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Assaying Protein Kinase Activity with Radiolabeled ATP
Published on: May 26, 2017
Differential activation of p38MAPK isoforms by MKK6 and MKK3
Gaëlle Remy1, Ana M Risco, Francisco A Iñesta-Vaquera
1Departamento de Inmunología y Oncología, Centro Nacional de Biotecnología/CSIC, Darwin 3, UAM Campus de Cantoblanco, 28049 Madrid, Spain.
Cellular Signalling
|December 17, 2009
Summary
Mitogen-activated protein kinase (MAPK) pathways are activated by specific upstream kinases. This study reveals MKK3 and MKK6 selectively regulate p38beta, p38gamma, and p38delta activation in response to cellular stress.
Area of Science:
- Cellular signaling pathways
- Protein kinase activation
- Stress response mechanisms
Background:
- p38 MAPK family members (p38alpha, p38beta, p38gamma, p38delta) are activated by dual phosphorylation.
- Upstream kinases MKK3, MKK6, and MKK4 mediate this phosphorylation.
- Previous studies focused on MKK's role in p38alpha activation, leaving other isoforms' activators unclear.
Purpose of the Study:
- Investigate the roles of MKK3 and MKK6 in activating p38beta, p38gamma, and p38delta.
- Utilize MKK knockout cell lines to determine physiological upstream activators.
- Elucidate the specific kinase involvement in p38MAPK isoform activation under various stress conditions.
Main Methods:
- Employing MKK3 and MKK6 knockout cell lines.
- Analyzing p38beta, p38gamma, and p38delta activation in response to environmental stress (UV, osmotic shock, anisomycin, TNFalpha).
- Assessing MKK3 and MKK6's role in p38gamma substrate (hDlg) phosphorylation and activity.
Main Results:
- MKK3 and MKK6 are essential for p38gamma and p38beta activation by environmental stress.
- MKK6 is the primary activator of p38gamma upon TNFalpha stimulation.
- MKK3 mediates p38delta activation by UV radiation, osmotic shock, anisomycin, and TNFalpha.
- MKK3 and MKK6 regulate p38gamma substrate hDlg phosphorylation and scaffold activity during osmotic stress.
Conclusions:
- Distinct p38MAPK isoforms are activated through selective regulation by MKK3 and MKK6.
- The synchronized action of MKK3 and MKK6 is crucial for p38MAPK activation in response to cellular stress.
- This study clarifies the upstream kinase-isoform specificity within the p38 MAPK signaling network.
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