Calcium release from InsP3‐sensitive internal stores initiates action potential in Chara

FEBS Letters

Gradmann, Dietrich¹  Thiel, Gerhard¹  Biskup, Bernhard¹ 

[1] Albrecht-von-Haller-Institut für Pflanzenwissenschaften, Abteilung Biophysik der Pflanze, Universität Göttingen, Untere Karspüle 2, 37073 Göttingen, Germany

关键词: Chara action potential;    Internal calcium store;    Excitatory reaction pathway;    Computer simulation;    Neomycin;    U73122;   

DOI  :  10.1016/S0014-5793(99)00600-6

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Neomycin and U73122 are known to suppress inositol 1,4,5-trisphosphate (InsP₃) production by inhibition of phospholipase C. We studied the effects of these inhibitors on the excitatory currents, I _ex, in Chara corallina under voltage-clamp conditions. Computer simulations of the experimental effects by a minimum model for the excitatory reaction pathway allow the assignment of the inhibitory effects to one specific reaction step, i.e. the release of Ca²⁺ from InsP₃-sensitive internal stores. In contrast, the inhibitory effect of La³⁺ on I _ex suggests inactivation of Cl⁻ channels. Furthermore, ryanodine-sensitive Ca²⁺ stores seem to be irrelevant for electrical excitation in Chara.

【 授权许可】

Unknown