Tyrosine-sulfated glycopeptide receptor with a serine/threonine-protein kinase activity (PubMed:17989228, PubMed:25267325). Regulates, in response to tyrosine-sulfated glycopeptide binding, a signaling cascade involved in cellular proliferation and plant growth (PubMed:17989228). Not involved in PSK perception (PubMed:17989228). Involved in plant immunity, with antagonistic effects on bacterial and fungal resistances (PubMed:23062058). Mediates activation of the plasma membrane H(+)-ATPase by PSY1 (PubMed:25267325). Phosphorylates AHA2 at Thr-881 (PubMed:25267325). ATP + L-seryl-[protein] = ADP + H(+) + O-phospho-L-seryl-[protein] ATP + L-threonyl-[protein] = ADP + H(+) + O-phospho-L-threonyl-[protein] Homo- and heterodimers with PSKR1. Interacts (via C-terminus) with AHA1 and AHA2 (via the R-domain). Expressed ubiquitously, including in the shoot apical meristem and in the elongation zone of the root meristem. Autophosphorylated. Loss of sensitivity to PSY1 (PubMed:17989228). Loss of PSY1 induced phosphorylation of AHA2 and reduced hypocotyl elongation (PubMed:25267325). Increased symptom formation, disease index, lesion size and fungal growth after infection with A.brassicicola, but increased resistance to bacterial infection (PubMed:23062058). PSYR1 and PSKR1 mediate a signaling pathway by two distinct ligands, which redundantly contribute to cellular proliferation and plant growth. Belongs to the protein kinase superfamily. Ser/Thr protein kinase family.