title: The novel Solanum tuberosum calcium dependent protein kinase, StCDPK3, is expressed in actively growing organs.
abstract: Calcium-dependent protein kinases (CDPKs) are key components of calcium regulated signaling cascades in plants. In this work, isoform StCDPK3 from Solanum tuberosum was studied and fully described. StCDPK3 encodes a 63 kDa protein with an N-terminal variable domain (NTV), rich in prolines and glutamines, which presents myristoylation and palmitoylation consensus sites and a PEST sequence indicative of rapid protein degradation. StCDPK3 gene (circa 11 kb) is localized in chromosome 3, shares the eight exons and seven introns structure with other isoforms from subgroup IIa and contains an additional intron in the 5'UTR region. StCDPK3 expression is ubiquitous being transcripts more abundant in early elongating stolons (ES), leaves and roots, however isoform specific antibodies only detected the protein in leaf particulate extracts. The recombinant 6xHis-StCDPK3 is an active kinase that differs in its kinetic parameters and calcium requirements from StCDPK1 and 2 isoforms. In vitro, StCDPK3 undergoes autophosphorylation regardless of the addition of calcium. The StCDPK3 promoter region (circa 1,800 bp) was subcloned by genome walking and fused to GUS. Light and ABRE responsive elements were identified in the promoter region as well as elements associated to expression in roots. StCDPK3 expression was enhanced by ABA while GA decreased it. Potato transgenic lines harboring StCDPK3 promoter∷GUS construct were generated by Agrobacterium tumefaciens mediated plant transformation. Promoter activity was detected in leaves, root tips and branching points, early ES, tuber eyes and developing sprouts indicating that StCDPK3 is expressed in actively growing organs.
authors.affiliation: Instituto de Investigaciones en Ingeniería Genética y Biología Molecular Dr. Hector N. Torres, Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina.
authors.forename: Carolina
authors.initials: C
authors.lastname: Grandellis
authors.forename: Verónica
authors.initials: V
authors.lastname: Giammaria
authors.forename: Magalí
authors.initials: M
authors.lastname: Bialer
authors.forename: Franco
authors.initials: F
authors.lastname: Santin
authors.forename: Tian
authors.initials: T
authors.lastname: Lin
authors.forename: David J
authors.initials: DJ
authors.lastname: Hannapel
authors.forename: Rita M
authors.initials: RM
authors.lastname: Ulloa
mesh_terms: D000595:Amino Acid Sequence; D015971:Gene Expression Regulation, Enzymologic / Q000235:genetics*; D018506:Gene Expression Regulation, Plant; D008969:Molecular Sequence Data; D009928:Organ Specificity; D010766:Phosphorylation; D010802:Phylogeny; D018515:Plant Leaves / Q000201:enzymology / Q000235:genetics / Q000254:growth & development / Q000502:physiology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D035281:Plant Tubers / Q000201:enzymology / Q000235:genetics / Q000254:growth & development / Q000502:physiology; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic / Q000235:genetics; D020033:Protein Isoforms; D011494:Protein Kinases / Q000235:genetics* / Q000378:metabolism; D018749:RNA, Plant / Q000235:genetics; D011993:Recombinant Fusion Proteins; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D015398:Signal Transduction; D011198:Solanum tuberosum / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development / Q000502:physiology; D013312:Stress, Physiological / Q000235:genetics*; D017871:Calcium-Calmodulin-Dependent Protein Kinases
chemical_list: D010940:Plant Proteins; D020033:Protein Isoforms; D011494:Protein Kinases; D018749:RNA, Plant; D011993:Recombinant Fusion Proteins; D017871:Calcium-Calmodulin-Dependent Protein Kinases