Sperm-specific intramembrane-cleaving aspartic protease (I-CLiP) that cleaves distinct tail-anchored proteins and SNARE proteins . In elongated spermatids, modulates intracellular Ca(2+) homeostasis by controlling PLN abundance through proteolytic cleavage (By similarity). During spermatogenesis, processes SNARE proteins and impacts vesicular trafficking which supports compartmental reorganization in maturating spermatids and may play a role in formation of the acrosome .
In round spermatids, acts as a scaffold protein supporting FREY1 in IZUMO1 recruitment at the endoplasmic reticulum membrane and coordination of IZUMO1 complex assembly. Stabilizes FREY1 at the endoplasmic reticulum membrane through interaction. May recruit IZUMO1 interaction partners.
Subcellular locations: Endoplasmic reticulum membrane
Highly expressed in testis where it is primarily localised in spermatids (at protein level).