Implication of PKC isozymes in the release of biogenic amines by mussel hemocytes: effect of PDGF, IL-2, and LPS.
The innate immune system of marine mussels (Mytilus galloprovincialis) is operated by phagocytic cells termed hemocytes. Lipopolysaccharide (LPS), interleukin-2 (IL-2), or platelet-derived growth factor (PDGF) increase biogenic amine synthesis in these cells, and the enzymes Ca(2+)-independent protein kinase C (PKC) (p105/108) and Ca(2+)-dependent PKC (p60) are involved in these processes. Stimulation by PDGF induces a down-regulation process affecting the form p108 of the Ca(2+)-independent PKC. In addition, PDGF produces the increase of expression of p60 in the membrane fraction. IL-2 induces the disappearance of p108 from the membrane but does not affect the presence of p60 in cytosol or membrane. For its part, LPS activates exclusively p60 by a down-regulation mechanism. The ensemble of results suggests that each agonist starts a pathway that implicates the PKC isoenzymes that mediate the regulation of the activities dopa decarboxylase, dopamine beta-hydroxilase, and phenyletanolamine N-methyltranferase, which lead to different actions related to biogenic amine synthesis.
Gonzalez-Riopedre
M
M
Department of Biochemistry and Molecular Biology, University of Santiago de Compostela, Campus of Lugo School of Veterinary, 27002 Lugo, Spain.
Barcia
R
R
Ramos-Martínez
J I
JI
D000818:Animals; D001679:Biogenic Amines / Q000378:metabolism*; D002478:Cells, Cultured; D004296:Dopa Decarboxylase / Q000378:metabolism; D004299:Dopamine beta-Hydroxylase / Q000378:metabolism; D015536:Down-Regulation / Q000187:drug effects; D006434:Hemocytes / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology; D007376:Interleukin-2 / Q000494:pharmacology*; D007527:Isoenzymes; D008070:Lipopolysaccharides / Q000494:pharmacology*; D049878:Mytilus / Q000502:physiology*; D010625:Phenylethanolamine N-Methyltransferase / Q000378:metabolism; D010982:Platelet-Derived Growth Factor / Q000494:pharmacology*; D011493:Protein Kinase C / Q000502:physiology*
D001679:Biogenic Amines; D007376:Interleukin-2; D007527:Isoenzymes; D008070:Lipopolysaccharides; D010982:Platelet-Derived Growth Factor; D004299:Dopamine beta-Hydroxylase; D010625:Phenylethanolamine N-Methyltransferase; D011493:Protein Kinase C; D004296:Dopa Decarboxylase