AUP1

The protein encoded this gene is involved in several pathways including quality control of misfolded proteins in the endoplasmic reticulum and lipid droplet accumulation. Lipid droplets are organelles in the cytoplasm that store neutral lipids such as cho

Full Name

AUP1, Lipid Droplet Regulating VLDL Assembly Factor

Function

Plays a role in the translocation of terminally misfolded proteins from the endoplasmic reticulum lumen to the cytoplasm and their degradation by the proteasome (PubMed:18711132, PubMed:21857022).
Plays a role in lipid droplet formation (PubMed:21857022).
Induces lipid droplet clustering (PubMed:24039768).
Recruits ubiquitin-conjugating enzyme UBE2G2 to lipid droplets which facilitates its interaction with ubiquitin ligases AMFR/gp78 and RNF139/TRC8, leading to sterol-induced ubiquitination of HMGCR and its subsequent proteasomal degradation (PubMed:23223569, PubMed:21127063).
Also required for the degradation of INSIG1, SREBF1 and SREBF2 (PubMed:23223569).
Plays a role in regulating assembly and secretion of very low density lipoprotein particles and stability of apolipoprotein APOB (PubMed:28183703).
(Microbial infection) Following Dengue virus infection, required for induction of lipophagy which facilitates production of virus progeny particles.

Biological Process

ER-associated misfolded protein catabolic process Source: UniProtKB
Lipid droplet formation Source: UniProtKB
Lipid droplet organization Source: UniProtKB
Lipophagy Source: UniProtKB
Protein localization to lipid droplet Source: UniProtKB
Response to virus Source: UniProtKB
Retrograde protein transport, ER to cytosol Source: ParkinsonsUK-UCL
Ubiquitin-dependent ERAD pathway Source: UniProtKB
Viral process Source: UniProtKB-KW

Cellular Location

Endoplasmic reticulum membrane; Lipid droplet; Autophagosome. (Microbial infection) Upon Dengue virus infection, relocates from lipid droplets to autophagosomes.

Topology

Cytoplasmic: 1-20 aa
Intramembrane: 21-41 aa
Cytoplasmic: 42-410 aa

PTM

Monoubiquitinated and diubiquitinated.
(Microbial infection) Not ubiquitinated following Dengue virus infection.