The modification of proteins with ubiquitin is an important cellular mechanism for targeting abnormal or short-lived proteins for degradation. Ubiquitination involves at least three classes of enzymes: ubiquitin-activating enzymes, or E1s, ubiquitin-conjugating enzymes, or E2s, and ubiquitin-protein ligases, or E3s. This gene encodes a member of the E2 ubiquitin-conjugating enzyme family. The encoded protein sequence is 100% identical to the mouse homolog and 98% identical to the frog and zebrafish homologs. Three alternatively spliced transcript variants have been found for this gene and they encode distinct isoforms. [provided by RefSeq, Feb 2011]