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Protein phosphatase 2A on track for nutrient‐induced signalling in yeast
Author(s) -
Zabrocki Piotr,
Hoof Christine Van,
Goris Jozef,
Thevelein Johan M.,
Winderickx Joris,
Wera Stefaan
Publication year - 2002
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1046/j.1365-2958.2002.02786.x
Subject(s) - protein phosphatase 2 , biology , heterotrimeric g protein , phosphatase , saccharomyces cerevisiae , yeast , signal transduction , biochemistry , microbiology and biotechnology , signalling , phosphorylation , genetics , g protein
Summary Early studies identified two bona fide protein phosphatase 2A (PP2A)‐encoding genes in Saccharo‐myces cerevisiae , designated PPH21 and PPH22 . In addition, three PP2A‐related phosphatases, encoded by PPH3, SIT4 and PPG1, have been identified. All share as much as 86% sequence similarity at the amino acid level. This review will focus primarily on Pph21 and Pph22, but some aspects of Sit4 regulation will also be discussed. Whereas a role for PP2A in yeast morphology and cell cycle has been readily recognized, uncovering its function in yeast signal transduction is a more recent breakthrough. Via their interaction with phosphorylated Tap42, PP2A and Sit4 play a pivotal role in target of rapamycin (TOR) signalling. PPH22 overexpression mimics overactive cAMP–PKA (protein kinase A) signalling and PP2A and Sit4 might represent ceramide signalling targets. The methylation of its catalytic subunit stabilizes the heterotrimeric form of PP2A and might counteract TOR signalling. We will show how these new elements could lead us to understand the role and regulation of PP2A in nutrient‐induced signalling in baker’s yeast.