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Detection of Alternative Splicing During Epithelial-Mesenchymal Transition
Published on: October 9, 2014
MicroRNAs regulate the expression of the alternative splicing factor nPTB during muscle development
Paul L Boutz1, Geetanjali Chawla, Peter Stoilov
1Department of Microbiology, Immunology, and Molecular Genetics, University of California at Los Angeles, Los Angeles, California 90095, USA.
Genes & Development
|January 11, 2007
Summary
Muscle development involves microRNA-133 (miR-133) targeting polypyrimidine tract-binding protein (PTB) to regulate gene splicing. This study shows miR-133 directly controls nPTB expression, impacting muscle differentiation.
Area of Science:
- Molecular Biology
- Developmental Biology
- Genetics
Background:
- Alternative pre-mRNA splicing is crucial for gene expression changes during development.
- Polypyrimidine tract-binding protein (PTB) and its neuronal homolog nPTB regulate splicing in neuron and muscle differentiation.
- PTB/nPTB proteins repress exons in early myoblasts, with reduced expression upon differentiation leading to increased exon inclusion.
Purpose of the Study:
- To investigate the role of microRNA-133 (miR-133) in regulating nPTB expression during myoblast differentiation.
- To elucidate the mechanism by which miR-133 controls nPTB and its impact on muscle-specific splicing.
Main Methods:
- C2C12 myoblast differentiation model.
- Quantitative analysis of nPTB protein and mRNA levels.
- Introduction of synthetic miR-133 and use of locked nucleic acid (LNA) oligonucleotides.
- Luciferase reporter assays to validate microRNA-responsive elements (MREs).
Main Results:
- nPTB protein, but not mRNA, decreased during C2C12 myoblast differentiation, coinciding with miR-133 upregulation.
- Synthetic miR-133 reduced endogenous nPTB expression in undifferentiated cells.
- miR-133 directly targets the nPTB 3' untranslated region (UTR) via MREs, as shown by luciferase assays.
- Inhibition of miR-133/miR-1/206 increased nPTB expression and decreased inclusion of PTB-dependent exons.
Conclusions:
- miR-133 directly down-regulates the splicing factor nPTB during muscle development.
- This study establishes a role for microRNAs in controlling developmentally regulated alternative splicing programs.
- The miR-133/nPTB regulatory axis is conserved across species and critical for muscle differentiation.
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There are five types of alternative RNA splicing that vary in the ways the pre-mRNA segments are removed or retained in the mature mRNA. The first...
There are five types of alternative RNA splicing that vary in the ways the pre-mRNA segments are removed or retained in the mature mRNA. The first...
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Alternative RNA splicing is the regulated splicing of exons and introns to produce different mature mRNAs from a single pre-mRNA. Unlike in constitutive splicing where a single gene produces a single type of mRNA, alternative splicing allows an organism to produce multiple proteins from a single gene and plays an important role in protein diversity.
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