May function as a regulator of both motility- and head-associated functions such as capacitation and the acrosome reaction. May bind calcium in vitro (By similarity).
Subcellular locations: Cytoplasm, Cytoplasm, Cytoskeleton, Cell projection, Cilium, Flagellum
Localized to fibrous sheath including the surface of the longitudinal columns and ribs of the principal piece of sperm flagella.