Low‐conductance high selective inositol (1,4,5)‐trisphosphate activated Ca2+ channels in plasma membrane of A431 carcinoma cells

FEBS Letters

Semyonova, Svetlana B.¹  Kiselyov, Kirill I.¹  Mamin, Anton G.¹  Mozhayeva, Galina N.¹ 

[1] Institute of Cytology, Russian Academy of Sciences, Tikhoretsky Ave, 4, 194064 St. Petersburg, Russia

关键词: Inositol (1;    4;    5)-trisphosphate;    Plasma membrane;    Calcium channel;    A431 cell;    IP3;    inositol (1;    4;    5)-trisphosphate;    [Ca2+]i;    intracellular free Ca2+ concentration;    PM;    plasma membrane;    IIP3;    IP3-activated Ca2+ currents;    Icrac;    calcium release-activated Ca2+ currents;    IP3R;    IP3 receptor;    NPo;    channel's open probability;    MP;    membrane potential;    PIP2;    phosphatidylinositol 4;    5-bisphosphate;    ER;    endoplasmic reticulum;    EGTA;    ethylenebis(oxonitrilo)tetraacetate;   

DOI  :  10.1016/S0014-5793(97)00366-9

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

In many cells, activation of receptors coupled to PIP₂ turnover results in Ca²⁺ release from the intracellular stores accompanied by Ca²⁺ influx across the PM. It is not well established yet whether Ca²⁺ influx is activated by IP₃ or by an unknown signal generated upon Ca²⁺ store depletion. We report here a single-channel study of low-conductance IP₃-activated channels of very high selectivity for Ca²⁺ in the PM of A431 carcinoma cells. The channels are strongly potential dependent and sensitive to [Ca²⁺]_i within the physiological range. The data obtained argues for IP₃ acting directly on plasma membrane Ca²⁺ channels.

【 授权许可】

Unknown