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Updated: May 30, 2025
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Generation and Purification of Human INO80 Chromatin Remodeling Complexes and Subcomplexes
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Structures and mRNP remodeling mechanism of the TREX-2 complex
Yihu Xie1, Bradley P Clarke2, Dongqi Xie3
1Department of Biochemistry, Vanderbilt University School of Medicine Basic Sciences, Nashville, TN 37232, USA; Center for Structural Biology, Vanderbilt University, Nashville, TN 37232, USA.
Structure (London, England : 1993)
|January 25, 2025
Summary
The TREX-2 complex facilitates the nuclear export of messenger ribonucleoprotein complexes (mRNPs) by remodeling the DEAD-box helicase DDX39B/Sub2. This interaction is crucial for completing mRNP assembly before cytoplasmic export.
Area of Science:
- Molecular Biology
- Cell Biology
- Gene Expression
Background:
- Messenger ribonucleoprotein complexes (mRNPs) are essential for eukaryotic gene expression.
- Nuclear mRNP remodeling, governed by DEAD-box helicase DDX39B/Sub2, precedes cytoplasmic export, but the mechanisms are unclear.
Purpose of the Study:
- To identify the factor responsible for completing the mRNP remodeling cycle.
- To elucidate the mechanism by which DDX39B/Sub2 is removed from mRNPs.
Main Methods:
- Crystallography
- Cryo-electron microscopy (cryo-EM)
- Biochemical analyses of protein interactions
Main Results:
- The conserved TREX-2 complex was identified as a key factor in mRNP remodeling.
- TREX-2 interacts with DDX39B/Sub2, modulating its activity.
- A TREX-2 "trigger loop" splits DDX39B/Sub2's RecA domains, promoting its release from mRNP.
Conclusions:
- TREX-2 facilitates DDX39B/Sub2-mediated mRNP remodeling.
- TREX-2 coordinates with DDX39B/Sub2 and export receptors (NXF1-NXT1) for nuclear mRNP assembly completion.
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