Deubiquitinating Enzyme 3 (DUB3)

The deduced 530-amino acid protein shares approximately 44% overall sequence identity with the mouse Dub sequences and approximately 56% identity over the catalytic core, which contains UBP conserved domains I-VI and active site cysteine, aspartate, and histidine residues. DUB3 also contains a conserved 19-amino acid sequence that is present in 2 or 3 copies in mouse Dub sequences. Northern blot analysis detected 2 DUB3 transcripts: a 1.6-kb transcript in several tissues including heart, skeletal muscle, colon, kidney, and liver, and a 1.7-kb transcript in brain and liver. The 1.6-kb transcript was also detected at high levels in numerous cell lines derived from hematopoietic tumors such as a Burkitt lymphoma cell line as well as in solid tumors. In contrast, little DUB3 expression was detected in normal peripheral blood leukocytes and spleen.