The small G-proteins Rac1 and Cdc42 are essential for myoblast fusion in the mouse

E Vasyutina, B Martarelli… - Proceedings of the …, 2009 - National Acad Sciences
E Vasyutina, B Martarelli, C Brakebusch, H Wende, C Birchmeier
Proceedings of the National Academy of Sciences, 2009National Acad Sciences
Rac1 and Cdc42 are small G-proteins that regulate actin dynamics and affect plasma
membrane protrusion and vesicle traffic. We used conditional mutagenesis in mice to
demonstrate that Rac1 and Cdc42 are essential for myoblast fusion in vivo and in vitro. The
deficit in fusion of Rac1 or Cdc42 mutant myoblasts correlates with a deficit in the
recruitment of actin fibers and vinculin to myoblast contact sites. Comparison of the changes
observed in mutant myogenic cells indicates that Rac1 and Cdc42 function in a …
Rac1 and Cdc42 are small G-proteins that regulate actin dynamics and affect plasma membrane protrusion and vesicle traffic. We used conditional mutagenesis in mice to demonstrate that Rac1 and Cdc42 are essential for myoblast fusion in vivo and in vitro. The deficit in fusion of Rac1 or Cdc42 mutant myoblasts correlates with a deficit in the recruitment of actin fibers and vinculin to myoblast contact sites. Comparison of the changes observed in mutant myogenic cells indicates that Rac1 and Cdc42 function in a nonredundant and not completely overlapping manner during the fusion process. Our genetic analysis demonstrates thus that the function of Rac in myoblast fusion is evolutionarily conserved from insects to mammals and that Cdc42, a molecule hitherto not implicated in myoblast fusion, is essential for the fusion of murine myoblasts.
National Acad Sciences