USP8
Domain
The MIT domain is required for endosomal localization, CHMP1B-binding, maintenance of ESCRT-0 stability and EGFR degradation.
The rhodanese domain is sufficient for RNF41-binding.
Function
Hydrolase that can remove conjugated ubiquitin from proteins and therefore plays an important regulatory role at the level of protein turnover by preventing degradation. Converts both 'Lys-48' an 'Lys-63'-linked ubiquitin chains. Catalytic activity is enhanced in the M phase. Involved in cell proliferation. Required to enter into S phase in response to serum stimulation. May regulate T-cell anergy mediated by RNF128 via the formation of a complex containing RNF128 and OTUB1. Probably regulates the stability of STAM2 and RASGRF1. Regulates endosomal ubiquitin dynamics, cargo sorting, membrane traffic at early endosomes, and maintenance of ESCRT-0 stability. The level of protein ubiquitination on endosomes is essential for maintaining the morphology of the organelle. Deubiquitinates EPS15 and controls tyrosine kinase stability. Removes conjugated ubiquitin from EGFR thus regulating EGFR degradation and downstream MAPK signaling. Involved in acrosome biogenesis through interaction with the spermatid ESCRT-0 complex and microtubules. Deubiquitinates BIRC6/bruce and KIF23/MKLP1. Deubiquitinates BACE1 which inhibits BACE1 lysosomal degradation and modulates BACE-mediated APP cleavage and amyloid-beta formation (PubMed:27302062).
Involvement in disease
Pituitary adenoma 4, ACTH-secreting
PITA4
A form of pituitary adenoma, a neoplasm of the pituitary gland and one of the most common neuroendocrine tumors. Pituitary adenomas are clinically classified as functional and non-functional tumors, and manifest with a variety of features, including local invasion of surrounding structures and excessive hormone secretion. Functional pituitary adenomas are further classified by the type of hormone they secrete. PITA4 results in excessive production of adrenocorticotropic hormone. This leads to hypersecretion of cortisol by the adrenal glands and ACTH-dependent Cushing syndrome. Clinical manifestations of Cushing syndrome include facial and truncal obesity, abdominal striae, muscular weakness, osteoporosis, arterial hypertension, diabetes.
None
The disease is caused by variants affecting the gene represented in this entry.
Post-translational modifications
Phosphorylation of Ser-718 is essential for interaction with YWHAE and for cytosol localization. Undergoes dephosphorylation at Ser-718 in the M phase. Tyrosine-phosphorylated in its N-terminal half in an EGFR-dependent manner.
Ubiquitinated. Inactive form is mostly monoubiquitinated, but polyubiquitination happens too. Ubiquitination is increased in EGF-stimulated cells. Ubiquitination of active form is undetectable, suggesting a possibility that USP8 deubiquitinates itself, thereby regulating its own function (By similarity).
Sequence Similarities
Belongs to the peptidase C19 family.
Cellular localization
- Cytoplasm
- Nucleus
- Endosome membrane
- Peripheral membrane protein
- Cell membrane
- Peripheral membrane protein
Alternative names
KIAA0055, UBPY, USP8, Ubiquitin carboxyl-terminal hydrolase 8, Deubiquitinating enzyme 8, Ubiquitin isopeptidase Y, Ubiquitin thioesterase 8, Ubiquitin-specific-processing protease 8, hUBPy