Redox Signaling

Redox Signaling through a Two-Component Relay

Science's STKE  27 Feb 2001:
Vol. 2001, Issue 71, pp. tw8
DOI: 10.1126/stke.2001.71.tw8

Schizosaccharomyces pombe responds to many environmental stresses by activation of the stress-activated protein kinase (SAPK), Sty1p. Buck et al. show that the activation of Sty1p in response to peroxide is dependent on a conserved aspartate residue in the protein Mcs4p, a response regulator that acts in a two-component relay system in the transduction pathway for the redox signal. Using degenerate, low-stringency polymerase chain reactions, Buck et al. identified a novel family of histidine kinases (Mak1p, Mak2p, and Mak3p). Analysis of yeast mutants showed that peroxide-stimulated phosphorylation of Sty1p and activation of genes by the Sty1p-regulated transcription factor Atf1p depended on Mak2p and Mak3p. Evidence was also presented that suggests that Mak1p may also be involved in peroxide sensing and the regulation of genes activated by the Sty1p-regulated transcription factor Pap1p, although this pathway was not described in detail. Thus, two separate two-component relay systems, one through Mak1p and another through Mak2p and Mak3p, appear to function in sensing and transducing changes in redox status in S. pombe.

V. Buck, J. Quinn, T. S. Pino, H. Martin, J. Saldanha, K. Makino, B. A. Morgan, J. B. A. Millar, Peroxide sensors for the fission yeast stress-activated mitogen-activated protein kinase pathway. Mol. Biol. Cell. 12, 407-419 (2001). [Abstract] [Full Text]