Chadwick et al. (1999) identified the Drosophila UBL3 gene. By searching an EST database using a Drosophila UBL3 cDNA as the query, they identified a human UBL3 EST. Using the EST, they isolated human keratinocyte stem cell cDNAs representing the complete UBL3 coding sequence.

The deduced 117-amino acid human UBL3 protein contains 2 potential N-glycosylation sites, a potential protein kinase C phosphorylation site, and a potential C-terminal prenylation site. It is relatively hydrophilic with no predicted transmembrane domains. Human UBL3 shares 69% amino acid sequence identity with 1 form of Drosophila UBL3 and 99% identity with mouse Ubl3, a cDNA of which Chadwick et al. (1999) also isolated.