Zea mays pollen coat protease (ZmPCP)

Zea mays pollen coat protease (ZmPCP), also known as ZmCP03, is a 25-kDa papain-like cysteine protease belonging to the C1-papain family. It is synthesized specifically in the anther tapetum cells and deposited onto the pollen surface during the final stages of maturation following tapetal programmed cell death. Biologically, ZmPCP is essential for successful plant reproduction as it facilitates pollen-stigma recognition, adhesion, and germination, likely by hydrolyzing proteins on the stigma surface to assist pollen tube penetration. In the context of human health, ZmPCP is recognized as an IgE-reactive component of maize pollen, contributing to seasonal rhinitis and asthma by potentially disrupting airway epithelial barriers. Within the agricultural biotechnology sector, ZmPCP is considered a target for engineering male sterility to facilitate hybrid seed production and for improving drought tolerance in crops. While there are currently no approved human therapeutic drugs targeting this protease, research utilized inhibitors such as E-64 to characterize its activity and its role in allergic sensitization.

Other names

ZmPCPZmCP03Maize 25-kD pollen-coat proteinCysteine protease ZmCP03Pollen-specific cysteine protease

Proteolytic cleavage of stigma surface proteins to facilitate pollen tube penetration and disruption of airway epithelial junctions in allergic responses