RT Journal Article
SR Electronic
T1 Phosphorylation-dependent routing of RLP44 towards brassinosteroid or phytosulfokine signalling
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 527754
DO 10.1101/527754
A1 Borja Garnelo Gómez
A1 Rosa Lozano-Durán
A1 Sebastian Wolf
YR 2019
UL http://biorxiv.org/content/early/2019/01/23/527754.abstract
AB Plants rely on a complex network of cell surface receptors to integrate developmental and environmental cues into behaviour adapted to the conditions. The largest group of these receptors, leucine-rich repeat receptor-like kinases, form a complex interaction network that is modulated and extended by receptor-like proteins. This raises the question of how specific outputs can be generated when receptor proteins are engaged in a plethora of promiscuous interactions. RECEPTOR-LIKE PROTEIN 44 acts to promote brassinosteroid and phytosulfokine signalling, which orchestrate a wide variety of cellular responses. However, it is unclear how these activities are coordinated. Here, we show that RLP44 is phosphorylated in its highly conserved C-terminal cytosolic tail and that this post-translational modification governs its subcellular localization. RLP44 variants in which phosphorylation is blocked enter endocytosis prematurely, leading to an almost entirely intracellular localization, whereas mimicking phosphorylation results in preferential RLP44 localization at the plasma membrane. Phosphorylation is crucial for regulating RLP44’s interaction with the brassinosteroid receptor BRASSINOSTEROID INSENSITIVE 1, and thus its function in BR signalling activation. In contrast, the interaction of RLP44 with PHYTOSULFOKINE RECEPTOR 1 is not affected by its phospho-status. Analysis of the contribution of individual amino acid modifications suggests that routing of RLP44 to its target receptor complexes is controlled by its phosphorylation pattern, providing a framework to understand how a common component of different receptor complexes can get specifically engaged in a particular signalling pathway.