{{Short description|Transport protein and coding gene in humans}} {{cs1 config|name-list-style=vanc|display-authors=6}} {{Infobox_gene}} '''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.<ref name="pmid2380170">{{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 }}</ref><ref name="pmid8406504">{{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 }}</ref><ref name="pmid11159936">{{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 }}</ref> 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&nbsp;FK506-binding proteins&nbsp;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.<ref name="pmid204310562">{{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 }}</ref>

== 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.&nbsp;To enable cardiac muscle contraction, calcium influx through voltage-gated&nbsp;L-type calcium channels&nbsp;in the plasma membrane allows calcium ions to bind to RYR2 located on the&nbsp;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&nbsp;troponin, which shifts tropomyosin and allows the myosin ATPase to bind to actin, enabling cardiac muscle contraction.<ref name="Uniprot2">{{cite web | title = Q92736 - RYR2_HUMAN| url = https://www.uniprot.org/uniprot/Q92736}}</ref> RYR2 channels are associated with many cellular functions, including mitochondrial metabolism, gene expression and cell survival, in addition to their role in cardiomyocyte contraction.<ref>{{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 }}</ref>

== 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."<ref name="pmid23408344">{{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 }}</ref>

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

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.<ref>{{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 }}</ref> 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.<ref name="pmid22869620">{{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 }}</ref>

== Interactions ==

Ryanodine receptor 2 has been shown to interact with:

* Protein kinase A (AKAP6,<ref name=pmid10830164/><ref name="pmid11352932">{{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 }}</ref> PRKACA,<ref name="pmid10830164">{{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 }}</ref> PRKACB,<ref name=pmid10830164/> PRKACG,<ref name=pmid10830164/>) (phosphorylation at serine position S2808 in rodents<ref name = "Huke_2008">{{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 }}</ref>) * CaMKII (via phosphorylation at serine positions S2808 and S2814 in humans and rodents, S2809<ref>{{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 }}</ref> and S2815<ref>{{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 }}</ref> in rabbits) * SRI<ref name="pmid7592856">{{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 }}</ref> * Protein phosphatase 1 (dephosphorylation at serine positions S2808 and S2814 in rodents<ref name = "Huke_2008" />) * Protein phosphatase 2 (dephosphorylation at serine position S2814 in rodents<ref name = "Huke_2008" />)

