Rbfox2-Coordinated Alternative Splicing of Mef2d and Rock2 Controls Myoblast Fusion during Myogenesis

• Published in: Molecular cell Vol. 55; no. 4; pp. 592 - 603
• Main Authors: Singh, Ravi K., Xia, Zheng, Bland, Christopher S., Kalsotra, Auinash, Scavuzzo, Marissa A., Curk, Tomaz, Ule, Jernej, Li, Wei, Cooper, Thomas A.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 21.08.2014
• Subjects: Alternative Splicing - genetics; Alternative Splicing - physiology; Animals; Cell Line; Chlorocebus aethiops; Conserved Sequence; COS Cells; Gene Expression Regulation; HEK293 Cells; Humans; MEF2 Transcription Factors - genetics; MEF2 Transcription Factors - metabolism; Mice; Muscle Development - genetics; Muscle Development - physiology; Myoblasts - physiology; Organ Specificity; Protein Isoforms - genetics; Protein Isoforms - metabolism; rho-Associated Kinases - genetics; rho-Associated Kinases - metabolism; RNA - genetics; RNA-Binding Proteins - physiology; Sequence Analysis, RNA
• ISSN: 1097-2765; 1097-4164; 1097-4164
• DOI: 10.1016/j.molcel.2014.06.035

Alternative splicing plays important regulatory roles during periods of physiological change. During development, a large number of genes coordinately express protein isoform transitions regulated by alternative splicing; however, the mechanisms that coordinate splicing and the functional integration of the resultant tissue-specific protein isoforms are typically unknown. Here we show that the conserved Rbfox2 RNA binding protein regulates 30% of the splicing transitions observed during myogenesis and is required for the specific step of myoblast fusion. Integration of Rbfox2-dependent splicing outcomes from RNA-seq with Rbfox2 iCLIP data identified Mef2d and Rock2 as Rbfox2 splicing targets. Restored activities of Mef2d and Rock2 rescued myoblast fusion in Rbfox2-depleted cultures, demonstrating functional cooperation of protein isoforms generated by coordinated alterative splicing. The results demonstrate that coordinated alternative splicing by a single RNA binding protein modulates transcription (Mef2d) and cell signaling (Rock2) programs to drive tissue-specific functions (cell fusion) to promote a developmental transition. [Display omitted] •Rbfox2, but not Rbfox1, is required for skeletal muscle differentiation•Rbfox2 regulates 30% splicing transitions associated with muscle differentiation•Rbfox2 controls myoblast fusion by regulating splicing of Mef2d and Rock2•Rock2 C-terminal alternative exons promote interactions with N terminus Singh et al. identify hundreds of splicing events regulated by Rbfox2 and show that Rbfox2-regulated alternative splicing of two messages, Mefd2 and Rock2, is responsible for the function of Rbfox2 in myoblast fusion.