenesis and clinical data available in this field. Oesophagitis onset after H. pylori eradication in duodenal ulcer patients has been ascribed to a gastric acid hypersecretion, which could develop following body gastritis healing. However, the absence of an acid hypersecretive status in these patients is documented by both pathophysiology and clinical studies. Indeed, duodenal ulcer recurrence is virtually abolished following H. pylori eradication. In addition, intra-oesophageal pH recording studies failed to demonstrated increased acid reflux following bacterial eradication. Moreover, oesophageal manometric studies suggest that H. pylori eradication would reduce--rather than favor--acid reflux into the oesophagus. Finally, data of clinical studies would suggest that H. pylori eradication is not significantly associated with either reflux symptoms or erosive oesophagitis onset, some data suggesting also an advantage in curing the infection when oesophagitis is already present. Therefore, the legend of "crazy acid" remains--as all the others--a fascinating, but imaginary tale.

In Vitro Ruminal Degradability of Soybean Meal Protein Protected with Natural Tannin

Science.gov (United States)

Prasetiyono, B. W. H. E.; Subrata, A.; Tampoebolon, B. I. M.; Surono; Widiyanto

2018-02-01

The influence of tannin from tea waste and gambier as natural tannin sources on ruminal protein degradability was studied in this investigation. The soybean meal was used as protein source in this investigation. There were three treatments in this investigation mainly without protection (NT); protection with tea waste (Tt); and protection with gambier (Tg). The measured parameters consisted of in vitro dry matter digestibility (IVDMD), in vitro organic matter digestibility (IVOMD), and the ruminal fermentation characteristics. Results of this experiment showed that protection with tannin from tea waste as well as gambier increased (pRUP) in Tt and Tg group was higher than that in NT group (66.29 and 69.20 vs 51.10%). The ruminal protozoa population decreased (pRUP. The ruminal protozoa population and ammonia concentration, on the other hand, were decreased by tannin protection from those tannin natural sources. The natural tannin from gambier was the most effective protection agent for soybean meal protein.

NSs Virulence Factor of Rift Valley Fever Virus Engages the F-Box Proteins FBXW11 and β-TRCP1 To Degrade the Antiviral Protein Kinase PKR.

Science.gov (United States)

Kainulainen, Markus; Lau, Simone; Samuel, Charles E; Hornung, Veit; Weber, Friedemann

2016-07-01

Rift Valley fever virus (RVFV, family Bunyaviridae, genus Phlebovirus) is a relevant pathogen of both humans and livestock in Africa. The nonstructural protein NSs is a major virulence factor known to suppress the type I interferon (IFN) response by inhibiting host cell transcription and by proteasomal degradation of a major antiviral IFN effector, the translation-inhibiting protein kinase PKR. Here, we identified components of the modular SCF (Skp1, Cul1, F-box protein)-type E3 ubiquitin ligases as mediators of PKR destruction by NSs. Small interfering RNAs (siRNAs) against the conserved SCF subunit Skp1 protected PKR from NSs-mediated degradation. Consequently, RVFV replication was severely reduced in Skp1-depleted cells when PKR was present. SCF complexes have a variable F-box protein subunit that determines substrate specificity for ubiquitination. We performed an siRNA screen for all (about 70) human F-box proteins and found FBXW11 to be involved in PKR degradation. The partial stabilization of PKR by FBXW11 depletion upregulated PKR autophosphorylation and phosphorylation of the PKR substrate eIF2α and caused a shutoff of host cell protein synthesis in RVFV-infected cells. To maximally protect PKR from the action of NSs, knockdown of structurally and functionally related FBXW1 (also known as β-TRCP1), in addition to FBXW11 deletion, was necessary. Consequently, NSs was found to interact with both FBXW11 and β-TRCP1. Thus, NSs eliminates the antiviral kinase PKR by recruitment of SCF-type E3 ubiquitin ligases containing FBXW11 and β-TRCP1 as substrate recognition subunits. This antagonism of PKR by NSs is essential for efficient RVFV replication in mammalian cells. Rift Valley fever virus is a pathogen of humans and animals that has the potential to spread from Africa and the Arabian Peninsula to other regions. A major virulence mechanism is the proteasomal degradation of the antiviral kinase PKR by the viral protein NSs. Here, we demonstrate that NSs

A critical role for protein degradation in the nucleus accumbens core in cocaine reward memory.

Science.gov (United States)

Ren, Zhen-Yu; Liu, Meng-Meng; Xue, Yan-Xue; Ding, Zeng-Bo; Xue, Li-Fen; Zhai, Suo-Di; Lu, Lin

2013-04-01

The intense associative memories that develop between cocaine-paired contexts and rewarding stimuli contribute to cocaine seeking and relapse. Previous studies have shown impairment in cocaine reward memories by manipulating a labile state induced by memory retrieval, but the mechanisms that underlie the destabilization of cocaine reward memory are unknown. In this study, using a Pavlovian cocaine-induced conditioned place preference (CPP) procedure in rats, we tested the contribution of ubiquitin-proteasome system-dependent protein degradation in destabilization of cocaine reward memory. First, we found that polyubiquitinated protein expression levels and polyubiquitinated N-ethylmaleimide-sensitive fusion (NSF) markedly increased 15 min after retrieval while NSF protein levels decreased 1 h after retrieval in the synaptosomal membrane fraction in the nucleus accumbens (NAc) core. We then found that infusion of the proteasome inhibitor lactacystin into the NAc core prevented the impairment of memory reconsolidation induced by the protein synthesis inhibitor anisomycin and reversed the effects of anisomycin on NSF and glutamate receptor 2 (GluR2) protein levels in the synaptosomal membrane fraction in the NAc core. We also found that lactacystin infusion into the NAc core but not into the shell immediately after extinction training sessions inhibited CPP extinction and reversed the extinction training-induced decrease in NSF and GluR2 in the synaptosomal membrane fraction in the NAc core. Finally, infusions of lactacystin by itself into the NAc core immediately after each training session or before the CPP retrieval test had no effect on the consolidation and retrieval of cocaine reward memory. These findings suggest that ubiquitin-proteasome system-dependent protein degradation is critical for retrieval-induced memory destabilization.

Global polio eradication initiative: lessons learned and legacy.

Science.gov (United States)

Cochi, Stephen L; Freeman, Andrew; Guirguis, Sherine; Jafari, Hamid; Aylward, Bruce

2014-11-01

The world is on the verge of achieving global polio eradication. During >25 years of operations, the Global Polio Eradication Initiative (GPEI) has mobilized and trained millions of volunteers, social mobilizers, and health workers; accessed households untouched by other health initiatives; mapped and brought health interventions to chronically neglected and underserved communities; and established a standardized, real-time global surveillance and response capacity. It is important to document the lessons learned from polio eradication, especially because it is one of the largest ever global health initiatives. The health community has an obligation to ensure that these lessons and the knowledge generated are shared and contribute to real, sustained changes in our approach to global health. We have summarized what we believe are 10 leading lessons learned from the polio eradication initiative. We have the opportunity and obligation to build a better future by applying the lessons learned from GPEI and its infrastructure and unique functions to other global health priorities and initiatives. In so doing, we can extend the global public good gained by ending for all time one of the world's most devastating diseases by also ensuring that these investments provide public health dividends and benefits for years to come. Published by Oxford University Press on behalf of the Infectious Diseases Society of America 2014. This work is written by (a) US Government employee(s) and is in the public domain in the US.

Endoplasmic Reticulum-Associated rht-PA Processing in CHO Cells: Influence of Mild Hypothermia and Specific Growth Rates in Batch and Chemostat Cultures.

