ryanodine receptor 2

{{Short description|Transport protein and coding gene in humans}}

Ryanodine receptor 2 (RYR2) is one of a class of ryanodine receptors and a protein found primarily in cardiac muscle. In humans, it is encoded by the RYR2 gene.{{cite journal | vauthors = Otsu K, Willard HF, Khanna VK, Zorzato F, Green NM, MacLennan DH | title = Molecular cloning of cDNA encoding the Ca2+ release channel (ryanodine receptor) of rabbit cardiac muscle sarcoplasmic reticulum | journal = The Journal of Biological Chemistry | volume = 265 | issue = 23 | pages = 13472–13483 | date = August 1990 | pmid = 2380170 | doi = 10.1016/S0021-9258(18)77371-7 | doi-access = free }}{{cite journal | vauthors = Otsu K, Fujii J, Periasamy M, Difilippantonio M, Uppender M, Ward DC, MacLennan DH | title = Chromosome mapping of five human cardiac and skeletal muscle sarcoplasmic reticulum protein genes | journal = Genomics | volume = 17 | issue = 2 | pages = 507–509 | date = August 1993 | pmid = 8406504 | doi = 10.1006/geno.1993.1357 | doi-access = free }}{{cite journal | vauthors = Tiso N, Stephan DA, Nava A, Bagattin A, Devaney JM, Stanchi F, Larderet G, Brahmbhatt B, Brown K, Bauce B, Muriago M, Basso C, Thiene G, Danieli GA, Rampazzo A | title = Identification of mutations in the cardiac ryanodine receptor gene in families affected with arrhythmogenic right ventricular cardiomyopathy type 2 (ARVD2) | journal = Human Molecular Genetics | volume = 10 | issue = 3 | pages = 189–194 | date = February 2001 | pmid = 11159936 | doi = 10.1093/hmg/10.3.189 | hdl-access = free | doi-access = free | hdl = 11577/2459215 }} In the process of cardiac calcium-induced calcium release, RYR2 is the major mediator for sarcoplasmic release of stored calcium ions.

Structure

The channel is composed of RYR2 homotetramers and FK506-binding proteins found in a 1:4 stoichiometric ratio. Calcium channel function is affected by the specific type of FK506 isomer interacting with the RYR2 protein, due to binding differences and other factors.{{cite journal | vauthors = Guo T, Cornea RL, Huke S, Camors E, Yang Y, Picht E, Fruen BR, Bers DM | title = Kinetics of FKBP12.6 binding to ryanodine receptors in permeabilized cardiac myocytes and effects on Ca sparks | journal = Circulation Research | volume = 106 | issue = 11 | pages = 1743–1752 | date = June 2010 | pmid = 20431056 | pmc = 2895429 | doi = 10.1161/CIRCRESAHA.110.219816 }}

Function

The RYR2 protein functions as the major component of a calcium channel located in the sarcoplasmic reticulum that supplies ions to the cardiac muscle during systole. To enable cardiac muscle contraction, calcium influx through voltage-gated L-type calcium channels in the plasma membrane allows calcium ions to bind to RYR2 located on the sarcoplasmic reticulum. This binding causes the release of calcium through RYR2 from the sarcoplasmic reticulum into the cytosol, where it binds to the C domain of troponin, which shifts tropomyosin and allows the myosin ATPase to bind to actin, enabling cardiac muscle contraction.{{cite web | title = Q92736 - RYR2_HUMAN| url = https://www.uniprot.org/uniprot/Q92736}} RYR2 channels are associated with many cellular functions, including mitochondrial metabolism, gene expression and cell survival, in addition to their role in cardiomyocyte contraction.{{cite journal | vauthors = Bround MJ, Wambolt R, Luciani DS, Kulpa JE, Rodrigues B, Brownsey RW, Allard MF, Johnson JD | title = Cardiomyocyte ATP production, metabolic flexibility, and survival require calcium flux through cardiac ryanodine receptors in vivo | journal = The Journal of Biological Chemistry | volume = 288 | issue = 26 | pages = 18975–18986 | date = June 2013 | pmid = 23678000 | pmc = 3696672 | doi = 10.1074/jbc.M112.427062 | doi-access = free }}

Clinical significance

Deleterious mutations of the ryanodine receptor family, and especially the RYR2 receptor, lead to a constellation of pathologies leading to both acute and chronic heart failure collectively known as "Ryanopathies."{{cite journal | vauthors = Belevych AE, Radwański PB, Carnes CA, Györke S | title = 'Ryanopathy': causes and manifestations of RyR2 dysfunction in heart failure | journal = Cardiovascular Research | volume = 98 | issue = 2 | pages = 240–247 | date = May 2013 | pmid = 23408344 | pmc = 3633158 | doi = 10.1093/cvr/cvt024 }}

Mutations in the RYR2 gene are associated with catecholaminergic polymorphic ventricular tachycardia and arrhythmogenic right ventricular dysplasia.{{cite web | title = Entrez Gene: RYR2 ryanodine receptor 2 (cardiac)| url = https://www.ncbi.nlm.nih.gov/sites/entrez?Db=gene&Cmd=ShowDetailView&TermToSearch=6262}}

Recently, sudden cardiac death in several young individuals in the Amish community (four of which were from the same family) was traced to homozygous duplication of a mutant RyR2 gene.{{cite journal | vauthors = Tester DJ, Bombei HM, Fitzgerald KK, Giudicessi JR, Pitel BA, Thorland EC, Russell BG, Hamrick SK, Kim CS, Haglund-Turnquist CM, Johnsrude CL, Atkins DL, Ochoa Nunez LA, Law I, Temple J, Ackerman MJ | title = Identification of a Novel Homozygous Multi-Exon Duplication in RYR2 Among Children With Exertion-Related Unexplained Sudden Deaths in the Amish Community | journal = JAMA Cardiology | volume = 5 | issue = 3 | pages = 13–18 | date = March 2020 | pmid = 31913406 | pmc = 6990654 | doi = 10.1001/jamacardio.2019.5400 }} Normal (wild type) RyR2 functions primarily in the myocardium (heart muscle).

