Involved in the degradation process of misfolded endoplasmic reticulum (ER) luminal proteins. Participates in the transfer of misfolded proteins from the ER to the cytosol, where they are destroyed by the proteasome in a ubiquitin-dependent manner. Probably acts by serving as a linker between DERL1, which mediates the retrotranslocation of misfolded proteins into the cytosol, and the ATPase complex VCP, which mediates the translocation and ubiquitination.
Elimination of misfolded proteins from the endoplasmic reticulum (ER) by retro-translocation is an important physiological adaptation to ER stress. This process requires recognition of a substrate in the ER lumen and its subsequent movement through the membrane by the cytosolic p97 ATPase. Here we identify a p97-interacting membrane protein complex in the mammalian ER that links these two events. The central component of the complex, Derlin-1, is a homologue of Der1, a yeast protein whose inactivation prevents the elimination of misfolded luminal ER proteins. Derlin-1 associates with different substrates as they move through the membrane, and inactivation of Derlin-1 in C. elegans causes ER stress. Derlin-1 interacts with US11, a virally encoded ER protein that specifically targets MHC class I heavy chains for export from the ER, as well as with VIMP, a novel membrane protein that recruits the p97 ATPase and its cofactor.
Inhibition of the reactions brought about by dioxygen (O2) or peroxides. Usually the antioxidant is effective because it can itself be more easily oxidized than the substance protected. The term is often applied to components that can trap free radicals, thereby breaking the chain reaction that normally leads to extensive biological damage.
SelS is a newly identified selenoprotein and its gene expression is up-regulated in the liver of Psammomys obesus after fasting. We have examined whether SelS is regulated by glucose deprivation and endoplasmic reticulum (ER) stress in HepG2 cells. Glucose deprivation and the ER stress inducers tunicamycin and thapsigargin increased SelS gene expression and protein content several-fold in parallel with glucose-regulated protein 78. The overexpression of SelS increased Min6 cell resistance to oxidative stress-induced toxicity. These results indicate that SelS is a novel member of the glucose-regulated protein family and its function is related to the regulation of cellular redox balance.
Elimination of misfolded proteins from the endoplasmic reticulum (ER) by retro-translocation is an important physiological adaptation to ER stress. This process requires recognition of a substrate in the ER lumen and its subsequent movement through the membrane by the cytosolic p97 ATPase. Here we identify a p97-interacting membrane protein complex in the mammalian ER that links these two events. The central component of the complex, Derlin-1, is a homologue of Der1, a yeast protein whose inactivation prevents the elimination of misfolded luminal ER proteins. Derlin-1 associates with different substrates as they move through the membrane, and inactivation of Derlin-1 in C. elegans causes ER stress. Derlin-1 interacts with US11, a virally encoded ER protein that specifically targets MHC class I heavy chains for export from the ER, as well as with VIMP, a novel membrane protein that recruits the p97 ATPase and its cofactor.
Interacting selectively and non-covalently with any protein or protein complex (a complex of two or more proteins that may include other nonprotein molecules).
Evidence
1:
Inferred from Physical InteractionUniProtKB
Elimination of misfolded proteins from the endoplasmic reticulum (ER) by retro-translocation is an important physiological adaptation to ER stress. This process requires recognition of a substrate in the ER lumen and its subsequent movement through the membrane by the cytosolic p97 ATPase. Here we identify a p97-interacting membrane protein complex in the mammalian ER that links these two events. The central component of the complex, Derlin-1, is a homologue of Der1, a yeast protein whose inactivation prevents the elimination of misfolded luminal ER proteins. Derlin-1 associates with different substrates as they move through the membrane, and inactivation of Derlin-1 in C. elegans causes ER stress. Derlin-1 interacts with US11, a virally encoded ER protein that specifically targets MHC class I heavy chains for export from the ER, as well as with VIMP, a novel membrane protein that recruits the p97 ATPase and its cofactor.
Elimination of misfolded proteins from the endoplasmic reticulum (ER) by retro-translocation is an important physiological adaptation to ER stress. This process requires recognition of a substrate in the ER lumen and its subsequent movement through the membrane by the cytosolic p97 ATPase. Here we identify a p97-interacting membrane protein complex in the mammalian ER that links these two events. The central component of the complex, Derlin-1, is a homologue of Der1, a yeast protein whose inactivation prevents the elimination of misfolded luminal ER proteins. Derlin-1 associates with different substrates as they move through the membrane, and inactivation of Derlin-1 in C. elegans causes ER stress. Derlin-1 interacts with US11, a virally encoded ER protein that specifically targets MHC class I heavy chains for export from the ER, as well as with VIMP, a novel membrane protein that recruits the p97 ATPase and its cofactor.