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Mauricio Vergara

Full Text Available Chinese hamster ovary (CHO cells are the main host for producing recombinant proteins with human therapeutic applications mainly because of their capability to perform proper folding and glycosylation processes. In addition, mild hypothermia is one of the main strategies for maximising the productivity of these systems. However, little information is available on the effect of culture temperature on the folding and degradation processes of recombinant proteins that takes place in the endoplasmic reticulum.In order to evaluate the effect of the mild hypothermia on processing/endoplasmatic reticulum-associated degradation (ERAD processes, batch cultures of CHO cells producing recombinant human tissue plasminogen activator (rht-PA were carried out at two temperatures (37°C and 33°C and treated with specific inhibitors of glycosylation and ERAD I (Ubiquitin/Proteasome system or ERAD II (Autophagosoma/Lisosomal system pathways. The effect of mild hypothermia was analysed separately from its indirect effect on specific cell growth rate. To do this, chemostat cultures were carried out at the same incubation conditions as the batch cultures, controlling cell growth at high (0.017 h-1 and low (0.012 h-1 dilution rates. For a better understanding of the investigated phenomenon, cell behaviour was also analysed using principal component analysis (PCA.Results suggest that rht-PA is susceptible to degradation by both ERAD pathways studied, revealing that processing and/or ERAD processes are sensitive to temperature cultivation in batch culture. Moreover, by isolating the effect of culture temperature from the effect of cell growth rate verifyed by using chemostat cultures, we have found that processing and/or ERAD processes are more sensitive to reduction in specific growth rate than low temperature, and that temperature reduction may have a positive effect on protein processing. Interestingly, PCA indicated that the integrated performance displayed by CHO

Progress Toward Poliomyelitis Eradication--Afghanistan, January 2014‒August 2015.

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Mbaeyi, Chukwuma; Saatcioglu, Akif; Tangermann, Rudolf H; Hadler, Stephen; Ehrhardt, Derek

2015-10-23

Despite recent progress toward global polio eradication, endemic transmission of wild poliovirus (WPV) continues to be reported in Afghanistan and Pakistan. The Afghanistan program must overcome many challenges to remain on track toward achieving the objectives set in the 2013–2018 strategic plan of the Global Polio Eradication Initiative (GPEI). Cross-border transmission of WPV type 1 (WPV1) continues to occur among children traveling to and from Pakistan. The country's routine immunization system remains weak and unable to reach recommended benchmarks in most regions; hence, the national Polio Eradication Initiative (PEI) relies mainly on providing children aged <5 years with oral poliovirus vaccine (OPV), administered during supplementary immunization activities (SIAs). Because of ongoing conflict and insecurity, some children continue to be missed during SIAs in areas not under government control; however, the majority of missed children live in accessible areas and are often unreached because of a failure to plan, implement, and supervise SIAs efficiently. This report describes polio eradication activities and progress in Afghanistan during January 2014‒August 2015 and updates previous reports. During 2014, a total of 28 WPV1 cases were reported in Afghanistan, compared with 14 cases in 2013; nine cases were reported during January‒August 2015, the same number as during the same period in 2014. To eliminate poliovirus transmission in Afghanistan, emergency operations centers (EOCs) need to be established at the national level and in critical regions without delay to improve overall coordination and oversight of polio eradication activities. The recently revised National Emergency Action Plan for polio eradication needs to be fully implemented, including detailed microplanning and enhanced monitoring and supervision of SIAs, as well as improved cross-border coordination with Pakistan.

Probiotics in Helicobacter pylori eradication therapy: Systematic review and network meta-analysis.

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Wang, Fan; Feng, Juerong; Chen, Pengfei; Liu, Xiaoping; Ma, Minxing; Zhou, Rui; Chang, Ying; Liu, Jing; Li, Jin; Zhao, Qiu

2017-09-01

Several probiotics were effective in the eradication treatment for Helicobacter pylori (Hp), but their comparative efficacy was unknown. To compare the efficacy of different probiotics when supplemented in Hp eradication therapy. A comprehensive search was conducted to identify all relevant studies in multiple databases and previous meta-analyses. Bayesian network meta-analysis was performed to combine direct and indirect evidence and estimate the relative effects. One hundred and forty studies (44 English and 96 Chinese) were identified with a total of 20,215 patients, and more than 10 probiotic strategies were supplemented in Hp eradication therapy. The rates of eradication and adverse events were 84.1 and 14.4% in probiotic group, while 70.5 and 30.1% in the control group. In general, supplementary probiotics were effective in improving the efficacy of Hp eradication and decreasing the incidence of adverse events, despite of few ineffective subtypes. In triple eradication therapy, there was no significant difference among the effective probiotics, and combined probiotics did not show a better efficacy and tolerance than single use. In triple therapy of 7 days and 14 days, Lactobacillus acidopilus was a slightly better choice, while Saccharomyces boulardii was more applicable for 10-day triple therapy. Compared to placebo, most probiotic strategies were effective when supplemented in Hp eradication therapy. In triple eradication therapy, no probiotic showed a superior efficacy to the others. Compared to single use, combined probiotics could not improve the efficacy or tolerance significantly. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

"Why we could not eradicate polio from pakistan and how can we?"

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Shah, Syed Zawar; Saad, Muhammad; Rahman Khattak, Mohammad Hasan; Rizwan, Muhammad; Haidari, Asma; Idrees, Fatima

2016-01-01

Polio is a major health problem and a deadly infectious disease in the developing countries. It is a viral illness caused by polio virus that can lead to paralysis, limb deformities, breathing problems or even death. Polio virus resides only in humans and passes on to the environment in the faeces of someone who is infected. Polio is still endemic in three countries, i.e., Pakistan, Nigeria and Afghanistan and is eradicated from the rest of the world. Pakistan is considered as the exporter of Wild Polio Virus (WPV) with highest number of polio outbreaks among endemic countries. With the start of World Polio Eradication Initiative in 1988, the number of polio cases has been reduced up to 99% worldwide until now. In 2015, Pakistan has shown a decrease of 70-75% in number of polio cases as compare to last year which is the result of good government's initiatives. Militant organizations such as Tehreek-e-Taliban Pakistan, Al-Qaeda and Boko haram movement of northern Nigeria are a major hurdle in the eradication of polio from these countries. The misconception of people about polio vaccine, insecurity within the country and poor health system are the reasons of failure of polio eradication campaigns in these regions. Awareness campaigns about polio for locals and development of proper health system will help in the eradication of polio. Once polio is eradicated, about 40-50 billion dollars can be saved globally. With the strong commitment, seriousness and good initiatives, polio will be eradicated from Pakistan within two years more likely.

Probiotics as an adjuvant treatment in Helicobacter pylori eradication therapy.

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Zhu, Xin Yan; Liu, Fei

2017-04-01

Over 80% of individuals infected with Helicobacter pylori (H. pylori) are asymptomatic. Increased resistance to antibiotics and decreased compliance to the therapeutic regimens have led to the failure of eradication therapy. Probiotics, with direct and indirect inhibitory effects on H. pylori in both animal models and clinical trials, have recently been used as a supplementary treatment in H. pylori eradication therapy. Probiotics have been considered useful because of the improvements in H. pylori eradication rates and therapy-related side effects although treatment outcomes using probiotics are controversial due to the heterogeneity of species, strains, doses and therapeutic duration of probiotics. Thus, despite the positive role of probiotics, several factors need to be further considered during their applications. Moreover, adverse events of probiotic use need to be noted. Further investigations into the safety of adjuvant probiotics to H. pylori eradication therapy are required. © 2017 Chinese Medical Association Shanghai Branch, Chinese Society of Gastroenterology, Renji Hospital Affiliated to Shanghai Jiaotong University School of Medicine and John Wiley & Sons Australia, Ltd.

Abscisic acid-regulated protein degradation causes osmotic stress-induced accumulation of branched-chain amino acids in Arabidopsis thaliana.

