INTRALUMINAL AND EXTRALUMINAL SARCOPLASMIC-RETICULUM MEMBRANE REGULATORY SITES FOR CA-2+-INDUCED CA-2+ RELEASE

被引：52

作者：

NELSON, TE

NELSON, KE

机构：

来源：

FEBS LETTERS | 1990年 / 263卷 / 02期

关键词：

Ca[!sup]2+[!/sup] channel; Ca[!sup]2+[!/sup] regulation; Ca[!sup]2+[!/sup] release; Sarcoplasmic reticulum; Skeletal muscle;

D O I：

10.1016/0014-5793(90)81396-6

中图分类号：

Q5 [生物化学]; Q7 [分子生物学];

学科分类号：

071010 ; 081704 ;

摘要：

A heavy skeletal muscle sarcoplasmic reticulum (SR) fraction was actively loaded stepwise with calcium until Ca2+-induced Ca2+ release occurred. The total Ca2+ load, T1, at which release occurred is postulated to be regulated by an intraluminal, low-affinity receptor. After obtaining T1, the critical concentration of Ca2+ required extraluminally (T2) was determined. T1 averaged 58.6 ± S.D., 6.9 nmol Ca2+/mg SR and T2 averaged 2.14 ± S.D., 0.24,μM. Both T1 and T2 were increased by Mg2+ and decreased by caffeine. Ruthenium red increased T2 more than T1 while ryanodine had no effect on T1 but markedly increased T2. The results suggest that two Ca2+ regulatory sites may be functional for Ca2+-induced Ca2+ release from SR. © 1990.

引用

页码：292 / 294

页数：3

共 10 条

[1] OPEN QUESTION - DOES MUSCLE ACTIVATION OCCUR BY DIRECT MECHANICAL COUPLING OF TRANSVERSE TUBULES TO SARCOPLASMIC-RETICULUM [J].