Ubiquitin carboxyl-terminal hydrolase 9Y (USP9Y)

Ubiquitin carboxyl-terminal hydrolase 9Y (USP9Y) is an enzyme encoded by the USP9Y gene located in the azoospermia factor (AZF) region on the Y chromosome. It is a member of the peptidase C19 family and functions as a deubiquitinase that cleaves the ubiquitin moiety from ubiquitin-fused precursors and ubiquitinylated proteins, playing a critical role in protein homeostasis and stabilization. USP9Y has an essential role in normal spermatogenesis, with mutations linked to male infertility and Sertoli cell-only syndrome. Although some individuals can remain fertile despite USP9Y deletions, it is generally considered necessary for optimal sperm production. USP9Y is testis-specific in expression and homologous to the X-linked USP9X.

Other names

DFFRYFAF-YSPGFY2Ubiquitin-specific protease 9, Y chromosomeUbiquitin specific peptidase 9 Y-linkedUbiquitin thioesterase FAF-YFat facets protein-related, Y-linkedUbiquitin-specific-processing protease FAF-YFat facets-like homolog (Drosophila)Azoospermia factor ADeubiquitinating enzyme FAF-Y

No therapeutic drugs targeting USP9Y are described; therefore, mechanism of action is not established. Its enzymatic activity relates to the removal of ubiquitin from target proteins.