PKC activation inhibition

Protein kinase C (PKC) has been implicated in the regulation of NO production in endothelial cells. Castro et al. (1998) reported that in porcine aortic endothelial cells ATP induced increase in NO production was mediated via activation of PKC [32]. There are, however, reports of PKC mediated inhibition of eNOS via phosphorylation in BAEC treated with a phorbol ester [33] as it has been demonstrated that PKC activation inhibits eNOS activity by phosphorylating at threonine 495 and dephosphorylating at serine 1177 [34]. Unlike PKC, activation of eNOS by PKA occurs via phosphorylation of the enzyme at serine 1177 and de-phosphorylation at threonine 495 [34] (see Figure 2). 

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