Point-mutated p21ras couples a muscarinic receptor to calcium channels and polyphosphoinositide hydrolysis.
A high-affinity muscarinic receptor is detectable both in normal 3T3 mouse fibroblasts and in their transformed counterpart obtained by transfection with the oncogene EJ/T24-H-ras. However, only the transformed cell line is responsive to muscarinic agonist carbamylcholine in terms of Ca2+ influx and polyphosphoinositide hydrolysis, whereas the normal cell line is unresponsive. Using a point-mutated p21ras protein and monoclonal antibodies anti-p21ras, we provide evidences that p21ras couples to receptor-operating calcium channels and to polyphosphoinositide hydrolysis a muscarinic receptor which is uncoupled in normal mouse fibroblasts.
D000818:Animals; D000911:Antibodies, Monoclonal; D002118:Calcium / Q000502:physiology; D002460:Cell Line; D019204:GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D007295:Inositol Phosphates / Q000378:metabolism; D007473:Ion Channels / Q000378:metabolism*; D008563:Membrane Lipids / Q000378:metabolism; D051379:Mice; D009154:Mutation; D009856:Oncogene Proteins, Viral / Q000378:metabolism*; D010716:Phosphatidylinositols / Q000378:metabolism*; D011976:Receptors, Muscarinic / Q000378:metabolism*; D013329:Structure-Activity Relationship
D000911:Antibodies, Monoclonal; D007295:Inositol Phosphates; D007473:Ion Channels; D008563:Membrane Lipids; D009856:Oncogene Proteins, Viral; D010716:Phosphatidylinositols; D011976:Receptors, Muscarinic; D019204:GTP-Binding Proteins; D002118:Calcium