BICD2 promotes ciliogenesis by facilitating CP110 removal from the mother centriole

Abstract Cilia are hair-like organelles that protrude from the cell surface and play vital roles in embryonic development and tissue homeostasis. Removal of centriolar coiled-coil protein 110 (CP110) from the mother centriole is a critical step in ciliogenesis, yet the underlying mechanism remains largely unknown. In this study, we identify bicaudal D cargo adaptor 2 (BICD2) as a mother centriole protein that directly binds CP110 and facilitates its removal to promote ciliogenesis. Depletion of BICD2 significantly inhibits ciliogenesis and the removal of CP110, whereas knockdown of CP110 rescues ciliogenesis defects in BICD2-deficient cells. Additionally, we show that BICD2 is recruited to the mother centriole during ciliogenesis, where it directly binds and removes CP110. Moreover, zebrafish bicd2 morphants exhibit developmental abnormalities and defective ciliogenesis, which can be reversed by reintroducing bicd2 mRNA or depleting Cp110. Our findings establish BICD2 as a key regulator of ciliogenesis through its role in CP110 removal, shedding light on the molecular mechanisms of cilia formation.