Sodium-calcium exchange does not require allosteric calcium activation at high cytosolic sodium concentrations
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چکیده
منابع مشابه
Allosteric Activation of Sodium–Calcium Exchange Activity by Calcium: Persistence at Low Calcium Concentrations
The activity of the cardiac Na /Ca 2 exchanger is stimulated allosterically by Ca 2 , but estimates of the half-maximal activating concentration have varied over a wide range. In Chinese hamster ovary cells expressing the cardiac Na /Ca 2 exchanger, the time course of exchange-mediated Ca 2 influx showed a pronounced lag period followed by an acceleration of Ca 2 uptake. Lag periods were absent...
متن کاملAllosteric Activation of Sodium–Calcium Exchange Activity by Calcium
The activity of the cardiac Na+/Ca2+ exchanger is stimulated allosterically by Ca2+, but estimates of the half-maximal activating concentration have varied over a wide range. In Chinese hamster ovary cells expressing the cardiac Na+/Ca2+ exchanger, the time course of exchange-mediated Ca2+ influx showed a pronounced lag period followed by an acceleration of Ca2+ uptake. Lag periods were absent ...
متن کاملSodium/calcium exchange: its physiological implications.
The Na+/Ca2+ exchanger, an ion transport protein, is expressed in the plasma membrane (PM) of virtually all animal cells. It extrudes Ca2+ in parallel with the PM ATP-driven Ca2+ pump. As a reversible transporter, it also mediates Ca2+ entry in parallel with various ion channels. The energy for net Ca2+ transport by the Na+/Ca2+ exchanger and its direction depend on the Na+, Ca2+, and K+ gradie...
متن کاملSodium-calcium exchange in the heart.
The sodium calcium exchange (NCX) was first discovered in cardiac muscle1 and squid axon2 and has since been found in most cell types (see reviews3,4). It accounts for the previously observed effects of sodium on cardiac contractility.5 The exchanger transports 3 Na ions per Ca .6–8 This stoichiometry has three important consequences.1 Ca fluxes and hence intracellular Ca concentration ([Ca ]i)...
متن کاملCardiac sodium-calcium exchanger is regulated by allosteric calcium and exchanger inhibitory peptide at distinct sites.
The sarcolemmal Na+-Ca2+ exchanger (NCX) is the main Ca2+ extrusion mechanism in cardiac myocytes and is thus essential for the regulation of Ca2+ homeostasis and contractile function. A cytosolic region (f-loop) of the protein mediates regulation of NCX function by intracellular factors including inhibition by exchanger inhibitory peptide (XIP), a 20 amino acid peptide matching the sequence of...
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ژورنال
عنوان ژورنال: The Journal of Physiology
سال: 2006
ISSN: 0022-3751
DOI: 10.1113/jphysiol.2006.113910