Three types of muscle-specific gene expression in fusion-blocked rat skeletal muscle cells: translational control in EGTA-treated cells.
When rat skeletal muscle cells were treated with EGTA, an inhibitor of cell fusion, a battery of muscle-specific mRNAs was synthesized but not translated despite the synthesis of many other proteins. Most of the muscle-specific mRNAs were associated with polysomes in fused myotubes, whereas they were found in postpolysomal fractions in EGTA-treated cells. Therefore, in addition to the well-documented transcriptional and posttranscriptional control of muscle-specific genes, translational control of this specific group of genes, presumably involving a Ca2+-dependent process, is also observed in these fusion-blocked cells. These findings and results obtained with other fusion inhibitors demonstrate that three types of muscle-specific gene expression take place in the fusion-blocked cells depending on the inhibitors used: one, neither muscle-specific mRNAs nor proteins are synthesized; two, the mRNAs are synthesized but not translated; and three, both the mRNAs and the proteins are synthesized.
D000818:Animals; D002459:Cell Fusion / Q000187:drug effects; D002460:Cell Line; D004533:Egtazic Acid / Q000494:pharmacology*; D005796:Genes / Q000187:drug effects*; D009124:Muscle Proteins / Q000235:genetics*; D009132:Muscles / Q000166:cytology / Q000378:metabolism*; D011132:Polyribosomes / Q000187:drug effects / Q000378:metabolism; D014176:Protein Biosynthesis / Q000187:drug effects*; D012333:RNA, Messenger / Q000187:drug effects / Q000235:genetics; D051381:Rats; D014158:Transcription, Genetic / Q000187:drug effects
D009124:Muscle Proteins; D012333:RNA, Messenger; D004533:Egtazic Acid