Molecular Target Synopsis
Domains and Structures
Drugs and Clinical Candidates
Ligand Efficiency Plot
Family Cladogram
Interaction Network
Gene Expression
Gene Copy Number Variation
Germline Genetics

CUL4B (Q13620) - Overview - Molecular Target Synopsis


CUL4B, Cullin-4B
UniProt Q13620

Also Known as CUL4B_HUMAN, CUL4B, KIAA0695

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. Component of multiple DCX (DDB1-CUL4-X-box) E3 ubiquitin-protein ligase complexes that seem to be formed of DDB1, CUL4A or CUL4B, RBX1 and a variable substrate recognition component which seems to belong to a protein family described as DCAF (Ddb1- and Cul4-associated factor) or CDW (CUL4-DDB1-associated WD40-repeat) proteins. Component of the DCX(DTL) complex with the putative substrate recognition component DTL. Component of the DCX(DDB2) complex with the putative substrate recognition component DDB2. Part of a complex with RBX1 and TIP120A/CAND1. Interacts with RBX1 GRWD1, MLST8, SMU1, TLE2, TLE3, DCAF1, DDA1, DCAF6, DCAF17, DDB2, DCAF8, TIP120A/CAND1 and TMEM113. Interacts with cyclin E and with importins alpha-1 (KPNA2), alpha-3 (KPNA4), alpha-5 (KPNA1) and beta-1 (KPNB1). May interact with WDR26, WDR51B, SNRNP40, WDR61, WDR76 and WDR5.

Inspect Structure
See all 3D Structures for CUL4B

Isoforms / Transcripts (Protein Coding)

Sub-cellular localization

UniProt: CUL4B is active in the following subcellular-locations: nucleus.
GO terms: CUL4B is active in the following subcellular-locations: Cul4-RING E3 ubiquitin ligase complex, Cul4B-RING E3 ubiquitin ligase complex, cullin-RING ubiquitin ligase complex, cytosol, extracellular exosome, nucleoplasm, SCF ubiquitin ligase complex.

GO terms

Gene Copy Number Variation

In COSMIC - Cell Lines Project CUL4B has gain in 0 cell-lines, loss in 31 cell-lines and no signal in 974 cell-lines. (see details)

Gene Expression

In NCI60, the highest expressing cell lines are: SF_268, SNB_19, MDA_MB_231

In Array Express (RNA-seq of 675 commonly used human cancer cell lines), the highest expressing cell lines are: HCC38, CAL-120, SNU-423

In Array Express (RNA-seq of long poly adenylated RNA and long non poly adenylated RNA from ENCODE cell lines), the highest expressing cell lines are: NHLF, SK-N-SH, BJ

(see details)

3D Structures

For CUL4B there are:
4 structures (9 chains) solved
0 are solved in complex with at least one small molecule ligand

(see details)
Molecular Target 3D Synopsis