Sperm acrosome associated 4 (SPACA4)

Sperm acrosome associated 4 (SPACA4) is a sperm-specific, acrosomal membrane-associated protein expressed exclusively in the sperm head, where it becomes exposed during the acrosome reaction. SPACA4 is essential for sperm binding and penetration of the zona pellucida, a critical step required for mammalian fertilization. Knockout models in mice show that loss of SPACA4 leads to severely reduced male fertility, as SPACA4-deficient sperm are unable to effectively interact with and traverse the zona pellucida, despite normal motility and acrosome reaction. SPACA4 is not required for sperm–egg plasma membrane (oolemma) binding. The gene is highly conserved and appears essential for efficient mammalian gamete interaction, but there is no current evidence for direct drug interaction or established use as a biomarker or therapeutic target[1][3][4][5].

Other names

SAMP14Sperm acrosome membrane-associated protein 4Sperm acrosomal membrane-associated protein 14Sperm acrosomal membrane protein 14Testicular tissue protein Li 167UNQ3046/PRO9862[5]