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Huang, Tengfang; Jander, Georg

2017-10-01

Whereas proline accumulates through de novo biosynthesis in plants subjected to osmotic stress, leucine, isoleucine, and valine accumulation in drought-stressed Arabidopsis thaliana is caused by abscisic acid-regulated protein degradation. In response to several kinds of abiotic stress, plants greatly increase their accumulation of free amino acids. Although stress-induced proline increases have been studied the most extensively, the fold-increase of other amino acids, in particular branched-chain amino acids (BCAAs; leucine, isoleucine, and valine), is often higher than that of proline. In Arabidopsis thaliana (Arabidopsis), BCAAs accumulate in response to drought, salt, mannitol, polyethylene glycol, herbicide treatment, and nitrogen starvation. Plants that are deficient in abscisic acid signaling accumulate lower amounts of BCAAs, but not proline and most other amino acids. Previous bioinformatic studies had suggested that amino acid synthesis, rather than protein degradation, is responsible for the observed BCAA increase in osmotically stressed Arabidopsis. However, whereas treatment with the protease inhibitor MG132 decreased drought-induced BCAA accumulation, inhibition of BCAA biosynthesis with the acetolactate synthase inhibitors chlorsulfuron and imazapyr did not. Additionally, overexpression of BRANCHED-CHAIN AMINO ACID TRANSFERASE2 (BCAT2), which is upregulated in response to osmotic stress and functions in BCAA degradation, decreased drought-induced BCAA accumulation. Together, these results demonstrate that BCAA accumulation in osmotically stressed Arabidopsis is primarily the result of protein degradation. After relief of the osmotic stress, BCAA homeostasis is restored over time by amino acid degradation involving BCAT2. Thus, drought-induced BCAA accumulation is different from that of proline, which is accumulated due to de novo synthesis in an abscisic acid-independent manner and remains elevated for a more prolonged period of time after removal of

Retinoblastoma protein co-purifies with proteasomal insulin-degrading enzyme: Implications for cell proliferation control

Energy Technology Data Exchange (ETDEWEB)

Radulescu, Razvan T., E-mail: ratura@gmx.net [Molecular Concepts Research (MCR), Muenster (Germany); Duckworth, William C. [Department of Medicine, Phoenix VA Health Care System, Phoenix, AZ (United States); Levy, Jennifer L. [Research Service, Phoenix VA Health Care System, Phoenix, AZ (United States); Fawcett, Janet, E-mail: janet.fawcett@va.gov [Research Service, Phoenix VA Health Care System, Phoenix, AZ (United States)

2010-04-30

Previous investigations on proteasomal preparations containing insulin-degrading enzyme (IDE; EC 3.4.24.56) have invariably yielded a co-purifying protein with a molecular weight of about 110 kDa. We have now found both in MCF-7 breast cancer and HepG2 hepatoma cells that this associated molecule is the retinoblastoma tumor suppressor protein (RB). Interestingly, the amount of RB in this protein complex seemed to be lower in HepG2 vs. MCF-7 cells, indicating a higher (cytoplasmic) protein turnover in the former vs. the latter cells. Moreover, immunofluorescence showed increased nuclear localization of RB in HepG2 vs. MCF-7 cells. Beyond these subtle differences between these distinct tumor cell types, our present study more generally suggests an interplay between RB and IDE within the proteasome that may have important growth-regulatory consequences.

Progress toward poliomyelitis eradication - Nigeria, January 2011-September 2012.

Science.gov (United States)

2012-11-09

In 1988, the World Health Assembly launched the Global Polio Eradication Initiative (GPEI) and, in 2012, declared the completion of polio eradication a programmatic emergency for global public health. To date, wild poliovirus (WPV) cases reported worldwide in 2012 are at historically low levels. Nigeria is one of only three countries with uninterrupted WPV transmission (in addition to Pakistan and Afghanistan) and has been the origin of WPV imported into 25 previously polio-free countries since 2003. This report updates previous reports and describes polio eradication activities and progress in Nigeria during January 2011-September 2012, as of October 30, 2012. The number of reported WPV cases increased from 21 in 2010 to 62 in 2011. During January-September 2012, a total of 99 WPV cases were reported, more than doubling from the 42 cases reported during the same period in 2011. During 2011, a total of 32 circulating vaccine-derived polio virus type 2 (cVDPV2) cases were confirmed; six cVDPV2 cases were confirmed during January-September 2012, compared with 18 cVDPV2 cases during the same period in 2011. Nigeria's 2012 Polio Eradication Emergency Plan includes senior government leadership oversight, new program management and strategic initiatives, an accountability framework, and a surge in human resources to address chronically missed children during supplemental immunization activities (SIAs).* In 2012, indicators of immunization campaign quality show modest improvements; available data indicate gaps in surveillance. Continuing WPV transmission in Nigeria poses an ongoing risk for WPV reintroduction and outbreaks in polio-free countries and is a major obstacle to achieving global eradication.

Ruminal and intestinal protein degradability of various seaweed species measured in situ in dairy cows

DEFF Research Database (Denmark)

Tayyab, Usama; Novoa-Garrido, Margarita; Roleda, Michael Y.

2016-01-01

, Laminaria, Mastocarpus, Palmaria, Pelvetia, Porphyra, and Ulva were sampled in spring (March) and autumn (October and November) 2014 at the coast of Bodø in Northern Norway, and were analysed for chemical composition, in situ rumen degradability and total tract crude protein (CP) digestibility. Ash content......The use of seaweeds in animal diets is not new. However, little is known about the feed value of seaweed, both in terms of chemical composition and protein digestibility, and regarding variation between species and season. In this study, eight seaweed species of the genus Acrosiphonia, Alaria....../kg CP). Digestible rumen escape protein (DEP) varied significantly between species (P Laminaria, Mastocarpus and Palmaria can supply...

A Programme for the Eradication of the New World Screwworm from North Africa

Energy Technology Data Exchange (ETDEWEB)

NONE

1990-04-15

The recent establishment of the New World Screwworm (NWS), Cochliomyia hominivorax, in North Africa poses an enormous threat to that continent, as well as the Mediterranean Basin and the Middle East. Because of the urgent need to initiate an eradication programme as soon as possible, three consultants met in Vienna from 8 to 19 January 1990 to prepare a programme outlining the eradication of the NWS from North Africa. Emphasis was placed on the Sterile Insect Technique (SIT) portion of an eradication programme. At the time the report was prepared the NWS had been reported only from Libya, therefore the report deals with eradication from that country. The document will be used by the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture as a guide to assist FAO in NWS eradication from North Africa.

A Programme for the Eradication of the New World Screwworm from North Africa

International Nuclear Information System (INIS)

1990-04-01

The recent establishment of the New World Screwworm (NWS), Cochliomyia hominivorax, in North Africa poses an enormous threat to that continent, as well as the Mediterranean Basin and the Middle East. Because of the urgent need to initiate an eradication programme as soon as possible, three consultants met in Vienna from 8 to 19 January 1990 to prepare a programme outlining the eradication of the NWS from North Africa. Emphasis was placed on the Sterile Insect Technique (SIT) portion of an eradication programme. At the time the report was prepared the NWS had been reported only from Libya, therefore the report deals with eradication from that country. The document will be used by the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture as a guide to assist FAO in NWS eradication from North Africa.

Tau protein degradation is catalyzed by the ATP/ubiquitin-independent 20S proteasome under normal cell conditions

OpenAIRE

Grune, Tilman; Botzen, Diana; Engels, Martina; Voss, Peter; Kaiser, Barbara; Jung, Tobias; Grimm, Stefanie; Ermak, Gennady; Davies, Kelvin J. A.

2010-01-01

Tau is the major protein exhibiting intracellular accumulation in Alzheimer disease. The mechanisms leading to its accumulation are not fully understood. It has been proposed that the proteasome is responsible for degrading tau but, since proteasomal inhibitors block both the ubiquitin-dependent 26S proteasome and the ubiqutin-independent 20S proteasome pathways, it is not clear which of these pathways is involved in tau degradation. Some involvement of the ubiquitin ligase, CHIP in tau degra...

Investing in justice: ethics, evidence, and the eradication investment cases for lymphatic filariasis and onchocerciasis.

