Required for optimal fertilization at the stage of sperm-oocyte fusion, plays a role in optimizing acrosome function, the translocation of IZUMO1 during the acrosome reaction and the fertilization process. Component of epididymosomes, one type of membranous microvesicules which mediate the transfer of lipids and proteins to spermatozoa plasma membrane during epididymal maturation. Also component of the CD9-positive microvesicules found in the cauda region.
Subcellular locations: Cytoplasmic vesicle, Secretory vesicle, Acrosome, Cell membrane, Membrane raft, Secreted
Located in the connecting piece of elongated spermatids and sperm. Also located in the apical region of the sperm head after sperm capacitation (By similarity). Weakly attached to the cell membrane and later secreted into the extracellular space (By similarity). Located on sperm equatorial segment and neck (By similarity). Associated with epididymosomes from the caput and cauda epididymis (By similarity).
Highly expressed in testis.