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Dissection of the HOG pathway activated by hydrogen peroxide in S accharomyces cerevisiae
Author(s) -
Lee Young Mi,
Kim Eunjung,
An Jieun,
Lee Yeji,
Choi Eunyong,
Choi Wonja,
Moon Eunpyo,
Kim Wankee
Publication year - 2017
Publication title -
environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.954
H-Index - 188
eISSN - 1462-2920
pISSN - 1462-2912
DOI - 10.1111/1462-2920.13499
Subject(s) - biology , microbiology and biotechnology , mapk/erk pathway , signal transduction , map kinase kinase kinase , kinase , protein kinase a , mitogen activated protein kinase , endoplasmic reticulum , phosphorylation , ask1 , mitogen activated protein kinase kinase , biochemistry
Summary Cells usually cope with oxidative stress by activating signal transduction pathways. In the budding yeast Sacchromyces cerevisiae , the high osmolarity glycerol (HOG) pathway has long been implicated in transducing the oxidative stress‐induced signal, but the underlying mechanisms are not well defined. Based on phosphorylation of the mitogen‐activated protein kinase (MAPK) Hog1, we reveal that the signal from hydrogen peroxide (H 2 O 2 ) flows through Ssk1, the response regulator of the two‐component system of the HOG pathway. Downstream signal transduction into the HOG MAPK cascade requires the MAP kinase kinase kinase (MAP3K) Ssk2 but not its paralog Ssk22 or another MAP3K Ste11 of the pathway, culminating in Hog1 phosphorylation via the MAP2K Pbs2. When overexpressed, Ssk2 is also activated in an Ssk1‐independent manner. Unlike in mammals, H 2 O 2 does not cause endoplasmic reticulum stress, which can activate Hog1 through the conventional unfolded protein response. Hog1 activated by H 2 O 2 is retained in the cytoplasm, but is still able to activate the cAMP‐ or stress‐responsive elements by unknown mechanisms.