title: Developmentally regulated dual-specificity kinase from peanut that is induced by abiotic stresses.
abstract: Tyrosine (Tyr) phosphorylation represents an important biochemical mechanism to regulate many cellular processes. No Tyr kinase has been cloned so far in plants. Dual-specificity kinases are reported in plants and the function of these kinases remains unknown. A 1.7-kb cDNA that encodes serine/threonine/Tyr (STY) kinase was isolated by screening peanut (Arachis hypogaea) expression library using the anti-phospho-Tyr antibody. The histidine-tagged recombinant kinase histidine-6-STY predominantly autophosphorylated on Tyr and phosphorylated the histone primarily on threonine. Genomic DNA gel-blot analysis revealed that STY kinase is a member of a small multigene family. The transcript of STY kinase is accumulated in the mid-maturation stage of seed development, suggesting a role in the signaling of storage of seed reserves. The STY kinase mRNA expression, as well as kinase activity, markedly increased in response to cold and salt treatments; however, no change in the protein level was observed, suggesting a posttranslational activation mechanism. The activation of the STY kinase is detected after 12 to 48 h of cold and salt treatments, which indicates that the kinase may not participate in the initial response to abiotic stresses, but may play a possible role in the adaptive process to adverse conditions. The transcript levels and kinase activity were unaltered with abscisic acid treatment, suggesting an abscisic acid-independent cold and salt signaling pathway. Here, we report the first identification of a non-MAP kinase cascade dual-specificity kinase involved in abiotic stress and seed development.
authors.affiliation: Department of Biochemistry, Indian Institute of Science, Bangalore 560012, India.
authors.forename: Parvathi
authors.initials: P
authors.lastname: Rudrabhatla
authors.forename: Ram
authors.initials: R
authors.lastname: Rajasekharan
mesh_terms: D000595:Amino Acid Sequence; D010367:Arachis / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D004789:Enzyme Activation / Q000187:drug effects; D018507:Gene Expression Regulation, Developmental; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D008969:Molecular Sequence Data; D010802:Phylogeny; D011499:Protein Processing, Post-Translational / Q000187:drug effects; D017346:Protein Serine-Threonine Kinases / Q000235:genetics* / Q000378:metabolism; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D012965:Sodium Chloride / Q000494:pharmacology; D013314:Stress, Mechanical; D013379:Substrate Specificity; D013696:Temperature; D015533:Transcriptional Activation / Q000187:drug effects
chemical_list: D018076:DNA, Complementary; D012965:Sodium Chloride; D017346:Protein Serine-Threonine Kinases