NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Regulation of RYR1 activity by Ca(2+) and calmodulinThe skeletal muscle calcium release channel (RYR1) is a Ca(2+)-binding protein that is regulated by another Ca(2+)-binding protein, calmodulin. The functional consequences of calmodulin's interaction with RYR1 are dependent on Ca(2+) concentration. At nanomolar Ca(2+) concentrations, calmodulin is an activator, but at micromolar Ca(2+) concentrations, calmodulin is an inhibitor of RYR1. This raises the question of whether the Ca(2+)-dependent effects of calmodulin on RYR1 function are due to Ca(2+) binding to calmodulin, RYR1, or both. To distinguish the effects of Ca(2+) binding to calmodulin from those of Ca(2+) binding to RYR1, a mutant calmodulin that cannot bind Ca(2+) was used to evaluate the effects of Ca(2+)-free calmodulin on Ca(2+)-bound RYR1. We demonstrate that Ca(2+)-free calmodulin enhances the affinity of RYR1 for Ca(2+) while Ca(2+) binding to calmodulin converts calmodulin from an activator to an inhibitor. Furthermore, Ca(2+) binding to RYR1 enhances its affinity for both Ca(2+)-free and Ca(2+)-bound calmodulin.
Document ID
20040141500
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Rodney, G. G.
(Baylor College of Medicine 1 Baylor Plaza, Houston, Texas 77030, United States)
Williams, B. Y.
Strasburg, G. M.
Beckingham, K.
Hamilton, S. L.
Date Acquired
August 22, 2013
Publication Date
July 4, 2000
Publication Information
Publication: Biochemistry
Volume: 39
Issue: 26
ISSN: 0006-2960
Subject Category
Life Sciences (General)
Funding Number(s)
CONTRACT_GRANT: GM49155
CONTRACT_GRANT: AR41729
Distribution Limits
Public
Copyright
Other
Keywords
Non-NASA Center
NASA Discipline Musculoskeletal
NASA Program Biomedical Research and Countermeasures

Available Downloads

There are no available downloads for this record.
No Preview Available