title: Two enzymes in one; two yeast peroxiredoxins display oxidative stress-dependent switching from a peroxidase to a molecular chaperone function.
abstract: Although a great deal is known biochemically about peroxiredoxins (Prxs), little is known about their real physiological function. We show here that two cytosolic yeast Prxs, cPrxI and II, which display diversity in structure and apparent molecular weights (MW), can act alternatively as peroxidases and molecular chaperones. The peroxidase function predominates in the lower MW forms, whereas the chaperone function predominates in the higher MW complexes. Oxidative stress and heat shock exposure of yeasts causes the protein structures of cPrxI and II to shift from low MW species to high MW complexes. This triggers a peroxidase-to-chaperone functional switch. These in vivo changes are primarily guided by the active peroxidase site residue, Cys(47), which serves as an efficient "H(2)O(2)-sensor" in the cells. The chaperone function of these proteins enhances yeast resistance to heat shock.
authors.affiliation: Division of Applied Life Sciences, Gyeonsang National University, Chinju, 660-701, South Korea.
authors.forename: Ho Hee
authors.initials: HH
authors.lastname: Jang
authors.forename: Kyun Oh
authors.initials: KO
authors.lastname: Lee
authors.forename: Yong Hun
authors.initials: YH
authors.lastname: Chi
authors.forename: Bae Gyo
authors.initials: BG
authors.lastname: Jung
authors.forename: Soo Kwon
authors.initials: SK
authors.lastname: Park
authors.forename: Jin Ho
authors.initials: JH
authors.lastname: Park
authors.forename: Jung Ro
authors.initials: JR
authors.lastname: Lee
authors.forename: Seung Sik
authors.initials: SS
authors.lastname: Lee
authors.forename: Jeong Chan
authors.initials: JC
authors.lastname: Moon
authors.forename: Jeong Won
authors.initials: JW
authors.lastname: Yun
authors.forename: Yeon Ok
authors.initials: YO
authors.lastname: Choi
authors.forename: Woe Yeon
authors.initials: WY
authors.lastname: Kim
authors.forename: Ji Seoun
authors.initials: JS
authors.lastname: Kang
authors.forename: Gang-Won
authors.initials: GW
authors.lastname: Cheong
authors.forename: Dae-Jin
authors.initials: DJ
authors.lastname: Yun
authors.forename: Sue Goo
authors.initials: SG
authors.lastname: Rhee
authors.forename: Moo Je
authors.initials: MJ
authors.lastname: Cho
authors.forename: Sang Yeol
authors.initials: SY
authors.lastname: Lee
mesh_terms: D006358:Hot Temperature; D018832:Molecular Chaperones / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D018384:Oxidative Stress / Q000502:physiology*; D010544:Peroxidases / Q000235:genetics / Q000378:metabolism*; D054464:Peroxiredoxins; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D018832:Molecular Chaperones; D029701:Saccharomyces cerevisiae Proteins; C410041:PRX1 protein, S cerevisiae; D010544:Peroxidases; D054464:Peroxiredoxins