How many and which are the different isoforms for the ryanodine receptor?
['Skeletal (RyR1) and cardiac muscle (RyR2) isoforms of ryanodine receptor calcium channels', 'Ryanodine receptors (RyRs) are located in the sarcoplasmic/endoplasmic reticulum membrane and are responsible for the release of Ca(2+) from intracellular stores during excitation-contraction coupling in both cardiac and skeletal muscle. RyRs are the largest known ion channels (> 2MDa) and exist as three mammalian isoforms (RyR 1-3),', 'Ryanodine receptors (RyRs) are a family of intracellular calcium release channels that mediate calcium-induced calcium release from the endoplasmic reticulum. Among the three RyR isoforms, RyR3 is preferentially expressed in the brain especially in the hippocampus and striatum.', 'In excitable cells such as skeletal and cardiac myocytes excitation-contraction coupling is an important intermediate step between initiation of the action potential and induction of contraction. This process is predominantly controlled by Ca(2+) release from the sarcoplasmic reticulum via the ryanodine receptor. This very large protein (MW 560 kDa) exists as a homotetramer (~2.2 MDa) and is expressed in three isoforms: RyR1, expressed in skeletal muscle; RyR2, expressed in cardiac muscle; and RyR3, expressed in various cells at lower levels than the other isoforms. ', 'Generally, three ryanodine receptor isoforms (RyR1-RyR3) are known; ', 'Ryanodine receptor (RyR) is a Ca(2+) channel that mediates Ca(2+) release from intracellular stores.', 'There are three RyR isoforms,', 'Ryanodine receptors (RyRs) are intracellular Ca(2+) channels that mediate the release of calcium from internal stores and therefore play an important role in Ca(2+) signaling and homeostasis. Three RyR isoforms have been described thus far,', 'RyR1 and RyR2', 'RyR3', 'Three different isoforms of the SR Ca2+ release channels, or ryanodine receptors (RyRs), have been isolated (RyR1, RyR2, and RyR3).']
['Generally, three ryanodine receptor isoforms (RyR1-RyR3) are known. RyR1, expressed in skeletal muscle; RyR2, expressed in cardiac muscle; and RyR3, expressed in various cells. RyR3 is preferentially expressed in the brain especially in the hippocampus and striatum.']
['Ryanodine Receptor type 1', 'RyR1', 'Ryanodine Receptor type 2', 'RyR2', 'Ryanodine Receptor type 3', 'RyR3']