Regulation of the p38 MAPK Signaling Pathway by the Circadian Clock

作者：Charles S. Goldsmith · 发表于：OakTrust (Texas A&M University Libraries) · 年份：2013 · 研究领域：Circadian rhythm and melatonin、Light effects on plants、Plant Molecular Biology Research

Mitogen activated protein kinase (MAPK) pathways are conserved biochemical signal transduction pathways in eukaryotic organisms. These signaling pathways demonstrate great versatility in their ability to detect various environmental stimuli and direct an appropriate cellular response. The circadian clock is a timekeeping mechanism that temporally coordinates diverse biological functions in an organism with the environment. Thus, it is not surprising that MAPK pathways have been utilized by the circadian clock to regulate many essential functions. Due to the conserved nature of circadian clocks and MAPK signaling pathways in eukaryotes, it is possible to develop hypotheses in simple model organisms, such as the fungus Neurospora, that are relevant to more complex organisms. \n\n The OS-2 MAPK pathway in the filamentous fungus Neurospora is rhythmically activated by the circadian clock. In order to generate this rhythmic signal, the circadian oscillator directly regulates the rhythmic transcription of the os-4 MAPKKK and histidine phosphotransferase hpt-1, which are upstream regulators of the OS-2 MAPK. Also, the circadian rhythm in MAPK activation produces a more robust stress response during the time of the day that stress is most likely to be encountered. Based on these data, a model for the clock regulation of MAPK activation is presented, and a biological significance is assigned to the rhythms in this pathway. \n\nInformed by these findings in Neurospora, the related p38 ...