Integrin alpha3 subunit participates in myoblast adhesion and fusion in vitro.
Satellite cells are myogenic precursor cells, participating in growth, and regeneration of skeletal muscles. The proteins that play a role in myogenesis are integrins. In this report, we show that the integrin alpha3 subunit is expressed in quiescent satellite cells and activated myoblasts. We also find that in myoblasts the integrin alpha3 subunit is localized at cell-cell and cell-extracellular matrix contacts. We notice that increase in protein and mRNA encoding the integrin alpha3 subunit accompanies myoblast differentiation. Using double immunofluorescence and immunoprecipitation experiments, we demonstrate that the integrin alpha3 subunit co-localizes with actin, and binds the integrin beta1 subunit and ADAM12, suggesting that the complex alpha3beta1/ADAM12 is probably involved in myoblast fusion. Importantly, overexpression of the full-length integrin alpha3 subunit increases myoblast fusion whereas an antibody against its extracellular domain inhibits fusion. These data demonstrate that the integrin alpha3 subunit may contribute to satellite cell activation and then myoblast adhesion and fusion.
Brzóska
Edyta
E
Faculty of Biology, Department of Cytology, Warsaw University, 1 Miecznikowa St., 02-096 Warsaw, Poland. edbrzoska@biol.uw.edu.pl
Bello
Valérie
V
Darribère
Thierry
T
Moraczewski
Jerzy
J
D051722:ADAM Proteins / Q000378:metabolism; D000072199:ADAM12 Protein; D000199:Actins / Q000378:metabolism; D000818:Animals; D000906:Antibodies / Q000494:pharmacology; D002448:Cell Adhesion; D002459:Cell Fusion; D002478:Cells, Cultured; D039422:Integrin alpha3 / Q000032:analysis / Q000235:genetics / Q000502:physiology*; D019012:Integrin beta1 / Q000378:metabolism; D008297:Male; D008565:Membrane Proteins / Q000378:metabolism; D032448:Myoblasts, Skeletal / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017208:Rats, Wistar; D032496:Satellite Cells, Skeletal Muscle / Q000166:cytology* / Q000378:metabolism
D000199:Actins; D000906:Antibodies; D039422:Integrin alpha3; D019012:Integrin beta1; D008565:Membrane Proteins; D012333:RNA, Messenger; D051722:ADAM Proteins; D000072199:ADAM12 Protein