Effect of @entity268 -dependent protein kinase on XXXX secretion from @entity291 adrenal chromaffin cells.

@entity268 @entity11040 @entity1025 @entity2922 @entity141 @entity2661 @entity20631 @entity291 @entity24398 @entity855
We examined the role of @entity268 -dependent protein kinase in @entity141 -elicited @entity2922 secretion from @entity291 adrenal chromaffin cells. When the @entity11040 -treated cells were incubated with the catalytic subunit of @entity268 -dependent protein kinase, the secretion of @entity2661 from the cells occurred in the absence of @entity141 . The effect of the catalytic subunit was dependent on its activity (50-100 units/ml) and the presence of @entity855 -Mg2+ in the incubation medium. However, incubation of the cells with the regulatory subunit of @entity268 -dependent protein kinase did not affect the secretion. @entity141 (43 nM-10 microM) also increased the secretion, which was @entity855 - @entity1025 -dependent. The catalytic subunit (25-200 units/ml) enhanced the @entity141 -evoked secretion at the suboptimal but not optimal @entity141 concentration, which induced maximal secretion. A potent synthetic peptide inhibitor of @entity268 -dependent protein kinase abolished the catalytic subunit-induced secretion, but not the @entity141 -evoked secretion. On the other hand, @entity20631 , a potent inhibitor of protein kinases, inhibited both the catalytic subunit-induced and the @entity141 -evoked secretion, but not @entity24398 , a much less potent inhibitor of protein kinases. These results strongly suggest that the catalytic subunit of @entity268 -dependent protein kinase produces the secretion of @entity2661 via protein phosphorylation. The results further suggest that the @entity268 -dependent protein kinase does not participate in an intrinsic process of @entity141 -elicited secretion but it may act as a modulator.
