Ring Finger Protein 220 (RNF220)

Modification of proteins by ubiquitination plays important roles in various cellular processes. During this process, the target specificity is determined by ubiquitin ligases.

RNF220, an E3 ubiquitin ligase that targets Sin3B for ubiquitination. As a conserved RING protein, RNF220 can bind E2 and mediate auto-ubiquitination of itself. Sin3B as one of its targets, which is a scaffold protein of the Sin3/HDAC (histone deacetylase) corepressor complex. RNF220 specifically interacts with Sin3B both in vitro and in vivo. Sin3B can be regulated by the ubiquitin-proteasome system. Co-expression of RNF220 promotes the ubiquitination and proteasomal degradation of Sin3B. Taken together, these results reveal a new mechanism for regulating the Sin3/HDAC complex.