Differential localization of protein kinase C isotypes in equine eosinophils and neutrophils.
Phorbol esters, which activate protein kinase C (PKC), stimulate equine eosinophil superoxide production and adherence. After showing that superoxide production could be inhibited by the nonselective PKC inhibitors, staurosporine and bisindolymaleimide I, the PKC isotypes in equine eosinophils were characterized, because evidence suggests that individual isotypes may play distinct roles in regulating eosinophil function. Western blots demonstrated that equine eosinophils expressed PKC alpha, beta, delta, epsilon, iota, and zeta. However, unlike the equine neutrophil, the majority of the PKC was detected in the particulate fraction of the cell. Despite this unusual location, the PKC in equine eosinophils was activatable, suggesting that it is functionally competent. The regulatory role of PKC in equine eosinophils may reflect the association of activity with the particulate fraction and the profile of isotype expression.
Greenaway
E C
EC
Department of Veterinary Basic Sciences, The Royal Veterinary College, London, UK.
Cunningham
F M
FM
Goode
N T
NT
D000818:Animals; D001921:Brain / Q000201:enzymology; D002462:Cell Membrane / Q000201:enzymology; D002467:Cell Nucleus / Q000201:enzymology; D003594:Cytoplasmic Granules / Q000201:enzymology; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004804:Eosinophils / Q000187:drug effects / Q000201:enzymology*; D006736:Horses / Q000097:blood*; D007211:Indoles / Q000494:pharmacology; D007425:Intracellular Membranes / Q000201:enzymology; D007527:Isoenzymes / Q000037:antagonists & inhibitors / Q000097:blood*; D008301:Maleimides / Q000494:pharmacology; D009504:Neutrophils / Q000187:drug effects / Q000201:enzymology*; D009928:Organ Specificity; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000097:blood*; D051381:Rats; D016897:Respiratory Burst / Q000187:drug effects; D019311:Staurosporine / Q000494:pharmacology; D013347:Subcellular Fractions / Q000201:enzymology; D013481:Superoxides / Q000097:blood; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D004791:Enzyme Inhibitors; D007211:Indoles; D007527:Isoenzymes; D008301:Maleimides; D013481:Superoxides; D011493:Protein Kinase C; D019311:Staurosporine; C070515:bisindolylmaleimide I; D013755:Tetradecanoylphorbol Acetate