RNF151 is a testis-specific RING finger protein with ubiquitin ligase activity. Based on limited published evidence, it contains a C3HC4-type RING finger domain and TRAF-type zinc finger domain, and is developmentally regulated during spermatogenesis 1. RNF151 localizes to the nucleus via its NLS and interacts physically with dysbindin 1. Given dysbindin's role in membrane biogenesis and fusion, RNF151 may be involved in acrosome formation of spermatids, though direct functional evidence remains limited.