Repositioning of Muscle-specific Genes Relative to the Periphery of SC-35 Domains during Skeletal Myogenesis
AUTOR(ES)
Moen, Phillip T.
FONTE
The American Society for Cell Biology
RESUMO
Previous studies have shown that in a given cell type, certain active genes associate with SC-35 domains, nuclear regions rich in RNA metabolic factors and excluded from heterochromatin. This organization is not seen for all active genes; therefore, it is important to determine whether and when this locus-specific organization arises during development and differentiation of specific cell types. Here, we investigate whether gene organization relative to SC-35 domains is cell type specific by following several muscle and nonmuscle genes in human fibroblasts, committed but proliferative myoblasts, and terminally differentiated muscle. Although no change was seen for other loci, two muscle genes (Human β-cardiac myosin heavy chain and myogenin) became localized to the periphery of an SC-35 domain in terminally differentiated muscle nuclei, but not in proliferative myoblasts or in fibroblasts. There was no apparent change in gene localization relative to either the chromosome territory or the heterochromatic compartment; thus, the gene repositioning seemed to occur specifically with respect to SC-35 domains. This gene relocation adjacent to a prominent SC-35 domain was recapitulated in mouse 3T3 cells induced into myogenesis by introduction of MyoD. Results demonstrate a cell type-specific reorganization of specific developmentally regulated loci relative to large domains of RNA metabolic factors, which may facilitate developmental regulation of genome expression.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=307540Documentos Relacionados
- MyoD is functionally linked to the silencing of a muscle-specific regulatory gene prior to skeletal myogenesis
- Muscle-specific inactivation of the IGF-I receptor induces compensatory hyperplasia in skeletal muscle
- Muscle-specific expression of IGF-1 blocks angiotensin II–induced skeletal muscle wasting
- Co-operativity of functional domains in the muscle-specific transcription factor Myf-5.
- The basic region of myogenin cooperates with two transcription activation domains to induce muscle-specific transcription.