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Phosphorylation of Hsl1 by Hog1 leads to a G 2 arrest essential for cell survival at high osmolarity
Author(s) -
Clotet Josep,
Escoté Xavier,
Adrover Miquel Àngel,
Yaakov Gilad,
Garí Eloi,
Aldea Martí,
de Nadal Eulàlia,
Posas Francesc
Publication year - 2006
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1038/sj.emboj.7601095
Subject(s) - cell cycle checkpoint , biology , microbiology and biotechnology , cell cycle , phosphorylation , kinase , mapk/erk pathway , cyclin dependent kinase 1 , chek1 , wee1 , p38 mitogen activated protein kinases , extracellular , cell , biochemistry
Control of cell cycle progression by stress‐activated protein kinases (SAPKs) is essential for cell adaptation to extracellular stimuli. Exposure of yeast to osmostress leads to activation of the Hog1 SAPK, which controls cell cycle at G 1 by the targeting of Sic1. Here, we show that survival to osmostress also requires regulation of G 2 progression. Activated Hog1 interacts and directly phosphorylates a residue within the Hsl7‐docking site of the Hsl1 checkpoint kinase, which results in delocalization of Hsl7 from the septin ring and leads to Swe1 accumulation. Upon Hog1 activation, cells containing a nonphosphorylatable Hsl1 by Hog1 are unable to promote Hsl7 delocalization, fail to arrest at G 2 and become sensitive to osmostress. Together, we present a novel mechanism that regulates the Hsl1–Hsl7 complex to integrate stress signals to mediate cell cycle arrest and, demonstrate that a single MAPK coordinately modulates different cell cycle checkpoints to improve cell survival upon stress.