SelS is a newly identified selenoprotein and its gene expression is up-regulated in the liver of Psammomys obesus after fasting. We have examined whether SelS is regulated by glucose deprivation and endoplasmic reticulum (ER) stress in HepG2 cells. Glucose deprivation and the ER stress inducers tunicamycin and thapsigargin increased SelS gene expression and protein content several-fold in parallel with glucose-regulated protein 78. The overexpression of SelS increased Min6 cell resistance to oxidative stress-induced toxicity. These results indicate that SelS is a novel member of the glucose-regulated protein family and its function is related to the regulation of cellular redox balance.
Any process that results in a change in state or activity of a cell (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of an insulin stimulus. Insulin is a polypeptide hormone produced by the islets of Langerhans of the pancreas in mammals, and by the homologous organs of other organisms.
Increased hepatic glucose output and decreased glucose utilization are implicated in the development of type 2 diabetes. We previously reported that the expression of a novel gene, Tanis, was upregulated in the liver during fasting in the obese/diabetic animal model Psammomys obesus. Here, we have further studied the protein and its function. Cell fractionation indicated that Tanis was localized in the plasma membrane and microsomes but not in the nucleus, mitochondria, or soluble protein fraction. Consistent with previous gene expression data, hepatic Tanis protein levels increased more significantly in diabetic P. obesus than in nondiabetic controls after fasting. We used a recombinant adenovirus to increase Tanis expression in hepatoma H4IIE cells and investigated its role in metabolism. Tanis overexpression reduced glucose uptake, basal and insulin-stimulated glycogen synthesis, and glycogen content and attenuated the suppression of PEPCK gene expression by insulin, but it did not affect insulin-stimulated insulin receptor phosphorylation or triglyceride synthesis. These results suggest that Tanis may be involved in the regulation of glucose metabolism, and increased expression of Tanis could contribute to insulin resistance in the liver.
Any process that results in a change in state or activity of a cell (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of a lipopolysaccharide stimulus; lipopolysaccharide is a major component of the cell wall of gram-negative bacteria.
To investigate the role of SelS in bacterial lipopolysaccharide (LPS) induced inflammatory response, some parameters in LPS-stimulated HepG2 cells were comparatively studied fore-and-aft SelS silence. LPS induced the decreases of cytoplasmic glutathione peroxidase (GPx-1) mRNA expression and activity, and the increases of reactive oxygen species (ROS) level, intracellular and extracellular nitric oxide (NO) levels, inducible nitric oxide synthase (iNOS) mRNA expression and activity, and serum amyloid A1 (SAA1) mRNA expression and secreted protein level in hepatoma HepG2 cells. When SelS was suppressed by small interfering RNA (siRNA), those decreases and increases were further aggravated under LPS stimulation, respectively. In conclusion, the negative association between SelS and the LPS-induced production of ROS, NO and SAA1 demonstrated that SelS had an important role in influencing inflammatory response, and that role may be related with SelS as a central component of retro-translocation channel in endoplasmic reticulum-associated protein degradation (ERAD) and its anti-oxidative property.
Any process that results in a change in state or activity of a cell (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of oxidative stress, a state often resulting from exposure to high levels of reactive oxygen species, e.g. superoxide anions, hydrogen peroxide (H2O2), and hydroxyl radicals.
To investigate the role of SelS in bacterial lipopolysaccharide (LPS) induced inflammatory response, some parameters in LPS-stimulated HepG2 cells were comparatively studied fore-and-aft SelS silence. LPS induced the decreases of cytoplasmic glutathione peroxidase (GPx-1) mRNA expression and activity, and the increases of reactive oxygen species (ROS) level, intracellular and extracellular nitric oxide (NO) levels, inducible nitric oxide synthase (iNOS) mRNA expression and activity, and serum amyloid A1 (SAA1) mRNA expression and secreted protein level in hepatoma HepG2 cells. When SelS was suppressed by small interfering RNA (siRNA), those decreases and increases were further aggravated under LPS stimulation, respectively. In conclusion, the negative association between SelS and the LPS-induced production of ROS, NO and SAA1 demonstrated that SelS had an important role in influencing inflammatory response, and that role may be related with SelS as a central component of retro-translocation channel in endoplasmic reticulum-associated protein degradation (ERAD) and its anti-oxidative property.
