# BICD2 promotes ciliogenesis by facilitating CP110 removal from the mother centriole

## TL;DR

This study shows that BICD2 helps form cilia by removing a protein called CP110 from the mother centriole, which is essential for cilia development and tissue function.

## Contribution

The study identifies BICD2 as a novel regulator of ciliogenesis by directly binding and removing CP110 from the mother centriole.

## Key findings

- BICD2 depletion inhibits ciliogenesis and CP110 removal, while CP110 knockdown rescues ciliogenesis defects in BICD2-deficient cells.
- Zebrafish bicd2 morphants show developmental abnormalities and defective ciliogenesis, which are reversed by reintroducing bicd2 mRNA or depleting Cp110.
- BICD2 is recruited to the mother centriole during ciliogenesis and directly binds and removes CP110.

## 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.

CP110 is located at the distal ends of both the mother and daughter centrioles under serum culture conditions. Upon serum starvation, BICD2 is recruited to the mother centriole, where it directly binds to and removes CP110, thereby initiating ciliogenesis.

BICD2 localizes to the mother centriole, and knockdown of BICD2 inhibits ciliogenesis and CP110 removal.BICD2 directly interacts with CP110, leading to the removal of CP110 from the mother centriole.BICD2 is crucial for ciliogenesis and cilia-associated developmental events in zebrafish.

BICD2 localizes to the mother centriole, and knockdown of BICD2 inhibits ciliogenesis and CP110 removal.

BICD2 directly interacts with CP110, leading to the removal of CP110 from the mother centriole.

BICD2 is crucial for ciliogenesis and cilia-associated developmental events in zebrafish.

CP110 is located at the distal ends of both the mother and daughter centrioles under serum culture conditions. Upon serum starvation, BICD2 is recruited to the mother centriole, where it directly binds to and removes CP110, thereby initiating ciliogenesis.