The WAVE regulatory complex interacts with Boc and is required for Shh-mediated axon guidance

Nursen Balekoglu; Jean-Francois Michaud; Rachelle Sauvé; Kehinde S Ayinde; Sichun Lin; Yijun Liu; Daniel A Kramer; Kaiyue Zhang; Anika Steffen; Theresia Stradal; Stephane Angers; Baoyu Chen; Patricia T Yam; Frédéric Charron

doi:10.1016/j.isci.2024.111333

The WAVE regulatory complex interacts with Boc and is required for Shh-mediated axon guidance

iScience. 2024 Nov 6;27(12):111333. doi: 10.1016/j.isci.2024.111333. eCollection 2024 Dec 20.

Authors

Nursen Balekoglu^{1

2}, Jean-Francois Michaud¹, Rachelle Sauvé^{1

3}, Kehinde S Ayinde⁴, Sichun Lin⁵, Yijun Liu⁴, Daniel A Kramer⁴, Kaiyue Zhang^{1

2}, Anika Steffen⁶, Theresia Stradal⁶, Stephane Angers^{5

7}, Baoyu Chen⁴, Patricia T Yam¹, Frédéric Charron^{1

2

3

8

9}

Affiliations

¹ Montreal Clinical Research Institute (IRCM), 110 Pine Avenue West, Montreal, Quebec H2W 1R7, Canada.
² Integrated Program in Neuroscience, McGill University, Montreal, QC H3A 2B4, Canada.
³ Molecular Biology Program, University of Montreal, Montreal, QC H3T 1J4, Canada.
⁴ Roy J. Carver Department of Biochemistry, Biophysics & Molecular Biology, Iowa State University, 2437 Pammel Drive, Ames, IA 50011, USA.
⁵ Donnelly Centre for Cellular and Biomolecular Research, Toronto, ON M5S 3E1, Canada.
⁶ Department of Cell Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany.
⁷ Department of Biochemistry, University of Toronto, Toronto, ON M5S 1A8, Canada.
⁸ Department of Medicine, University of Montreal, Montreal QC H3T 1J4, Canada.
⁹ Department of Anatomy and Cell Biology, Division of Experimental Medicine, McGill University, Montreal QC H3A 0G4, Canada.

Abstract

During development, Shh attracts axons of spinal cord commissural neurons to the floor plate. Shh-mediated attraction of commissural axons requires the receptor Boc. How Boc regulates cytoskeletal changes in growth cones in response to Shh is not fully understood. To identify effectors of Boc in Shh-mediated axon guidance, we used BioID to screen for proteins in proximity to Boc. Top hits included members of the WAVE regulatory complex (WRC), which acts downstream of Rac1 to promote actin cytoskeleton assembly. Therefore, we hypothesized that the WRC is important for Shh-mediated growth cone turning. Using biochemical and cellular assays, we found that Boc directly interacts with the WRC and that this interaction can occur in live cells. Moreover, we found that knockdown of Nckap1 and Cyfip1/2, two subunits of the WRC, in commissural neurons, impairs axon attraction toward a Shh gradient. Our results demonstrate that the WRC is required for Shh-mediated axon attraction.

Keywords: biological sciences; cell biology; neuroscience.