RNF139
Description
The RNF139 (ring finger protein 139) is a protein-coding gene located on chromosome 8.
RING finger protein 139, also known as TRC8, is a protein that in humans is encoded by the RNF139 gene. The protein encoded by this gene is a multi-membrane spanning protein containing a RING-H2 finger. This protein is located in the endoplasmic reticulum, and has been shown to possess ubiquitin ligase activity. This gene was found to be interrupted by a t(3:8) translocation in a family with hereditary renal and non-medullary thyroid cancer. Studies of the Drosophila counterpart suggested that this protein may interact with tumor suppressor protein VHL, as well as with COPS5/JAB1, a protein responsible for the degradation of tumor suppressor CDKN1B/P27KIP.
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). {ECO:0000269|PubMed:10500182, ECO:0000269|PubMed:12032852, ECO:0000269|PubMed:17016439, ECO:0000269|PubMed:19706601, ECO:0000269|PubMed:19720873, ECO:0000269|PubMed:20068067, ECO:0000269|PubMed:22143767, ECO:0000269|PubMed:23223569}
RNF139 is also known as HRCA1, RCA1, TRC8.
