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Ryanodine receptor 3; RYR-3; RyR3; brain-type ryanodine receptor; brain ryanodine receptor-Ca+2 release channel (RYR3, HBRR)

Function: - Ca+2 channel - mediates release of Ca+2 from the sarcoplasmic reticulum into the cytoplasm in muscle, thus plays a role in triggering muscle contraction - mediates Ca+2-induced Ca+2 release from the endoplasmic reticulum in non-muscle cells - may regulate Ca+2 release by other Ca+2 channels - contributes to cellular Ca+2 homeostasis (putative) - role in cellular Ca+2 signaling - communication between transverse-tubules & sarcoplasmic reticulum - contraction of skeletal muscle is triggered by release of Ca+2 from SR following depolarization of T-tubules (putative) - Ca+2 release channel is modulated by Ca+2, Mg+2, ATP & calmodulin - channel activity is modulated by the alkaloid ryanodine - ryanodine binds to the open Ca+2-release channel with high affinity - at low concentrations, ryanodine maintains the channel in an open conformation - at high concentrations, ryanodine inhibits channel activity - channel activity is regulated by calmodulin - the Ca+2 release is activated by elevated cytoplasmic Ca+2 levels in the micromolar range, by caffeine & adenine nucleotides, such as AMP & ATP - homotetramer, heterotetramer with RYR2 - interacts with CALM (putative) - interacts with FKBP1A Inhibition: - inhibited by Mg+2 & ruthenium red (putative) Structure: - homotetramer (putative) - belongs to the ryanodine receptor family - contains 3 B30.2/SPRY domains - contains 1 EF-hand domain - contains 5 MIR domains - Ca+2 release channel activity resides in the C-terminal region while the remaining part of the protein constitutes the 'foot' structure spanning the junctional gap between the SR & the T-tubule; it is possible that the foot structure interacts with the cytoplasmic region of the dihydropyridine receptor Compartment: - sarcoplasmic reticulum membrane - microsome membrane - multi-pass membrane protein - the number of predicted transmembrane domains varies between orthologs, but both N-terminus & C-terminus seem to be cytoplasmic (putative) Alternative splicing: named isoforms=3 Expression: - expressed in brain, skeletal muscle, placenta & possibly liver & kidney - in brain, highest levels are found in the cerebellum, hippocampus, caudate nucleus & amygdala, with lower levels in the corpus callosum, substantia nigra & thalamus

Related

ryanodine

General

glycoprotein human longevity protein ryanodine receptor (RyR)

Properties

SIZE: entity length = 4870 aa MW = 552 kD COMPARTMENT: cellular membrane MOTIF: cytoplasmic domain {1-2984} MOTIF: MIR 1 {100-155} MIR 2 {162-207} MIR 3 {215-269} MIR 4 {275-333} MIR 5 {343-400} B30.2/SPRY 1 {585-796} 4 X approximate repeats {840-2820} consensus repeat {840-953} consensus repeat {954-1068} B30.2/SPRY 2 {1012-1208} B30.2/SPRY 3 {1254-1466} consensus repeat {2589-2707} consensus repeat {2708-2820} transmembrane domain {2985-3005} exoplasmic loop {3006-3048} transmembrane domain {3049-3067} cytoplasmic loop {3068-3835} MOTIF: N-glycosylation site {N3276} N-glycosylation site {N3760} N-glycosylation site {N3801} transmembrane domain {3836-3855} exoplasmic loop {3856-3873} transmembrane domain {3874-3892} cytoplasmic loop {3893-4131} MOTIF: EF hand SITE: 3919-3954 N-glycosylation site {N4000} N-glycosylation site {N4007} transmembrane domain {4132-4153} exoplasmic loop {4154-4194} transmembrane domain {4195-4215} cytoplasmic loop {4216-4409} transmembrane domain {4410-4431} exoplasmic loop {4432-4481} transmembrane domain {4482-4505} cytoplasmic loop {4506-4621} transmembrane domain {4622-4642} exoplasmic loop {4643-4669} transmembrane domain {4670-4689} cytoplasmic loop {4690-4711} MOTIF: N-glycosylation site {N4697} transmembrane domain {4712-4731} exoplasmic loop {4732-4755} transmembrane domain {4756-4770} cytoplasmic domain {4771-4870} ION-PERMEABILITY: Ca+2

Database Correlations

OMIM 180903 UniProt Q15413 PFAM correlations Entrez Gene 6263 KEGG correlations

References

  1. UniProt :accession Q15413
  2. Wikipedia; Note: Ryanodine receptor entry http://en.wikipedia.org/wiki/Ryanodine_receptor
  3. Sorrentino V, Volpe P. Ryanodine receptors: how many, where and why? Trends Pharmacol Sci. 1993 Mar;14(3):98-103. Review. PMID: 8387707