Apo calmodulin binding to the L-type voltage-gated calcium channel Ca{sub v}1.2 IQ peptide
- School of Biological Sciences, University of Liverpool, P.O. Box 147, Liverpool L69 7ZB (United Kingdom)
- School of Medicine, Cardiovascular and Endocrine Sciences, University of Manchester, Manchester M13 9NT (United Kingdom)
The influx of calcium through the L-type voltage-gated calcium channels (LTCCs) is the trigger for the process of calcium-induced calcium release (CICR) from the sarcoplasmic recticulum, an essential step for cardiac contraction. There are two feedback mechanisms that regulate LTCC activity: calcium-dependent inactivation (CDI) and calcium-dependent facilitation (CDF), both of which are mediated by calmodulin (CaM) binding. The IQ domain (aa 1645-1668) housed within the cytoplasmic domain of the LTCC Ca{sub v}1.2 subunit has been shown to bind both calcium-loaded (Ca{sup 2+}CaM ) and calcium-free CaM (apoCaM). Here, we provide new data for the structural basis for the interaction of apoCaM with the IQ peptide using NMR, revealing that the apoCaM C-lobe residues are most significantly perturbed upon complex formation. In addition, we have employed transmission electron microscopy of purified LTCC complexes which shows that both apoCaM and Ca{sup 2+}CaM can bind to the intact channel.
- OSTI ID:
- 20979793
- Journal Information:
- Biochemical and Biophysical Research Communications, Vol. 353, Issue 3; Other Information: DOI: 10.1016/j.bbrc.2006.12.070; PII: S0006-291X(06)02700-8; Copyright (c) 2006 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0006-291X
- Country of Publication:
- United States
- Language:
- English
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