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Bailey, Theodore C; Merritt, Maria W; Tediosi, Fabrizio

2015-04-01

It has been suggested that initiatives to eradicate specific communicable diseases need to be informed by eradication investment cases to assess the feasibility, costs, and consequences of eradication compared with elimination or control. A methodological challenge of eradication investment cases is how to account for the ethical importance of the benefits, burdens, and distributions thereof that are salient in people's experiences of the diseases and related interventions but are not assessed in traditional approaches to health and economic evaluation. We have offered a method of ethical analysis grounded in theories of social justice. We have described the method and its philosophical rationale and illustrated its use in application to eradication investment cases for lymphatic filariasis and onchocerciasis, 2 neglected tropical diseases that are candidates for eradication.

Lessons for Implementation from the World's Most Successful Programme: The Global Eradication of Smallpox.

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Pratt, David

1999-01-01

Focuses on lessons educators might learn from the Intensified Campaign for the Global Eradication of Smallpox. Outlines the history of smallpox eradication. Discusses the eradication effort's obstacles, campaign, and costs and benefits. Considers five factors relevant to the successful implementation of educational programs. (CMK)

Calcitriol Inhibits HCV Infection via Blockade of Activation of PPAR and Interference with Endoplasmic Reticulum-Associated Degradation

Directory of Open Access Journals (Sweden)

Yu-Min Lin

2018-01-01

Full Text Available Vitamin D has been identified as an innate anti-hepatitis C virus (HCV agent but the possible mechanisms for this issue remain unclear. Here, we clarified the mechanisms of calcitriol-mediated inhibition of HCV infection. Calcitriol partially inhibited HCV infection, nitric oxide (NO release and lipid accumulation in Huh7.5 human hepatoma cells via the activation of vitamin D receptor (VDR. When cells were pretreated with the activators of peroxisome proliferator-activated receptor (PPAR-α (Wy14643 and -γ (Ly171883, the calcitriol-mediated HCV suppression was reversed. Otherwise, three individual stimulators of PPAR-α/β/γ blocked the activation of VDR. PPAR-β (linoleic acid reversed the inhibition of NO release, whereas PPAR-γ (Ly171883 reversed the inhibitions of NO release and lipid accumulation in the presence of calcitriol. The calcitriol-mediated viral suppression, inhibition of NO release and activation of VDR were partially blocked by an inhibitor of endoplasmic reticulum-associated degradation (ERAD, kifunensine. Furthermore, calcitriol blocked the HCV-induced expressions of apolipoprotein J and 78 kDa glucose-regulated protein, which was restored by pretreatment of kifunensine. These results indicated that the calcitriol-mediated HCV suppression was associated with the activation of VDR, interference with ERAD process, as well as blockades of PPAR, lipid accumulation and nitrative stress.

Quantifying the impact of expanded age group campaigns for polio eradication.

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Wagner, Bradley G; Behrend, Matthew R; Klein, Daniel J; Upfill-Brown, Alexander M; Eckhoff, Philip A; Hu, Hao

2014-01-01

A priority of the Global Polio Eradication Initiative (GPEI) 2013-2018 strategic plan is to evaluate the potential impact on polio eradication resulting from expanding one or more Supplementary Immunization Activities (SIAs) to children beyond age five-years in polio endemic countries. It has been hypothesized that such expanded age group (EAG) campaigns could accelerate polio eradication by eliminating immunity gaps in older children that may have resulted from past periods of low vaccination coverage. Using an individual-based mathematical model, we quantified the impact of EAG campaigns in terms of probability of elimination, reduction in polio transmission and age stratified immunity levels. The model was specifically calibrated to seroprevalence data from a polio-endemic region: Zaria, Nigeria. We compared the impact of EAG campaigns, which depend only on age, to more targeted interventions which focus on reaching missed populations. We found that EAG campaigns would not significantly improve prospects for polio eradication; the probability of elimination increased by 8% (from 24% at baseline to 32%) when expanding three annual SIAs to 5-14 year old children and by 18% when expanding all six annual SIAs. In contrast, expanding only two of the annual SIAs to target hard-to-reach populations at modest vaccination coverage-representing less than one tenth of additional vaccinations required for the six SIA EAG scenario-increased the probability of elimination by 55%. Implementation of EAG campaigns in polio endemic regions would not improve prospects for eradication. In endemic areas, vaccination campaigns which do not target missed populations will not benefit polio eradication efforts.

Hepatitis C virus induces E6AP-dependent degradation of the retinoblastoma protein.

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Tsubasa Munakata

2007-09-01

Full Text Available Hepatitis C virus (HCV is a positive-strand RNA virus that frequently causes persistent infections and is uniquely associated with the development of hepatocellular carcinoma. While the mechanism(s by which the virus promotes cancer are poorly defined, previous studies indicate that the HCV RNA-dependent RNA polymerase, nonstructural protein 5B (NS5B, forms a complex with the retinoblastoma tumor suppressor protein (pRb, targeting it for degradation, activating E2F-responsive promoters, and stimulating cellular proliferation. Here, we describe the mechanism underlying pRb regulation by HCV and its relevance to HCV infection. We show that the abundance of pRb is strongly downregulated, and its normal nuclear localization altered to include a major cytoplasmic component, following infection of cultured hepatoma cells with either genotype 1a or 2a HCV. We further demonstrate that this is due to NS5B-dependent ubiquitination of pRb and its subsequent degradation via the proteasome. The NS5B-dependent ubiquitination of pRb requires the ubiquitin ligase activity of E6-associated protein (E6AP, as pRb abundance was restored by siRNA knockdown of E6AP or overexpression of a dominant-negative E6AP mutant in cells containing HCV RNA replicons. E6AP also forms a complex with pRb in an NS5B-dependent manner. These findings suggest a novel mechanism for the regulation of pRb in which the HCV NS5B protein traps pRb in the cytoplasm, and subsequently recruits E6AP to this complex in a process that leads to the ubiquitination of pRb. The disruption of pRb/E2F regulatory pathways in cells infected with HCV is likely to promote hepatocellular proliferation and chromosomal instability, factors important for the development of liver cancer.

Lysosomal degradation of membrane lipids.

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Kolter, Thomas; Sandhoff, Konrad

2010-05-03

The constitutive degradation of membrane components takes place in the acidic compartments of a cell, the endosomes and lysosomes. Sites of lipid degradation are intralysosomal membranes that are formed in endosomes, where the lipid composition is adjusted for degradation. Cholesterol is sorted out of the inner membranes, their content in bis(monoacylglycero)phosphate increases, and, most likely, sphingomyelin is degraded to ceramide. Together with endosomal and lysosomal lipid-binding proteins, the Niemann-Pick disease, type C2-protein, the GM2-activator, and the saposins sap-A, -B, -C, and -D, a suitable membrane lipid composition is required for degradation of complex lipids by hydrolytic enzymes. Copyright 2009 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

Polerovirus protein P0 prevents the assembly of small RNA-containing RISC complexes and leads to degradation of ARGONAUTE1.

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Csorba, Tibor; Lózsa, Rita; Hutvágner, György; Burgyán, József

2010-05-01

RNA silencing plays an important role in plants in defence against viruses. To overcome this defence, plant viruses encode suppressors of RNA silencing. The most common mode of silencing suppression is sequestration of double-stranded RNAs involved in the antiviral silencing pathways. Viral suppressors can also overcome silencing responses through protein-protein interaction. The poleroviral P0 silencing suppressor protein targets ARGONAUTE (AGO) proteins for degradation. AGO proteins are the core component of the RNA-induced silencing complex (RISC). We found that P0 does not interfere with the slicer activity of pre-programmed siRNA/miRNA containing AGO1, but prevents de novo formation of siRNA/miRNA containing AGO1. We show that the AGO1 protein is part of a high-molecular-weight complex, suggesting the existence of a multi-protein RISC in plants. We propose that P0 prevents RISC assembly by interacting with one of its protein components, thus inhibiting formation of siRNA/miRNA-RISC, and ultimately leading to AGO1 degradation. Our findings also suggest that siRNAs enhance the stability of co-expressed AGO1 in both the presence and absence of P0.

