May be a substrate-specific adapter of a CUL3-based E3 ubiquitin-protein ligase complex which mediates the ubiquitination and subsequent proteasomal degradation of target proteins during spermatogenesis. Required for male fertility. Protein modification; protein ubiquitination. Self-associates (By similarity). Interacts with CUL3; indicative for the participation in an E3 ubiquitin ligase complex. Testis specific. Expressed in elongating and elongated spermatids (steps 9-16). Heterozygous males are completely infertile because of disrupted spermiogenesis characterized by asynchronous spermatid maturation, degeneration of late spermatids, sloughing of postmeiotic germ cells from the seminiferous epithelium, and marked reduction in the numbers of late spermatids. Does not seem to associate with actin.