The series of molecular signals generated as a consequence of the presence of unfolded proteins in the endoplasmic reticulum (ER) or other ER-related stress; results in changes in the regulation of transcription and translation.
Elimination of misfolded proteins from the endoplasmic reticulum (ER) by retro-translocation is an important physiological adaptation to ER stress. This process requires recognition of a substrate in the ER lumen and its subsequent movement through the membrane by the cytosolic p97 ATPase. Here we identify a p97-interacting membrane protein complex in the mammalian ER that links these two events. The central component of the complex, Derlin-1, is a homologue of Der1, a yeast protein whose inactivation prevents the elimination of misfolded luminal ER proteins. Derlin-1 associates with different substrates as they move through the membrane, and inactivation of Derlin-1 in C. elegans causes ER stress. Derlin-1 interacts with US11, a virally encoded ER protein that specifically targets MHC class I heavy chains for export from the ER, as well as with VIMP, a novel membrane protein that recruits the p97 ATPase and its cofactor.
The series of molecular signals generated by the accumulation of normal or misfolded proteins in the endoplasmic reticulum and leading to activation of transcription by NF-kappaB.
SEPS1 (also called selenoprotein S, SelS) plays an important role in the production of inflammatory cytokines and its expression is activated by endoplasmic reticulum (ER) stress. In this report, we have identified two binding sites for the nuclear factor kappa B in the human SEPS1 promoter. SEPS1 gene expression, protein levels and promoter activity were all increased 2-3-fold by TNF-alpha and IL-1beta in HepG2 cells. We have also confirmed that the previously proposed ER stress response element GGATTTCTCCCCCGCCACG in the SEPS1 proximate promoter is fully functional and responsive to ER stress. However, concurrent treatment of HepG2 cells with IL-1beta and ER stress produced no additive effect on SEPS1 gene expression. We conclude that SEPS1 is a new target gene of NF-kappaB. Together with our previous findings that SEPS1 may regulate cytokine production in macrophage cells, we propose a regulatory loop between cytokines and SEPS1 that plays a key role in control of the inflammatory response.
Selenoprotein S (SEPS1) is a novel endoplasmic reticulum (ER) resident protein and it is known to play an important role in production of inflammatory cytokines. Here, we show evidence that SEPS1 is stimulated by pharmacological ER stress agents in RAW264.7 macrophages as well as other cell types. Overexpression studies reveal a protective action of SEPS1 in macrophages against ER stress-induced cytotoxicity and apoptosis, resulting in promoting cell survival during ER stress. The protective action of SEPS1 is largely dependent on ER stress-mediated cell death signal with less effect on non-ER stress component cell death signals. Conversely, suppression of SEPS1 in macrophages results in sensitization of cells to ER stress-induced cell death. These findings suggest that SEPS1 could be a new ER stress-dependent survival factor that protects macrophage against ER stress-induced cellular dysfunction.
The chemical reactions and pathways resulting in the breakdown of proteins transported from the endoplasmic reticulum and targeted to cytoplasmic proteasomes for degradation. This process acts on misfolded proteins as well as in the regulated degradation of correctly folded proteins.
Elimination of misfolded proteins from the endoplasmic reticulum (ER) by retro-translocation is an important physiological adaptation to ER stress. This process requires recognition of a substrate in the ER lumen and its subsequent movement through the membrane by the cytosolic p97 ATPase. Here we identify a p97-interacting membrane protein complex in the mammalian ER that links these two events. The central component of the complex, Derlin-1, is a homologue of Der1, a yeast protein whose inactivation prevents the elimination of misfolded luminal ER proteins. Derlin-1 associates with different substrates as they move through the membrane, and inactivation of Derlin-1 in C. elegans causes ER stress. Derlin-1 interacts with US11, a virally encoded ER protein that specifically targets MHC class I heavy chains for export from the ER, as well as with VIMP, a novel membrane protein that recruits the p97 ATPase and its cofactor.
Elimination of misfolded proteins from the endoplasmic reticulum (ER) by retro-translocation is an important physiological adaptation to ER stress. This process requires recognition of a substrate in the ER lumen and its subsequent movement through the membrane by the cytosolic p97 ATPase. Here we identify a p97-interacting membrane protein complex in the mammalian ER that links these two events. The central component of the complex, Derlin-1, is a homologue of Der1, a yeast protein whose inactivation prevents the elimination of misfolded luminal ER proteins. Derlin-1 associates with different substrates as they move through the membrane, and inactivation of Derlin-1 in C. elegans causes ER stress. Derlin-1 interacts with US11, a virally encoded ER protein that specifically targets MHC class I heavy chains for export from the ER, as well as with VIMP, a novel membrane protein that recruits the p97 ATPase and its cofactor.
