EF-hand Calcium-binding Proteins
Published Online: 15 JAN 2010
Copyright © 2001 John Wiley & Sons, Ltd. All rights reserved.
How to Cite
Nelson, M. R., Chagot, B. and Chazin, W. J. 2010. EF-hand Calcium-binding Proteins. eLS.
- Published Online: 15 JAN 2010
Calcium and the proteins that bind to it play important roles in normal physiological processes and have been implicated in a variety of diseases. The importance of calcium is due mainly to its role as a second messenger in signal transduction. The calcium signal is mediated and controlled by many proteins in the cell, the majority of which belong to the EF-hand super-family of calcium-binding proteins. EF-hand proteins are classified into calcium signal sensors and modulators. The calcium modulators fine-tune the shape and duration of calcium signals. The sensors undergo significant conformational changes when they bind calcium, which exposes new surfaces that interact with target proteins. Together, EF-hand calcium-binding proteins serve in the critical process of converting the ionic signal into activation of signalling pathways in cells.
The EF-hand is a helix–loop–helix structural motif.
Calcium binds to oxygen atoms from the backbone and side-chain atoms of specific amino acids in EF-hand calcium-binding proteins.
The basic structural and functional unit of EF-hand calcium-binding proteins is a pair of EF-hand motifs.
EF-hand calcium-binding proteins can be classified as sensors or modulators of calcium signals.
EF-hand calcium senor proteins need to transition from an ‘off ’ state at the resting level of calcium in the cell, to an ‘on’ (activated) state when calcium signals increase the concentration of calcium.
The activation of EF-hand calcium sensor proteins results from changes in structure induced by the binding of calcium ions.
The binding of calcium activates EF-hand calcium sensor proteins, triggering their interaction with target proteins.
- signal transduction;