Structural basis for plant plasma membrane protein dynamics and organization into functional nanodomains.

Julien Gronnier,Paul Gouguet,Jean-Marc Crowet,Christophe Der,Antoine Loquet,Laurence Lins,Magali Deleu,Yvon Jaillais,Françoise Simon-Plas,Sylvain Raffaele,Mehmet Nail Nasir,Vincent Bayle,Matthieu Pierre Platre,Sébastien Mongrand,Birgit Habenstein,Patricia Gerbeau-Pissot,Eric Hosy,Axelle Grélard ,Emmanuelle Bayer ,Dênis Martinez ,V Germain

doi:10.7554/elife.26404

Abstract

Plasma Membrane is the primary structure for adjusting to ever changing conditions. PM sub-compartmentalization in domains is thought to orchestrate signaling. Yet, mechanisms governing membrane organization are mostly uncharacterized. The plant-specific REMORINs are proteins regulating hormonal crosstalk and host invasion. REMs are the best-characterized nanodomain markers via an uncharacterized moiety called REMORIN C-terminal Anchor. By coupling biophysical methods, super-resolution microscopy and physiology, we decipher an original mechanism regulating the dynamic and organization of nanodomains. We showed that targeting of REMORIN is independent of the COP-II-dependent secretory pathway and mediated by PI4P and sterol. REM-CA is an unconventional lipid-binding motif that confers nanodomain organization. Analyses of REM-CA mutants by single particle tracking demonstrate that mobility and supramolecular organization are critical for immunity. This study provides a unique mechanistic insight into how the tight control of spatial segregation is critical in the definition of PM domain necessary to support biological function.

Highlights

IntroductionMembrane proteins and lipids are dynamically organized in domains or compartments.Emerging evidences suggest that membrane compartmentalization is critical for cell signalling and for development and survival of organisms 1
REMs belong to a multigenic family of 6 groups encoding plant-specific membrane-bound proteins involved in responses to biotic and abiotic stimuli involvement has been clearly reported in plant‐microbe interactions and hormonal crosstalk: in Solanaceae, group 1 REMs limits the spreading of Potato Virus X (PVX), without affecting viral replication 2, and promotes susceptibility to Phytophthora infestans 8
We showed that StREM1.3 is a functional homolog of the PM-localized Nicotinana benthamiana endogenous group 1b REMs toward the restriction of Potato Virus X (PVX) spreading

Summary

Introduction

IntroductionMembrane proteins and lipids are dynamically organized in domains or compartments.Emerging evidences suggest that membrane compartmentalization is critical for cell signalling and for development and survival of organisms 1. A group 4 REM is upregulated by abscissic acid and negatively regulates brassinosteroid signalling output geminiviral infection channels called plasmodesmata (PD), specialized nanochannels allowing intercellular communication in plants. These latter isoforms of REMs were found to be able to modify PD aperture leading respectively to a modification of viral movement [2, 13], and an impact on the grain setting in rice 6. To fulfil these functions, REMs need to localize to the PM

Methods

Results

Conclusion