Two enzymes in one; two yeast peroxiredoxins display oxidative stress-dependent switching from a peroxidase to a molecular chaperone function.
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.
Jang
Ho Hee
HH
Division of Applied Life Sciences, Gyeonsang National University, Chinju, 660-701, South Korea.
Lee
Kyun Oh
KO
Chi
Yong Hun
YH
Jung
Bae Gyo
BG
Park
Soo Kwon
SK
Park
Jin Ho
JH
Lee
Jung Ro
JR
Lee
Seung Sik
SS
Moon
Jeong Chan
JC
Yun
Jeong Won
JW
Choi
Yeon Ok
YO
Kim
Woe Yeon
WY
Kang
Ji Seoun
JS
Cheong
Gang-Won
GW
Yun
Dae-Jin
DJ
Rhee
Sue Goo
SG
Cho
Moo Je
MJ
Lee
Sang Yeol
SY
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*
D018832:Molecular Chaperones; D029701:Saccharomyces cerevisiae Proteins; C410041:PRX1 protein, S cerevisiae; D010544:Peroxidases; D054464:Peroxiredoxins