Global eradication of measles: Are we poised?

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Raghavendra D Kulkarni

2017-01-01

Full Text Available Measles, a highly infectious viral disease is the next target for eradication following poliovirus. Decades of experience with highly effective vaccination has invigorated us to take on this virus. The task is not only Titanic but is laced with intricate issues. Recently, an outbreak of fever with rash occurred on a tertiary care teaching hospital campus and was confirmed serologically as measles outbreak by IgMELISA. Therefore, we searched the literature related to outbreaks, transmission of the measles virus, age groups involved, vaccination strategies, vaccination failure and epidemiological features of the disease and reviewed the possible reasons for such outbreaks and problems in the global eradication of the virus.

Lessons learned during the successful eradication of bovine tuberculosis from Australia

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More, S. J.; Radunz, B.; Glanville, R. J.

2015-01-01

There are very few international examples of the successful eradication of bovine tuberculosis (TB, caused by infection with Mycobacterium bovis) from a national cattle population. This paper presents a brief overview of the successful TB eradication programme in Australia from 1970, with primary emphasis on lessons of international relevance that were learned from the Australian experience. The national brucellosis and tuberculosis eradication campaign ran for 27 years from 1970 to 1997 and has been followed by ongoing abattoir surveillance. Rapid progress towards eradication was made in southern Australia, but proved much more challenging in extensive pastoral areas of northern Australia. Declaration of TB freedom was made on December 31, 1997. A range of factors were critical to this success, including a compelling rationale for eradication, an agreed final outcome, industry commitment and financial support, a business model for programme planning, implementation and review, consistent and transparent technical standards underpinned by a strict regulatory regime and applied research, the critical role of abattoir surveillance, effective elimination of residual infection and objective measures of programme progress. Although direct translation of some of these experiences may not be possible, many of the lessons learned from the Australian experience may be relevant to other countries. PMID:26338937

Developing strategies for HIV-1 eradication

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Durand, Christine M.; Blankson, Joel N.; Siliciano, Robert F.

2014-01-01

Highly active antiretroviral therapy (HAART) suppresses HIV-1 replication, transforming the outlook for infected patients. However, reservoirs of replication-competent forms of the virus persist during HAART, and when treatment is stopped, high rates of HIV-1 replication return. Recent insights into HIV-1 latency, as well as a report that HIV-1 infection was eradicated in one individual, have renewed interest in finding a cure for HIV-1 infection. Strategies for HIV-1 eradication include gene therapy and hematopoietic stem cell transplantation, stimulating host immunity to control HIV-1 replication, and targeting latent HIV-1 in resting memory CD4+ T cells. Future efforts should aim to provide better understanding of how to reconstitute the CD4+ T cell compartment with genetically engineered cells, exert immune control over HIV-1 replication, and identify and eliminate all viral reservoirs. PMID:22867874

GSK3 is required for rapalogs to induce degradation of some oncogenic proteins and to suppress cancer cell growth.

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Koo, Junghui; Wang, Xuerong; Owonikoko, Taofeek K; Ramalingam, Suresh S; Khuri, Fadlo R; Sun, Shi-Yong

2015-04-20

The single-agent activity of rapalogs (rapamycin and its analogues) in most tumor types has been modest at best. The underlying mechanisms are largely unclear. In this report, we have uncovered a critical role of GSK3 in regulating degradation of some oncogenic proteins induced by rapalogs and cell sensitivity to rapalogs. The basal level of GSK3 activity was positively correlated with cell sensitivity of lung cancer cell lines to rapalogs. GSK3 inhibition antagonized rapamycin's growth inhibitory effects both in vitro and in vivo, while enforced activation of GSK3β sensitized cells to rapamycin. GSK3 inhibition rescued rapamcyin-induced reduction of several oncogenic proteins such as cyclin D1, Mcl-1 and c-Myc, without interfering with the ability of rapamycin to suppress mTORC1 signaling and cap binding. Interestingly, rapamycin induces proteasomal degradation of these oncogenic proteins, as evidenced by their decreased stabilities induced by rapamcyin and rescue of their reduction by proteasomal inhibition. Moreover, acute or short-time rapamycin treatment dissociated not only raptor, but also rictor from mTOR in several tested cell lines, suggesting inhibition of both mTORC1 and mTORC2. Thus, induction of GSK3-dependent degradation of these oncogenic proteins is likely secondary to mTORC2 inhibition; this effect should be critical for rapamycin to exert its anticancer activity.

[POLIOMYELITIS ERADICATION--ONE STEP TO ACHIEVE THE GOAL].

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Ljubin-Sternak, Sunčanica; Kaić, Bernard; Vilibić-Čavlek, Tatjana; Mlinarić-Galinović, Gordana

2014-12-01

Poliomyelitis is a very old disease of humans, caused by poliovirus. With appearance of the epidemics in the 20th century, poliomyelitis became a global public health issue. In 1988, the World Health Organization started a campaign for global eradication of poliomyelitis and till now poliomyelitis cases have been reduced by more than 99%. In Croatia, the introduction of vaccination in 1961 resulted in dramatic reduction of paralytic disease. The European region, including Croatia was certified polio free in 2002. However, the final goal of the "polio-free world" has not yet been reached. To reinforce the campaign, the global polio eradication initiative has come up with the Polio Eradication & Endgame Strategic Plan 2013-2018 with detailed program how to resolve the main challenges: (a) continued transmission of wild polioviruses in endemic reservoirs; (b) reinfection of polio-free areas; and (c) outbreaks due to the circulating vaccine-derived polioviruses (cVDPV). Global oral polio vaccine cessation will follow, with the introduction of universal use of inactivated polio vaccine.

Proteomic Insights into the Protective Mechanisms of an In Vitro Oxidative Stress Model of Early Stage Parkinson’s Disease

OpenAIRE

Bauereis, Brian; Haskins, William E.; LeBaron, Richard G.; Renthal, Robert

2010-01-01

Previous studies in Parkinson's disease (PD) models suggest that early events along the path to neurodegeneration involve activation of the ubiquitin-proteasome system (UPS), endoplasmic reticulum-associated degradation (ERAD), and the unfolded protein response (UPR) pathways, in both the sporadic and familial forms of the disease, and thus ER stress may be a common feature. Furthermore, impairments in protein degradation have been linked to oxidative stress as well as pathways associated wit...

[Histological changes of gastric atrophy and intestinal metaplasia after Helicobacter pylori eradication].

Science.gov (United States)

Lee, Yonggu; Jeon, Yong Cheol; Koo, Tai Yeon; Cho, Hyun Seok; Byun, Tae Jun; Kim, Tae Yeob; Lee, Hang Lak; Eun, Chang Soo; Lee, Oh Young; Han, Dong Soo; Sohn, Joo Hyun; Yoon, Byung Chul

2007-11-01

Long-term Helicobater pylori infection results in atrophic gastritis and intestinal metaplasia, and increases the risk of gastric cancer. However, it is still controversial that eradication of H. pylori improves atrophy or metaplasia. Therefore, we investigated histological changes after the H. pylori eradication in patients with atrophy or metaplasia. One hundred seven patients who received successful eradication of H. pylori infection in Hanyang University, Guri Hospital from March 2001 to April 2006, were enrolled. Antral biopsy was taken before the eradication to confirm the H. pylori infection and grade of atrophy or metaplasia by updated Sydney System. After a certain period of time, antral biopsy was repeatedly taken to confirm the eradication and investigate histological changes of atrophy or metaplasia. Mean age of the patients was 55.3+/-11.3, and average follow-up period was 28.7+/-13.9 months. Endoscopic diagnosis included gastric ulcer, duodenal ulcer, non-ulcer antral gastritis. Atrophy was observed in 41 of 91 and their average score was 0.73+/-0.92. After the eradication of H. pylori, atrophy was improved (0.38+/-0.70, p=0.025). However, metaplasia which was observed in 49 of 107, did not significantly improve during the follow-up period. Newly developed atrophy (7 of 38) or metaplasia (18 of 49) was observed in patients who without atrophy or metaplasia initially. Their average scores were slightly lower than those of cases with pre-existing atrophy or metaplasia without statistical significance. After the eradication of H. pylori infection, atrophic gastritis may be improved, but change of intestinal metaplasia is milder and may take longer duration for improvement.

