RNF139: E3-ubiquitin ligase; acts as a negative regulator of the cell proliferation through mechanisms involving G2/M arrest and cell death. Required for MHC class I ubiquitination in cells expressing the cytomegalovirus protein US2 before dislocation from the endoplasmic reticulum (ER). Affects SREBP processing by hindering the SREBP/SCAP complex translocation from the ER to the Golgi, thereby reducing SREBF2 target gene expression. Required for INSIG1 ubiquitination. May be required for EIF3 complex ubiquitination. May function as a signaling receptor. Defects in RNF139 may be a cause of renal cell carcinoma (RCC). It is a heterogeneous group of sporadic or hereditary carcinoma derived from cells of the proximal renal tubular epithelium. It is subclassified into clear cell renal carcinoma (non-papillary carcinoma), papillary renal cell carcinoma, chromophobe renal cell carcinoma, collecting duct carcinoma with medullary carcinoma of the kidney, and unclassified renal cell carcinoma. A chromosomal aberration involving RNF139 has been found in a lymphoblastoid cell line established from a family with renal cell carcinoma and thyroid carcinoma. Translocation (3;8)(q14.2;q24.1) with FHIT. RNF139 is found to be fused to FHIT and disrupted within the sterol-sensing domain. In contrast, the FHIT coding region is maintained and expressed. Sporadic cases of renal carcinoma, where an acquired mutation in RNF139 results in the duplication of 12 nucleotides in the 5'-UTR, has also been identified.
Protein type: Membrane protein, multi-pass; Ubiquitin ligase; Ligase; EC 6.3.2.-; Ubiquitin conjugating system; EC 6.3.2.19; Membrane protein, integral
Chromosomal Location of Human Ortholog: 8q24
Cellular Component: endoplasmic reticulum; integral to membrane
Molecular Function: ligase activity; protease binding; protein binding; receptor activity; small conjugating protein ligase activity; ubiquitin-protein ligase activity; zinc ion binding
Biological Process: negative regulation of cell proliferation; negative regulation of translation; proteasomal ubiquitin-dependent protein catabolic process; protein destabilization; protein polyubiquitination; protein ubiquitination; regulation of protein ubiquitination
Disease: Renal Cell Carcinoma, Nonpapillary
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