Phospholipase C and phospholipase A2are involved in the antiviral activity of human interferon-α

Cell-membrane phospholipase C is involved in inducing the antiviral effect of interferon.

A monospecific inhibitory antibody directed to phospholipase C (phosphoinositidase C) blocked the antiviral effect of human interferons alpha and beta when tested on human quiescent fibroblasts challenged with the vesicular stomatitis virus. This action was due to specific inhibition of polyphosphoinositide hydrolysis because (a) the F(ab')2 fragment of the antibody molecule was also inhibitory...

Tyrosine phosphorylation is involved in receptor coupling to phospholipase D but not phospholipase C in the human neutrophil.

The tyrosine kinase inhibitors ST271, ST638 and erbstatin inhibited phospholipase D (PLD) activity in human neutrophils stimulated by fMet-Leu-Phe, platelet-activating factor and leukotriene B4. These compounds did not inhibit phorbol ester-stimulated PLD, indicating that they do not inhibit PLD per se, but probably act at a site between the receptor and the phospholipase. In contrast, the prot...

Regulation of nuclear phospholipase C activity.

A body of evidence, linking inositide-specific phospholipase C (PI-PLC) to the nucleus, is quite extensive. The main isoform in the nucleus is PI-PLCbeta1, whose activity is up-regulated in response to insulin-like growth factor-1 (IGF-1) or insulin stimulation. Whilst at the plasma membrane this PI-PLC is activated and regulated by Galphaq/alpha(11) and Gbetagamma subunits, there is yet no evi...

Cloning and Characterization of a Novel Phospholipase C Enzyme, Human Phospholipase C Eta2

Trypsin-induced phospholipase activity in human platelets.

Trypsin mediates a release of arachidonic acid with resultant increase in O2 consumption (a reflection of cyclo-oxygenase activity) by whole human platelets that is similar to thrombin's effect on these cells. The trypsin and thrombin effects can be differentiated in two ways: (1) at saturating concentrations the measured effects of trypsin greatly exceed those of thrombin; (2) EGTA [ethanediox...