A Research Agenda for Malaria Eradication: Modeling

Science.gov (United States)

2011-01-01

Malaria modeling can inform policy and guide research for malaria elimination and eradication from local implementation to global policy. A research and development agenda for malaria modeling is proposed, to support operations and to enhance the broader eradication research agenda. Models are envisioned as an integral part of research, planning, and evaluation, and modelers should ideally be integrated into multidisciplinary teams to update the models iteratively, communicate their appropriate use, and serve the needs of other research scientists, public health specialists, and government officials. A competitive and collaborative framework will result in policy recommendations from multiple, independently derived models and model systems that share harmonized databases. As planned, modeling results will be produced in five priority areas: (1) strategic planning to determine where and when resources should be optimally allocated to achieve eradication; (2) management plans to minimize the evolution of drug and pesticide resistance; (3) impact assessments of new and needed tools to interrupt transmission; (4) technical feasibility assessments to determine appropriate combinations of tools, an associated set of target intervention coverage levels, and the expected timelines for achieving a set of goals in different socio-ecological settings and different health systems; and (5) operational feasibility assessments to weigh the economic costs, capital investments, and human resource capacities required. PMID:21283605

Transient degradation of NF-κB proteins in macrophages after interaction with mast cell granules

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Noriko Ito

1998-01-01

Full Text Available The exposure of the macrophage cell line, J774 to mast cell granules (MCG led to the form ation of altered nuclear transcription factor proteins (NFκBx, which had faster electrophoretic mobility than the p50 homodimer of NF-κB, but retained comparable DNA binding capacity. Antibodies to N-terminal peptides of p50, p52, p65 or c-Rel supershifted only a fraction of NF-κBx. Western blot analyses revealed that nuclear p65 and c-Rel were progressively degraded after exposure to MCG, whereas nuclear p50 appeared to be unaffected. In contrast, cytoplasmic p50, p65, c-Rel as well as IkBα remained intact after MCG treatment, although p52 was clearly degraded. In comparison to J774 cells, incubation of m ouse peritoneal macrophages with MCG resulted in more extensive alterations to NF-κB proteins. The alterations in NF-κB proteins did not affect the expression of inducible nitric oxide synthase (iNOS or TNF-α mRNA in J774 cells. These data indicate that exposure of J774 cells to MCG leads to generation of altered nuclear p52, p65 and c-Rel, which retain intact N-terminal peptides, specific oligonucleotide binding and transactivating activity. On the other hand, in peritoneal macrophages, MCG induce more extensive modifications to NF-κB proteins with associated inhibition of iNOS or TNF-α mRNA expression.

Polio eradication efforts in regions of geopolitical strife: the Boko ...

African Journals Online (AJOL)

rous boundary, with a length of about 1690 km. The last cases of poliomyelitis were reported in Cameroon and. Nigeria on 9 and 24 July 2014 respectively6,16. The WHO has called for these countries to eradicate WPV and pre- vent its spread6,17. The commitment of both countries to eradicate it and stop its spread is clear, ...

Degradation of some representative polycyclic aromatic hydrocarbons by the water-soluble protein extracts from Zea mays L. cv PR32-B10.

Science.gov (United States)

Barone, Roberto; de Biasi, Margherita-Gabriella; Piccialli, Vincenzo; de Napoli, Lorenzo; Oliviero, Giorgia; Borbone, Nicola; Piccialli, Gennaro

2016-10-01

The ability of the water-soluble protein extracts from Zea mais L. cv. PR32-B10 to degrade some representative polycyclic aromatic hydrocarbons (PAHs), has been evaluated. Surface sterilized seeds of corn (Zea mais L. Pioneer cv. PR32-B10) were hydroponically cultivated in a growth chamber under no-stressful conditions. The water-soluble protein extracts isolated from maize tissues showed peroxidase, polyphenol oxidase and catalase activities. Incubation of the extracts with naphthalene, fluorene, phenanthrene and pyrene, led to formation of oxidized and/or degradation products. GC-MS and TLC monitoring of the processes showed that naphthalene, phenanthrene, fluorene and pyrene underwent 100%, 78%, 92% and 65% oxidative degradation, respectively, after 120 min. The chemical structure of the degradation products were determined by (1)H NMR and ESI-MS spectrometry. Copyright © 2016 Elsevier Ltd. All rights reserved.

Protein degradation and post-deboning tenderization in broiler breast meat with different degrees of muscle shortening

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Deboning broiler breast fillets prior to rigor mortis negatively influences tenderness due to sarcomere shortening. The effects of sarcomere shortening on muscle protein degradation and breast meat tenderization during post-deboning aging are not well understood. The objective of this study was to m...

Regulating the 20S Proteasome Ubiquitin-Independent Degradation Pathway

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Gili Ben-Nissan

2014-09-01

Full Text Available For many years, the ubiquitin-26S proteasome degradation pathway was considered the primary route for proteasomal degradation. However, it is now becoming clear that proteins can also be targeted for degradation by the core 20S proteasome itself. Degradation by the 20S proteasome does not require ubiquitin tagging or the presence of the 19S regulatory particle; rather, it relies on the inherent structural disorder of the protein being degraded. Thus, proteins that contain unstructured regions due to oxidation, mutation, or aging, as well as naturally, intrinsically unfolded proteins, are susceptible to 20S degradation. Unlike the extensive knowledge acquired over the years concerning degradation by the 26S proteasome, relatively little is known about the means by which 20S-mediated proteolysis is controlled. Here, we describe our current understanding of the regulatory mechanisms that coordinate 20S proteasome-mediated degradation, and highlight the gaps in knowledge that remain to be bridged.

Eradication of Helicobacter pylori Is Associated with the Progression of Dementia: A Population-Based Study

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Yang-Pei Chang

2013-01-01

Full Text Available Objective. To evaluate the effect of eradication of Helicobacter pylori (H. pylori on the progression of dementia in Alzheimer’s disease (AD patients with peptic ulcer. Methods. Participants with the diagnosis of AD and peptic ulcer were recruited between 2001 and 2008. We examined the association between eradication of H. pylori and the progression of AD using the multiple regression models. Medication shift from Donepezil, Rivastgmine, and Galantamine to Mematine is defined as progression of dementia according to the insurance of National Health Insurance (NHI under expert review. Results. Among the 30142 AD patients with peptic ulcers, the ratio of medication shift in AD patients with peptic ulcers is 79.95%. There were significant lower incidence comorbidities (diabetes mellitus, hypertension, cerebrovascular disease, coronary artery disease, congestive heart failure and hyperlipidemia in patients with H. pylori eradication as compared with no H. pylori eradication. Eradication of H. pylori was associated with a decreased risk of AD progression (odds ratio [OR] 0.35 [0.23–0.52] as compared with no H. pylori eradication, which was not modified by comorbidities. Conclusions. Eradication of H. pylori was associated with a decreased progression of dementia as compared to no eradication of H. pylori in AD patients with peptic ulcers.

Effects of Dietary Crude Protein Levels and Cysteamine Supplementation on Protein Synthetic and Degradative Signaling in Skeletal Muscle of Finishing Pigs.

