RNF40
Description
The RNF40 (ring finger protein 40) is a protein-coding gene located on chromosome 16.
RNF40 gene encodes an enzyme called E3 ubiquitin-protein ligase BRE1B. This protein contains a RING finger, a motif involved in protein-protein and protein-DNA interactions. It was found to interact with the tumor suppressor protein RB1. Research on the rat counterpart suggests that RNF40 functions as an E3 ubiquitin-protein ligase, facilitating the ubiquitination and degradation of syntaxin 1, a key component of neurotransmitter release.
RNF40, also known as BRE1B, plays a key role in epigenetic gene regulation as part of the RNF20/40 E3 ubiquitin-protein ligase complex. This complex monoubiquitinates histone H2B at lysine 120 (H2BK120ub1), a modification crucial for transcriptional activation. H2BK120ub1 acts as a specific tag, enabling subsequent methylation of histone H3 at lysine 4 and lysine 79 (H3K4me and H3K79me, respectively), further contributing to gene regulation. The RNF20/40 complex collaborates with the E2 enzymes UBE2A or UBE2B to achieve H2B ubiquitination, although the interaction with UBE2E1/UBCH is debated. RNF40 is essential for activating the transcription of Hox genes.
RNF40 is also known as BRE1B, RBP95, STARING.
