Inositol 1,4,5-trisphosphate receptor, type 2, also known as ITPR2, is a protein which in humans is encoded by the ITPR2 gene. [5] The protein encoded by this gene is both a receptor for inositol triphosphate and a calcium channel. [6]
Inositol 1,4,5-trisphosphate receptor, type 2, also known as ITPR2, is a protein which in humans is encoded by the ITPR2 gene. [5] The protein encoded by this gene is both a receptor for inositol triphosphate and a calcium channel. [6]
Inositol trisphosphate or inositol 1,4,5-trisphosphate abbreviated InsP3 or Ins3P or IP3 is an inositol phosphate signaling molecule. It is made by hydrolysis of phosphatidylinositol 4,5-bisphosphate (PIP2), a phospholipid that is located in the plasma membrane, by phospholipase C (PLC). Together with diacylglycerol (DAG), IP3 is a second messenger molecule used in signal transduction in biological cells. While DAG stays inside the membrane, IP3 is soluble and diffuses through the cell, where it binds to its receptor, which is a calcium channel located in the endoplasmic reticulum. When IP3 binds its receptor, calcium is released into the cytosol, thereby activating various calcium regulated intracellular signals.
Inositol trisphosphate receptor (InsP3R) is a membrane glycoprotein complex acting as a Ca2+ channel activated by inositol trisphosphate (InsP3). InsP3R is very diverse among organisms, and is necessary for the control of cellular and physiological processes including cell division, cell proliferation, apoptosis, fertilization, development, behavior, learning and memory. Inositol triphosphate receptor represents a dominant second messenger leading to the release of Ca2+ from intracellular store sites. There is strong evidence suggesting that the InsP3R plays an important role in the conversion of external stimuli to intracellular Ca2+ signals characterized by complex patterns relative to both space and time, such as Ca2+ waves and oscillations.
2-Aminoethoxydiphenyl borate (2-APB) is a chemical that acts to inhibit both IP3 receptors and TRP channels (although it activates TRPV1, TRPV2, & TRPV3 at higher concentrations). In research it is used to manipulate intracellular release of calcium ions (Ca2+) and modify TRP channel activity, although the lack of specific effects make it less than ideal under some circumstances. Additionally, there is evidence that 2-APB acts directly to inhibit gap junctions made of connexin. Increasing evidence showed that 2-APB is a powerful modifier of store-operated calcium channels (SOC) function, low concentration of 2-APB can enhance SOC while high concentration induces a transient increase followed by complete inhibition.
Transient receptor potential canonical 1 (TRPC1) is a protein that in humans is encoded by the TRPC1 gene.
Inositol-trisphosphate 3-kinase B is an enzyme that in humans is encoded by the ITPKB gene.
Inositol 1,4,5-trisphosphate receptor type 1 is a protein that in humans is encoded by the ITPR1 gene.
Probable G-protein coupled receptor 75 is a protein that in humans is encoded by the GPR75 gene.
Inositol (1,4,5) trisphosphate 3-kinase (EC 2.7.1.127), abbreviated here as ITP3K, is an enzyme that facilitates a phospho-group transfer from adenosine triphosphate to 1D-myo-inositol 1,4,5-trisphosphate. This enzyme belongs to the family of transferases, specifically those transferring phosphorus-containing groups (phosphotransferases) with an alcohol group as acceptor. The systematic name of this enzyme class is ATP:1D-myo-inositol-1,4,5-trisphosphate 3-phosphotransferase. ITP3K catalyzes the transfer of the gamma-phosphate from ATP to the 3-position of inositol 1,4,5-trisphosphate to form inositol 1,3,4,5-tetrakisphosphate. ITP3K is highly specific for the 1,4,5-isomer of IP3, and it exclusively phosphorylates the 3-OH position, producing Ins(1,3,4,5)P4, also known as inositol tetrakisphosphate or IP4.
