ID:TOPRS_HUMAN DESCRIPTION: RecName: Full=E3 ubiquitin-protein ligase Topors; EC=6.3.2.-; AltName: Full=SUMO1-protein E3 ligase Topors; AltName: Full=Topoisomerase I-binding RING finger protein; AltName: Full=Topoisomerase I-binding arginine/serine-rich protein; AltName: Full=Tumor suppressor p53-binding protein 3; Short=p53-binding protein 3; Short=p53BP3; FUNCTION: Functions as an E3 ubiquitin-protein ligase and as an E3 SUMO1-protein ligase. Probable tumor suppressor involved in cell growth, cell proliferation and apoptosis that regulates p53/TP53 stability through ubiquitin-dependent degradation. May regulate chromatin modification through sumoylation of several chromatin modification-associated proteins. May be involved in DNA damage- induced cell death through IKBKE sumoylation. SUBUNIT: Interacts with PARK7/DJ-1 (By similarity). Interacts with TOP1. Interacts with p53/TP53; can both ubiquitinate and sumoylate p53/TP53. Interacts with the SUMO1 conjugating enzyme UBE2I. Interacts with SUMO1. Interacts with NKX3-1; polyubiquitinates NKX3-1 and induces its proteasomal degradation. Interacts with SIN3A; sumoylates SIN3A. Interacts with IKBKE; induced by DNA damage. SUBCELLULAR LOCATION: Nucleus. Nucleus, PML body. Note=Localizes to discrete nuclear foci which partly overlap with PML nuclear bodies. Targeted to PML nuclear bodies upon DNA damage. TISSUE SPECIFICITY: Expressed at highest levels in testis and at lower levels in adrenal gland, bone marrow, brain, colon, heart, kidney, liver, muscle, ovary, pancreas, placenta, prostate, skeletal muscle, skin, small intestine, spleen, stomach, testis, thymus, thyroid and uterus. Expressed in the alveolar epithelium of the lung. Expression is commonly decreased in colon adenocarcinomas and lung cancers. INDUCTION: By genotoxic agents such as cisplatin and camptothecin. PTM: Phosphorylation at Ser-98 regulates the E3 ubiquitin-protein ligase activity but not the SUMO1-protein ligase activity. Phosphorylation at Ser-718 increases the E3 ubiquitin-protein ligase activity versus the SUMO1-protein ligase activity resulting in increased p53/TP53 ubiquitination and degradation. PTM: Sumoylated. DISEASE: Defects in TOPORS are the cause of retinitis pigmentosa type 31 (RP31) [MIM:609923]. RP leads to degeneration of retinal photoreceptor cells. Patients typically have night vision blindness and loss of midperipheral visual field. As their condition progresses, they lose their far peripheral visual field and eventually central vision as well. RP31 inheritance is autosomal dominant. SIMILARITY: Contains 1 RING-type zinc finger. CAUTION: Was originally (PubMed:11278651) thought to bind to the palindromic consensus sequence 5'-TCCCAGCACTTTGGGA-3' and to regulate the transcription of numerous genes in the lung. SEQUENCE CAUTION: Sequence=AAC98530.1; Type=Erroneous initiation;
The RNAfold program from the Vienna RNA Package is used to perform the secondary structure predictions and folding calculations. The estimated folding energy is in kcal/mol. The more negative the energy, the more secondary structure the RNA is likely to have.
ModBase Predicted Comparative 3D Structure on Q9NS56
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Orthologous Genes in Other Species
Orthologies between human, mouse, and rat are computed by taking the best BLASTP hit, and filtering out non-syntenic hits. For more distant species reciprocal-best BLASTP hits are used. Note that the absence of an ortholog in the table below may reflect incomplete annotations in the other species rather than a true absence of the orthologous gene.
Biological Process: GO:0000209 protein polyubiquitination GO:0006351 transcription, DNA-templated GO:0006511 ubiquitin-dependent protein catabolic process GO:0006513 protein monoubiquitination GO:0006974 cellular response to DNA damage stimulus GO:0008630 intrinsic apoptotic signaling pathway in response to DNA damage GO:0010842 retina layer formation GO:0016925 protein sumoylation GO:0034504 protein localization to nucleus GO:0035845 photoreceptor cell outer segment organization GO:0042127 regulation of cell proliferation GO:0042771 intrinsic apoptotic signaling pathway in response to DNA damage by p53 class mediator GO:0043066 negative regulation of apoptotic process GO:0043161 proteasome-mediated ubiquitin-dependent protein catabolic process GO:0045893 positive regulation of transcription, DNA-templated GO:0046548 retinal rod cell development GO:0046549 retinal cone cell development GO:0051443 positive regulation of ubiquitin-protein transferase activity GO:0051457 maintenance of protein location in nucleus GO:0070936 protein K48-linked ubiquitination
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Sequence and Links to Tools and Databases 
Common Gene Haplotype Alleles 
