Transactivation of capn2 by myogenic regulatory factors during myogenesis.

Date publication

février 2003

Journal

Journal of molecular biology

Auteurs

Membres identifiés du Cancéropôle Est :
Pr DEDIEU Stéphane

Tous les auteurs :
Dedieu S, Mazères G, Dourdin N, Cottin P, Brustis JJ

Lien Pubmed

https://www.ncbi.nlm.nih.gov/pubmed/12559913

Résumé

The calcium-activated cysteine protease m-calpain plays a pivotal role during the earlier stages of myogenesis, particularly during fusion. The enzyme is a heterodimer, encoded by the genes capn2, for the large subunit, and capn4, for the small subunit. To study the regulation of m-calpain, the DNA sequence upstream of capn2 was analyzed for promoter elements, revealing the existence of five consensus-binding sites (E-box) for several myogenic regulatory factors and one binding site for myocyte enhancer factor-2 (MEF-2). Transient transfections with reporter gene constructs containing the E-box revealed that MyoD presents a high level of transactivation of reporter constructs containing this region, in particular the sequences including the MEF-2/E4-box. In addition, over-expression of various myogenic factors demonstrated that MyoD and myogenin with much less efficiency, can up-regulate capn2, both singly and synergistically, while Myf5 has no effect on synthesis of the protease. Experiments with antisense oligonucleotides directed against each myogenic factor revealed that MyoD plays a specific and pivotal role during capn2 regulation, and cannot be replaced wholly by myogenin and Myf5.

Mots clés

Animals, Base Sequence, Binding Sites, Blotting, Western, COS Cells, Calpain, genetics, Cells, Cultured, Cercopithecus aethiops, DNA Primers, chemistry, DNA-Binding Proteins, physiology, Fibroblasts, physiology, Gene Expression Regulation, Humans, Immunoenzyme Techniques, Luciferases, metabolism, MEF2 Transcription Factors, Mice, Molecular Sequence Data, Muscle Development, physiology, Muscle Proteins, antagonists & inhibitors, MyoD Protein, antagonists & inhibitors, Myoblasts, physiology, Myogenic Regulatory Factor 5, Myogenic Regulatory Factors, Myogenin, antagonists & inhibitors, Oligonucleotides, Antisense, pharmacology, Promoter Regions, Genetic, Recombinant Proteins, Trans-Activators, Transcription Factors, metabolism, Transcriptional Activation, genetics, Transfection, Up-Regulation

Référence

J. Mol. Biol.. 2003 Feb;326(2):453-65