To investigate the role of SelS in bacterial lipopolysaccharide (LPS) induced inflammatory response, some parameters in LPS-stimulated HepG2 cells were comparatively studied fore-and-aft SelS silence. LPS induced the decreases of cytoplasmic glutathione peroxidase (GPx-1) mRNA expression and activity, and the increases of reactive oxygen species (ROS) level, intracellular and extracellular nitric oxide (NO) levels, inducible nitric oxide synthase (iNOS) mRNA expression and activity, and serum amyloid A1 (SAA1) mRNA expression and secreted protein level in hepatoma HepG2 cells. When SelS was suppressed by small interfering RNA (siRNA), those decreases and increases were further aggravated under LPS stimulation, respectively. In conclusion, the negative association between SelS and the LPS-induced production of ROS, NO and SAA1 demonstrated that SelS had an important role in influencing inflammatory response, and that role may be related with SelS as a central component of retro-translocation channel in endoplasmic reticulum-associated protein degradation (ERAD) and its anti-oxidative property.
Selenoprotein S (SEPS1) is a novel endoplasmic reticulum (ER) resident protein and it is known to play an important role in production of inflammatory cytokines. Here, we show evidence that SEPS1 is stimulated by pharmacological ER stress agents in RAW264.7 macrophages as well as other cell types. Overexpression studies reveal a protective action of SEPS1 in macrophages against ER stress-induced cytotoxicity and apoptosis, resulting in promoting cell survival during ER stress. The protective action of SEPS1 is largely dependent on ER stress-mediated cell death signal with less effect on non-ER stress component cell death signals. Conversely, suppression of SEPS1 in macrophages results in sensitization of cells to ER stress-induced cell death. These findings suggest that SEPS1 could be a new ER stress-dependent survival factor that protects macrophage against ER stress-induced cellular dysfunction.
Any process that stops, prevents, or reduces the frequency, rate or extent of the import of the hexose monosaccharide glucose into a cell or organelle.
Increased hepatic glucose output and decreased glucose utilization are implicated in the development of type 2 diabetes. We previously reported that the expression of a novel gene, Tanis, was upregulated in the liver during fasting in the obese/diabetic animal model Psammomys obesus. Here, we have further studied the protein and its function. Cell fractionation indicated that Tanis was localized in the plasma membrane and microsomes but not in the nucleus, mitochondria, or soluble protein fraction. Consistent with previous gene expression data, hepatic Tanis protein levels increased more significantly in diabetic P. obesus than in nondiabetic controls after fasting. We used a recombinant adenovirus to increase Tanis expression in hepatoma H4IIE cells and investigated its role in metabolism. Tanis overexpression reduced glucose uptake, basal and insulin-stimulated glycogen synthesis, and glycogen content and attenuated the suppression of PEPCK gene expression by insulin, but it did not affect insulin-stimulated insulin receptor phosphorylation or triglyceride synthesis. These results suggest that Tanis may be involved in the regulation of glucose metabolism, and increased expression of Tanis could contribute to insulin resistance in the liver.
Any process that stops, prevents, or reduces the frequency, rate or extent of the chemical reactions and pathways resulting in the formation of glycogen.
Increased hepatic glucose output and decreased glucose utilization are implicated in the development of type 2 diabetes. We previously reported that the expression of a novel gene, Tanis, was upregulated in the liver during fasting in the obese/diabetic animal model Psammomys obesus. Here, we have further studied the protein and its function. Cell fractionation indicated that Tanis was localized in the plasma membrane and microsomes but not in the nucleus, mitochondria, or soluble protein fraction. Consistent with previous gene expression data, hepatic Tanis protein levels increased more significantly in diabetic P. obesus than in nondiabetic controls after fasting. We used a recombinant adenovirus to increase Tanis expression in hepatoma H4IIE cells and investigated its role in metabolism. Tanis overexpression reduced glucose uptake, basal and insulin-stimulated glycogen synthesis, and glycogen content and attenuated the suppression of PEPCK gene expression by insulin, but it did not affect insulin-stimulated insulin receptor phosphorylation or triglyceride synthesis. These results suggest that Tanis may be involved in the regulation of glucose metabolism, and increased expression of Tanis could contribute to insulin resistance in the liver.
