4z64 | pdb_00004z64
the plant peptide hormone receptor complex in arabidopsis
Structural highlights
Function[PSKR1_ARATH] Phytosulfokine receptor with a serine/threonine-protein kinase activity. Regulates, in response to phytosulfokine binding, a signaling cascade involved in plant cell differentiation, organogenesis, somatic embryogenesis, cellular proliferation and plant growth. Not involved in PSY perception.[1] [2] [SERK1_ARATH] Dual specificity kinase acting on both serine/threonine- and tyrosine-containing substrates. Phosphorylates BRI1 on 'Ser-887' and CDC48 on at least one threonine residue and on 'Ser-41'. Confers embryogenic competence. Acts redundantly with SERK2 as a control point for sporophytic development controlling male gametophyte production. Involved in the brassinolide signaling pathway.[3] [4] Publication Abstract from PubMedPhytosulfokine (PSK) is a disulfated pentapeptide that has a ubiquitous role in plant growth and development. PSK is perceived by its receptor PSKR, a leucine-rich repeat receptor kinase (LRR-RK). The mechanisms underlying the recognition of PSK, the activation of PSKR and the identity of the components downstream of the initial binding remain elusive. Here we report the crystal structures of the extracellular LRR domain of PSKR in free, PSK- and co-receptor-bound forms. The structures reveal that PSK interacts mainly with a beta-strand from the island domain of PSKR, forming an anti-beta-sheet. The two sulfate moieties of PSK interact directly with PSKR, sensitizing PSKR recognition of PSK. Supported by biochemical, structural and genetic evidence, PSK binding enhances PSKR heterodimerization with the somatic embryogenesis receptor-like kinases (SERKs). However, PSK is not directly involved in PSKR-SERK interaction but stabilizes PSKR island domain for recruitment of a SERK. Our data reveal the structural basis for PSKR recognition of PSK and allosteric activation of PSKR by PSK, opening up new avenues for the design of PSKR-specific small molecules. Allosteric receptor activation by the plant peptide hormone phytosulfokine.,Wang J, Li H, Han Z, Zhang H, Wang T, Lin G, Chang J, Yang W, Chai J Nature. 2015 Sep 10;525(7568):265-8. doi: 10.1038/nature14858. Epub 2015 Aug 26. PMID:26308901[5] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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