Two-Component Mediated Peroxide Sensing and Signal Transduction in Fission Yeast

Abstract

Two-component related proteins play a major role in regulating the oxidative stress response in the fission yeast, Schizosaccharomyces pombe. For example, the peroxide-sensing Mak2 and Mak3 histidine kinases regulate H(2)O(2)-induced activation of the Sty1 stress-activated protein kinase pathway, and the Skn7-related response regulator transcription factor, Prr1, is essential for activation of the core oxidative stress response genes. Here, we investigate the mechanism by which the S. pombe two-component system senses H(2)O(2), and the potential role of two-component signaling in the regulation of Prr1. Significantly, we demonstrate that PAS and GAF domains present in the Mak2 histidine kinase are essential for redox-sensing and activation of Sty1. In addition, we find that Prr1 is required for the transcriptional response to a wide range of H(2)O(2) concentrations and, furthermore, that two-component regulation of Prr1 is specifically required for the response of cells to high levels of H(2)O(2). Significantly, this provides the first demonstration that the conserved two-component phosphorylation site on Skn7-related proteins influences resistance to oxidative stress and oxidative stress-induced gene expression. Collectively, these data provide new insights into the two-component mediated sensing and signaling mechanisms underlying the response of S. pombe to oxidative stress.

Oxidative stress response pathways: Fission yeast as archetype

“…Most of these branches remain, however, active even in very high HP doses (e.g. the SAPK pathway and the multistep phosphorelay sytem) (Quinn et al, 2002(Quinn et al, , 2011. Whether other faded parts of the figure represent active events in very high HP doses awaits validation (e.g.…”

“…The nuclear localization of Mpr1 and Prr1 and the essential role of a conserved Prr1 residue in stress induced by extreme HP doses (41.0 mM) led to the conclusion that Prr1 could be phosphorylated by Mpr1 to control its TF activity. However, the Mpr1-mediated phosphotransfer does not seem to affect Prr1 stabilization (Quinn et al, 2011).…”

“…In HP stress two conserved protein domains in the structures of Mak2 and Mak3, i.e. the GAF and PAS domains, are essential for sensing and relaying signals to the downstream MAPK pathway (Quinn et al, 2011;Taylor & Zhulin, 1999). Both domains bind diverse cofactors to sense different stimuli, with the PAS domain being also involved in protein-protein interactions (Erbel et al, 2003).…”

“…Instead, the fission yeast His kinases are cytoplasmic and, thus, evolutionarily optimized to sense internal and external oxidative stress signals (Quinn et al, 2011). Mcs4 localizes in the cytoplasm, Mpr1 is located in both the cytoplasm and the nucleus and, the Prr1 RR resides constitutively in the nucleus (Quinn et al, 2011).…”

“…Mcs4 localizes in the cytoplasm, Mpr1 is located in both the cytoplasm and the nucleus and, the Prr1 RR resides constitutively in the nucleus (Quinn et al, 2011). Interestingly, this localization pattern is not altered after treatment of cells with HP (Figures 4-6) (Quinn et al, 2011). The nuclear localization of Mpr1 and Prr1 and the essential role of a conserved Prr1 residue in stress induced by extreme HP doses (41.0 mM) led to the conclusion that Prr1 could be phosphorylated by Mpr1 to control its TF activity.…”