Intragenic epigenetic changes modulate NCAM alternative splicing in neuronal differentiation.
Ignacio E Schor1, Ana Fiszbein, Ezequiel Petrillo
1Laboratorio de Fisiología y Biología Molecular, Departamento de Fisiología, Biología Molecular y Celular, IFIBYNE-UBA-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Buenos Aires, Argentina.
The EMBO Journal
|July 30, 2013
Summary
Repressive chromatin marks regulate neural cell adhesion molecule (NCAM) alternative splicing during neuronal differentiation. Epigenetic changes, including H3K9me2 and H3K27me3, control exon 18 inclusion, impacting neuronal transcriptomes.
Area of Science:
- Molecular Biology
- Epigenetics
- Neuroscience
Background:
- Alternative splicing generates transcriptomic diversity crucial for cell type specificity.
- Neural cell adhesion molecule (NCAM) alternative splicing is vital for neuronal development and function.
Purpose of the Study:
- To investigate the role of intragenic chromatin modifications in regulating NCAM exon 18 (E18) alternative splicing during neuronal differentiation.
- To elucidate how specific epigenetic marks influence NCAM splicing patterns in different cellular contexts.
Main Methods:
- Analysis of chromatin marks (H3K9me2, H3K27me3) along the NCAM gene body during neuronal differentiation.
- Treatment with DNA methylation and H3K9 dimethylation inhibitors (5-azacytidine, BIX 01294).
- Induction of intragenic repressive chromatin marks using small interfering RNAs targeting NCAM intron 18.
Main Results:
- Increased repressive marks (H3K9me2, H3K27me3) correlated with inhibited polymerase II elongation and altered NCAM E18 splicing during differentiation.
- Inhibitors of DNA methylation and H3K9 dimethylation blocked differentiation-induced E18 inclusion.
- Intronic small interfering RNAs promoting repressive marks induced E18 inclusion in undifferentiated cells.
Conclusions:
- Intragenic repressive chromatin marks are sufficient to induce NCAM E18 alternative splicing.
- Two distinct epigenetic mechanisms (repressive marks and acetylation) regulate NCAM alternative splicing in response to cellular signals.
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