Reference - PMID:17762864 - Conserved function of RNF4 family proteins in eukaryotes: targeting a ubiquitin ligase to SUMOylated proteins.
Reference summary
- PubMed ID
- PMID:17762864
- Title
- Conserved function of RNF4 family proteins in eukaryotes: targeting a ubiquitin ligase to SUMOylated proteins.
- Authors
- Sun H, Leverson JD, Hunter T
- Citation
- EMBO J 2007 Sep 19;26(18):4102-12
- Publication year
- 2007
- Abstract
- The function of small ubiquitin-like modifier (SUMO)-binding proteins is key to understanding how SUMOylation regulates cellular processes. We identified two related Schizosaccharomyces pombe proteins, Rfp1 and Rfp2, each having an N-terminal SUMO-interacting motif (SIM) and a C-terminal RING-finger domain. Genetic analysis shows that Rfp1 and Rfp2 have redundant functions; together, they are essential for cell growth and genome stability. Mammalian RNF4, an active ubiquitin E3 ligase, is an orthologue of Rfp1/Rfp2. Rfp1 and Rfp2 lack E3 activity but recruit Slx8, an active RING-finger ubiquitin ligase, through a RING-RING interaction, to form a functional E3. RNF4 complements the growth and genomic stability defects of rfp1rfp2, slx8, and rfp1rfp2slx8 mutant cells. Both the Rfp-Slx8 complex and RNF4 specifically ubiquitylate artificial SUMO-containing substrates in vitro in a SUMO binding-dependent manner. SUMOylated proteins accumulate in rfp1rfp2 double-null cells, suggesting that Rfp/Slx8 proteins may promote ubiquitin-dependent degradation of SUMOylated targets. Hence, we describe a family of SIM-containing RING-finger proteins that potentially regulates eukaryotic genome stability through linking SUMO-interaction with ubiquitin conjugation.
