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Temporal Quantification of MAPK Induced Expression in Single Yeast Cells
Published on: October 4, 2013
Single-cell analysis reveals that insulation maintains signaling specificity between two yeast MAPK pathways with
Jesse C Patterson1, Evguenia S Klimenko, Jeremy Thorner
1Division of Biochemistry and Molecular Biology, Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720-3202, USA.
Science Signaling
|October 21, 2010
Summary
Yeast cells use distinct mitogen-activated protein kinase (MAPK) pathways for mating and stress responses. Specificity is maintained by an "insulation" mechanism, not cross-inhibition, ensuring appropriate cellular reactions to different signals.
Area of Science:
- Cellular Biology
- Molecular Biology
- Biochemistry
Background:
- Eukaryotic cells employ multiple mitogen-activated protein kinase (MAPK) cascades for stimulus response.
- In yeast, Fus3 MAPK governs mating, while Hog1 MAPK manages the high-osmolarity glycerol (HOG) response.
- These pathways share components but exhibit distinct responses to specific stimuli.
Purpose of the Study:
- To investigate the signaling specificity between the Fus3 and Hog1 MAPK pathways in Saccharomyces cerevisiae.
- To determine the mechanism underlying pathway insulation during dual activation.
- To identify critical temporal requirements for HOG pathway insulation.
Main Methods:
- Utilized fluorescence localization and transcription reporters to monitor pathway activation at the single-cell level.
- Assessed pathway dynamics on minute and hour time scales.
- Examined wild-type yeast cells under conditions of dual stimulation (pheromone and osmolyte).
Main Results:
- Dual activation of MAPK pathways occurred across various stimulant concentrations and temporal conditions.
- Signaling specificity is maintained by an "insulation" mechanism, not cross-inhibition.
- A critical time window for Hog1 activity was identified as essential for HOG pathway insulation.
Conclusions:
- Yeast MAPK pathways achieve specificity through an insulation mechanism, preventing signal crosstalk.
- This insulation is dynamic and dependent on the temporal activation of specific pathways, particularly Hog1.
- Understanding these mechanisms provides insights into cellular signal processing and response specificity.
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