Reciprocal control of the conformational state of the sarcoplasmic reticulum calcium channel protein by polarization and depolarization in the transverse tubule

FEBS Letters

El-Hayek, Roque¹  Ikemoto, Noriaki¹ 

[1] Boston Biomedical Research Institute, 20 Staniford Street, Boston, MA 02114, USA

关键词: Excitation-contraction coupling;    Triad;    Junctional foot protein;    Conformational change;    Transverse tubule;    BAPTA;    1;    2-bis(o-aminophenoxy)ethane-N;    N;    N′;    N′-tetraacetic;    acid;    DHPR;    dihydropyridine receptor;    E-C coupling;    excitation-contraction coupling;    HEPES;    N-2-hydroxyethyl piperazine-N′-2-ethane sulfonic acid;    JFP;    junctional foot protein;    MCA;    methylcoumarin acetate;    MES;    2-(N-morpholino)ethanesulfonic acid;    PI buffer;    buffer solution containing proteolytic enzyme inhibitors;    PMSF;    phenylmethanesulfonyl fluoride;    SAED;    sulfosuccinimidyl 3-((2-(7-azido-4-methylcoumarin-3-acetamido) ethyl) dithio)propionate;    SR;    sarcoplasmic reticulum;    T-tubule;    transverse tubular system;   

DOI  :  10.1016/0014-5793(96)00973-8

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

We attached the conformational probe methylcoumarin acetate (MCA) specifically to the junctional foot protein (JFP) moiety of triads, and monitored conformational changes in the JFP during polarization and depolarization of the T-tubule moiety. The MCA fluorescence decreased upon T-tubule polarization, and the fluorescence changes were blocked by preventing T-tubule polarization or by a nimodipine block of the T-tubule-to-sarcoplasmic reticulum communication. Depolarization of the T-tubule reversed the MCA fluorescence decrease which had been produced by T-tubule polarization. These results suggest that the conformational and functional states of the JFP are regulated by T-tubule polarization and depolarization in a reciprocal fashion.

【 授权许可】

Unknown