Anti-DDB1 Antibody Picoband®

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. And 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.

DNA damage-binding protein 1; DDB p127 subunit; DNA damage-binding protein a; DDBa; Damage-specific DNA-binding protein 1; HBV X-associated protein 1; XAP-1; UV-damaged DNA-binding factor; UV-damaged DNA-binding protein 1; UV-DDB 1; XPE-binding factor; XPE-BF; Xeroderma pigmentosum group E-complementing protein; XPCe; DDB1; XAP1

E.coli-derived human DDB1 recombinant protein (Position: S1011-H1140) . Human DDB1 shares 99.2% amino acid (aa) sequence identity with both mouse and rat DDB1.

Expressed in all tissues examined including fetal brain, fibroblasts, heart, brain, placenta, lung, liver, skeletal muscle, kidney, pancreas, spleen, thymus, prostate, testis, ovary, small intestine, colon and leukocytes. Highest levels in heart and skeletal muscle. .

Required for DNA repair. Binds to DDB2 to form the UV- damaged DNA-binding protein complex (the UV-DDB complex) . 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 TP53 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 CDKN1B/p27kip when associated with CUL4 and SKP2. .

1. Entrez Gene: DDB1 damage-specific DNA binding protein 1, 127kDa. 2. Dualan R, Brody T, Keeney S, Nichols AF, Admon A, Linn S (Feb 1996) . Chromosomal localization and cDNA cloning of the genes (DDB1 and DDB2) for the p127 and p48 subunits of a human damage-specific DNA binding protein. Genomics 29 (1) : 62–9. 3. Seki N, Hayashi A, Hattori A, Kozuma S, Sasaki M, Suzuki Y, Sugano S, Muramatsu M, Saito T (Jan 2000) . cDNA cloning, tissue expression, and chromosomal assignment of a mouse gene, encoding a 127 kDa UV-damaged DNA binding protein which is defective in XPE cells. DNA Res 6 (5) : 319–22.

Store at -20°C for one year from date of receipt. After reconstitution, at 4°C for one month. It can also be aliquotted and stored frozen at -20°C for six months. Avoid repeated freeze-thaw cycles.