USP16 is an active deubiquitinating enzyme (DUB) encoded on chromosome 21, trisomy of which causes Downs syndrome (DS). USP16 is a phosphoprotein, phosphorylation of USP16 controls its cellular localization, but no effect on its DUB activity. USP16 deubiquitinates histone 2A (H2A), through which USP16 might regulate gene expression and cell cycle progression. Increased USP16 protein levels in people with DS might contribute to the development of certain phenotypes of DS.
