Arpin Regulates Migration Persistence by Interacting with Both Tankyrases and the Arp2/3 Complex.

Gleb Simanov,Valérie Campanacci,Alexis M Gautreau,Ksenia Oguievetskaia,Artem I Fokin,Jacqueline Cherfils,Irene Dang

doi:10.3390/ijms22084115

Abstract

During cell migration, protrusion of the leading edge is driven by the polymerization of Arp2/3-dependent branched actin networks. Migration persistence is negatively regulated by the Arp2/3 inhibitory protein Arpin. To better understand Arpin regulation in the cell, we looked for its interacting partners and identified both Tankyrase 1 and 2 (TNKS) using a yeast two-hybrid screening and coimmunoprecipitation with full-length Arpin as bait. Arpin interacts with ankyrin repeats of TNKS through a C-terminal-binding site on its acidic tail, which overlaps with the Arp2/3-binding site. Arpin was found to dissolve the liquid–liquid phase separation of TNKS upon overexpression. To uncouple the interactions of Arpin with TNKS and Arp2/3, we introduced point mutations in the Arpin tail and attempted to rescue the increased migration persistence of the Arpin knockout cells using random plasmid integration or compensating knock-ins at the ARPIN locus. Arpin mutations impairing interactions with either Arp2/3 or TNKS were insufficient to fully abolish Arpin activity. Only the mutation that affected both interactions rendered Arpin completely inactive, suggesting the existence of two independent pathways, whereby Arpin controls the migration persistence.

Highlights

Cell migration depends on various types of membrane protrusions
All the migration parameters extracted from the cell trajectories are displayed in Figure S4 for reference, but the only parameter that was regulated by Arpin in all the cell systems was migration persistence, not speed or the mean square displacement [4,6,32]. These results suggested that the Arpin–Tankyrase and 2 (TNKS) interaction could regulate the migration persistence, but we sought to confirm them in cell clones where
These results suggested that the Arpin–TNKS interaction could regulate the migration persistence, 7 of 16 but we sought to confirm them in cell clones where Arpin was not overexpressed

Summary

Introduction

Cell migration depends on various types of membrane protrusions. Most membrane protrusions are driven by cortical actin polymerization [1]. Adherent membrane protrusions at the leading edge fuel the cell movement. Actin networks at the leading edge are branched by the Arp2/3 complex that nucleates new actin filaments from the side of pre-existing ones. Arp2/3 activation in membrane protrusions is under the control of the WAVE complex, which, in turn, is regulated by the small GTPase Rac1 [2,3]. Arpin was identified as an Arp2/3 inhibitory protein that antagonizes WAVE activity [4]. Arpin competes with the nucleation-promoting factors (NPFs), such as WAVE [4]. Arpin acts earlier than other Arp2/3 inhibitory proteins, such as coronins or GMFs, which remove Arp2/3 from junctions of branched actin networks [3]

Methods

Results

Conclusion