Phospholipase C (PLC) is a class of membrane-associated enzymes that cleave phospholipids just before the phosphate group (see figure). It is most commonly taken to be synonymous with the human forms of this enzyme, which play an important role in eukaryotic cell physiology, in particular signal transduction pathways. Phospholipase C's role in signal transduction is its cleavage of phosphatidylinositol 4,5-bisphosphate (PIP2) into diacyl glycerol (DAG) and inositol 1,4,5-trisphosphate (IP3), which serve as second messengers. Activators of each PLC vary, but typically include heterotrimeric G protein subunits, protein tyrosine kinases, small G proteins, Ca2+, and phospholipids.
1-Phosphatidylinositol-4,5-bisphosphate phosphodiesterase delta-1 is an enzyme that in humans is encoded by the PLCD1 gene. PLCd1 is essential to maintain homeostasis of the skin.
Phospholipase C epsilon 1 (PLCE1) is an enzyme that in humans is encoded by the PLCE1 gene. This gene encodes a phospholipase enzyme (PLCE1) that catalyzes the hydrolysis of phosphatidylinositol-4,5-bisphosphate to generate two second messengers: inositol 1,4,5-triphosphate (IP3) and diacylglycerol (DAG). Mutations in this gene cause early-onset nephrotic syndrome and have been associated with respiratory chain deficiency with diffuse mesangial sclerosis.
1-Phosphatidylinositol-4,5-bisphosphate phosphodiesterase delta-3 is an enzyme that in humans is encoded by the PLCD3 gene.
Inositol-trisphosphate 3-kinase A is an enzyme that in humans is encoded by the ITPKA gene.
Calcium binding protein 1 is a protein that in humans is encoded by the CABP1 gene. Calcium-binding protein 1 is a calcium-binding protein discovered in 1999. It has two EF hand motifs and is expressed in neuronal cells in such areas as hippocampus, habenular nucleus of the epithalamus, Purkinje cell layer of the cerebellum, and the amacrine cells and cone bipolar cells of the retina.
1-Phosphatidylinositol-4,5-bisphosphate phosphodiesterase beta-4 is an enzyme that in humans is encoded by the PLCB4 gene.
Putative adenosylhomocysteinase 2 is an enzyme that in humans is encoded by the AHCYL1 gene.
Type I inositol-1,4,5-trisphosphate 5-phosphatase is an enzyme that in humans is encoded by the INPP5A gene.
Inositol 1,4,5-trisphosphate receptor, type 3, also known as ITPR3, is a protein which in humans is encoded by the ITPR3 gene. The protein encoded by this gene is both a receptor for inositol triphosphate and a calcium channel.
Ryanodine receptor 3 is one of a class of ryanodine receptors and a protein that in humans is encoded by the RYR3 gene. The protein encoded by this gene is both a calcium channel and a receptor for the plant alkaloid ryanodine. RYR3 and RYR1 control the resting calcium ion concentration in skeletal muscle.
The ryanodine-inositol 1,4,5-triphosphate receptor Ca2+ channel (RIR-CaC) family includes Ryanodine receptors and Inositol trisphosphate receptors. Members of this family are large proteins, some exceeding 5000 amino acyl residues in length. This family belongs to the Voltage-gated ion channel (VIC) superfamily. Ry receptors occur primarily in muscle cell sarcoplasmic reticular (SR) membranes, and IP3 receptors occur primarily in brain cell endoplasmic reticular (ER) membranes where they effect release of Ca2+ into the cytoplasm upon activation (opening) of the channel. They are redox sensors, possibly providing a partial explanation for how they control cytoplasmic Ca2+. Ry receptors have been identified in heart mitochondria where they provide the main pathway for Ca2+ entry. Sun et al. (2011) have demonstrated oxygen-coupled redox regulation of the skeletal muscle ryanodine receptor-Ca2+ release channel (RyR1;TC# 1.A.3.1.2) by NADPH oxidase 4.
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