title: Heat-induced chaperone activity of serine/threonine protein phosphatase 5 enhances thermotolerance in Arabidopsis thaliana.
abstract: • This study reports that Arabidopsis thaliana protein serine/threonine phosphatase 5 (AtPP5) plays a pivotal role in heat stress resistance. A high-molecular-weight (HMW) form of AtPP5 was isolated from heat-treated A. thaliana suspension cells. AtPP5 performs multiple functions, acting as a protein phosphatase, foldase chaperone, and holdase chaperone. The enzymatic activities of this versatile protein are closely associated with its oligomeric status, ranging from low oligomeric protein species to HMW complexes. • The phosphatase and foldase chaperone functions of AtPP5 are associated primarily with the low-molecular-weight (LMW) form, whereas the HMW form exhibits holdase chaperone activity. Transgenic over-expression of AtPP5 conferred enhanced heat shock resistance to wild-type A. thaliana and a T-DNA insertion knock-out mutant was defective in acquired thermotolerance. A recombinant phosphatase mutant (H290N) showed markedly increased holdase chaperone activity. • In addition, enhanced thermotolerance was observed in transgenic plants over-expressing H290N, which suggests that the holdase chaperone activity of AtPP5 is primarily responsible for AtPP5-mediated thermotolerance. • Collectively, the results from this study provide the first evidence that AtPP5 performs multiple enzymatic activities that are mediated by conformational changes induced by heat-shock stress.
authors.affiliation: Division of Applied Life Science, Gyeongsang National University, Jinju 660-701, Korea.
authors.forename: Jin Ho
authors.initials: JH
authors.lastname: Park
authors.affiliation: Division of Applied Life Science, Gyeongsang National University, Jinju 660-701, Korea.
authors.forename: Sun Yong
authors.initials: SY
authors.lastname: Lee
authors.affiliation: Division of Applied Life Science, Gyeongsang National University, Jinju 660-701, Korea.
authors.forename: Woe Yeon
authors.initials: WY
authors.lastname: Kim
authors.affiliation: Division of Applied Life Science, Gyeongsang National University, Jinju 660-701, Korea.
authors.forename: Young Jun
authors.initials: YJ
authors.lastname: Jung
authors.affiliation: Division of Applied Life Science, Gyeongsang National University, Jinju 660-701, Korea.
authors.forename: Ho Byoung
authors.initials: HB
authors.lastname: Chae
authors.affiliation: Division of Electron Microscopic Research, Korea Basic Science Institute, 52 Eoeun-dong, Daejeon 305-333, Korea.
authors.forename: Hyun Suk
authors.initials: HS
authors.lastname: Jung
authors.affiliation: Division of Applied Life Science, Gyeongsang National University, Jinju 660-701, Korea.
authors.forename: Chang Ho
authors.initials: CH
authors.lastname: Kang
authors.affiliation: Division of Applied Life Science, Gyeongsang National University, Jinju 660-701, Korea.
authors.forename: Mi Rim
authors.initials: MR
authors.lastname: Shin
authors.affiliation: Division of Applied Life Science, Gyeongsang National University, Jinju 660-701, Korea.
authors.forename: Sun Young
authors.initials: SY
authors.lastname: Kim
authors.affiliation: National Academy of Agricultural Science, RDA, Suwon 441-856, Korea.
authors.forename: Mukhamad
authors.initials: M
authors.lastname: Su'udi
authors.affiliation: Division of Applied Life Science, Gyeongsang National University, Jinju 660-701, Korea.
authors.forename: Dae Jin
authors.initials: DJ
authors.lastname: Yun
authors.affiliation: Division of Applied Life Science, Gyeongsang National University, Jinju 660-701, Korea.
authors.forename: Kyun Oh
authors.initials: KO
authors.lastname: Lee
authors.affiliation: National Academy of Agricultural Science, RDA, Suwon 441-856, Korea.
authors.forename: Min Gab
authors.initials: MG
authors.lastname: Kim
authors.affiliation: Division of Applied Life Science, Gyeongsang National University, Jinju 660-701, Korea.
authors.forename: Sang Yeol
authors.initials: SY
authors.lastname: Lee
mesh_terms: D000222:Adaptation, Physiological; D017360:Arabidopsis / Q000737:chemistry / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D002478:Cells, Cultured; D018506:Gene Expression Regulation, Plant; D015723:Gene Library; D018869:Heat-Shock Response / Q000502:physiology*; D006358:Hot Temperature; D018832:Molecular Chaperones / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D009154:Mutation; D009687:Nuclear Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D010749:Phosphoprotein Phosphatases / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000737:chemistry / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D055503:Protein Multimerization; D011994:Recombinant Proteins
chemical_list: D029681:Arabidopsis Proteins; D018832:Molecular Chaperones; D009687:Nuclear Proteins; D011994:Recombinant Proteins; D010749:Phosphoprotein Phosphatases; C089641:protein phosphatase 5