DDB1 Antibody – Mouse Monoclonal

The protein encoded by this gene is the large subunit (p127) of the heterodimeric DNA damage-binding (DDB) complex while another protein (p48) forms the small subunit. This protein complex functions in nucleotide-excision repair and binds to DNA following UV damage. Defective activity of this complex causes the repair defect in patients with xeroderma pigmentosum complementation group E (XPE) - an autosomal recessive disorder characterized by photosensitivity and early onset of carcinomas. However, it remains for mutation analysis to demonstrate whether the defect in XPE patients is in this gene or the gene encoding the small subunit. In addition, Best vitelliform mascular dystrophy is mapped to the same region as this gene on 11q, but no sequence alternations of this gene are demonstrated in Best disease patients. The protein encoded by this gene also functions as an adaptor molecule for the cullin 4 (CUL4) ubiquitin E3 ligase complex by facilitating the binding of substrates to this complex and the ubiquitination of proteins. [provided by RefSeq, May 2012]

DDB1: the large subunit of theUV- damaged DNA-binding protein complex (the UV-DDB complex) required for DNA repair. The UV- DDB complex may recognize UV-induced DNA damage and recruit proteins of the nucleotide excision repair pathway (the NER pathway) to initiate DNA repair. The UV-DDB complex preferentially binds to cyclobutane pyrimidine dimers (CPD), 6-4 photoproducts (6-4 PP), apurinic sites and short mismatches. Also appears to function as a component of numerous distinct DCX (DDB1-CUL4-X-box) E3 ubiquitin-protein ligase complexes which mediate the ubiquitination and subsequent proteasomal degradation of target proteins. The functional specificity of the DCX E3 ubiquitin- protein ligase complex is determined by the variable substrate recognition component recruited by DDB1. DCX(DDB2) (also known as DDB1-CUL4-ROC1, CUL4-DDB-ROC1 and CUL4-DDB-RBX1) may ubiquitinate histone H2A, histone H3 and histone H4 at sites of UV-induced DNA damage. The ubiquitination of histones may facilitate their removal from the nucleosome and promote subsequent DNA repair. DCX(DDB2) also ubiquitinates XPC, which may enhance DNA-binding by XPC and promote NER. DCX(DTL) plays a role in PCNA-dependent polyubiquitination of CDT1 and MDM2-dependent ubiquitination of p53 in response to radiation-induced DNA damage and during DNA replication. DCX(ERCC8) (the CSA complex) plays a role in transcription-coupled repair (TCR). May also play a role in ubiquitination of p27kip when associated with CUL4 and SKP2. Component of the UV-DDB complex which includes DDB1 and DDB2. The UV-DDB complex interacts with monoubiquitinated histone H2A and binds to XPC via the DDB2 subunit. Component of numerous DCX (DDB1-CUL4-X-box) E3 ubiquitin-protein ligase complexes which consist of a core of DDB1, CUL4A or CUL4B and RBX1. DDB1 may recruit specific substrate targeting subunits to the DCX complex. These substrate targeting subunits are generally known as DCAF (DDB1- and CUL4-associated factor) or CDW (CUL4-DDB1-associated WD40-repeat) proteins. Interacts with AMBRA1, ATG16L1, BTRC, DCAF1, DCAF17, DCAF16, DCAF15, DDA1, DET1, DTL, ERCC8, FBXW5, FBXW8, GRWD1, DCAF6, KATNB1, NLE1, NUP43, PAFAH1B1, PHIP, PWP1, RBBP4, RBBP5, RBBP7, RFWD2, SNRNP40, VPRBP, WDR5, WDR5B, WDR12, DCAF4, DCAF5, DCAF11, WDR26, DCAF10, WDR39, DCAF12, WDR42, DCAF8, WDR53, WDR59, WDR61, DCAF7, WSB1, WSB2 and WDTC1. DCX complexes may associate with the COP9 signalosome, and this inhibits the E3 ubiquitin-protein ligase activity of the complex. Interacts with NF2, TSC1 and TSC2. Interacts with Simian virus 5 protein V and the HBV X protein. Interaction with SV5 protein V may prevent the recruitment of DCAF proteins to DCX complexes. Interacts with EIF2C1 and EIF2C2. Associates with the E3 ligase complex containing DYRK2, UBR5, DDB1 and VPRBP proteins (EDVP complex). Interacts directly with DYRK2. Belongs to the DDB1 family.

Protein type: DNA repair, damage

Chromosomal Location of Human Ortholog: 11q12.2

Cellular Component: cytoplasm; extracellular space; nuclear chromosome, telomeric region; nucleoplasm; nucleus

Molecular Function: damaged DNA binding; DNA binding; protein binding

Biological Process: DNA damage response, detection of DNA damage; DNA repair; interaction with symbiont; nucleotide-excision repair; nucleotide-excision repair, DNA damage recognition; nucleotide-excision repair, DNA duplex unwinding; nucleotide-excision repair, DNA incision; nucleotide-excision repair, DNA incision, 3'-to lesion; nucleotide-excision repair, DNA incision, 5'-to lesion; nucleotide-excision repair, preincision complex assembly; nucleotide-excision repair, preincision complex stabilization; positive regulation of viral genome replication; positive regulation of viral protein levels in host cell; proteasomal ubiquitin-dependent protein catabolic process; protein ubiquitination during ubiquitin-dependent protein catabolic process; transcription-coupled nucleotide-excision repair