CUL4B Core component of multiple cullin-RING-based E3 ubiquitin-protein ligase complexes which mediate the ubiquitination and subsequent proteasomal degradation of target proteins. The functional specificity of the E3 ubiquitin-protein ligase complex depends on the variable substrate recognition subunit. CUL4B may act within the complex as a scaffold protein, contributing to catalysis through positioning of the substrate and the ubiquitin-conjugating enzyme. Plays a role as part of the E3 ubiquitin-protein ligase complex in polyubiquitination of CDT1, histone H2A, histone H3 and histone H4 in response to radiation-induced DNA damage. Targeted to UV damaged chromatin by DDB2 and may be important for DNA repair and DNA replication. Required for ubiquitination of cyclin E, and consequently, normal G1 cell cycle progression. Regulates the mammalian target-of-rapamycin (mTOR) pathway involved in control of cell growth, size and metabolism. Specific CUL4B regulation of the mTORC1-mediated pathway is dependent upon 26S proteasome function and requires interaction between CUL4B and MLST8. With CUL4A, contributes to ribosome biogenesis. Belongs to the cullin family. 3 alternatively spliced human isoforms have been reported. Note: This description may include information from UniProtKB.
Protein type: Cell cycle regulation
Chromosomal Location of mouse Ortholog: X|X A3.3
Cellular Component:  Cul4-RING E3 ubiquitin ligase complex; Cul4B-RING E3 ubiquitin ligase complex; cullin-RING ubiquitin ligase complex; cytosol; nucleoplasm; nucleus; SCF ubiquitin ligase complex
Molecular Function:  ubiquitin protein ligase binding
Biological Process:  cell cycle; cellular response to DNA damage stimulus; DNA repair; histone H2A monoubiquitination; neuron projection development; positive regulation of G1/S transition of mitotic cell cycle; positive regulation of protein catabolic process; proteasomal protein catabolic process; proteasome-mediated ubiquitin-dependent protein catabolic process; protein ubiquitination; ribosome biogenesis; SCF-dependent proteasomal ubiquitin-dependent protein catabolic process; ubiquitin-dependent protein catabolic process; UV-damage excision repair
Reference #:  A2A432 (UniProtKB)
Alt. Names/Synonyms: 2700050M05Rik; AA409770; CUL-4B; Cul4b; Cullin 4B; Cullin-4B; KIAA0695; mKIAA0695; OTTMUSP00000018749
Gene Symbols: Cul4b
Molecular weight: 110,699 Da
Basal Isoelectric point: 8.56  Predict pI for various phosphorylation states
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Protein Structure Not Found.

Cross-references to other databases:  AlphaFold  |  STRING  |  BioGPS  |  Pfam  |  Phospho.ELM  |  NetworKIN  |  UniProtKB  |  Entrez-Gene  |  Ensembl Gene