Deubiquitinating enzymes UBP12 and UBP13 stabilize the brassinosteroid receptor BRI1.

Protein ubiquitination is a dynamic and reversible post-translational modification that controls diverse cellular processes in eukaryotes. Ubiquitin-dependent internalization, recycling, and degradation are important mechanisms that regulate the activity and the abundance of plasma membrane (PM)-localized proteins. In plants, although several ubiquitin ligases are implicated in these processes, no deubiquitinating enzymes (DUBs), have been identified that directly remove ubiquitin from membrane proteins and limit their vacuolar degradation.

Endocytosis of BRASSINOSTEROID INSENSITIVE1 Is Partly Driven by a Canonical Tyr-Based Motif.

Clathrin-mediated endocytosis (CME) and its core endocytic machinery are evolutionarily conserved across all eukaryotes. In mammals, the heterotetrameric adaptor protein complex-2 (AP-2) sorts plasma membrane (PM) cargoes into vesicles via the recognition of motifs based on Tyr or di-Leu in their cytoplasmic tails. However, in plants, very little is known about how PM proteins are sorted for CME and whether similar motifs are required.

Ligand-induced monoubiquitination of BIK1 regulates plant immunity.

Recognition of microbe-associated molecular patterns (MAMPs) by pattern recognition receptors (PRRs) triggers the first line of inducible defence against invading pathogens. Receptor-like cytoplasmic kinases (RLCKs) are convergent regulators that associate with multiple PRRs in plants. The mechanisms that underlie the activation of RLCKs are unclear.

GOLVEN peptide signalling through RGI receptors and MPK6 restricts asymmetric cell division during lateral root initiation.

During lateral root initiation, lateral root founder cells undergo asymmetric cell divisions that generate daughter cells with different sizes and fates, a prerequisite for correct primordium organogenesis. An excess of the GLV6/RGF8 peptide disrupts these initial asymmetric cell divisions, resulting in more symmetric divisions and the failure to achieve lateral root organogenesis. Here, we show that loss-of-function GLV6 and its homologue GLV10 increase asymmetric cell divisions during lateral root initiation, and we identified three members of the RGF1 INSENSITIVE/RGF1 receptor subfamily as likely GLV receptors in this process.

Proteolytic Processing of SERK3/BAK1 Regulates Plant Immunity, Development, and Cell Death.

Plants have evolved many receptor-like kinases (RLKs) to sense extrinsic and intrinsic cues. The signaling pathways mediated by multiple Leucine-rich repeat (LRR) RLK (LRR-RLK) receptors require ligand-induced receptor-coreceptor heterodimerization and transphosphorylation with BRI1-ASSOCIATED RECEPTOR KINASE1 (BAK1)/SOMATIC EMBRYOGENESIS RECEPTOR KINASES family LRR-RLKs. Here we reveal an additional layer of regulation of BAK1 via a Ca-dependent proteolytic cleavage process that is conserved in Arabidopsis (), , and The proteolytic cleavage of BAK1 is intrinsically regulated in response to developmental cues and immune stimulation.

The crossroads of receptor-mediated signaling and endocytosis in plants.

Plants deploy numerous plasma membrane receptors to sense and rapidly react to environmental changes. Correct localization and adequate protein levels of the cell-surface receptors are critical for signaling activation and modulation of plant development and defense against pathogens. After ligand binding, receptors are internalized for degradation and signaling attenuation.

rapid alkalinization factor 1-mediated root growth inhibition is dependent on calmodulin-like protein 38.

rapid alkalinization factor 1 (AtRALF1) is a small secreted peptide hormone that inhibits root growth by repressing cell expansion. Although it is known that AtRALF1 binds the plasma membrane receptor FERONIA and conveys its signals via phosphorylation, the AtRALF1 signaling pathway is largely unknown. Here, using a yeast two-hybrid system to search for AtRALF1-interacting proteins in , we identified calmodulin-like protein 38 (CML38) as an AtRALF1-interacting partner.