Folding and assembly of proteins synthesized in the endoplasmic reticulum is closely monitored by a quality control apparatus that diverts folding-defective products to the cytosol to be degraded by the ubiquitin-proteasome system by a process known as endoplasmic reticulum-associated degradation (ERAD). The long-term goal of this project is to elucidate the mechanisms by which ERAD recognizes and destroys its targets. In the previous funding period we successfully implemented a large scale functional genomic analysis of the mammalian ERAD system that allowed us to perform unbiased analysis of substrate-selective ERAD in mammals. These data led to critical discoveries about the mechanisms of substrate triage and delivery to the HRD1 dislocon/ligase and the role of unconventional ubiquitin conjugation in coupling dislocation to degradation. The studies proposed in the present application harness state-of-the-art technologies that extend these discoveries and if successful will bring about a detailed molecular-level understanding of triage and quality control in the early secretory pathway. !

Public Health Relevance

Protein quality control (PQC) is the process by which cells monitor and maintain the conformational integrity of their proteome and defects in PQC underlie the pathogenesis of many human diseases. PQC systems ensure that proteins which fail correctly fold or assemble are recognized and degraded by the ubiquitin-proteasome system (UPS). This proposal seeks to elucidate the molecular mechanisms by which such folding-defective proteins are recognized and handed off to the UPS.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM074874-15
Application #
10106472
Study Section
Membrane Biology and Protein Processing Study Section (MBPP)
Program Officer
Phillips, Andre W
Project Start
2006-05-01
Project End
2023-01-31
Budget Start
2021-02-01
Budget End
2022-01-31
Support Year
15
Fiscal Year
2021
Total Cost
Indirect Cost
Name
Stanford University
Department
Biology
Type
Schools of Arts and Sciences
DUNS #
009214214
City
Stanford
State
CA
Country
United States
Zip Code
94305
van der Goot, Annemieke T; Pearce, Margaret M P; Leto, Dara E et al. (2018) Redundant and Antagonistic Roles of XTP3B and OS9 in Decoding Glycan and Non-glycan Degrons in ER-Associated Degradation. Mol Cell 70:516-530.e6
Leto, Dara E; Morgens, David W; Zhang, Lichao et al. (2018) Genome-wide CRISPR Analysis Identifies Substrate-Specific Conjugation Modules in ER-Associated Degradation. Mol Cell :
Pataki, Camille I; Rodrigues, João; Zhang, Lichao et al. (2018) Proteomic analysis of monolayer-integrated proteins on lipid droplets identifies amphipathic interfacial ?-helical membrane anchors. Proc Natl Acad Sci U S A 115:E8172-E8180
Hwang, Jiwon; Walczak, Christopher P; Shaler, Thomas A et al. (2017) Characterization of protein complexes of the endoplasmic reticulum-associated degradation E3 ubiquitin ligase Hrd1. J Biol Chem 292:9104-9116
Schrul, Bianca; Kopito, Ron R (2016) Peroxin-dependent targeting of a lipid-droplet-destined membrane protein to ER subdomains. Nat Cell Biol 18:740-51
Olzmann, James A; Kopito, Ron R; Christianson, John C (2013) The mammalian endoplasmic reticulum-associated degradation system. Cold Spring Harb Perspect Biol 5:
Olzmann, James A; Richter, Caleb M; Kopito, Ron R (2013) Spatial regulation of UBXD8 and p97/VCP controls ATGL-mediated lipid droplet turnover. Proc Natl Acad Sci U S A 110:1345-50
Tyler, Ryan E; Pearce, Margaret M P; Shaler, Thomas A et al. (2012) Unassembled CD147 is an endogenous endoplasmic reticulum-associated degradation substrate. Mol Biol Cell 23:4668-78
Dowlatshahi, Dara P; Sandrin, Virginie; Vivona, Sandro et al. (2012) ALIX is a Lys63-specific polyubiquitin binding protein that functions in retrovirus budding. Dev Cell 23:1247-54
Greenblatt, Ethan J; Olzmann, James A; Kopito, Ron R (2012) Making the cut: intramembrane cleavage by a rhomboid protease promotes ERAD. Nat Struct Mol Biol 19:979-81

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