Calcium-binding protein (By similarity). Essential for maintaining the structural integrity of the sperm flagella (By similarity).
Subcellular locations: Cytoplasm, Mitochondrion inner membrane, Cell projection, Cilium, Flagellum, Cytoplasmic vesicle, Secretory vesicle, Acrosome
Mostly cytoplasmic, but associated with the mitochondrial inner membrane during the last steps of spermatid differentiation. Localizes to the principal piece of the sperm flagellum (By similarity).