Receptor-like protein kinases in plants: Post-translational regulation and functional effects

Receptor-like protein kinases (RLKs) serve as critical regulators of diverse biological processes, ranging from the modulation of growth and development to responses to complex environmental stimuli. These proteins typically mediate cellular signaling through diverse post-translational modifications (PTMs), including reversible phosphorylation and dephosphorylation, ubiquitination and deubiquitination, N-glycosylation, lipid anchoring via N-myristoylation and S-acylation, SUMOylation and deSUMOylation, and pathogen effector-mediated acetylation and uridylylation. Emerging evidence demonstrates that multiple RLKs undergo proteolytic cleavage, generating truncated intracellular kinase domains that translocate to specific subcellular compartments, where they execute non-canonical signaling functions. This review summarizes two pivotal regulatory mechanisms: 1) dynamic PTM-mediated control of RLK activation states and signaling outputs and 2) proteolytic-cleavage-dependent generation of mobile kinase modules that spatially and temporally expand the functions of RLKs. Unraveling the sophisticated post-translational regulatory mechanisms of RLKs will remain an important direction and challenge for future research, facilitating the genetic improvement of crops through targeted manipulation of these mechanisms.