Differentiation of F9 teratocarcinoma stem cells to primitive endoderm is regulated by the Gialpha2/Gsalpha axis via phospholipase C and not adenylylcyclase.
Morphogen-induced decline in Gialpha triggers F9 teratocarcinoma stem cells to progress to primitive endoderm via activation of protein kinase C and mitogen-activated protein kinase (Gao, P., and Malbon, C. C. (1996) J. Biol. Chem. 271, 9002-9008). Constitutive expression of Gialpha2 blocks, whereas expression of Gsalpha provokes, progression to primitive endoderm, permitting identification of the effectors of the response-utilizing chimera created between Gialpha2 and Gsalpha. N-terminal substitution of Gsalpha with Gialpha2 sequence to create chimera Gialpha2 (1-54)/Gsalpha produced a chimera that activated adenylylcyclase but abolished progression to primitive endoderm and activation of phospholipase C. C-terminal substitution of Gsalpha with Gialpha2 sequence to Gsalpha/Gialpha2 (320-355) enhanced the ability of Gsalpha to promote progression. The Q205L-activated mutant of Gialpha2 suppresses, whereas the G225T-activated mutant of Gsalpha strongly activates phospholipase C and progression in these cells. The N-terminal region of Gsalpha (residues 62-86) appears to act as a dominant switch for the Gsalpha- (activation) versus Gialpha2- (suppression) mediated control of phospholipase C and progression to primitive endoderm.
Gao
P
P
Department of Molecular Pharmacology, Diabetes and Metabolic Diseases Research Center, School of Medicine-HSC, State University of New York, Stony Brook, New York 11794-8651, USA.
Malbon
C C
CC
D000262:Adenylyl Cyclases / Q000502:physiology*; D000818:Animals; D002454:Cell Differentiation; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000502:physiology; D004075:Diglycerides / Q000378:metabolism; D004707:Endoderm / Q000166:cytology*; D004789:Enzyme Activation; D019206:GTP-Binding Protein alpha Subunits, Gi-Go / Q000502:physiology*; D019205:GTP-Binding Protein alpha Subunits, Gs / Q000502:physiology*; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism; D051379:Mice; D008958:Models, Molecular; D011493:Protein Kinase C / Q000502:physiology; D011993:Recombinant Fusion Proteins; D015398:Signal Transduction; D013329:Structure-Activity Relationship; D013724:Teratoma / Q000473:pathology*; D010959:Tissue Plasminogen Activator / Q000378:metabolism; D010738:Type C Phospholipases / Q000502:physiology*
D004075:Diglycerides; D011993:Recombinant Fusion Proteins; D015544:Inositol 1,4,5-Trisphosphate; D000242:Cyclic AMP; D011493:Protein Kinase C; D010738:Type C Phospholipases; D010959:Tissue Plasminogen Activator; D019206:GTP-Binding Protein alpha Subunits, Gi-Go; D019205:GTP-Binding Protein alpha Subunits, Gs; D000262:Adenylyl Cyclases