WIP Regulates Persistence of Cell Migration and Ruffle Formation in Both Mesenchymal and Amoeboid Modes of Motility

Inmaculada Banon-Rodriguez,Julia Saez De Guinoa,Gareth E Jones,Chiara Ragazzini,Estefania Fernandez,Francisco Wandosell,Yolanda R Carrasco,Ines Maria Anton,Alejandra Bernardini,Scott A Weed

doi:10.1371/journal.pone.0070364

Abstract

The spatial distribution of signals downstream from receptor tyrosine kinases (RTKs) or G-protein coupled receptors (GPCR) regulates fundamental cellular processes that control cell migration and growth. Both pathways rely significantly on actin cytoskeleton reorganization mediated by nucleation-promoting factors such as the WASP-(Wiskott-Aldrich Syndrome Protein) family. WIP (WASP Interacting Protein) is essential for the formation of a class of polarised actin microdomain, namely dorsal ruffles, downstream of the RTK for PDGF (platelet-derived growth factor) but the underlying mechanism is poorly understood. Using lentivirally-reconstituted WIP-deficient murine fibroblasts we define the requirement for WIP interaction with N-WASP (neural WASP) and Nck for efficient dorsal ruffle formation and of WIP-Nck binding for fibroblast chemotaxis towards PDGF-AA. The formation of both circular dorsal ruffles in PDGF-AA-stimulated primary fibroblasts and lamellipodia in CXCL13-treated B lymphocytes are also compromised by WIP-deficiency. We provide data to show that a WIP-Nck signalling complex interacts with RTK to promote polarised actin remodelling in fibroblasts and provide the first evidence for WIP involvement in the control of migratory persistence in both mesenchymal (fibroblast) and amoeboid (B lymphocytes) motility.

Highlights

Dynamic remodeling of the actin cytoskeleton plays an essential role in cell motility [1]
WIP deficiency impairs amoeboid cell motility To investigate the role of WIP in amoeboid migration, we studied B lymphocyte behaviour in response to the most specific B cell chemokine CXCL13 (C-X-C motif chemokine 13)
We show that WIP localizes to and regulates lamellipodium formation in CXCL13-treated B cells and circular dorsal ruffle formation in PDFG-AA-stimulated fibroblasts

Summary

Introduction

Dynamic remodeling of the actin cytoskeleton plays an essential role in cell motility [1]. Many actin-binding proteins that organise actin filaments into functionally specialized arrays such as filopodia, lamellipodia or ruffles are involved in cell displacement, contributing to individual amoeboid (rounded) or mesenchymal (elongated) migration [2]. One of the pathways that regulate the formation of dorsal ruffles involves the Wiskott–Aldrich Syndrome protein (WASP) family proteins and the Arp2/3 (actin-related protein) complex that is activated by WASP proteins [12,13]. WIP interacts with other cytoskeletalrelated proteins involved in dorsal ruffle formation such as cortactin, mAbp (murine actin-binding protein-1), and Nck [18]. Chemokines trigger amoeboid forms of cell movement in lymphocytes This diverse family of small proteins all signal through G-protein coupled receptors (GPCR); the activated signalling cascades lead to actin cytoskeleton rearrangements and integrin activation to induce cell polarization and motility. We show that WIP binding to Nck is essential for fibroblast chemotaxis towards PDGF-AA

Materials and Methods

Results

Discussion