Ornithine decarboxylase antizyme 3 (OAZ3)

**Ornithine decarboxylase antizyme 3 (OAZ3)** is a member of the antizyme family, proteins known to regulate ornithine decarboxylase (ODC) and thus polyamine biosynthesis[1][3][6]. OAZ3 expression is highly specific to haploid germ cells in the testis, where it is essential for spermatogenesis and for the structural coupling of sperm head and tail[1][2][8]. Unlike OAZ1 and OAZ2, OAZ3 does not efficiently promote ODC degradation, and its primary protein product in sperm is a 12 kDa protein (p12) that lacks the canonical antizyme-ODC interaction domain[2][8]. This protein interacts with myosin phosphatase targeting subunit 3 (MYPT3) and modulates protein phosphatase activity relevant to sperm structure[2][8]. Knockout of the OAZ3 gene in mice causes male infertility due to detachment of sperm heads and tails, confirming its specialized role in sperm morphology[1][2][8]. There are currently no drugs known to directly target OAZ3, and it is not considered a classical therapeutic target. Its unique, testis-specific function makes it biologically interesting but limits its relevance for drug therapy outside reproductive medicine.

Other names

AZ3ODC-Az 3OAZ-tTISP15antizyme 3testicular secretory protein Li 31