The protein encoded by this gene is a highly conserved ring finger protein. It is an essential subunit of SKP1-cullin/CDC53-F box protein ubiquitin ligases, which are a part of the protein degradation machinery important for cell cycle progression and signal transduction. This protein interacts with, and is a substrate of, casein kinase II (CSNK2A1/CKII). The phosphorylation of this protein by CSNK2A1 has been shown to promote the degradation of IkappaBalpha (CHUK/IKK-alpha/IKBKA) and p27Kip1(CDKN1B). Alternatively spliced transcript variants encoding distinct isoforms have been reported. [provided by RefSeq, Jul 2008].