Regulation of tropomyosin gene expression during myogenesis

Journal Article · Sun Mar 01 04:00:00 EST 1981 · Mol. Cell. Biol.; (United States)

DOI:https://doi.org/10.1128/MCB.1.3.289· OSTI ID:5887856

Moss, M; Schwartz, R

In skeletal muscle, tropomyosin has a critical role in transduction of calcium-induced contraction. Presently, little is known about the regulation of tropomyosin gene expression during myogenesis. In the present study, qualitative and quantitative changes in the nucleic acid populations of differentiating chicken embryo muscle cells in culture have been examined. Total nucleic acid content per nucleus increased about fivefold in fully developed myotubes as compared to mononucleated myoblasts. The contribution of deoxyribonucleic acid to the total nucleic acid population decreased from 24% in myoblasts to 5% of total nucleic acid in myotubes. Concomitant with the decrement in deoxyribonucleic acid contribution to total nucleic acid was an increase in polyadenylated ribonucleic acid (RNA) content per cell which reached levels in myotubes that were 17-fold higher than those of myoblasts. Specific changes in the RNA population during myogenesis were further investigated by quantitation of the synthetic capacity (messenger RNA levels) per cell for ..cap alpha..- and ..beta..-tropomyosin. Cell-free translation and immunoprecipitation demonstrated an approximately 40-fold increase in messenger RNA levels per nucleus for ..cap alpha..- and ..beta..-tropomyosin after fusion in the terminally differentiated myotubes. Indirect immunofluorescence with affinity-purified tropomyosin antibodies demonstrated the presence of tropomyosin-containing filaments in cells throughout myogenesis. Thus, the tropomyosin genes are constitutively expressed during muscle differentiation through the production of tropomyosin messenger RNA and translation into tropomyosin protein.

• Research Organization: Dept. of Microbiology, College of Medicine, Univ. of California-Irvine, Irvine, CA 92717
• OSTI ID: 5887856
• Journal Information: Mol. Cell. Biol.; (United States), Journal Name: Mol. Cell. Biol.; (United States) Vol. 1:3; ISSN MCEBD
• Country of Publication: United States
• Language: English

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59 BASIC BIOLOGICAL SCIENCES
ANIMALS
ANTIGEN-ANTIBODY REACTIONS
BIRDS
CALCIUM IONS
CELL CONSTITUENTS
CELL CULTURES
CELL DIFFERENTIATION
CHARGED PARTICLES
CHICKENS
CLASSIFICATION
DNA
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTROPHYSIOLOGY
EMBRYOS
FLUORESCENCE
FOWL
GENE REGULATION
GENES
IONS
LUMINESCENCE
MESSENGER-RNA
MICROTUBULES
MOLECULAR BIOLOGY
MUSCLES
MYOBLASTS
NUCLEIC ACIDS
ORGANIC COMPOUNDS
PHYSICAL PROPERTIES
PHYSIOLOGY
RNA
RNA PROCESSING
TRANSCRIPTION
TROPOMYOSIN
VERTEBRATES