DDB1-CUL4-X-box complex

Function: - E3 ubiquitin-protein ligase complex - DDB1 may recruit specific substrate targeting subunits to the DCX complex - these substrate targeting subunits are generally known as DCAF (DDB1- & CUL4-associated factor) or CDW (CUL4-DDB1-associated WD40-repeat) proteins - DCX complexes may associate with the COP9 signalosome, & this inhibits the E3 ubiquitin-protein ligase activity of the complex Structure: - subunits seem to include DDB1, CUL4A or CUL4B, RBX1 & a variable substrate recognition components DCAF or CDW (see above) Notes: - DDCX complexes include a) DCX(DET1-COP1) complex with the substrate recognition component DET1 & COP1 b) DCX(DDB2) complex 1] also known as - DDB1-CUL4-ROC1, - CUL4-DDB-ROC1 - CUL4-DDB-RBX1) 2] substrate recognition component DDB2 3] may ubiquitinate histone H2A, histone H3 & histone H4 at sites of UV-induced DNA damage 4] ubiquitination of histones may facilitate their removal from the nucleosome & promote subsequent DNA repair 5] also ubiquitinates XPC, which may enhance DNA-binding by XPC & promote nucleotide excision repair c) DCX(ERCC8) complex 1] putative substrate recognition component ERCC8 2] role in transcription-coupled repair (TCR) 3] role in ubiquitination of CDKN1B/p27kip when associated with CUL4 & SKP2 d) DCX(DTL) complex 1] putative substrate recognition component DTL 2] role in PCNA-dependent polyubiquitination of CDT1 3] MDM2-dependent ubiquitination of TP53 in response to radiation-induced DNA damage & during DNA replication

Properties

SUBUNITS: DNA damage-binding protein 1 COMPARTMENT: cytoplasm cell nucleus MOTIF: CDT1 interaction {1-768} MOTIF: Thr phosphorylation site {T8} CUL4A interaction {391-709} Ser phosphorylation site {S757} Ser phosphorylation site {S766} CDT1/CUL4A interaction {771-1140} Cullin-4A MOTIF: Ser phosphorylation site {S10} Thr phosphorylation site {T22} Ser phosphorylation site {S99} Tyr phosphorylation site {Y227} Cullin-4B COMPARTMENT: cell nucleus MOTIF: serine-rich region {3-193} MOTIF: serine residue (SEVERAL) Thr phosphorylation site {T48} Thr phosphorylation site {T49} Thr phosphorylation site {T52} Ser phosphorylation site {S53} nuclear translocation signal {55-58} Ser phosphorylation site {S138} Ser phosphorylation site {S141} Ser phosphorylation site {S142} Ser phosphorylation site {S143} Ser phosphorylation site {S144} Ser phosphorylation site {S145} Ser phosphorylation site {S146} Thr phosphorylation site {T148} Ser phosphorylation site {S152} Ser phosphorylation site {S193} RING-box protein 1 COMPARTMENT: cytoplasm cell nucleus MOTIF: acetylation site SITE: N-TERMINUS EFFECTOR-BOUND: acetyl Ser phosphorylation site {S11} Zn+2-binding site SITE: 42-42 Zn+2-binding site SITE: 45-45 RING-finger {53-98} MOTIF: Zn+2-binding site SITE: 53-53 Zn+2-binding site SITE: 56-56 Zn+2-binding site SITE: 68-68 Zn+2-binding site SITE: 75-75 Zn+2-binding site SITE: 77-77 Zn+2-binding site SITE: 80-80 Zn+2-binding site SITE: 82-82 Zn+2-binding site SITE: 83-83 Zn+2-binding site SITE: 94-94 Zn+2-binding site SITE: 97-97 EFFECTOR-BOUND: Zn+2 FOR-BINDING-OF: DNA motif

References

UniProt :accession Q13619

Components

Cullin-4A; CUL-4A (CUL4A) Cullin-4B; CUL-4B (CUL4B KIAA0695) DNA damage-binding protein 1; damage-specific DNA-binding protein 1; UV-damaged DNA-binding factor; DDB p127 subunit; DNA damage-binding protein a; DDBa; UV-damaged DNA-binding protein 1; UV-DDB 1; Xeroderma pigmentosum group E-complementing protein; XPCe; XPE-binding factor; XPE-BF; HBV X-associated protein 1; XAP-1 (DDB1, XAP1) RING-box protein 1; Rbx1; regulator of cullins 1; RING finger protein 75; protein ZYP (RBX1 RNF75 ROC1)