CASK interacts with PMCA4b and JAM‐A on the mouse sperm flagellum to regulate Ca 2+ homeostasis and motility

Deletion of the highly conserved gene for the major Ca 2+ efflux pump, Plasma membrane calcium/calmodulin‐dependent ATPase 4b (Pmca4b) , in the mouse leads to loss of progressive and hyperactivated sperm motility and infertility. Here we first demonstrate that compared to wild‐type (WT), Junctional adhesion molecule‐A ( Jam‐A ) null sperm, previously shown to have motility defects and an abnormal mitochondrial phenotype reminiscent of that seen in Pmca4b nulls, exhibit reduced ( P