Research Article Open Access
Volume 2 | Issue 1 | DOI: https://doi.org/10.33696/Signaling.2.032

FOXP1 Interacts with MyoD to Repress its Transcription and Myoblast Conversion

  • 1Department of Cell Biology, UT Southwestern Medical School, Dallas TX 75235, USA
  • 2Department of Microbiology, University of Texas Southwestern Medical Center, Dallas TX 75235, USA
  • 3Department of Molecular Biosciences, the University of Texas at Austin, Austin TX 78712, USA
+ Affiliations - Affiliations

Corresponding Author

Haley O. Tucker, haleytucker@austin.utexas.edu

Received Date: August 11, 2020

Accepted Date: December 03, 2020


Forkhead transcription factors (TFs) often dimerize outside their extensive family, whereas bHLH transcription factors typically dimerize with E12/E47. Based on structural similarities, we predicted that a member of the former, Forkhead Box P1 (FOXP1), might heterodimerize with a member of the latter, MYOD1 (MyoD). Data shown here support this hypothesis and further demonstrate the specificity of this forkhead/myogenic interaction among other myogenic regulatory factors. We found that FOXP1-MyoD heterodimerization compromises the ability of MyoD to bind to E-boxes and to transactivate E box- containing promoters. We observed that FOXP1 is required for the full ability of MyoD to convert fibroblasts into myotubules. We provide a model in which FOXP1 displaces ID and E12/E47 to repress MyoD during the proliferative phase of myoblast differentiation. These data identify FOXP1 as a hitherto unsuspected transcriptional repressor of MyoD. We suggest that isolation of paired E-box and forkhead sites within 1 turn helical spacings provides potential for cooperative interactions among heretofore distinct classes of transcription factors.


Transcriptional regulation, Myogenic regulatory factors, Forkhead box P1, Myoblast differentiation

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