title: Gatekeeper Tyrosine Phosphorylation of SYMRK Is Essential for Synchronizing the Epidermal and Cortical Responses in Root Nodule Symbiosis.
abstract: Symbiosis receptor kinase (SYMRK) is indispensable for activation of root nodule symbiosis (RNS) at both epidermal and cortical levels and is functionally conserved in legumes. Previously, we reported SYMRK to be phosphorylated on "gatekeeper" Tyr both in vitro as well as in planta. Since gatekeeper phosphorylation was not necessary for activity, the significance remained elusive. Herein, we show that substituting gatekeeper with nonphosphorylatable residues like Phe or Ala significantly affected autophosphorylation on selected targets on activation segment/αEF and β3-αC loop of SYMRK. In addition, the same gatekeeper mutants failed to restore proper symbiotic features in a symrk null mutant where rhizobial invasion of the epidermis and nodule organogenesis was unaffected but rhizobia remain restricted to the epidermis in infection threads migrating parallel to the longitudinal axis of the root, resulting in extensive infection patches at the nodule apex. Thus, gatekeeper phosphorylation is critical for synchronizing epidermal/cortical responses in RNS.
authors.affiliation: Department of Biochemistry, University of Calcutta, Kolkata 700019, India (S. Saha, A.P., A.D., A.B., S. Samaddar, M.D.); andDepartment of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, North Carolina 27695 (L.H., M.B.G.).
authors.forename: Sudip
authors.identifier: 0000-0001-9742-3306
authors.initials: S
authors.lastname: Saha
authors.affiliation: Department of Biochemistry, University of Calcutta, Kolkata 700019, India (S. Saha, A.P., A.D., A.B., S. Samaddar, M.D.); andDepartment of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, North Carolina 27695 (L.H., M.B.G.).
authors.forename: Anindita
authors.initials: A
authors.lastname: Paul
authors.affiliation: Department of Biochemistry, University of Calcutta, Kolkata 700019, India (S. Saha, A.P., A.D., A.B., S. Samaddar, M.D.); andDepartment of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, North Carolina 27695 (L.H., M.B.G.).
authors.forename: Laura
authors.identifier: 0000-0003-4496-7312
authors.initials: L
authors.lastname: Herring
authors.affiliation: Department of Biochemistry, University of Calcutta, Kolkata 700019, India (S. Saha, A.P., A.D., A.B., S. Samaddar, M.D.); andDepartment of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, North Carolina 27695 (L.H., M.B.G.).
authors.forename: Ayan
authors.initials: A
authors.lastname: Dutta
authors.affiliation: Department of Biochemistry, University of Calcutta, Kolkata 700019, India (S. Saha, A.P., A.D., A.B., S. Samaddar, M.D.); andDepartment of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, North Carolina 27695 (L.H., M.B.G.).
authors.forename: Avisek
authors.initials: A
authors.lastname: Bhattacharya
authors.affiliation: Department of Biochemistry, University of Calcutta, Kolkata 700019, India (S. Saha, A.P., A.D., A.B., S. Samaddar, M.D.); andDepartment of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, North Carolina 27695 (L.H., M.B.G.).
authors.forename: Sandip
authors.initials: S
authors.lastname: Samaddar
authors.affiliation: Department of Biochemistry, University of Calcutta, Kolkata 700019, India (S. Saha, A.P., A.D., A.B., S. Samaddar, M.D.); andDepartment of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, North Carolina 27695 (L.H., M.B.G.).
authors.forename: Michael B
authors.initials: MB
authors.lastname: Goshe
authors.affiliation: Department of Biochemistry, University of Calcutta, Kolkata 700019, India (S. Saha, A.P., A.D., A.B., S. Samaddar, M.D.); andDepartment of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, North Carolina 27695 (L.H., M.B.G.) maitrayee_d@hotmail.com.
authors.forename: Maitrayee
authors.identifier: 0000-0002-7260-3746
authors.initials: M
authors.lastname: DasGupta
mesh_terms: D000595:Amino Acid Sequence; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D007887:Fabaceae / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D016296:Mutagenesis; D009154:Mutation; D010641:Phenotype; D019606:Phosphoamino Acids / Q000032:analysis; D010766:Phosphorylation; D019441:Plant Epidermis; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D055170:Plant Root Nodulation; D018517:Plant Roots / Q000378:metabolism* / Q000382:microbiology; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism*; D012231:Rhizobium / Q000502:physiology; D053204:Root Nodules, Plant / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D013559:Symbiosis; D014443:Tyrosine / Q000378:metabolism*
chemical_list: D002352:Carrier Proteins; D019606:Phosphoamino Acids; D010940:Plant Proteins; D014443:Tyrosine; D011494:Protein Kinases