cl11156

Kua-ubiquitin conjugating enzyme hybrid localisation domain; This domain is part of the transcript of the fusion of two genes, the UEV1, an enzymatically inactive variant of the E2 ubiquitin-conjugating enzymes that regulate non-canonical elongation of ubiquitin chains, and Kua, an otherwise unknown gene. UEV1A is a nuclear protein, whereas both Kua and Kua-UEV localize to cytoplasmic structures, indicating that the addition of a Kua domain to UEV confers new biological properties. UEV1-Kua carries the B domain with its characteristic double histidine motif, and it is probably this domain which determines the cytoplasmic localisation. It is postulated that this hybrid transcript could preferentially direct the variant polyubiquitination of substrates closely associated with the cytoplasmic face of the endoplasmic reticulum, possibly, although not necessarily, in conjunction with membrane-bound ubiquitin-conjugating enzymes.