HGS
Domain
Has a double-sided UIM that can bind 2 ubiquitin molecules, one on each side of the helix.
The FYVE-type zinc finger domain mediates interactions with phosphatidylinositol 3-phosphate in membranes of early endosomes and penetrates bilayers. The FYVE domain insertion into PtdIns(3)P-enriched membranes is substantially increased in acidic conditions.
Function
Involved in intracellular signal transduction mediated by cytokines and growth factors. When associated with STAM, it suppresses DNA signaling upon stimulation by IL-2 and GM-CSF. Could be a direct effector of PI3-kinase in vesicular pathway via early endosomes and may regulate trafficking to early and late endosomes by recruiting clathrin. May concentrate ubiquitinated receptors within clathrin-coated regions. Involved in down-regulation of receptor tyrosine kinase via multivesicular body (MVBs) when complexed with STAM (ESCRT-0 complex). The ESCRT-0 complex binds ubiquitin and acts as a sorting machinery that recognizes ubiquitinated receptors and transfers them to further sequential lysosomal sorting/trafficking processes. May contribute to the efficient recruitment of SMADs to the activin receptor complex. Involved in receptor recycling via its association with the CART complex, a multiprotein complex required for efficient transferrin receptor recycling but not for EGFR degradation.
Post-translational modifications
Phosphorylated on Tyr-334. A minor site of phosphorylation on Tyr-329 is detected (By similarity). Phosphorylation occurs in response to EGF, IL-2, GM-CSF and HGF.
Ubiquitinated (PubMed:25588945). Ubiquitinated by ITCH (PubMed:14602072, PubMed:24790097).
Tissue Specificity
Ubiquitous expression in adult and fetal tissues with higher expression in testis and peripheral blood leukocytes.
Cellular localization
- Cytoplasm
- Early endosome membrane
- Peripheral membrane protein
- Cytoplasmic side
- Endosome
- Multivesicular body membrane
- Peripheral membrane protein
- Colocalizes with UBQLN1 in ubiquitin-rich cytoplasmic aggregates that are not endocytic compartments.
Alternative names
HRS, HGS, Hepatocyte growth factor-regulated tyrosine kinase substrate, Hrs, Protein pp110