CCDC189 is involved in sperm flagellum formation by interacting with CABCOCO1

Abstract Multiple morphological abnormalities of the sperm flagella (MMAF) is one major causes male infertility and characterized by multiple defects. In this study, we found that coiled-coil domain-containing 189 (Ccdc189) gene was predominantly expressed in mouse testes inactivation Ccdc189 caused infertility. Histological studies revealed most from Ccdc189-deficient mice carried coiled, curved, or short flagella, which are typical MMAF phenotypes. Immunoelectron microscopy showed CCDC189 protein located at radial spoke first peripheral microtubule doublets (MTDs) axoneme. A CCDC189-interacting protein, CABCOCO1, discovered via coimmunoprecipitation mass spectrometry, Cabcoco1 malformation consistent with findings obtained mice. Further downregulation CABCOCO1 expression both interacted spoke-specific RSPH1 intraflagellar transport proteins. This study demonstrated a spoke-associated involved flagellum formation through its interactions