Methylglyoxal, a metabolite derived from glycolysis, functions as a signal initiator of the high osmolarity glycerol-mitogen-activated protein kinase cascade and calcineurin/Crz1-mediated pathway in Saccharomyces cerevisiae.
Methylglyoxal (MG) is a typical 2-oxoaldehyde derived from glycolysis, although it inhibits the growth of cells in all types of organism. Hence, it has been questioned why such a toxic metabolite is synthesized via the ubiquitous energy-generating pathway. We have previously reported that expression of GLO1, coding for the major enzyme detoxifying MG, was induced by osmotic stress in a high osmolarity glycerol (HOG)-mitogen-activated protein (MAP) kinase-dependent manner in Saccharomyces cerevisiae. Here we show that MG activates the HOG-MAP kinase cascade. Two osmosensors, Sln1 and Sho1, have been identified to function upstream of the HOG-MAP kinase cascade, and we reveal that MG initiates the signal transduction to this MAP kinase cascade through the Sln1 branch. We also demonstrate that MG activates the Msn2 transcription factor. Moreover, MG activated the uptake of Ca(2+) in yeast cells, thereby stimulating the calcineurin/Crz1-mediated Ca(2+) signaling pathway. We propose that MG functions as a signal initiator in yeast.
Maeta
Kazuhiro
K
Laboratory of Molecular Microbiology, Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan.
Izawa
Shingo
S
Inoue
Yoshiharu
Y
D006019:Glycolysis; D047908:Intracellular Signaling Peptides and Proteins; D007791:Lactoylglutathione Lyase / Q000378:metabolism*; D020935:MAP Kinase Signaling System; D008565:Membrane Proteins / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D009994:Osmolar Concentration; D011494:Protein Kinases / Q000378:metabolism; D011765:Pyruvaldehyde / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism
D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; C459787:SHO1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D011765:Pyruvaldehyde; D011494:Protein Kinases; D020928:Mitogen-Activated Protein Kinases; C083749:SLN1 protein, S cerevisiae; D007791:Lactoylglutathione Lyase