Mice with genetically reduced RYR2 exhibit a lower basal heart rate and fatal arrhythmias.{{cite journal | vauthors = Bround MJ, Asghari P, Wambolt RB, Bohunek L, Smits C, Philit M, Kieffer TJ, Lakatta EG, Boheler KR, Moore ED, Allard MF, Johnson JD | title = Cardiac ryanodine receptors control heart rate and rhythmicity in adult mice | journal = Cardiovascular Research | volume = 96 | issue = 3 | pages = 372–380 | date = December 2012 | pmid = 22869620 | pmc = 3500041 | doi = 10.1093/cvr/cvs260 }}

Interactions

Ryanodine receptor 2 has been shown to interact with:

Protein kinase A (AKAP6,{{cite journal | vauthors = Marx SO, Reiken S, Hisamatsu Y, Gaburjakova M, Gaburjakova J, Yang YM, Rosemblit N, Marks AR | title = Phosphorylation-dependent regulation of ryanodine receptors: a novel role for leucine/isoleucine zippers | journal = The Journal of Cell Biology | volume = 153 | issue = 4 | pages = 699–708 | date = May 2001 | pmid = 11352932 | pmc = 2192391 | doi = 10.1083/jcb.153.4.699 }} PRKACA,{{cite journal | vauthors = Marx SO, Reiken S, Hisamatsu Y, Jayaraman T, Burkhoff D, Rosemblit N, Marks AR | title = PKA phosphorylation dissociates FKBP12.6 from the calcium release channel (ryanodine receptor): defective regulation in failing hearts | journal = Cell | volume = 101 | issue = 4 | pages = 365–376 | date = May 2000 | pmid = 10830164 | doi = 10.1016/S0092-8674(00)80847-8 | s2cid = 6496567 | doi-access = free }} PRKACB, PRKACG,) (phosphorylation at serine position S2808 in rodents{{cite journal | vauthors = Huke S, Bers DM | title = Ryanodine receptor phosphorylation at Serine 2030, 2808 and 2814 in rat cardiomyocytes | journal = Biochemical and Biophysical Research Communications | volume = 376 | issue = 1 | pages = 80–85 | date = November 2008 | pmid = 18755143 | pmc = 2581610 | doi = 10.1016/j.bbrc.2008.08.084 }})
CaMKII (via phosphorylation at serine positions S2808 and S2814 in humans and rodents, S2809{{cite journal | vauthors = Witcher DR, Kovacs RJ, Schulman H, Cefali DC, Jones LR | title = Unique phosphorylation site on the cardiac ryanodine receptor regulates calcium channel activity | journal = The Journal of Biological Chemistry | volume = 266 | issue = 17 | pages = 11144–11152 | date = June 1991 | pmid = 1645727 | doi = 10.1016/S0021-9258(18)99140-4 | doi-access = free }} and S2815{{cite journal | vauthors = Wehrens XH, Lehnart SE, Reiken SR, Marks AR | title = Ca2+/calmodulin-dependent protein kinase II phosphorylation regulates the cardiac ryanodine receptor | journal = Circulation Research | volume = 94 | issue = 6 | pages = e61–e70 | date = April 2004 | pmid = 15016728 | doi = 10.1161/01.RES.0000125626.33738.E2 }} in rabbits)
SRI{{cite journal | vauthors = Meyers MB, Pickel VM, Sheu SS, Sharma VK, Scotto KW, Fishman GI | title = Association of sorcin with the cardiac ryanodine receptor | journal = The Journal of Biological Chemistry | volume = 270 | issue = 44 | pages = 26411–26418 | date = November 1995 | pmid = 7592856 | doi = 10.1074/jbc.270.44.26411 | doi-access = free }}
Protein phosphatase 1 (dephosphorylation at serine positions S2808 and S2814 in rodents)
Protein phosphatase 2 (dephosphorylation at serine position S2814 in rodents)

References

External links

[https://www.ncbi.nlm.nih.gov/books/NBK1289/ GeneReviews/NCBI/NIH/UW entry on Catecholaminergic Polymorphic Ventricular Tachycardia]
[https://www.ncbi.nlm.nih.gov/books/NBK1131/ GeneReviews/NCBI/NIH/UW entry on Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy, Autosomal Dominant]
[https://www.ncbi.nlm.nih.gov/omim/604772,605676,601214,107970,125645,125647,125671,173325,180902,190230,600996,602086,602087,602861,604400,604401,607450,609040,609160,610193,610476,611528,612048,107970,125645,125647,125671,173325,180902,190230,600996,602086,602087,602861,604400,604401,607450,609040,609160,610193,610476,611528,612048 OMIM entries on Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy, Autosomal Dominant]
{{MeshName|RYR2+protein,+human}}

Category:Ion channels

Category:EF-hand-containing proteins