Required for formation of the sperm connecting piece during spermiogenesis. Sperm connecting piece is essential for linking the developing flagellum to the head during late spermiogenesis. May be involved in myosin-based microfilament transport through interaction with myosin subunits. Interacts with MYL6. Specifically localizes to the segmented columns and the capitulum of the sperm connecting piece. Testis-specific, in spermatocytes. Expression, first detected at 5 weeks of age, increases up to 15 weeks and remains high for at least 63 weeks. Belongs to the SPATA6 family. Truncated N-terminus. Truncated N-terminus.