A negatively charged region of the skeletal muscle ryanodine receptor is involved in Ca(2+)-dependent regulation of the Ca(2+) release channel.

Autor: Hayek SM; Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA., Zhao J, Bhat M, Xu X, Nagaraj R, Pan Z, Takeshima H, Ma J
Jazyk: angličtina
Zdroj: FEBS letters [FEBS Lett] 1999 Nov 19; Vol. 461 (3), pp. 157-64.
DOI: 10.1016/s0014-5793(99)01464-7
Abstrakt: The ryanodine receptor/Ca(2+) release channels from skeletal (RyR1) and cardiac (RyR2) muscle cells exhibit different inactivation profiles by cytosolic Ca(2+). D3 is one of the divergent regions between RyR1 (amino acids (aa) 1872-1923) and RyR2 (aa 1852-1890) and may contain putative binding site(s) for Ca(2+)-dependent inactivation of RyR. To test this possibility, we have deleted the D3 region from RyR1 (DeltaD3-RyR1), residues 1038-3355 from RyR2 (Delta(1038-3355)-RyR2) and inserted the skeletal D3 into Delta(1038-3355)-RyR2 to generate sD3-RyR2. The channels formed by DeltaD3-RyR1 and Delta(1038-3355)-RyR2 are resistant to inactivation by mM [Ca(2+)], whereas the chimeric sD3-RyR2 channel exhibits significant inactivation at mM [Ca(2+)]. The DeltaD3-RyR1 channel retains its sensitivity to activation by caffeine, but is resistant to inactivation by Mg(2+). The data suggest that the skeletal D3 region is involved in the Ca(2+)-dependent regulation of the RyR1 channel.
Databáze: MEDLINE