RING Finger-B Box-Coiled Coil (RBCC) Proteins As Ubiquitin Ligase in the Control of Protein Degradation and Gene Regulation

The protein family harboring the RING finger motif, defined as a linear array of conserved cysteines and histidines, has grown enormously in the last decade. The members of the family are involved in various biological processes including growth, differentiation, apoptosis, transcription and also in diseases and oncogenesis. It has been postulated that the RING finger domains have crucial roles in these phenomena themselves, in some cases, working with other domains in other proteins, although the precise mechanisms and common features of RING finger function have not been fully elucidated. However, most recently, an accumulating body of evidence has revealed that some of the RING finger proteins work as E3 ubiquitin ligases in ubiquitin-mediated specific protein degradation pathway. In this review, we focus on the RING finger protein with special reference to E3 ligase.