Roles of protein kinase C in regulation of P2X7 receptor-mediated calcium signalling of cultured type-2 astrocyte cell line, RBA-2.
The role of protein kinase C (PKC) on regulation of P2X(7) receptor-mediated Ca(2+) signalling was examined on RBA-2 astrocytes. Activation of PKC decreased the receptor-mediated Ca(2+) signalling and the decrease was restored by PKC inhibitors. Down regulation of PKC also caused a decrease in the Ca(2+) signalling. Thus PKC might play a dual role on the P2X(7) receptor signalling. Successive stimulation of the P2X(7) receptor induced a gradual decline of Ca(2+) signalling but PKC inhibitors failed to restore the decline. Nevertheless, PMA stimulated translocation of PKC-alpha, -betaI, -betaII, and -gamma, but only anti-PKC-gamma co-immunoprecipitated the receptors. To examine the role of PKC-gamma, Ca(2+) signalling was measured by Ca(2+) imaging. Our results revealed that the agonist-stimulated Ca(2+) signalling were reduced in the cells that the transfection of either P2X(7) receptor or PKC-gamma morpholino antisense oligo was identified. Thus, we concluded that PKC-gamma interacted with P2X(7) receptor complex and positively regulated the receptor-mediated Ca(2+) signalling.
Institute of Neuroscience, College of Life Science, National Yang-Ming University and Brain Research Center, Shi-Pai, Taipei 112, Taiwan, ROC.
Amos C
AC
Hung
You-Jing
YJ
Chu
Ya-Hui
YH
Lin
Ju-Yun
JY
Weng
Hammer B
HB
Chen
Yin-Chung
YC
Au
Synthia H
SH
Sun
D000255:Adenosine Triphosphate / Q000031:analogs & derivatives / Q000494:pharmacology; D000818:Animals; D001253:Astrocytes / Q000166:cytology / Q000502:physiology*; D020013:Calcium Signaling; D002460:Cell Line; D015536:Down-Regulation; D004789:Enzyme Activation; D007527:Isoenzymes / Q000502:physiology; D016376:Oligonucleotides, Antisense / Q000494:pharmacology; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000502:physiology*; D051381:Rats; D018048:Receptors, Purinergic P2 / Q000502:physiology*; D058486:Receptors, Purinergic P2X7; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D007527:Isoenzymes; D016376:Oligonucleotides, Antisense; D018048:Receptors, Purinergic P2; D058486:Receptors, Purinergic P2X7; C033901:3'-O-(4-benzoyl)benzoyladenosine 5'-triphosphate; D000255:Adenosine Triphosphate; C087857:protein kinase C gamma; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate