Luminal calcium regulation of calcium release from sarcoplasmic reticulum.
نویسندگان
چکیده
This article discusses how changes in luminal calcium concentration affect calcium release rates from triad-enriched sarcoplasmic reticulum vesicles, as well as single channel opening probability of the ryanodine receptor/calcium release channels incorporated in bilayers. The possible participation of calsequestrin, or of other luminal proteins of sarcoplasmic reticulum in this regulation is addressed. A comparison with the regulation by luminal calcium of calcium release mediated by the inositol 1,4,5-trisphosphate receptor/calcium channel is presented as well.
منابع مشابه
Ca2+ stores regulate ryanodine receptor Ca2+ release channels via luminal and cytosolic Ca2+ sites.
1. In muscle, intracellular calcium concentration, hence skeletal muscle force and cardiac output, is regulated by uptake and release of calcium from the sarcoplasmic reticulum. The ryanodine receptor (RyR) forms the calcium release channel in the sarcoplasmic reticulum. 2. The free [Ca2+] in the sarcoplasmic reticulum regulates the excitability of this store by stimulating the Ca2+ release cha...
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The amount of Ca2+ released from the sarcoplasmic reticulum (SR) is a principal determinant of cardiac contractility. Normally, the SR Ca2+ stores are mobilized through the mechanism of Ca2+-induced Ca2+ release (CICR). In this process, Ca2+ enters the cell through plasmalemmal voltage-dependent Ca2+ channels to activate the Ca2+ release channels in the SR membrane. Consequently, the control of...
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A lipophilic anion, tetraphenylboron (TPB-)-induced Ca2+ release from fragmented sarcoplasmic reticulum (SR) of frog skeletal muscle was monitored by chlortetracycline fluorescence. TPB- caused change in surface charge of the membrane and in the protein conformation with a time course similar to that of the Ca2+ release. Tetraphenylarsonium (TPA+) inhibited these effects of TPB-. Change in surf...
متن کاملRyanodine receptor luminal Ca2+ regulation: swapping calsequestrin and channel isoforms.
Sarcoplasmic reticulum (SR) Ca(2+) release in striated muscle is mediated by a multiprotein complex that includes the ryanodine receptor (RyR) Ca(2+) channel and the intra-SR Ca(2+) buffering protein calsequestrin (CSQ). Besides its buffering role, CSQ is thought to regulate RyR channel function. Here, CSQ-dependent luminal Ca(2+) regulation of skeletal (RyR1) and cardiac (RyR2) channels is exp...
متن کاملModulation of ryanodine receptor by luminal calcium and accessory proteins in health and cardiac disease.
The cardiac ryanodine receptor (RyR2) is the sarcoplasmic reticulum (SR) Ca(2+) release channel which is responsible for generation of the cytosolic Ca(2+) transient required for activation of cardiac contraction. RyR2 functional activity is governed by changes in [Ca(2+)] on both the cytosolic and luminal phase of the RyR2 channel. Activation of RyR2 by cytosolic Ca(2+) results in Ca(2+)-induc...
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عنوان ژورنال:
- Bioscience reports
دوره 15 5 شماره
صفحات -
تاریخ انتشار 1995