Monovalent cation channel required for maintenance of rapid intracellular calcium release. May act as a potassium counter-ion channel that functions in synchronization with calcium release from intracellular stores (By similarity).
Catalysis of facilitated diffusion of a potassium ion (by an energy-independent process) involving passage through a transmembrane aqueous pore or channel without evidence for a carrier-mediated mechanism.
Ca(2+) mobilization from intracellular stores is mediated by Ca(2+) release channels, designated ryanodine and IP(3) receptors, and directly regulates important cellular reactions including muscle contraction, endo/exocrine secretion, and neural excitability. In order to function as an intracellular store, the endo/sarcoplasmic reticulum is equipped with cooperative Ca(2+) uptake, storage and release machineries, comprising synergic collaborations among integral-membrane, cytoplasmic and luminal proteins. Our recent studies have demonstrated that junctophilins form junctional membrane complexes between the plasma membrane and the endo/sarcoplasmic reticulum in excitable cells, and that TRIC (trimeric intracellular cation) channels act as novel monovalent cation-specific channels on intracellular membrane systems. Knockout mice have provided evidence that both junctophilins and TRIC channels support efficient ryanodine receptor-mediated Ca(2+) release in muscle cells. This review focuses on cardiac Ca(2+) release by discussing pathological defects of mutant cardiomyocytes lacking ryanodine receptors, junctophilins, or TRIC channels.
Protein involved in the transport of ions. Such proteins are usually transmembrane and mediate a movement of ions across cell membranes. Transport may be passive (facilitated diffusion; down the electrochemical gradient), or active (against the electrochemical gradient). Active transport requires energy which may come from light, oxidation reactions, ATP hydrolysis, or cotransport of other ions or molecules.
Protein involved in the transport of a molecule (metabolite, protein, etc), a ion or an electron across cell membranes, inside the cell or in a tissue fluid.
Protein which is part of a transmembrane protein complex that forms a hydrophilic channel across the lipid bilayer through which specific inorganic ions can diffuse down their electrochemical gradients. The channels are usually gated and only open in response to a specific stimulus, such as a change in membrane potential (voltage-gated) or the binding of a ligand (ligand-gated channel).
Protein which is part of a transmembrane protein complex that forms a hydrophilic channel across the lipid bilayer through which potassium ions can diffuse down their electrochemical gradient. The channels are gated and only open in response to a specific stimulus, such as a change in membrane potential (voltage-gated). They are important for the regulation of the resting membrane potential and for the control of the shape and frequency of action potentials.
A reference proteome is a set of protein sequences derived from a complete proteome which constitutes a defined standard for a particular user community. Reference proteomes are manually defined according to a number of criteria. They cover the proteomes of well- studied model organisms and other proteomes of interest for biomedical and biotechnological research. Reference proteomes have been selected to provide broad coverage of the tree of life, and constitute a representative cross-section of the taxonomic diversity to be found within UniProtKB.