title: Protein tyrosine phosphorylation during phytohormone-stimulated cell proliferation in Arabidopsis Hypocotyls.
abstract: Very little is known about the molecular events triggering differentiated cells to re-enter the cell cycle. We have investigated the possible role of tyrosine phosphorylation in this process with hypocotyl explants of Arabidopsis thaliana. Phytohormone-stimulated cell cycle reactivation in hypocotyls was accompanied by tyrosine phosphorylation of several proteins. Such regulation of the tyrosine phosphorylation in these proteins was not observed in a callus-formation-deficient mutant, srd2, a result which suggests that the induction of tyrosine phosphorylation occurs as a specific event in callus cell proliferation. The promoter activity of cyclin-dependent kinase, CDKA;1, was also examined in phytohormone-stimulated hypocotyls. This study highlighted that protein tyrosine phosphorylation may play an important regulatory role in phytohormone-stimulated cell proliferation.
authors.affiliation: Department of Biology, National Cheng Kung University, Tainan, 701 Taiwan. haojen@mail.ncku.edu
authors.forename: Hao-Jen
authors.initials: HJ
authors.lastname: Huang
authors.forename: Yu-Mei
authors.initials: YM
authors.lastname: Lin
authors.forename: Dinq-Ding
authors.initials: DD
authors.lastname: Huang
authors.forename: Takuya
authors.initials: T
authors.lastname: Takahashi
authors.forename: Munetaka
authors.initials: M
authors.lastname: Sugiyama
mesh_terms: D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D016203:CDC2 Protein Kinase / Q000235:genetics; D002455:Cell Division / Q000187:drug effects; D046508:Culture Techniques; D005966:Glucuronidase / Q000235:genetics / Q000378:metabolism; D018546:Hypocotyl / Q000166:cytology / Q000187:drug effects / Q000254:growth & development*; D009154:Mutation; D010766:Phosphorylation; D010937:Plant Growth Regulators / Q000494:pharmacology*; D010940:Plant Proteins / Q000378:metabolism*; D011401:Promoter Regions, Genetic / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D014443:Tyrosine / Q000378:metabolism*
chemical_list: D010937:Plant Growth Regulators; D010940:Plant Proteins; D011993:Recombinant Fusion Proteins; D014443:Tyrosine; D016203:CDC2 Protein Kinase; D005966:Glucuronidase