Requirement for G protein activity at a specific time during embryonic chick myogenesis.
Signaling between embryonic myoblasts involves prostaglandin metabolism, the activation of a membrane receptor and changes in polyphosphatidyl inositol metabolism. Many of these membrane-localized events occur between 33 to 35 h of differentiation, concomitant with a dramatic change in membrane organization, in myoblast aggregates in culture. Since many receptors affect inositol phosphate metabolism by activating a GTP-binding protein (G protein), we asked if there was evidence for such a protein in myogenic signaling. We show that during the period of differentiation in culture when prostaglandin is needed to bind to a transient receptor, a pertussis toxin-sensitive but cholera toxin-insensitive G protein must act. If this activation is blocked, the characteristic change in myoblast cell adhesion and subsequent membrane fusion do not occur. We suggest that a G protein couples the activated prostaglandin receptor and the change in polyphosphatidyl inositol metabolism and that this membrane transduction step is necessary for subsequent membrane differentiation events during myogenesis.
Hausman
R E
RE
Biological Science Center, Boston University, MA 02215.
elGendy
H
H
Craft
F
F
D000818:Animals; D002448:Cell Adhesion / Q000187:drug effects; D002459:Cell Fusion / Q000187:drug effects; D002642:Chick Embryo; D002772:Cholera Toxin / Q000494:pharmacology; D019204:GTP-Binding Proteins / Q000502:physiology*; D009132:Muscles / Q000166:cytology / Q000196:embryology* / Q000378:metabolism; D037342:Pertussis Toxin; D010716:Phosphatidylinositols / Q000378:metabolism; D011982:Receptors, Prostaglandin / Q000378:metabolism; D010566:Virulence Factors, Bordetella / Q000494:pharmacology
D010716:Phosphatidylinositols; D011982:Receptors, Prostaglandin; D010566:Virulence Factors, Bordetella; D002772:Cholera Toxin; D037342:Pertussis Toxin; D019204:GTP-Binding Proteins