Single channel activity of the ryanodine receptor calcium release channel is modulated by FK‐506

FEBS Letters

Dulhunty, Angela F.¹  Junankar, Pauline R.¹  Ahern, Gerard P.¹ 

[1] Division of Neuroscience, John Curtin School of Medical Research, Australian National University, P.O. Box 334, Canberra City, ACT 2601, Australia

关键词: FK-506;    Skeletal muscle;    Sarcoplasmic reticulum;    Excitation—contraction coupling;    Ryanodine receptor calcium release channel;    PMSF;    phenylmethylsulphonyl fluoride;    BSA;    bovine serum albumin;    DMSO;    dimethyl sulfoxide;    TES;    N-tris-(hydroxymethyl)methyl-2-aminoethanesulphonic acid;    BAPTA;    1;    2-bis(2-aminophenoxy)ethane-N;    N;    N′;    N′-tetra-acetic acid;    TC;    terminal cisternae;    P o;    open probability;    I′;    mean current;    S.E.M.;    standard error of the mean;    r;    coefficient of correlation;   

DOI  :  10.1016/0014-5793(94)01001-3

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The immunosuppressant drug FK-506 (3–20 μM) increased the open probability of ryanodine receptor calcium release channels, formed by incorporation of terminal cisternae vesicles from rabbit skeletal muscle into lipid bilayers, with cis (cytoplasmic) calcium concentrations between 10⁻⁷ M and 10⁻³ M. FK-506 increased mean current and channel open time and induced long sojourns at subconductance levels that were between 28% and 38% of the maximum conductance and were distinct from the ryanodine-induced subconductance level at about 45% of the maximum conductance. FK-506 relieved the Ca²⁺ inactivation of the ryanodine receptor seen at 10⁻³ M Ca²⁺. The results are consistent with FK-506 removal of FK-506 binding protein from the ryanodine receptor [15].

【 授权许可】

Unknown