RNF139
Domain
The RING-type zinc finger domain mediates ubiquitin ligase activity.
Function
E3-ubiquitin ligase; acts as a negative regulator of cell proliferation through mechanisms involving G2/M arrest and cell death (PubMed:10500182, PubMed:12032852, PubMed:17016439). Required for MHC class I ubiquitination in cells expressing the cytomegalovirus protein US2 before dislocation from the endoplasmic reticulum (ER) (PubMed:19720873). Affects SREBP processing by hindering the SREBP-SCAP complex translocation from the ER to the Golgi, thereby reducing SREBF2 target gene expression (PubMed:19706601, PubMed:20068067). Involved in the sterol-accelerated degradation of HMGCR (PubMed:22143767, PubMed:23223569). This is achieved through binding of RNF139 to INSIG1 and/or INSIG2 at the ER membrane (PubMed:22143767). In addition, interaction of RNF139 with AUP1 facilitates interaction of RNF139 with ubiquitin-conjugating enzyme UBE2G2 and ubiquitin ligase AMFR, leading to ubiquitination of HMGCR (PubMed:23223569). The ubiquitinated HMGCR is then released from the ER into the cytosol for subsequent destruction (PubMed:22143767, PubMed:23223569). Required for INSIG1 ubiquitination (PubMed:20068067). May be required for EIF3 complex ubiquitination (PubMed:20068067).
Involvement in disease
Renal cell carcinoma
RCC
Renal cell carcinoma 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. Clear cell renal cell carcinoma is the most common subtype.
None
The disease may be caused by variants affecting the gene represented in this entry. 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.
Pathway
Protein modification; protein ubiquitination.
Post-translational modifications
Autoubiquitinated. Ubiquitination is induced by sterol and leads to ist degradation via the ubiquitin-proteasome pathway.
Tissue Specificity
Highly expressed in testis, placenta and adrenal gland. Moderate expression in heart, brain, liver, skeletal muscle and pancreas, and low expression in lung and kidney.
Cellular localization
- Endoplasmic reticulum membrane
- Multi-pass membrane protein
Alternative names
TRC8, RNF139, E3 ubiquitin-protein ligase RNF139, RING finger protein 139, RING-type E3 ubiquitin transferase RNF139, Translocation in renal carcinoma on chromosome 8 protein