Zonadhesin (ZAN)

Zonadhesin (abbreviated as ZAN) is a mosaic, multi-domain protein localized on the apical head of spermatozoa in mammals[1][2][3][4]. It is essential for mediating *species-specific adhesion* between sperm and the components of the egg’s extracellular matrix, known as the zona pellucida[1][2][3][4]. Zonadhesin is unique among sperm proteins for its direct and species-selective interaction with the zona pellucida, facilitating the initial steps of gamete recognition at fertilization[1][2][3][4]. Its domain structure typically includes multiple MAM (meprin/A5 antigen/mu receptor tyrosine phosphatase) domains, mucin-like domains, von Willebrand factor D (VWD) cell adhesion domains, epidermal growth factor (EGF)-like domains, and a transmembrane region[2][3][4]. Zonadhesin is expressed exclusively in testis and incorporated into the acrosome of developing sperm, becoming exposed during sperm capacitation and the acrosome reaction[1][2][3][4]. The protein shows rapid evolutionary change and domain diversification among species, reflecting its role in reproductive isolation and species specificity[1][2][3][4]. There are no established therapeutic drugs, biomarker uses, or safety concerns associated with zonadhesin, and it is not considered a conventional therapeutic target.

Other names

ZonadhesinZANzonadhesin