Calcium dependence of ryanodine‐sensitive calcium channels from brain cortex endoplasmic reticulum

FEBS Letters

Hidalgo, Cecilia¹  Marengo, Juan José¹  Bull, Ricardo¹ 

[1] Departamento de Físiología y Biofisica, Facultad de Medicina, Universidad de Chile, Casilla 70005, Correo 7, Santiago, Chile

关键词: Ca2+ release;    Ca2+ regulation;    Brain cortex;    Neuron;    Intracellular calcium;    Ryanodine receptor isoform;   

DOI  :  10.1016/0014-5793(96)00222-0

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Endoplasmic reticulum vesicles isolated from rat brain cortex and fused with lipid bilayers displayed ryanodine-sensitive calcium channels, with three cytoplasmic calcium dependences. A: Channels (n = 5) stimulated by Ca²⁺ (K _0.5 = 1.2 μM and n _Hill = 1.9) and not inhibited up to 0.5 mM Ca²⁺. B: Channels (n = 14) cooperatively activated (K _0.5 = 6.9 μM and n _Hill = 1.8), and inhibited by Ca²⁺ (K _0.5 = 152 μM and n _Hill = 1.8). C: Low P _o (< 0.1) channels (n = 22), non-cooperatively activated and inhibited with the same K _0.5 = 26.3 μM Ca²⁺. These three types of responses to cytoplasmic [Ca²⁺] may underlie separate calcium release pathways in neurons of rat brain cortex.

【 授权许可】

Unknown