Hog1 Mitogen-Activated Protein Kinase (MAPK) Interrupts Signal Transduction between the Kss1 MAPK and the Tec1 Transcription Factor To Maintain Pathway Specificity
Hog1 Mitogen-Activated Protein Kinase (MAPK) Interrupts Signal Transduction between the Kss1 MAPK and the Tec1 Transcription Factor To Maintain Pathway Specificity
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DOI：
10.1128/ec.00005-09
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发表时间：
2009-04-01
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影响因子：
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通讯作者：
Madhani, Hiten D.
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文献类型：
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作者：
Shock, Teresa R.;Thompson, James;Madhani, Hiten D.
在酿酒酵母中，交配、丝状生长（FG）和高渗透压甘油（HOG）促分裂原活化蛋白激酶（MAPK）信号通路共享组分，但介导对不同细胞外信号的不同响应。交配和FG通路之间的串扰被抑制，因为交配信号诱导FG转录因子Tec 1的破坏。我们在这里表明，HOG通路激活的结果在FG MAPK，Kss 1，和MAPKK，Ste 7的磷酸化。然而，FG转录没有被激活，因为HOG信号传导阻止了Tec 1的激活。与交配途径相反，我们发现该机制涉及Tec 1对DNA结合的抑制，而不是对其的破坏。我们还发现Tec 1的核积累不受HOG信号的影响。Hog 1的抑制作用显然是间接的，因为它不需要Tec 1上的任何共有S/TP MAPK磷酸化位点、其DNA结合伴侣Ste 12或相关调节因子Dig 1或Dig 2。它也不需要的共识MAPK网站的Ste 11激活剂Ste 50，在最近的建议相反，负反馈的作用，特异性。我们的研究结果表明，HOG信号中断FG途径之间的信号转导Kss 1的磷酸化和Tec 1的DNA结合的激活。
In Saccharomyces cerevisiae, the mating, filamentous growth (FG), and high-osmolarity glycerol (HOG) mitogen-activated protein kinase (MAPK) signaling pathways share components and yet mediate distinct responses to different extracellular signals. Cross talk is suppressed between the mating and FG pathways because mating signaling induces the destruction of the FG transcription factor Tec1. We show here that HOG pathway activation results in phosphorylation of the FG MAPK, Kss1, and the MAPKK, Ste7. However, FG transcription is not activated because HOG signaling prevents the activation of Tec1. In contrast to the mating pathway, we find that the mechanism involves the inhibition of DNA binding by Tec1 rather than its destruction. We also find that nuclear accumulation of Tec1 is not affected by HOG signaling. Inhibition by Hog1 is apparently indirect since it does not require any of the consensus S/TP MAPK phosphorylation sites on Tec1, its DNA-binding partner Ste12, or the associated regulators Dig1 or Dig2. It also does not require the consensus MAPK sites of the Ste11 activator Ste50, in contrast to a recent proposal for a role for negative feedback in specificity. Our results demonstrate that HOG signaling interrupts the FG pathway signal transduction between the phosphorylation of Kss1 and the activation of DNA binding by Tec1.