Ubiquitin carboxyl-terminal hydrolase 44 (USP44)

Deubiquitinase that plays a key regulatory role in the spindle assembly checkpoint or mitotic checkpoint by preventing premature anaphase onset. Acts by especially mediating deubiquitination of CDC20, a negative regulator of the anaphase promoting complex/cyclosome (APC/C).

Deubiquitination of CDC20 leads to stabilize the MAD2L1-CDC20-APC/C ternary complex (also named mitotic checkpoint complex), thereby preventing premature activation of the APC/C. Promotes association of MAD2L1 with CDC20 and strengthens the spindle assembly checkpoint.