REM1.3's phospho-status defines its plasma membrane nanodomain organization and activity in restricting PVX cell-to-cell movement.

Artemis Perraki,Marie Boudsocq,Cyril Zipfel,Emmanuelle Bayer,Véronique Germain,Paul Gouguet,Anne-Flore Deroubaix,Sylvie German-Retana,Julien Gronnier,Anthony Legrand,Sébastien Mongrand,Birgit Habenstein,Vincent Simon

doi:10.1371/journal.ppat.1007378

Abstract

Plants respond to pathogens through dynamic regulation of plasma membrane-bound signaling pathways. To date, how the plant plasma membrane is involved in responses to viruses is mostly unknown. Here, we show that plant cells sense the Potato virus X (PVX) COAT PROTEIN and TRIPLE GENE BLOCK 1 proteins and subsequently trigger the activation of a membrane-bound calcium-dependent kinase. We show that the Arabidopsis thaliana CALCIUM-DEPENDENT PROTEIN KINASE 3-interacts with group 1 REMORINs in vivo, phosphorylates the intrinsically disordered N-terminal domain of the Group 1 REMORIN REM1.3, and restricts PVX cell-to-cell movement. REM1.3's phospho-status defines its plasma membrane nanodomain organization and is crucial for REM1.3-dependent restriction of PVX cell-to-cell movement by regulation of callose deposition at plasmodesmata. This study unveils plasma membrane nanodomain-associated molecular events underlying the plant immune response to viruses.

Highlights

The cell plasma membrane (PM) constitutes a regulatory hub for information processing [1]
REM1.3 plays a role in restricting Potato virus X (PVX) passage through PD channels [8], [33] counteracting PVX movement proteins which promote PD opening [41]
Our analysis showed a significant increase in callose deposition in PVX-infected cells compared to mock conditions (Fig 1A and 1B)

Summary

Introduction

The cell plasma membrane (PM) constitutes a regulatory hub for information processing [1]. Current knowledge suggests that PM proteins and lipids dynamically associate with each other to create specialized sub-compartments or nanodomains [2], that regulate the cellular responses in space and time [3,4,5]. The REMORIN (REM) family is one of the best-characterized PM nanodomain-associated proteins in plants [7,8,9,10,11,12]. Members of the REM family have been associated with plant responses to biotic [9, 17, 18], abiotic stress [19, 20] and developmental clues [12] and current view suggests they could regulate signaling events through nanodomain association [21]. The molecular mechanisms leading to REM-associated downstream events remain elusive

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Conclusion