== See also == *Ryanodine receptor

== References == {{Reflist|30em}}

== Further reading == {{Refbegin|30em}} * {{cite journal | vauthors = Ogawa Y, Kurebayashi N, Murayama T | title = Ryanodine receptor isoforms in excitation-contraction coupling | journal = Advances in Biophysics | volume = 36 | pages = 27–64 | year = 1999 | pmid = 10463072 | doi = 10.1016/S0065-227X(99)80004-5 }} * {{cite journal | vauthors = Marks AR, Priori S, Memmi M, Kontula K, Laitinen PJ | title = Involvement of the cardiac ryanodine receptor/calcium release channel in catecholaminergic polymorphic ventricular tachycardia | journal = Journal of Cellular Physiology | volume = 190 | issue = 1 | pages = 1–6 | date = January 2002 | pmid = 11807805 | doi = 10.1002/jcp.10031 | doi-access = free }} * {{cite journal | vauthors = Marks AR | title = Ryanodine receptors, FKBP12, and heart failure | journal = Frontiers in Bioscience | volume = 7 | issue = 1–3 | pages = d970–d977 | date = April 2002 | pmid = 11897558 | doi = 10.2741/marks | doi-access = free }} * {{cite journal | vauthors = Danieli GA, Rampazzo A | title = Genetics of arrhythmogenic right ventricular cardiomyopathy | journal = Current Opinion in Cardiology | volume = 17 | issue = 3 | pages = 218–221 | date = May 2002 | pmid = 12015469 | doi = 10.1097/00001573-200205000-00002 }} * {{cite journal | vauthors = Ma J, Hayek SM, Bhat MB | title = Membrane topology and membrane retention of the ryanodine receptor calcium release channel | journal = Cell Biochemistry and Biophysics | volume = 40 | issue = 2 | pages = 207–224 | year = 2005 | pmid = 15054223 | doi = 10.1385/CBB:40:2:207 | s2cid = 25375622 }} * {{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 }} * {{cite journal | vauthors = Rampazzo A, Nava A, Erne P, Eberhard M, Vian E, Slomp P, Tiso N, Thiene G, Danieli GA | title = A new locus for arrhythmogenic right ventricular cardiomyopathy (ARVD2) maps to chromosome 1q42-q43 | journal = Human Molecular Genetics | volume = 4 | issue = 11 | pages = 2151–2154 | date = November 1995 | pmid = 8589694 | doi = 10.1093/hmg/4.11.2151 | hdl = 11577/2463114 | hdl-access = free }} * {{cite journal | vauthors = Tunwell RE, Wickenden C, Bertrand BM, Shevchenko VI, Walsh MB, Allen PD, Lai FA | title = The human cardiac muscle ryanodine receptor-calcium release channel: identification, primary structure and topological analysis | journal = The Biochemical Journal | volume = 318 ( Pt 2) | issue = Pt 2 | pages = 477–487 | date = September 1996 | pmid = 8809036 | pmc = 1217646 | doi = 10.1042/bj3180477 }} * {{cite journal | vauthors = Awad SS, Lamb HK, Morgan JM, Dunlop W, Gillespie JI | title = Differential expression of ryanodine receptor RyR2 mRNA in the non-pregnant and pregnant human myometrium | journal = The Biochemical Journal | volume = 322 ( Pt 3) | issue = Pt 3 | pages = 777–783 | date = March 1997 | pmid = 9148749 | pmc = 1218255 | doi = 10.1042/bj3220777 }} * {{cite journal | vauthors = Martin C, Chapman KE, Seckl JR, Ashley RH | title = Partial cloning and differential expression of ryanodine receptor/calcium-release channel genes in human tissues including the hippocampus and cerebellum | journal = Neuroscience | volume = 85 | issue = 1 | pages = 205–216 | date = July 1998 | pmid = 9607712 | doi = 10.1016/S0306-4522(97)00612-X | s2cid = 25634042 }} * {{cite journal | vauthors = Chambers P, Neal DE, Gillespie JI | title = Ryanodine receptors in human bladder smooth muscle | journal = Experimental Physiology | volume = 84 | issue = 1 | pages = 41–46 | date = January 1999 | pmid = 10081705 | doi = 10.1111/j.1469-445x.1999.tb00070.x | doi-access = free }} * {{cite journal | vauthors = Mori F, Fukaya M, Abe H, Wakabayashi K, Watanabe M | title = Developmental changes in expression of the three ryanodine receptor mRNAs in the mouse brain | journal = Neuroscience Letters | volume = 285 | issue = 1 | pages = 57–60 | date = May 2000 | pmid = 10788707 | doi = 10.1016/S0304-3940(00)01046-6 | s2cid = 32514035 }} * {{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 }} * {{cite journal | vauthors = Laitinen PJ, Brown KM, Piippo K, Swan H, Devaney JM, Brahmbhatt B, Donarum EA, Marino M, Tiso N, Viitasalo M, Toivonen L, Stephan DA, Kontula K | title = Mutations of the cardiac ryanodine receptor (RyR2) gene in familial polymorphic ventricular tachycardia | journal = Circulation | volume = 103 | issue = 4 | pages = 485–490 | date = January 2001 | pmid = 11157710 | doi = 10.1161/01.cir.103.4.485 | hdl-access = free | doi-access = free | hdl = 11577/153951 }} * {{cite journal | vauthors = Priori SG, Napolitano C, Tiso N, Memmi M, Vignati G, Bloise R, Sorrentino V, Danieli GA | title = Mutations in the cardiac ryanodine receptor gene (hRyR2) underlie catecholaminergic polymorphic ventricular tachycardia | journal = Circulation | volume = 103 | issue = 2 | pages = 196–200 | date = January 2001 | pmid = 11208676 | doi = 10.1161/01.cir.103.2.196 | doi-access = free }} * {{cite journal | vauthors = Jeyakumar LH, Ballester L, Cheng DS, McIntyre JO, Chang P, Olivey HE, Rollins-Smith L, Barnett JV, Murray K, Xin HB, Fleischer S | title = FKBP binding characteristics of cardiac microsomes from diverse vertebrates | journal = Biochemical and Biophysical Research Communications | volume = 281 | issue = 4 | pages = 979–986 | date = March 2001 | pmid = 11237759 | doi = 10.1006/bbrc.2001.4444 }} {{Refend}}

== 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://omim.org/search/?index=entry&start=1&limit=10&search=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&sort=score+desc&field=number OMIM entries on Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy, Autosomal Dominant] * {{MeshName|RYR2+protein,+human}}

{{Ion channels|g1}}

Category:Ion channels Category:EF-hand-containing proteins