UBE2I (ubiquitin-conjugating enzyme E2I) is a protein coding gene. Proteins modified with ubiquitin are able to target abnormal or short-lived proteins for degradation. Ubiquitination uses three classes of enzymes: ubiquitin-activating enzymes (E1s), ubiquitin-conjugating enzymes (E2s), and ubiquitin-protein ligases (E3s). UBE2I encodes a member of the E2 ubiquitin-conjugating enzyme family. Four alternatively spliced transcript variants encoding the same protein have been identified for this gene.