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Updated: Mar 1, 2026
Analysis of mRNA Nuclear Export Kinetics in Mammalian Cells by Microinjection
Published on: December 4, 2010
The actin binding cytoskeletal protein Moesin is involved in nuclear mRNA export
Ildikó Kristó1, Csaba Bajusz1, Barbara N Borsos2
1Biological Research Center of the Hungarian Academy of Sciences, Szeged, Hungary.
Abstract:
Current models imply that the evolutionarily conserved, actin-binding Ezrin-Radixin-Moesin (ERM) proteins perform their activities at the plasma membrane by anchoring membrane proteins to the cortical actin network. Here we show that beside its cytoplasmic functions, the single ERM protein of Drosophila, Moesin, has a novel role in the nucleus. The activation of transcription by heat shock or hormonal treatment increases the amount of nuclear Moesin, indicating biological function for the protein in the nucleus. The distribution of Moesin in the nucleus suggests a function in transcription and the depletion of mRNA export factors Nup98 or its interacting partner, Rae1, leads to the nuclear accumulation of Moesin, suggesting that the nuclear function of the protein is linked to mRNA export. Moesin localizes to mRNP particles through the interaction with the mRNA export factor PCID2 and knock down of Moesin leads to the accumulation of mRNA in the nucleus. Based on our results we propose that, beyond its well-known, manifold functions in the cytoplasm, the ERM protein of Drosophila is a new, functional component of the nucleus where it participates in mRNA export.
Insights
The Ezrin-Radixin-Moesin (ERM) protein Moesin functions in the nucleus, not just the cytoplasm. It plays a novel role in mRNA export, interacting with key export factors.
Area of Science:
- Cell Biology
- Molecular Biology
- Genetics
Background:
- Ezrin-Radixin-Moesin (ERM) proteins are conserved and known for cytoplasmic roles.
- ERM proteins typically anchor membrane proteins to the actin network at the plasma membrane.
Purpose of the Study:
- To investigate novel nuclear functions of the Drosophila ERM protein, Moesin.
- To elucidate Moesin's role in nuclear processes beyond its established cytoplasmic activities.
Main Methods:
- Analyzing Moesin localization and expression under different cellular conditions (heat shock, hormonal treatment).
- Investigating Moesin's interaction with mRNA export factors (Nup98, Rae1, PCID2).
- Utilizing knockdown experiments to assess Moesin's impact on mRNA export.
Main Results:
- Nuclear Moesin levels increase with transcriptional activation, suggesting a nuclear role.
- Moesin accumulates in the nucleus upon depletion of mRNA export factors Nup98 or Rae1.
- Moesin interacts with PCID2 and is found on mRNP particles, and its knockdown causes nuclear mRNA accumulation.
Conclusions:
- Drosophila Moesin has a novel, functional role within the nucleus.
- Moesin actively participates in the mRNA export process.
- This finding expands the known functions of ERM proteins to include nuclear mRNA export.
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