Surface plasmon resonance studies prove the interaction of skeletal muscle sarcoplasmic reticular Ca(2+) release channel/ryanodine receptor with calsequestrin.
A high affinity molecular interaction is demonstrated between calsequestrin and the sarcoplasmic reticular Ca(2+) release channel/ryanodine receptor (RyR) by surface plasmon resonance. K(D) values of 92 nM and 102 nM for the phosphorylated and dephosphorylated calsequestrin have been determined, respectively. Phosphorylation of calsequestrin seems not to influence this high affinity interaction, i.e. calsequestrin might always be bound to RyR. However, the phosphorylation state of calsequestrin determines the amount of Ca(2+) released from the lumen. Dephosphorylation of approximately 1% of the phosphorylated calsequestrin could be enough to activate the RyR channel half-maximally, as we have shown previously [Szegedi et al., Biochem. J. 337 (1999) 19].
Herzog
A
A
Institut für Physiologische Chemie, Ruhr Universität, D-44780, Bochum, Germany.
Szegedi
C
C
Jona
I
I
Herberg
F W
FW
Varsanyi
M
M
D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal; D002155:Calsequestrin / Q000737:chemistry* / Q000378:metabolism; D003001:Cloning, Molecular; D051379:Mice; D008969:Molecular Sequence Data; D010766:Phosphorylation; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D011817:Rabbits; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019837:Ryanodine Receptor Calcium Release Channel / Q000737:chemistry* / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D012519:Sarcoplasmic Reticulum / Q000737:chemistry* / Q000378:metabolism; D020349:Surface Plasmon Resonance
D000911:Antibodies, Monoclonal; D002155:Calsequestrin; D019837:Ryanodine Receptor Calcium Release Channel