External Ids for CUL4B Gene
Previous GeneCards Identifiers for CUL4B Gene
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]
GeneCards Summary for CUL4B Gene
CUL4B (Cullin 4B) is a Protein Coding gene. Diseases associated with CUL4B include mental retardation, x-linked, syndromic 15 and x-linked intellectual disability, vitale type. Among its related pathways are DNA Double-Strand Break Repair and Antigen processing- Ubiquitination and Proteasome degradation. GO annotations related to this gene include ubiquitin protein ligase binding and damaged DNA binding. An important paralog of this gene is CUL1.
UniProtKB/Swiss-Prot for CUL4B Gene
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.