A peptide hormone and its receptor protein kinase regulate plant cell expansion.
Plant cells are immobile; thus, plant growth and development depend on cell expansion rather than cell migration. The molecular mechanism by which the plasma membrane initiates changes in the cell expansion rate remains elusive. We found that a secreted peptide, RALF (rapid alkalinization factor), suppresses cell elongation of the primary root by activating the cell surface receptor FERONIA in Arabidopsis thaliana. A direct peptide-receptor interaction is supported by specific binding of RALF to FERONIA and reduced binding and insensitivity to RALF-induced growth inhibition in feronia mutants. Phosphoproteome measurements demonstrate that the RALF-FERONIA interaction causes phosphorylation of plasma membrane H(+)-adenosine triphosphatase 2 at Ser(899), mediating the inhibition of proton transport. The results reveal a molecular mechanism for RALF-induced extracellular alkalinization and a signaling pathway that regulates cell expansion.
Biotechnology Center, University of Wisconsin, Madison, WI 53706, USA.
Miyoshi
M
Haruta
Grzegorz
G
Sabat
Kelly
K
Stecker
Benjamin B
BB
Minkoff
Michael R
MR
Sussman
D017360:Arabidopsis / Q000166:cytology* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000819:agonists* / Q000235:genetics / Q000378:metabolism*; D049108:Cell Enlargement; D002462:Cell Membrane / Q000201:enzymology*; D008969:Molecular Sequence Data; D036361:Peptide Hormones / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D010770:Phosphotransferases / Q000235:genetics / Q000378:metabolism; D059828:Plant Cells / Q000378:metabolism / Q000502:physiology; D018517:Plant Roots / Q000166:cytology / Q000378:metabolism; D011485:Protein Binding; D020543:Proteome / Q000378:metabolism; D006180:Proton-Translocating ATPases / Q000378:metabolism*; D012694:Serine / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases
D029681:Arabidopsis Proteins; D036361:Peptide Hormones; D010770:Phosphotransferases; D020543:Proteome; D006180:Proton-Translocating ATPases; D012694:Serine; C529880:RALF1 protein, Arabidopsis; C522131:At3g51550 protein, Arabidopsis; D017346:Protein Serine-Threonine Kinases