Coupling of histamine H1 and adenosine A1 receptors to phospholipase C in DDT1MF-2 cells: synergistic interactions and regulation by cyclic AMP.
Intracellular cross-talk or synergism between receptors coupled negatively to adenylate cyclase via PTX-sensitive Gi-protein(s) and receptors coupled to phospholipase C via PTX-insensitive G-proteins is prevalent in a variety of cell types (see above) and may represent a universal mechanism for the modulation of phospholipase C activity (and hence calcium mobilization). However, the precise mechanism(s) involved in these synergistic interactions remain to be unravelled. In view of the recent findings by Camps et al. (1992), it may be that Gi-protein-derived beta gamma subunits are responsible for the potentiation of phospholipase C activity observed in DDT1MF-2 cells (and other cell types). Clearly, the DDT1MF-2 smooth muscle cell line appears to provide an ideal model system in which to investigate the mechanisms underlying the intracellular cross-talk between receptors coupled to PTX-sensitive and to PTX-insensitive G-proteins.
Dickenson
J M
JM
Department of Physiology and Pharmacology, Medical School, Queen's Medical Centre, Nottingham, U.K.
Hill
S J
SJ
D037361:Adenylate Cyclase Toxin; D000818:Animals; D002118:Calcium / Q000378:metabolism / Q000494:pharmacology; D002460:Cell Line; D005576:Colforsin / Q000494:pharmacology; D000242:Cyclic AMP / Q000378:metabolism*; D019204:GTP-Binding Proteins / Q000378:metabolism; D011969:Receptors, Histamine H1 / Q000187:drug effects / Q000502:physiology*; D018047:Receptors, Purinergic P1 / Q000187:drug effects / Q000502:physiology*; D015290:Second Messenger Systems; D010738:Type C Phospholipases / Q000378:metabolism*; D010566:Virulence Factors, Bordetella / Q000494:pharmacology
D037361:Adenylate Cyclase Toxin; D011969:Receptors, Histamine H1; D018047:Receptors, Purinergic P1; D010566:Virulence Factors, Bordetella; D005576:Colforsin; D000242:Cyclic AMP; D010738:Type C Phospholipases; D019204:GTP-Binding Proteins; D002118:Calcium