T. BRUCEI SPEF1/CLAMP IS REQUIRED FOR THE ANCHORAGE OF CYTOSKELETAL ORGANELLES TO THE BASAL BODIES

Abstract

Sperm flagellar protein 1 (Spef1), also known as CLAMP, with its microtubule functions, plays roles in spermatogenesis and central pair assembly in mouse and facilitates embryonic intercalation in Xenopus. In Trypanosoma brucei (T. brucei), the Spef1 ortholog (TbSpef1) associates with a specialized microtubule quartet (MTQ), which originates between the pro- and mature basal bodies. Knocking down of TbSpef1 results in defects in MTQ biogenesis and its linked organelles’ biogenesis/division. This study identified 37 putative TbSpef1 interacting partners and characterized 8 of them. One of them was found between the pro- and mature basal bodies. When being knocked down, this candidate severed the connection between the basal bodies and MTQ linked organelles. This study provided the first molecular identification of the connection between the MTQ and the basal bodies and revealed a conserved cellular function of Spef1 in polarized cell development in T. brucei.