P2-purinergic agonists activate phospholipase C in a guanine nucleotide- and Ca2+-dependent manner in FRTL-5 thyroid cell membranes.
Various adenine nucleotides activated phospholipase C of FRTL-5 cell membranes in the following order of activity, ATP gamma S greater than ATP greater than AppNp greater than AppCp = ADP greater than MeSATP. This order was well consistent with that observed in intact cells. Such activation occurred only in the presence of appropriate concentrations of GTP gamma S and Ca2+, in a way similar to the norepinephrine-induced activation. NaF, a non-specific GTP-binding protein (G-protein) activator, also stimulated the enzyme. These adenine nucleotides, norepinephrine and NaF-induced activations were inhibited by GDP beta S. We conclude that a G-protein is involved in the adenine nucleotides-induced activation of phospholipase C via P2-purinergic receptor in FRTL-5 cells.
Okajima
F
F
Department of Physical Biochemistry, Gunma University, Maebashi, Japan.
Sato
K
K
Kondo
Y
Y
D000266:Adenylyl Imidodiphosphate / Q000494:pharmacology; D000818:Animals; D002118:Calcium / Q000502:physiology*; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D002474:Cell-Free System; D004789:Enzyme Activation; D019204:GTP-Binding Proteins / Q000502:physiology*; D006150:Guanine Nucleotides / Q000502:physiology*; D066298:In Vitro Techniques; D007295:Inositol Phosphates / Q000378:metabolism; D009638:Norepinephrine / Q000494:pharmacology; D051381:Rats; D011942:Receptors, Adrenergic, alpha / Q000502:physiology; D011983:Receptors, Purinergic / Q000502:physiology*; D012969:Sodium Fluoride / Q000494:pharmacology; D013961:Thyroid Gland / Q000502:physiology*; D010738:Type C Phospholipases / Q000378:metabolism*
D006150:Guanine Nucleotides; D007295:Inositol Phosphates; D011942:Receptors, Adrenergic, alpha; D011983:Receptors, Purinergic; D000266:Adenylyl Imidodiphosphate; D012969:Sodium Fluoride; D010738:Type C Phospholipases; D019204:GTP-Binding Proteins; D002118:Calcium; D009638:Norepinephrine