Tbio CUL4B Cullin-4B

Protein Summary

Description

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. This gene is a member of the cullin family. The encoded protein forms a complex that functions as an E3 ubiquitin ligase and catalyzes the polyubiquitination of specific protein substrates in the cell. The protein interacts with a ring finger protein, and is required for the proteolysis of several regulators of DNA replication including chromatin licensing and DNA replication factor 1 and cyclin E. Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jul 2008]

Uniprot Accession IDs

• Q13620
• B1APK5
• B3KVX4
• B7Z5K8
• Q6PIE4
• Q6UP07
• Q7Z673
• Q9BY37
• Q9UEB7
• Q9UED7
• CUL-4B

Gene Name

• CUL4B

Ensembl ID

• ENST00000371322
• ENSP00000360373
• ENSG00000158290
• ENST00000404115
• ENSP00000384109

Symbol

• KIAA0695
• SFM2
• MRXSC
• CUL-4B
• MRXHF2
• MRXS15

Knowledge Table

Most Knowledge About	Knowledge Value (0 to 1 scale)
transcription factor perturbation	0.97
protein domain	0.85
biological process	0.71
tissue	0.67
tissue sample	0.67

Protein Classes

PANTHER Classes

Protein / Ligase / Ubiquitin-protein Ligase / Cullin-4b

DTO Classes

Protein / Enzyme / Ligase / Ubiquitin-protein Ligase / Cullin-4b

IDG Development Level Summary

Tdark

These are targets about which virtually nothing is known. They do not have known drug or small molecule activities
- AND - satisfy two or more of the following criteria:

Pubmed score: 112.18   (req: < 5)

Gene RIFs: 46   (req: <= 3)

Antibodies: 351   (req: <= 50)

Tbio

These targets do not have known drug or small molecule activities
- AND - satisfy two or more of the following criteria:

Pubmed score: 112.18   (req: >= 5)

Gene RIFs: 46   (req: > 3)

Antibodies: 351   (req: > 50)

- OR - satisfy the following criterion:

Gene Ontology Terms: 20

Tchem

Target has at least one ChEMBL compound with an activity cutoff of < 30 nM - AND - satisfies the preceding conditions

Active Ligand: 0

Tclin

Target has at least one approved drug - AND - satisfies the preceding conditions

Active Drug: 0