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Ping Zhou

Full Text Available Dietary protein levels and cysteamine (CS supplementation can affect growth performance and protein metabolism of pigs. However, the influence of dietary protein intake on the growth response of CS-treated pigs is unclear, and the mechanisms involved in protein metabolism remain unknown. Hence, we investigated the interactions between dietary protein levels and CS supplementation and the effects of dietary crude protein levels and CS supplementation on protein synthetic and degradative signaling in skeletal muscle of finishing pigs. One hundred twenty barrows (65.84 ± 0.61 kg were allocated to a 2 × 2 factorial arrangement with five replicates of six pigs each. The primary variations were dietary crude protein (CP levels (14% or 10% and CS supplemental levels (0 or 700 mg/kg. The low-protein (LP diets (10% CP were supplemented with enough essential amino acids (EAA to meet the NRC AA requirements of pigs and maintain the balanced supply of eight EAA including lysine, methionine, threonine, tryptophan, valine, phenylalanine, isoleucine, and leucine. After 41 days, 10 pigs per treatment were slaughtered. We found that LP diets supplemented with EAA resulted in decreased concentrations of plasma somatostatin (SS (P<0.01 and plasma urea nitrogen (PUN (P<0.001, while dietary protein levels did not affect other traits. However, CS supplementation increased the average daily gain (P<0.001 and lean percentage (P<0.05, and decreased the feed conversion ratio (P<0.05 and back fat (P<0.05. CS supplementation also increased the concentrations of plasma insulin-like growth factor 1 (IGF-1 (P<0.001, and reduced the concentrations of leptin, SS, and PUN (P<0.001. Increased mRNA abundance of Akt1 and IGF-1 signaling (P<0.001 and decreased mRNA abundance of Forkhead Box O (FOXO 4 (P<0.01 and muscle atrophy F-box (P<0.001 were observed in pigs receiving CS. Additionally, CS supplementation increased the protein levels for the phosphorylated mammalian target of

Ciliopathy proteins regulate paracrine signaling by modulating proteasomal degradation of mediators

Science.gov (United States)

Liu, Yangfan P.; Tsai, I-Chun; Morleo, Manuela; Oh, Edwin C.; Leitch, Carmen C.; Massa, Filomena; Lee, Byung-Hoon; Parker, David S.; Finley, Daniel; Zaghloul, Norann A.; Franco, Brunella; Katsanis, Nicholas

2014-01-01

Cilia are critical mediators of paracrine signaling; however, it is unknown whether proteins that contribute to ciliopathies converge on multiple paracrine pathways through a common mechanism. Here, we show that loss of cilopathy-associated proteins Bardet-Biedl syndrome 4 (BBS4) or oral-facial-digital syndrome 1 (OFD1) results in the accumulation of signaling mediators normally targeted for proteasomal degradation. In WT cells, several BBS proteins and OFD1 interacted with proteasomal subunits, and loss of either BBS4 or OFD1 led to depletion of multiple subunits from the centrosomal proteasome. Furthermore, overexpression of proteasomal regulatory components or treatment with proteasomal activators sulforaphane (SFN) and mevalonolactone (MVA) ameliorated signaling defects in cells lacking BBS1, BBS4, and OFD1, in morphant zebrafish embryos, and in induced neurons from Ofd1-deficient mice. Finally, we tested the hypothesis that other proteasome-dependent pathways not known to be associated with ciliopathies are defective in the absence of ciliopathy proteins. We found that loss of BBS1, BBS4, or OFD1 led to decreased NF-κB activity and concomitant IκBβ accumulation and that these defects were ameliorated with SFN treatment. Taken together, our data indicate that basal body proteasomal regulation governs paracrine signaling pathways and suggest that augmenting proteasomal function might benefit ciliopathy patients. PMID:24691443

Success in Zanzibar: Eradication of tsetse

International Nuclear Information System (INIS)

Msangi, A.R.; Kiwia, N.; Malele, I.I.; Mramba, F.; Saleh, K.M.; Mussa, W.A.; Juma, K.G.; Dyck, V.A.; Vreysen, M.J.B.; Parker, A.G.; Feldmann, U.; Zhu, Z.R.; Pan, H.

2000-01-01

There are about 22 species of tsetse flies found nowhere else in the world except in 36 countries of sub-Saharan Africa. Tsetse flies transmit a debilitating and often fatal disease, trypanosomosis, which causes tremendous losses of livestock, and severely limits agricultural production (it reduces output of milk and meat, causes mortality, infertility and abortion in livestock, deprives the rural population of draught power and manure to improve and increase crop production). Tsetse flies also transmit human trypanosomosis, commonly known as 'sleeping sickness'. It is estimated that over 55 million people living in rural sub-Saharan Africa are at risk from this fatal disease. Tanzania's Zanzibar Island is situated 35 km off the eastern coast and comprises two main islands, Unguja and Pemba. Previous surveys revealed that out of the seven tsetse species found on mainland Tanzania, only Glossina austeni Newstead infested Unguja Island. No tsetse fly was found on the island of Pemba. The fly is responsible for the cyclical transmission of trypanosomosis in livestock, the causative agents being mainly Trypanosoma congolense and, to a lesser extent, T. vivax. It is estimated that in Zanzibar, the disease causes annual losses of US$2 million. Since fly suppression by conventional techniques has often resulted in short-term success, Tanzania has always appreciated that the long-term solution to the trypanosomosis problem is the eradication of tsetse flies in the country. In 1994, the International Atomic Energy Agency (IAEA) and the United Republic of Tanzania embarked on a project with the objective of eradicating tsetse flies from Zanzibar Island by applying the sterile insect technique (SIT) (Dyck et al. 1995, in press). Previous tsetse eradication efforts in Tanzania using SIT, enabled the establishment of a modest capacity on tsetse mass rearing in Tanga (Williamson et al. 1983). The Zanzibar tsetse project was successfully completed in 1997. The estimated cost was

Streptococcus pneumoniae eradicates preformed Staphylococcus aureus biofilms through a mechanism requiring physical contact

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Faidad Khan

2016-09-01

Full Text Available Staphylococcus aureus (Sau strains are a main cause of disease, including nosocomial infections which have been linked to the production of biofilms and the propagation of antibiotic resistance strains such as methicillin-resistant Staphylococcus aureus (MRSA. A previous study found that Streptococcus pneumoniae (Spn strains kill planktonic cultures of Sau strains. In this work, we have further evaluated in detail the eradication of Sau biofilms and investigated ultrastructural interactions of the biofilmicidal effect. Spn strain D39, which produces the competence stimulating peptide 1 (CSP1, reduced Sau biofilms within 8 h of inoculation, while TIGR4, producing CSP2, eradicated Sau biofilms and planktonic cells within 4 h. Differences were not attributed to pherotypes as other Spn strains producing different pheromones eradicated Sau within 4 h. Experiments using Transwell devices, which physically separated both species growing in the same well, demonstrated that direct contact between Spn and Sau was required to efficiently eradicate Sau biofilms and biofilm-released planktonic cells. Physical contact-mediated killing of Sau was not related to production of hydrogen peroxide as an isogenic TIGR4spxB mutant eradicated Sau bacteria within 4 h. Confocal micrographs confirmed eradication of Sau biofilms by TIGR4 and allowed us to visualize ultrastructural point of contacts between Sau and Spn. A time-course study further demonstrated spatial colocalization of Spn chains and Sau tetrads as early as 30 min post-inoculation (Pearson’s coefficient >0.72. Finally, precolonized biofilms produced by Sau strain Newman, or MRSA strain USA300, were eradicated by mid-log phase cultures of washed TIGR4 bacteria within 2 h post-inoculation. In conclusion, Spn strains rapidly eradicate pre-colonized Sau aureus biofilms, including those formed by MRSA strains, by a mechanism(s requiring bacterium-bacterium contact, but independent from the production of

Which factors affect the success or failure of eradication campaigns against alien species?

