title: CrMPK3, a mitogen activated protein kinase from Catharanthus roseus and its possible role in stress induced biosynthesis of monoterpenoid indole alkaloids.
abstract: BACKGROUND
  Mitogen activated protein kinase (MAPK) cascade is an important signaling cascade that operates in stress signal transduction in plants. The biologically active monoterpenoid indole alkaloids (MIA) produced in Catharanthus roseus are known to be induced under several abiotic stress conditions such as wounding, UV-B etc. However involvement of any signaling component in the accumulation of MIAs remains poorly investigated so far. Here we report isolation of a novel abiotic stress inducible Catharanthus roseus MAPK, CrMPK3 that may have role in accumulation of MIAs in response to abiotic stress.
  
  
  RESULTS
  CrMPK3 expressed in bacterial system is an active kinase as it showed auto-phosphorylation and phosphorylation of Myelin Basic Protein. CrMPK3 though localized in cytoplasm, moves to nucleus upon wounding. Wounding, UV treatment and MeJA application on C. roseus leaves resulted in the transcript accumulation of CrMPK3 as well as activation of MAPK in C. roseus leaves. Immuno-precipitation followed by immunoblot analysis revealed that wounding, UV treatment and methyl jasmonate (MeJA) activate CrMPK3. Transient over-expression of CrMPK3 in C. roseus leaf tissue showed enhanced expression of key MIA biosynthesis pathway genes and also accumulation of specific MIAs.
  
  
  CONCLUSIONS
  Results from our study suggest a possible involvement of CrMPK3 in abiotic stress signal transduction towards regulation of transcripts of key MIA biosynthetic pathway genes, regulators and accumulation of major MIAs.
authors.affiliation: National Institute of Plant Genome Research, New Delhi, India.
authors.forename: Susheel Kumar
authors.initials: SK
authors.lastname: Raina
authors.forename: Dhammaprakash Pandhari
authors.initials: DP
authors.lastname: Wankhede
authors.forename: Monika
authors.initials: M
authors.lastname: Jaggi
authors.forename: Pallavi
authors.initials: P
authors.lastname: Singh
authors.forename: Siddhi Kashinath
authors.initials: SK
authors.lastname: Jalmi
authors.forename: Badmi
authors.initials: B
authors.lastname: Raghuram
authors.forename: Arsheed Hussain
authors.initials: AH
authors.lastname: Sheikh
authors.forename: Alok Krishna
authors.initials: AK
authors.lastname: Sinha
mesh_terms: D000085:Acetates / Q000494:pharmacology; D000595:Amino Acid Sequence; D053898:Biosynthetic Pathways; D030008:Catharanthus / Q000187:drug effects / Q000201:enzymology* / Q000528:radiation effects; D002467:Cell Nucleus / Q000235:genetics / Q000378:metabolism; D003001:Cloning, Molecular; D003517:Cyclopentanes / Q000494:pharmacology; D003593:Cytoplasm / Q000235:genetics / Q000378:metabolism; D004789:Enzyme Activation; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D047468:Immunoprecipitation; D020935:MAP Kinase Signaling System; D020928:Mitogen-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D004676:Myelin Basic Protein / Q000378:metabolism; D054883:Oxylipins / Q000494:pharmacology; D010766:Phosphorylation; D018515:Plant Leaves / Q000187:drug effects / Q000201:enzymology / Q000528:radiation effects; D010940:Plant Proteins / Q000378:metabolism; D021381:Protein Transport; D046948:Secologanin Tryptamine Alkaloids / Q000378:metabolism*; D016415:Sequence Alignment; D013312:Stress, Physiological; D014466:Ultraviolet Rays
chemical_list: D000085:Acetates; D003517:Cyclopentanes; D004676:Myelin Basic Protein; D054883:Oxylipins; D010940:Plant Proteins; D046948:Secologanin Tryptamine Alkaloids; C072239:methyl jasmonate; D020928:Mitogen-Activated Protein Kinases