Has an essential role in the formation of sperm flagella and flagellar structure maintainance. It acts as a suppressor of ubiquitination and degradation of proteins involved in flagellar development and motility. Interacts with AKAP3, ODF2 and TSSK4. Localization varies during spermatozoa development. The protein is distributed in the nuclear membrane of the spermatogonia, in the nucleus of round spermatids, in the nucleus and cytoplasm of early elongating spermatids, in the cytoplasm of late elongating spermatids, and in the flagella of epididymal spermatozoa. Expressed in testis (PubMed:30683861). Not detected in heart, brain, kidney, stomach, ovary, liver, lung and uterus. Significant expression begins at postnatal day 15 and reaches a peak at postnatal day 22. Stable and high expression is detected after postnatal day 22. Knockout mice show coiled, bent, irregular, short or absent flagella, defects of sperm flagellar ultrastructure, a significant reduction in sperm locomotion, and decreased sperm count.