TY - JOUR
T1 - Protein kinase C inhibits the Ca(2+)-dependent stimulation of phospholipase C-beta 1 in vitro.
AU - Litosch, I.
N1 - Copyright:
This record is sourced from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
PY - 1996
Y1 - 1996
N2 - Protein kinase C (PKC) inhibited the Ca(2+)-dependent stimulation of a 600-fold purified phospholipase C beta 1 (PLC-beta 1). Inhibition by PKC was time-dependent, and required ATP and diacylglycerol. Inhibition was more pronounced when the PLC assay was conducted with a PIP2 substrate mixture containing phosphatidylserine, then with a substrate mixture containing phosphatidyle-thanolamine. Cyclic AMP-dependent protein kinase A did not inhibit PLC-beta 1 activity. PKC did not affect the rate of PLC-beta 1 activation by Ca2+ or the rate of PLC-beta 1 deactivation by EGTA. PLC-beta 1 purified 1700-fold was less sensitive to inhibition by PKC despite stoichiometric phosphorylation. These results demonstrate that PKC inhibits the Ca(2+)-dependent stimulation of a 600-fold purified PLC-beta 1 in vitro. Furthermore, purification of PLC-beta 1 to homogeneity results in a diminished sensitivity to inhibition by PKC, indicating that other components may participate in mediating the effect of PKC on the Ca(2+)-dependent stimulation of PLC-beta 1 in vitro.
AB - Protein kinase C (PKC) inhibited the Ca(2+)-dependent stimulation of a 600-fold purified phospholipase C beta 1 (PLC-beta 1). Inhibition by PKC was time-dependent, and required ATP and diacylglycerol. Inhibition was more pronounced when the PLC assay was conducted with a PIP2 substrate mixture containing phosphatidylserine, then with a substrate mixture containing phosphatidyle-thanolamine. Cyclic AMP-dependent protein kinase A did not inhibit PLC-beta 1 activity. PKC did not affect the rate of PLC-beta 1 activation by Ca2+ or the rate of PLC-beta 1 deactivation by EGTA. PLC-beta 1 purified 1700-fold was less sensitive to inhibition by PKC despite stoichiometric phosphorylation. These results demonstrate that PKC inhibits the Ca(2+)-dependent stimulation of a 600-fold purified PLC-beta 1 in vitro. Furthermore, purification of PLC-beta 1 to homogeneity results in a diminished sensitivity to inhibition by PKC, indicating that other components may participate in mediating the effect of PKC on the Ca(2+)-dependent stimulation of PLC-beta 1 in vitro.
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M3 - Article
C2 - 9015864
AN - SCOPUS:0030346154
VL - 6
SP - 87
EP - 98
JO - Receptors & signal transduction
JF - Receptors & signal transduction
SN - 1087-8475
IS - 2
ER -