Adenosine evokes potassium currents by protein kinase C activated via a novel signaling pathway in superior colliculus neurons

FEBS Letters

Nishizaki, Tomoyuki¹  Ikeuchi, Youji¹ 

[1] Department of Physiology, Kobe University School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe 650, Japan

关键词: Purinoceptor;    Potassium channel;    G-protein;    Protein kinase C;    Patch clamp;    Ca2+ assay;    Superior colliculus neuron;   

DOI  :  10.1016/0014-5793(95)01399-7

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Adenosine evoked whole-cell potassium currents and enhanced intracellular free Ca²⁺ concentration ([Ca²⁺]i) in superior colliculus neurons through a P_2Y purinoceptor linked to a pertussis toxin-insensitive G-protein, possibly Gq-protein, which is involved in a protein kinase C(PKC) activation pathway. The [Ca²⁺]i increase was inhibited by a phospholipase C(PLC) inhibitor, whereas the evoked currents were not affected by a PLC inhibitor or a phospholipase A₂(PLA₂) inhibitor. Adenosine elicited single channel currents via PKC activation in cell-attached patches and furthermore, those currents with conductances of the same slope were induced even in excised patches, suggesting that PKC can be activated only by cell membrane factors without intracellular components. These results thus indicate that the P_2Y purinoceptor-coupled potassium channel is regulated via a novel PKC activation pathway independent of PLC or PLA₂.

【 授权许可】

Unknown