Membrane-binding domains define REMORIN phylogeny and provide a predicted structural basis for distinctive membrane nano-environments

Abstract

REMORIN (REM) proteins are structural components of the plant plasma membrane that modulate membrane nano-organization and biophysics. They have been proposed to function as versatile scaffolds in the context of hormone signaling, immunity and symbiosis. REMs have been classified into six groups based the length and the amino acid composition of their intrinsically disordered N-terminal domain. Here we show that REM phylogeny is dominated by the evolution of their conserved C-terminal domain and defines four major REM clades. Structural bioinformatics analyses predict the conservation of a putative membrane binding interface formed by REM C-terminal domains and reveal a striking diversity in their curvatures and lengths. A subset of REMs is predicted to form C-terminal domain-mediated higher-order oligomers providing an additional level of diversity in REM membrane-binding interfaces. We discuss the implications of the predicted variations in REM C-terminal domain structure for their molecular function and membrane organization.