Ca2+ oscillation induced by P2Y2 receptor activation and its regulation by a neuron-specific subtype of PKC (gammaPKC).
We found that stimulation of P2Y2 receptor (P2Y2R), which is endogenously expressed in CHO-K1 cells, induced intracellular calcium ([Ca2+]i) oscillation with a low frequency of 11.4 +/- 2.7 mHz. When CHO-K1 cells expressing GFP-tagged kinase-negative gammaPKC (gammaPKC-KN-GFP), which is a neuron-specific subtype of PKC, were stimulated with UDP, gammaPKC-KN-GFP, but not wild-type gammaPKC (gammaPKC-GFP) showed an oscillatory translocation. The oscillatory translocation of gammaPKC-KN-GFP corresponded with [Ca2+]i oscillation, which was not observed in the cells expressing gammaPKC-GFP. We examined the mechanism ofP2Y2R-induced [Ca2+]i oscillation pharmacologically. gammaPKC-KN-GFP oscillation was stopped by an extracellular Ca2+ chelator, EGTA, an antagonist of P2Y2R, Suramin, and store-operated calcium channel (SOC) inhibitors, SKF96365 and 2-ABP. Taken together, P2Y2R-induced [Ca2+]i oscillation in CHO-K1 cells is related with Ca2+ influx through SOC, whose function may be negatively regulated by gammaPKC. This [Ca2]i oscillation was distinct from that induced by metabotropic glutamate receptor 5 (mGluR5) stimulation in the frequency (72.3 +/- 5.3 mHz) and in the regulatory mechanism.
Ashida
Noriaki
N
Laboratory of Molecular Pharmacology, Biosignal Research Center, Kobe University, Rokkodai-cho 1-1, Nada-ku, Kobe 657-8501, Japan.
Ueyama
Takehiko
T
Rikitake
Kyoko
K
Shirai
Yasuhito
Y
Eto
Mika
M
Kondoh
Takeshi
T
Kohmura
Eiji
E
Saito
Naoaki
N
D000818:Animals; D001683:Biological Clocks / Q000187:drug effects / Q000502:physiology*; D016466:CHO Cells; D002118:Calcium / Q000378:metabolism; D002121:Calcium Channel Blockers / Q000494:pharmacology; D015220:Calcium Channels / Q000187:drug effects / Q000378:metabolism; D020013:Calcium Signaling / Q000187:drug effects / Q000502:physiology*; D002490:Central Nervous System / Q000378:metabolism*; D002614:Chelating Agents / Q000494:pharmacology; D006224:Cricetinae; D003412:Cricetulus; D049452:Green Fluorescent Proteins; D007424:Intracellular Fluid / Q000187:drug effects / Q000378:metabolism; D009474:Neurons / Q000378:metabolism*; D011493:Protein Kinase C / Q000187:drug effects / Q000378:metabolism*; D021381:Protein Transport / Q000502:physiology; D064529:Receptor, Metabotropic Glutamate 5; D018094:Receptors, Metabotropic Glutamate / Q000187:drug effects / Q000378:metabolism; D018048:Receptors, Purinergic P2 / Q000187:drug effects / Q000378:metabolism*; D058473:Receptors, Purinergic P2Y2; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D013498:Suramin / Q000494:pharmacology; D014344:Trypanocidal Agents / Q000494:pharmacology
D002121:Calcium Channel Blockers; D015220:Calcium Channels; D002614:Chelating Agents; D064529:Receptor, Metabotropic Glutamate 5; D018094:Receptors, Metabotropic Glutamate; D018048:Receptors, Purinergic P2; D058473:Receptors, Purinergic P2Y2; D011993:Recombinant Fusion Proteins; D014344:Trypanocidal Agents; D049452:Green Fluorescent Proteins; D013498:Suramin; C087857:protein kinase C gamma; D011493:Protein Kinase C; D002118:Calcium