SEPS1 (also called selenoprotein S, SelS) plays an important role in the production of inflammatory cytokines and its expression is activated by endoplasmic reticulum (ER) stress. In this report, we have identified two binding sites for the nuclear factor kappa B in the human SEPS1 promoter. SEPS1 gene expression, protein levels and promoter activity were all increased 2-3-fold by TNF-alpha and IL-1beta in HepG2 cells. We have also confirmed that the previously proposed ER stress response element GGATTTCTCCCCCGCCACG in the SEPS1 proximate promoter is fully functional and responsive to ER stress. However, concurrent treatment of HepG2 cells with IL-1beta and ER stress produced no additive effect on SEPS1 gene expression. We conclude that SEPS1 is a new target gene of NF-kappaB. Together with our previous findings that SEPS1 may regulate cytokine production in macrophage cells, we propose a regulatory loop between cytokines and SEPS1 that plays a key role in control of the inflammatory response.
Any process that stops, prevents, or reduces the frequency, rate or extent of the chemical reactions and pathways resulting in the formation of a nitric-oxide synthase enzyme.
To investigate the role of SelS in bacterial lipopolysaccharide (LPS) induced inflammatory response, some parameters in LPS-stimulated HepG2 cells were comparatively studied fore-and-aft SelS silence. LPS induced the decreases of cytoplasmic glutathione peroxidase (GPx-1) mRNA expression and activity, and the increases of reactive oxygen species (ROS) level, intracellular and extracellular nitric oxide (NO) levels, inducible nitric oxide synthase (iNOS) mRNA expression and activity, and serum amyloid A1 (SAA1) mRNA expression and secreted protein level in hepatoma HepG2 cells. When SelS was suppressed by small interfering RNA (siRNA), those decreases and increases were further aggravated under LPS stimulation, respectively. In conclusion, the negative association between SelS and the LPS-induced production of ROS, NO and SAA1 demonstrated that SelS had an important role in influencing inflammatory response, and that role may be related with SelS as a central component of retro-translocation channel in endoplasmic reticulum-associated protein degradation (ERAD) and its anti-oxidative property.
Any process that modulates the frequency, rate or extent of gluconeogenesis, the formation of glucose from noncarbohydrate precursors, such as pyruvate, amino acids and glycerol.
Increased hepatic glucose output and decreased glucose utilization are implicated in the development of type 2 diabetes. We previously reported that the expression of a novel gene, Tanis, was upregulated in the liver during fasting in the obese/diabetic animal model Psammomys obesus. Here, we have further studied the protein and its function. Cell fractionation indicated that Tanis was localized in the plasma membrane and microsomes but not in the nucleus, mitochondria, or soluble protein fraction. Consistent with previous gene expression data, hepatic Tanis protein levels increased more significantly in diabetic P. obesus than in nondiabetic controls after fasting. We used a recombinant adenovirus to increase Tanis expression in hepatoma H4IIE cells and investigated its role in metabolism. Tanis overexpression reduced glucose uptake, basal and insulin-stimulated glycogen synthesis, and glycogen content and attenuated the suppression of PEPCK gene expression by insulin, but it did not affect insulin-stimulated insulin receptor phosphorylation or triglyceride synthesis. These results suggest that Tanis may be involved in the regulation of glucose metabolism, and increased expression of Tanis could contribute to insulin resistance in the liver.
Any process that modulates the frequency, rate or extent of the chemical reactions and pathways involving nitric oxide, nitrogen monoxide (NO), a colorless gas only slightly soluble in water.
To investigate the role of SelS in bacterial lipopolysaccharide (LPS) induced inflammatory response, some parameters in LPS-stimulated HepG2 cells were comparatively studied fore-and-aft SelS silence. LPS induced the decreases of cytoplasmic glutathione peroxidase (GPx-1) mRNA expression and activity, and the increases of reactive oxygen species (ROS) level, intracellular and extracellular nitric oxide (NO) levels, inducible nitric oxide synthase (iNOS) mRNA expression and activity, and serum amyloid A1 (SAA1) mRNA expression and secreted protein level in hepatoma HepG2 cells. When SelS was suppressed by small interfering RNA (siRNA), those decreases and increases were further aggravated under LPS stimulation, respectively. In conclusion, the negative association between SelS and the LPS-induced production of ROS, NO and SAA1 demonstrated that SelS had an important role in influencing inflammatory response, and that role may be related with SelS as a central component of retro-translocation channel in endoplasmic reticulum-associated protein degradation (ERAD) and its anti-oxidative property.
Any process that results in a change in state or activity of a cell or an organism (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of a glucose stimulus.
Evidence
1:
Inferred from Expression PatternBHF-UCL
Here we describe a novel protein, which we have named Tanis, that is implicated in type 2 diabetes and inflammation. In Psammomys obesus, a unique polygenic animal model of type 2 diabetes and the metabolic syndrome, Tanis is expressed in the liver in inverse proportion to circulating glucose (P = 0.010) and insulin levels (P = 0.004) and in direct proportion with plasma triglyceride concentrations (P = 0.007). Hepatic Tanis gene expression was markedly increased (3.1-fold) after a 24-h fast in diabetic but not in nondiabetic P. obesus. In addition, glucose inhibited Tanis gene expression in cultured hepatocytes (P = 0.006) as well as in several other cell types (P = 0.001-0.011). Thus, Tanis seems to be regulated by glucose and is dysregulated in the diabetic state. Yeast-2 hybrid screening identified serum amyloid A (SAA), an acute-phase inflammatory response protein, as an interacting protein of Tanis, and this was confirmed by Biacore experiments. SAA and other acute-phase proteins have been the focus of recent attention as risk factors for cardiovascular disease, and we contend that Tanis and its interaction with SAA may provide a mechanistic link among type 2 diabetes, inflammation, and cardiovascular disease.
Evidence
2:
Inferred from Expression PatternUniProtKB
SelS is a newly identified selenoprotein and its gene expression is up-regulated in the liver of Psammomys obesus after fasting. We have examined whether SelS is regulated by glucose deprivation and endoplasmic reticulum (ER) stress in HepG2 cells. Glucose deprivation and the ER stress inducers tunicamycin and thapsigargin increased SelS gene expression and protein content several-fold in parallel with glucose-regulated protein 78. The overexpression of SelS increased Min6 cell resistance to oxidative stress-induced toxicity. These results indicate that SelS is a novel member of the glucose-regulated protein family and its function is related to the regulation of cellular redox balance.
Any process that results in a change in state or activity of a cell or an organism (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of a stimulus indicating redox state. Redox state refers to the balance of oxidized versus reduced forms of electron donors and acceptors in an organelle, cell or organ; plastoquinone, glutathione (GSH/GSSG), and nicotinamide nucleotides (NAD+/NADH and NADP+/NADPH) are among the most important.
SelS is a newly identified selenoprotein and its gene expression is up-regulated in the liver of Psammomys obesus after fasting. We have examined whether SelS is regulated by glucose deprivation and endoplasmic reticulum (ER) stress in HepG2 cells. Glucose deprivation and the ER stress inducers tunicamycin and thapsigargin increased SelS gene expression and protein content several-fold in parallel with glucose-regulated protein 78. The overexpression of SelS increased Min6 cell resistance to oxidative stress-induced toxicity. These results indicate that SelS is a novel member of the glucose-regulated protein family and its function is related to the regulation of cellular redox balance.
Elimination of misfolded proteins from the endoplasmic reticulum (ER) by retro-translocation is an important physiological adaptation to ER stress. This process requires recognition of a substrate in the ER lumen and its subsequent movement through the membrane by the cytosolic p97 ATPase. Here we identify a p97-interacting membrane protein complex in the mammalian ER that links these two events. The central component of the complex, Derlin-1, is a homologue of Der1, a yeast protein whose inactivation prevents the elimination of misfolded luminal ER proteins. Derlin-1 associates with different substrates as they move through the membrane, and inactivation of Derlin-1 in C. elegans causes ER stress. Derlin-1 interacts with US11, a virally encoded ER protein that specifically targets MHC class I heavy chains for export from the ER, as well as with VIMP, a novel membrane protein that recruits the p97 ATPase and its cofactor.
A reference proteome is a set of protein sequences derived from a complete proteome which constitutes a defined standard for a particular user community. Reference proteomes are manually defined according to a number of criteria. They cover the proteomes of well- studied model organisms and other proteomes of interest for biomedical and biotechnological research. Reference proteomes have been selected to provide broad coverage of the tree of life, and constitute a representative cross-section of the taxonomic diversity to be found within UniProtKB.
My favorites 
My labels 
Login
