Activation of Gi-like proteins, a receptor-independent effect of kinins in mast cells
The peptide hormones bradykinin and kallidin (Lys-bradykinin), as well as their analogues [des-Arg9]-bradykinin, a selective B1 agonist, [des-Arg9,Leu8]-bradykinin, a selective B1 antagonist, and [Thi5,8,D-Phe7]-bradykinin and D-Arg0-[Hyp3,D-Phe7]-bradykinin, two selective B2 antagonists, induced ra...
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Published in | Molecular pharmacology Vol. 38; no. 6; pp. 816 - 822 |
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Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
United States
American Society for Pharmacology and Experimental Therapeutics
01.12.1990
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Subjects | |
Online Access | Get full text |
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Summary: | The peptide hormones bradykinin and kallidin (Lys-bradykinin), as well as their analogues [des-Arg9]-bradykinin, a selective
B1 agonist, [des-Arg9,Leu8]-bradykinin, a selective B1 antagonist, and [Thi5,8,D-Phe7]-bradykinin and D-Arg0-[Hyp3,D-Phe7]-bradykinin,
two selective B2 antagonists, induced rapid histamine release from purified rat peritoneal mast cells. In contrast, the N-terminal
fragment bradykinin-(1-5) was inactive. These peptides also activate the GTPase activity of GTP-binding proteins (G proteins)
(Go/Gi) purified from calf brain, with an order of potency identical to that observed on mast cells, [Thi5,8,D-Phe7]-bradykinin
much greater than kallidin greater than bradykinin greater than D-Arg0-[Hyp3,D-Phe7]-bradykinin greater than [des-Arg9]-bradykinin
greater than [des-Arg9,Leu8]-bradykinin greater than bradykinin-(1-5). This correlation suggested that G proteins are the
targets of kinins in mast cells. Accordingly, the concomitant increase in inositol trisphosphates and release of histamine
elicited by kinins were inhibited by pertussis toxin pretreatment of mast cells. The inhibitory effect of benzalkonium chloride
showed that the G proteins involved belong to the Gi type. GTPase activity was measured in the supernatant of homogenized
mast cells but not in the membranous fraction. This activity was stimulated by kinins and by the venom peptide mastoparan.
The potency of peptides was similar to that observed with purified bovine G proteins. Sodium dodecyl sulfate-gel electrophoresis
of mast cell supernatant revealed pertussis toxin-induced ADP-ribosylation of two proteins, in the Mr 41,000 and 40,000 range,
i.e., similar to purified alpha-subunits of Gi1 and Gi2 or Gi3 subtypes. The data support the proposal that bradykinin and
analogues act like mastoparan, substance P, and compound 48/80, interacting first with sialic acid residues of the cell surface
and then with Gi-like proteins, inducing phospholipase C activation and intracellular calcium mobilization. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0026-895X 1521-0111 |