Ubiquitin carboxyl-terminal hydrolase 21 (USP21)

Deubiquitinates histone H2A, a particular tag for epigenetic transcriptional repression, thereby acting as a coactivator. Deubiquitination of histone H2A releaves the repression of both di- and trimethylation of histone H3 in'Lys-4', resulting in regulation of transcriptional initiation.

Regulates gene expression through histone H2A deubiquitination (By similarity). Also capable of removing NEDD8 from NEDD8 conjugates but has no impact on Sentrin-1 conjugates (PubMed:10799498).