The cell wall regulates dynamics and size of plasma-membrane nanodomains in Arabidopsis

Abstract

Plant plasma-membrane (PM) proteins are involved in several vital processes, such as detection of pathogens, solute transport, and cellular signaling. For these proteins to function effectively there needs to be structure within the PM allowing, for example, proteins in the same signaling cascade to be spatially organized. Here we demonstrate that several proteins with divergent functions are located in clusters of differing size in the membrane using subdiffraction-limited Airyscan confocal microscopy. Single particle tracking reveals that these proteins move at different rates within the membrane. Actin and microtubule cytoskeletons appear to significantly regulate the mobility of one of these proteins (the pathogen receptor FLS2) and we further demonstrate that the cell wall is critical for the regulation of cluster size by quantifying single particle dynamics of proteins with key roles in morphogenesis (PIN3) and pathogen perception (FLS2). We propose a model in which the cell wall and cytoskeleton are pivotal for regulation of protein cluster size and dynamics, thereby contributing to the formation and functionality of membrane nanodomains.

A wall with integrity: surveillance and maintenance of the plant cell wall under stress

“…Lateral diffusion of plasma membrane proteins is constrained by the cell wall (Martini ere et al, 2012). The cell wall and cytoskeleton regulate the size and dynamics of plasma membrane nanodomains, where signaling and transport proteins are localized (McKenna et al, 2019). Membrane proteins that bridge the wall and the cytoskeleton have the potential to transduce extracellular signals to regulate intracellular dynamics.…”

Deviating from the Beaten Track: New Twists in Brassinosteroid Receptor Function

“…It is assumed that these protein classes are involved in the generation and the maintenance of membrane nanodomains, of which several types co-exist in a given cell [114], by way of their capability to oligomerize and provide a scaffold for the clustering of transmembrane domain proteins such as RLKs [115][116][117][118][119]. The cell wall also contributes to the size and dynamics of nanodomains [120], potentially by restricting lateral mobility of plant transmembrane proteins [121,122]. Alternatively, receptor clustering after cell wall alterations could be indicative of a cellular response to mechanical stimuli [120].…”

“…The cell wall also contributes to the size and dynamics of nanodomains [120], potentially by restricting lateral mobility of plant transmembrane proteins [121,122]. Alternatively, receptor clustering after cell wall alterations could be indicative of a cellular response to mechanical stimuli [120].…”

“…More generally, segregation of receptors in the relatively immobile nanodomains is assumed to restrict the access to potential interaction partners and thus allow tighter control of signalling activation. Indeed, it has been recently demonstrated that BRI1 resides in nanoclusters that are marked by FLOT1 and REM6.2 [120,[124][125][126]. BRI1 is spatially separated from FLS2, which is present in nanodomains marked by REM1.2 and REM1.3, despite the fact that both receptors depend on SERK co-receptors such as BAK1 [124].…”

The BIR2/BIR3-Associated Phospholipase Dγ1 Negatively Regulates Plant Immunity

“…The PM is organized in highly dynamic sub-compartments, so called micro-or nanodomains, depending on size and shape, which allow the accommodation of specific protein clusters (Malinsky et al, 2013;Ott, 2017). Protein clustering within the PM has been demonstrated for the immune receptor FLS2 (Bücherl et al, 2017;McKenna et al, 2019) as well as its co-receptor BAK1 (Hutten et al, 2017). Importantly, the stability of FLS2-protein clusters depends on the lipid composition of the surrounding membrane patch (Bücherl et al, 2017).…”