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Updated: May 11, 2025
Temporal Quantification of MAPK Induced Expression in Single Yeast Cells
Published on: October 4, 2013
Real time characterization of the MAPK pathway using native mass spectrometry
Elena Scott1, Sangho D Yun1, Zahra Moghadamchargari1
1Department of Chemistry, Texas A&M University, College Station, TX, 77843, USA.
Abstract:
The MAPK pathway is a crucial cell-signaling cascade that is composed of RAS, MEK, BRAF, and ERK, which serves to connect extracellular signals to intracellular responses. Over-activating mutations in the MAPK pathway can lead to uncontrolled cell growth ultimately resulting in various types of cancer. While this pathway has been heavily studied using a battery of techniques, herein we employ native mass spectrometry (MS) to characterize the MAPK pathway, including nucleotide, drug, and protein interactions. We utilize native MS to provide detailed insights into nucleotide and drug binding to BRAF complexes, such as modulation of nucleotide binding in the presence of MEK1. We then demonstrate that different CRAF segments vary in their complex formation with KRAS, with the addition of the cysteine rich domain (CRD) enhancing complex formation compared to Ras binding domain (RBD) alone. We report differences in KRAS GTPase activity in the presence of different RAF segments, with KRAS exhibiting significantly enhanced nucleotide turnover when bound to CRAF fragments. We use ERK2 as a downstream readout to monitor the MAPK phosphorylation cascade. This study demonstrates the utility of native MS to provide detailed characterization of individual MAPK pathway components and monitor the phosphorylation cascade in real time.
Insights
Native mass spectrometry (MS) offers new insights into the Mitogen-Activated Protein Kinase (MAPK) pathway. This research details protein interactions and nucleotide binding, advancing our understanding of cancer-related signaling.
Area of Science:
- Biochemistry
- Molecular Biology
- Cell Signaling
Background:
- The Mitogen-Activated Protein Kinase (MAPK) pathway is vital for cell signaling, connecting external stimuli to internal cellular activities.
- Dysregulation of the MAPK pathway, often due to activating mutations, is implicated in the development of various cancers.
- Existing methods for studying the MAPK pathway are extensive, but native mass spectrometry (MS) offers a novel approach for detailed molecular characterization.
Purpose of the Study:
- To employ native mass spectrometry (MS) for a comprehensive characterization of the MAPK pathway.
- To investigate nucleotide, drug, and protein interactions within the MAPK pathway using native MS.
- To monitor the MAPK phosphorylation cascade in real-time.
Main Methods:
- Utilized native mass spectrometry (MS) to analyze protein complexes and interactions within the MAPK pathway.
- Characterized nucleotide and drug binding to BRAF complexes, assessing the influence of MEK1.
- Examined the complex formation between different CRAF segments and KRAS, including the Ras binding domain (RBD) and cysteine-rich domain (CRD).
Main Results:
- Native MS provided detailed insights into nucleotide and drug interactions with BRAF, showing modulation by MEK1.
- Different CRAF segments exhibited varied complex formation with KRAS; the CRD significantly enhanced binding compared to RBD alone.
- KRAS displayed notably increased GTPase activity when interacting with specific CRAF fragments, indicating functional consequences of these interactions.
- ERK2 was used as a downstream reporter to track the MAPK phosphorylation cascade.
Conclusions:
- Native MS is a powerful tool for detailed characterization of individual MAPK pathway components.
- This technique allows for real-time monitoring of the complex MAPK phosphorylation cascade.
- The findings enhance our understanding of MAPK pathway regulation and its role in diseases like cancer.
