Involvement of cyclic GMP in the fusion of chick embryonic myoblasts in culture.
We found that a transient rise in cGMP levels, which was closely associated with the Ca2+ influx, occurred concomitant with the onset of myoblast fusion. The Ca2+ channel blocker D600 decreased both the cell fusion and the normal rise in cGMP levels. In contrast, the Ca2+ ionophore A23187 transiently increased cGMP levels and induced precocious fusion. In addition, the cGMP analog 8-Br-cGMP induced precocious fusion as A23187 did. The guanylate cyclase inhibitor, methylene blue delayed the fusion in a dose-dependent manner without significantly affecting cell alignment, proliferation, or muscle-specific protein expression. Furthermore, methylene blue delayed the normal rise in cGMP levels, and the fusion block imposed by methylene blue was significantly recovered by 8-Br-cGMP. On the basis of our present findings, we suggest that a Ca2+ influx-dependent rise in cGMP levels is an important step in myoblast fusion.
Choi
S W
SW
Department of Molecular Biology, College of Natural Science, Seoul National University, Korea.
Baek
M Y
MY
Kang
M S
MS
D000818:Animals; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D002459:Cell Fusion / Q000187:drug effects / Q000502:physiology*; D002478:Cells, Cultured; D002642:Chick Embryo; D003402:Creatine Kinase / Q000378:metabolism; D006152:Cyclic GMP / Q000031:analogs & derivatives / Q000378:metabolism* / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005711:Gallopamil / Q000494:pharmacology; D007700:Kinetics; D008751:Methylene Blue / Q000494:pharmacology; D009132:Muscles / Q000166:cytology / Q000196:embryology*
C016276:8-bromocyclic GMP; D000001:Calcimycin; D005711:Gallopamil; D003402:Creatine Kinase; D006152:Cyclic GMP; D002118:Calcium; D008751:Methylene Blue