Ancient antagonism between CELF and RBFOX families tunes mRNA splicing outcomes

Area of Science:

• Molecular Biology
• Genetics
• Developmental Biology

Background:

• Alternative splicing is a key regulatory mechanism in eukaryotic gene expression, with over 95% of human multi-exon genes undergoing this process.
• Dysregulation of alternative splicing is implicated in various human diseases.
• CELF2 is a critical splicing regulator in T cell development and function.

Purpose of the Study:

• To investigate the global splicing regulatory network of CELF2 in human T cells.
• To identify potential antagonistic interactions between CELF2 and other splicing factors.
• To explore the conserved role of this regulatory network in different tissues and organisms.

Main Methods:

• Integration of high-throughput sequencing data (binding and splicing quantification).
• Application of sequence feature analysis and probabilistic splicing code models.
• Validation through knockdown and overexpression experiments in human cells.
• Analysis of publicly available data in mouse and human disease models.

Main Results:

• Evidence of splicing antagonism between CELF2 and the RBFOX family of splicing factors.
• CELF2 was found to repress RBFOX2 mRNA and protein levels.
• Antagonistic coregulation by CELF and RBFOX proteins identified in mouse muscle and heart, affecting targets like calcium signaling proteins and MEF2 transcription factors.
• Aberrant splicing of coregulated events observed in diseases such as heart failure, diabetes, and myotonic dystrophy.
• Evolutionary conservation of CELF-RBFOX antagonism demonstrated across species.

Conclusions:

• CELF2 and RBFOX proteins exhibit a conserved, antagonistic regulatory relationship impacting alternative splicing.
• This antagonism plays a role in the development and maintenance of neuronal, muscle, and heart tissues.
• Dysregulation of this splicing network contributes to human diseases affecting these tissues.
• The findings provide insights into the complex splicing regulatory networks underlying normal development and disease pathogenesis.