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Therese Pluess

Full Text Available Although issues related to the management of invasive alien species are receiving increasing attention, little is known about which factors affect the likelihood of success of management measures. We applied two data mining techniques, classification trees and boosted trees, to identify factors that relate to the success of management campaigns aimed at eradicating invasive alien invertebrates, plants and plant pathogens. We assembled a dataset of 173 different eradication campaigns against 94 species worldwide, about a half of which (50.9% were successful. Eradications in man-made habitats, greenhouses in particular, were more likely to succeed than those in (semi-natural habitats. In man-made habitats the probability of success was generally high in Australasia, while in Europe and the Americas it was higher for local infestations that are easier to deal with, and for international campaigns that are likely to profit from cross-border cooperation. In (semi- natural habitats, eradication campaigns were more likely to succeed for plants introduced as an ornamental and escaped from cultivation prior to invasion. Averaging out all other factors in boosted trees, pathogens, bacteria and viruses were most, and fungi the least likely to be eradicated; for plants and invertebrates the probability was intermediate. Our analysis indicates that initiating the campaign before the extent of infestation reaches the critical threshold, starting to eradicate within the first four years since the problem has been noticed, paying special attention to species introduced by the cultivation pathway, and applying sanitary measures can substantially increase the probability of eradication success. Our investigations also revealed that information on socioeconomic factors, which are often considered to be crucial for eradication success, is rarely available, and thus their relative importance cannot be evaluated. Future campaigns should carefully document

Helicobacter pylori eradication in complicated peptic ulcer: Beneficial in most?

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Subair Mohsina

2016-01-01

Full Text Available Helicobacter pylori eradication therapy has a role in minimizing the complications of peptic ulcer disease, namely, bleeding, perforation, and obstruction. However, the precise role of H. pylori eradication therapy in the complicated ulcers remains inconclusive, especially in perforation and gastric outlet obstruction. The prevalence of H. pylori in peptic ulcer bleeding patients has been widely underestimated owing to the differences in diagnostic tests and patient characteristics, and hence, it is recommended that an initial negative test should be followed up by a delayed repeat testing to rule out false negativity. It is well established now that eradication of H. pylori in patients with bleeding ulcers reduces rebleeding and ulcer recurrence. Multiple studies have attributed high recurrence rates of duodenal ulcer following simple closure to a high prevalence of H. pylori infection. Eradication therapy decreases the recurrence rate of perforated ulcers, thus justifying the role of H. pylori eradication therapy following the primary surgical management of perforated ulcers. The role of H. pylori in duodenal ulcer with gastric outlet obstruction is yet to be evaluated clearly. There are some reports of resolution of gastric outlet obstruction following therapy for H. pylori, obviating the need for surgery. Clarithromycin-containing regimens are recommended as first-line in areas of low resistance, whereas bismuth-containing quadruple therapy is the first-line empirical treatment in areas of high clarithromycin resistance. Treatment of H. pylori is beneficial in most of the patients with complicated peptic ulcer disease, especially in reducing recurrence of ulcer with or without complications.

Stabilization and Degradation Mechanisms of Cytoplasmic Ataxin-1

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Mayumi F. Kohiyama

2015-01-01

Full Text Available Aggregation-prone proteins in neurodegenerative disease disrupt cellular protein stabilization and degradation pathways. The neurodegenerative disease spinocerebellar ataxia type 1 (SCA1 is caused by a coding polyglutamine expansion in the Ataxin-1 gene ( ATXN1 , which gives rise to the aggregation-prone mutant form of ATXN1 protein. Cerebellar Purkinje neurons, preferentially vulnerable in SCA1, produce ATXN1 protein in both cytoplasmic and nuclear compartments. Cytoplasmic stabilization of ATXN1 by phosphorylation and 14-3-3-mediated mechanisms ultimately drive translocation of the protein to the nucleus where aggregation may occur. However, experimental inhibition of phosphorylation and 14-3-3 binding results in rapid degradation of ATXN1, thus preventing nuclear translocation and cellular toxicity. The exact mechanism of cytoplasmic ATXN1 degradation is currently unknown; further investigation of degradation may provide future therapeutic targets. This review examines the present understanding of cytoplasmic ATXN1 stabilization and potential degradation mechanisms during normal and pathogenic states.

Control and eradication of endemic infectious diseases in cattle

DEFF Research Database (Denmark)

Houe, Hans; Nielsen, Liza Rosenbaum; Nielsen, Søren Saxmose

"Control and eradication of endemic infectious diseases in cattle" provides the key elements that should be addressed in the establishment of bovine disease control and eradication programmes. The book aims to reach a broad group of readers, including: students; professionals in veterinary practice...... "disease profiling", which is governed by the characteristics of the agent and its interaction with the host and environment. This profile, along with due consideration of the socioeconomic circumstances, can be used to determine how best to address the problem....

Eradication of multidrug-resistant pseudomonas biofilm with pulsed electric fields.

Science.gov (United States)

Khan, Saiqa I; Blumrosen, Gaddi; Vecchio, Daniela; Golberg, Alexander; McCormack, Michael C; Yarmush, Martin L; Hamblin, Michael R; Austen, William G

2016-03-01

Biofilm formation is a significant problem, accounting for over eighty percent of microbial infections in the body. Biofilm eradication is problematic due to increased resistance to antibiotics and antimicrobials as compared to planktonic cells. The purpose of this study was to investigate the effect of Pulsed Electric Fields (PEF) on biofilm-infected mesh. Prolene mesh was infected with bioluminescent Pseudomonas aeruginosa and treated with PEF using a concentric electrode system to derive, in a single experiment, the critical electric field strength needed to kill bacteria. The effect of the electric field strength and the number of pulses (with a fixed pulse length duration and frequency) on bacterial eradication was investigated. For all experiments, biofilm formation and disruption were confirmed with bioluminescent imaging and Scanning Electron Microscopy (SEM). Computation and statistical methods were used to analyze treatment efficiency and to compare it to existing theoretical models. In all experiments 1500 V are applied through a central electrode, with pulse duration of 50 μs, and pulse delivery frequency of 2 Hz. We found that the critical electric field strength (Ecr) needed to eradicate 100-80% of bacteria in the treated area was 121 ± 14 V/mm when 300 pulses were applied, and 235 ± 6.1 V/mm when 150 pulses were applied. The area at which 100-80% of bacteria were eradicated was 50.5 ± 9.9 mm(2) for 300 pulses, and 13.4 ± 0.65 mm(2) for 150 pulses. 80% threshold eradication was not achieved with 100 pulses. The results indicate that increased efficacy of treatment is due to increased number of pulses delivered. In addition, we that showed the bacterial death rate as a function of the electrical field follows the statistical Weibull model for 150 and 300 pulses. We hypothesize that in the clinical setting, combining systemic antibacterial therapy with PEF will yield a synergistic effect leading to improved

Vitamin C degradation products and pathways in the human lens.

Science.gov (United States)

Nemet, Ina; Monnier, Vincent M

2011-10-28

Vitamin C and its degradation products participate in chemical modifications of proteins in vivo through non-enzymatic glycation (Maillard reaction) and formation of different products called advanced glycation end products. Vitamin C levels are particularly high in selected tissues, such as lens, brain and adrenal gland, and its degradation products can inflict substantial protein damage via formation of advanced glycation end products. However, the pathways of in vivo vitamin C degradation are poorly understood. Here we have determined the levels of vitamin C oxidation and degradation products dehydroascorbic acid, 2,3-diketogulonic acid, 3-deoxythreosone, xylosone, and threosone in the human lens using o-phenylenediamine to trap both free and protein-bound adducts. In the protein-free fraction and water-soluble proteins (WSP), all five listed degradation products were identified. Dehydroascorbic acid, 2,3-diketogulonic acid, and 3-deoxythreosone were the major products in the protein-free fraction, whereas in the WSP, 3-deoxythreosone was the most abundant measured dicarbonyl. In addition, 3-deoxythreosone in WSP showed positive linear correlation with age (p degradation product bound to human lens proteins provides in vivo evidence for the non-oxidative pathway of dehydroascorbate degradation into erythrulose as a major pathway for vitamin C degradation in vivo.

National surveillance of Helicobacter pylori eradication therapy in Denmark. Results from registration of 34,582 prescriptions

DEFF Research Database (Denmark)