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Activation of Protein Kinase C in Permeabilized Human Neuroblastoma SH‐SY5Y Cells
Author(s) -
Larsson Christer,
Saermark Torben,
Mau Søren,
Simonsson Per
Publication year - 1992
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1992.tb09418.x
Subject(s) - protein kinase c , protein kinase a , cgmp dependent protein kinase , biology , biochemistry , protein kinase inhibitor , calcium , phorbol , protein phosphorylation , mitogen activated protein kinase kinase , chemistry , phosphorylation , organic chemistry
The activation of protein kinase C was investigated in digitonin‐permeabilized human neuroblastoma SH‐SY5Y cells by measuring the phosphorylation of the specific protein kinase C substrate myelin basic protein 4‐14 . The phosphorylation was inhibited by the protein kinase C inhibitory peptide PKC 19‐36 and was associated to a translocation of the enzyme to the membrane fractions of the SHSY5Y cells. 1,2‐Dioctanoyl‐ sn ‐glycerol had no effect on protein kinase C activity unless the calcium concentration was raised to concentrations found in stimulated cells (above 100 n M ). Calcium in the absence of other activators did not stimulate protein kinase C. Phorbol 12‐myristate 13‐acetate was not dependent on calcium for the activation or the translocation of protein kinase C. The induced activation was sustained for 10 min, and thereafter only a small net phosphorylation of the substrate could be detected. Calcium or dioctanoylglycerol, when applied alone, only caused a minor translocation, whereas in combination a marked translocation was observed. Arachidonic acid (10 p M ) enhanced protein kinase C activity in the presence of submaximal concentrations of calcium and dioctanoylglycerol. Quinacrine and p‐bromophenacyl bromide did not inhibit calcium‐ and dioctanoylglycerol‐induced protein kinase C activity at concentrations which are considered to be sufficient for phospholipase A2 inhibition.