May be an accessory component of axonemal dynein and cytoplasmic dynein 1 (PubMed:11278908, PubMed:12584439). Candidate for involvement in male sterility (By similarity). Interacts with CSNK2B. Found on the surface of sperm tail. Stored in cytoplasmic granules during spermatogenesis. Expressed predominantly in testis. Also expressed in brain, lung and trachea. Belongs to the dynein light chain Tctex-type family.