1. Requirement for down-regulation of the CCAAT-binding activity of the NF-Y transcription factor during skeletal muscle differentiation
- Author
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Fiorella Guadagni, Isabella Manni, Paola Fuschi, Giulia Piaggio, Ada Sacchi, Aymone Gurtner, and Roberto Mantovani
- Subjects
Cellular differentiation ,Cyclin A ,Muscle Fibers, Skeletal ,Down-Regulation ,Cyclin B ,Mice ,medicine ,Myocyte ,Animals ,Muscle, Skeletal ,Promoter Regions, Genetic ,Molecular Biology ,Myogenin ,Cells, Cultured ,Cell Nucleus ,biology ,Cell Cycle ,Cardiac muscle ,Skeletal muscle ,Cell Differentiation ,Cell Biology ,Articles ,Molecular biology ,Cyclin-Dependent Kinases ,Protein Subunits ,P19 cell ,medicine.anatomical_structure ,CCAAT-Binding Factor ,Gene Expression Regulation ,biology.protein ,Chromatin immunoprecipitation - Abstract
NF-Y is composed of three subunits, NF-YA, NF-YB, and NF-YC, all required for DNA binding. All subunits are expressed in proliferating skeletal muscle cells, whereas NF-YA alone is undetectable in terminally differentiated cells in vitro. By immunohistochemistry, we show that the NF-YA protein is not expressed in the nuclei of skeletal and cardiac muscle cells in vivo. By chromatin immunoprecipitation experiments, we demonstrate herein that NF-Y does not bind to the CCAAT boxes of target promoters in differentiated muscle cells. Consistent with this, the activity of these promoters is down-regulated in differentiated muscle cells. Finally, forced expression of the NF-YA protein in cells committed to differentiate leads to an impairment in the down-regulation of cyclin A, cyclin B1, and cdk1 expression and is accompanied by a delay in myogenin expression. Thus, our results indicate that the suppression of NF-Y function is of crucial importance for the inhibition of several cell cycle genes and the induction of the early muscle-specific program in postmitotic muscle cells.
- Published
- 2003