From Surf Wiki (app.surf) — the open knowledge base

Calsequestrin

Calcium-binding protein

Field	Value
Name	calsequestrin 1 (fast-twitch, skeletal muscle)
caption	Calsequestrin monomer showing the three repeating calsequestrin domains
image	Calsequestrin1.png
HGNCid	1512
Symbol	CASQ1
AltSymbols	CASQ
EntrezGene	844
OMIM	114250
RefSeq	NM_001231
UniProt	P31415
PDB	1A8Y
Chromosome	1
Arm	q
Band	21

Calsequestrin is a calcium-binding protein that acts as a calcium buffer within the sarcoplasmic reticulum. The protein helps hold calcium in the cisterna of the sarcoplasmic reticulum after a muscle contraction, even though the concentration of calcium in the sarcoplasmic reticulum is much higher than in the cytosol. It also helps the sarcoplasmic reticulum store an extraordinarily high amount of calcium ions. Each molecule of calsequestrin can bind 18 to 50 Ca2+ ions.{{cite book

Cardiac calsequestrin

Cardiac calsequestrin (CASQ2) plays an integral role in cardiac regulation. Mutations in the cardiac calsequestrin gene have been associated with cardiac arrhythmia and sudden death. CASQ2 is thought to have a role in regulating cardiac excitation-contraction coupling and calcium-induced calcium release (CICR) in the heart, as overexpression of CASQ2 has been shown to substantially raise the magnitude of cell-averaged ICA-induced calcium transients and spontaneous calcium sparks in isolated heart cells. Furthermore, CASQ2 modulates the CICR mechanism by lengthening to process to functionally recharge the sarcoplasmic reticulum's calcium ion stores. A lack of or mutation in CASQ2 has been directly associated with catecholaminergic polymorphic ventricular tachycardia (CPVT). A mutation can have a significant effect if it disrupts the linear polymerization ability of CASQ2, which directly accounts for its high-capacity to bind Ca2+. In addition, the hydrophobic core of domain II appears to be necessary for CASQ2's function, because a single amino acid mutation that disrupts this hydrophobic core directly leads to molecular aggregates, which are unable to respond to calcium ions.

References

(October 1987). "Characterization of cardiac calsequestrin". Biochemistry.
(January 1991). "Phosphorylation of cardiac and skeletal muscle calsequestrin isoforms by casein kinase II. Demonstration of a cluster of unique rapidly phosphorylated sites in cardiac calsequestrin". J. Biol. Chem..
(2011-06-30). "Calsequestrin Distribution, Structure and Function, Its Role in Normal and Pathological Situations and the Effect of Thyroid Hormones". Physiological Research.
Gryoke, Sandor. (2003). "Calsequestrin determines the functional size and stability of cardiac intracellular calcium stores: Mechanism for hereditary arrhythmia". Proceedings of the National Academy of Sciences of the United States of America.
(2007-11-02). "Characterization of Human Cardiac Calsequestrin and its Deleterious Mutants". Journal of Molecular Biology.

Info: Wikipedia Source

This article was imported from Wikipedia and is available under the Creative Commons Attribution-ShareAlike 4.0 License. Content has been adapted to SurfDoc format. Original contributors can be found on the article history page.

protein-families endoplasmic-reticulum-resident-proteins

Want to explore this topic further?

Ask Mako anything about Calsequestrin — get instant answers, deeper analysis, and related topics.

Research with Mako

Free with your Surf account

Content sourced from Wikipedia, available under CC BY-SA 4.0.

This content may have been generated or modified by AI. CloudSurf Software LLC is not responsible for the accuracy, completeness, or reliability of AI-generated content. Always verify important information from primary sources.

Report