TY - JOUR
T1 - Bradykinin stimulates the tyrosine phosphorylation and bradykinin B2 receptor association of phospholipase Cγ1 in vascular endothelial cells
AU - Venema, Virginia J.
AU - Ju, Hong
AU - Sun, Jimin
AU - Eaton, Douglas C.
AU - Marrero, Mario B.
AU - Venema, Richard C.
PY - 1998/5/8
Y1 - 1998/5/8
N2 - Bradykinin (BK) B2 receptor signaling involves activation of phospholipase C (PLC). PLC activation by other receptors consists of either allosteric activation of PLCβ isoforms by G-proteins or tyrosine phosphorylation of PLCγ isoforms. Because the B2 receptor is a G-protein-coupled receptor, it has been assumed that the receptor signals through PLCβ. In the present study, however, we have found that BK stimulation of IP3 production and the Ca2+ signal in endothelial cells is dependent on tyrosine phosphorylation. Furthermore, stimulation of B2 receptors in these cells is accompanied by a transient tyrosine phosphorylation of PLCγ1. Phosphorylation is correlated with increased IP3 production and association of PLCγ1 with the C-terminal intracellular domain of the B2 receptor. The B2 receptor can thus physically associate with intracellular proteins other than G-proteins. Activation of PLCγ isoforms, rather than PLCβ isoforms, may, therefore, be primarily responsible for BK-stimulated IP3 generation in endothelial cells.
AB - Bradykinin (BK) B2 receptor signaling involves activation of phospholipase C (PLC). PLC activation by other receptors consists of either allosteric activation of PLCβ isoforms by G-proteins or tyrosine phosphorylation of PLCγ isoforms. Because the B2 receptor is a G-protein-coupled receptor, it has been assumed that the receptor signals through PLCβ. In the present study, however, we have found that BK stimulation of IP3 production and the Ca2+ signal in endothelial cells is dependent on tyrosine phosphorylation. Furthermore, stimulation of B2 receptors in these cells is accompanied by a transient tyrosine phosphorylation of PLCγ1. Phosphorylation is correlated with increased IP3 production and association of PLCγ1 with the C-terminal intracellular domain of the B2 receptor. The B2 receptor can thus physically associate with intracellular proteins other than G-proteins. Activation of PLCγ isoforms, rather than PLCβ isoforms, may, therefore, be primarily responsible for BK-stimulated IP3 generation in endothelial cells.
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U2 - 10.1006/bbrc.1998.8574
DO - 10.1006/bbrc.1998.8574
M3 - Article
C2 - 9600070
AN - SCOPUS:0032495980
VL - 246
SP - 70
EP - 75
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
SN - 0006-291X
IS - 1
ER -