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Updated: Mar 19, 2026
09:16
Oligopeptide Competition Assay for Phosphorylation Site Determination
Published on: May 18, 2017
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Phosphorylation acts positively and negatively to regulate MRTF-A subcellular localisation and activity.
Richard Panayiotou1, Francesc Miralles1, Rafal Pawlowski1
1Signaling and Transcription Group, Francis Crick Institute, London, United Kingdom.
Elife
|June 16, 2016
Summary
Myocardin-related transcription factors (MRTF-A) phosphorylation by Rho and ERK signals regulates cytoskeletal gene expression. Phosphorylation controls MRTF-A
Area of Science:
- Molecular Biology
- Cell Biology
- Biochemistry
Background:
- Myocardin-related transcription factors (MRTF-A and MRTF-B) partner with SRF to regulate cytoskeletal genes.
- MRTF nuclear accumulation is controlled by G-actin levels.
- The roles of MRTF phosphorylation and nuclear export mechanisms are not well understood.
Purpose of the Study:
- Investigate the functional significance of MRTF-A phosphorylation.
- Identify signals and elements governing MRTF-A nuclear export.
Main Methods:
- Phosphorylation site mapping of MRTF-A.
- Analysis of Rho- and ERK-dependent signaling pathways.
- Assessment of MRTF-A nuclear import/export dynamics.
Main Results:
- Rho-dependent phosphorylation relieves inhibition by nuclear actin.
- Serum-induced phosphorylation at S/T-P motifs is crucial for transcriptional activation.
- ERK-mediated S98 phosphorylation promotes nuclear import by inhibiting G-actin binding.
- S33 phosphorylation enhances Crm1-dependent nuclear export.
Conclusions:
- MRTF-A phosphorylation has dual roles in regulating its activity.
- Phosphorylation modulates MRTF-A interactions with actin and nuclear export machinery.
- This study elucidates a complex regulatory network controlling MRTF-A function.
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