Transient receptor potential channel

Hofmann T., Schaefer M., Schultz G. and Gudermann T. (2000a). Transient receptor potential channels as molecular substrates of receptor-mediated cation entry. J Mol Med 78, 14-25. 

Perez, C. A. et al. A transient receptor potential channel expressed in taste receptor cells. Nat. Neurosci. 5 1169-1176, 2002. 

Clapham, D. E., Montell, C., Schultz, G. and Julius, D. International Union of Pharmacology. XLIII. Compendium of voltage-gated ion channels transient receptor potential channels. Pharmacol. Rev. 55 591-596,2003. 

Helliwell RM, Large WA 1997 Alphal-adrenoceptor activation of a non-selective cation current in rabbit portal vein by 1,2-diacyl-sn-glycerol. J Physiol 499 417-428 Hofmann F, Lacinova L, Klugbauer N 1999 Voltage-dependent calcium channels from structure to function. Rev Physiol Biochem Pharmacol 139 33—87 Hofmann T, Schaefer M, Schultz G, Gundermann T 2000 Transient receptor potential channels as molecular substrates of receptor-mediated cation entry. J Mol Med 78 14—25 Inoue R, Okada T, Onoue H et al 2001 The transient receptor potential protein homologue TRP6 is the essential component of vascular aj-adrenoceptor-activated Ca2+-permeable cation channel. Circ Res 88 325—332... 

Welsh DG, Morielli AD, Nelson MT, Brayden JE 2002 Transient receptor potential channels regulate myogenic tone of resistance arteries. Circ Res 90 248-250 Xu SZ, Beech DJ 2001 TrpCl is a membrane-spanning subunit of store-operated Ca2+ channels in native vascular smooth muscle cells. Circ Res 88 84-87 Yamazawa T, lino M, Endo M 1992 Presence of functionally different compartments of the Ca2+ store in single intestinal smooth muscle cells. FEBS Lett 301 181—184... 

Clapham DE et al Compendium of voltage-gated ion channels Transient receptor potential channels. Pharmacol Rev 2003 55 591. [PMID 14657417]... 

Thebault, S., Flourakis, M., Vanoverberghe, K., Vandermoere, F., Roudbaraki, M., Lehen kyi, V., Slomianny, C., Beck, B., Mariot, P., Bonnal, J. L., Mauroy, B., Shuba, Y., Capiod, T., Skryma, R. and Prevarskaya, N., 2006, Differential role of transient receptor potential channels in Ca2+ entry and proliferation of prostate cancer epithelial cells. Cancer Res 66, 2038-47. 

SOCs, also known as ICRAC (calcium-release activated channels), have been observed in a wide range of cell types (Parekh and Penner, 1997). The defining property is that depletion of intracellular calcium stores results in increased calcium influx at the plasma membrane. The actual SOC that carries this calcium influx may vary between cells, and cloning studies have identified transient receptor potential channel (TRPC) (Parekh and Penner, 1997, Vandebrouck et al., 2002b) and CRACM1 (Peinelt et al., 2006) as candidate genes. Also, the exact mechanism by which SOCs are activated by store depletion has only been partly elucidated, with a role suggested for a calcium sensor on the endoplasmic reticulum (see Peinelt et al., 2006) and for IP3 (Kiselyov et al., 1998). 

Zhou X-L, Batiza AF, Loukin SH, Palmer CP, Kung C, Saimi Y. The transient receptor potential channel on the yeast vacuole is mechanosensitive. Proc. Natl. Acad. Sci. U.S.A. 2003 100 7105-7110. 

The carboxyl-terminal 469 amino acids of NompC resemble a class of ion channel proteins called TRP (transient receptor potential) channels. This region includes six putative transmembrane helices with a porelike region between the fifth and sixth helices. The amino-terminal 1150 amino acids consist almost exclusively of 29 ankyrin repeats (Figure 32.35). Ankyrin repeats are structural motifs formed by 33 amino acids folded into a hairpin loop followed by a helix-tum-helix. Importantly, in other proteins, regions with tandem arrays of these motifs mediate protein-protein interactions, suggesting that these arrays couple the motions of other proteins to the activity of the NompC channel. 

Fig. 2 The bitter taste signal transduction cascade. Bitter taste receptors are G-protein-coupled receptors. Activation of TAS2Rs results in the activation of the heterotrimeric G-protein complex a-gustducin (a-gust), 3 or pi, and yl3. The Py-subunits activate phospholipase C P2, (PLCj52) resulting in the production of inositol 1,4,5-trisphosphate (/P3). The IP3-mediated increase of intracellular calcium activates transient receptor potential channel 5 (TRPM5)...

Yoshida Y, Saitoh K, Aihara Y, Okada S, Misaka T, Abe K (2007) Transient receptor potential channel M5 and phospholipaseC-beta2 colocalizing in zebrafish taste receptor cells. Neuroreport 18 1517-1520... 

Calcium ions are mostly present in bones or chelated to biological molecules. In blood plasma, only 1% of the calcium ions present are unbound 78% is bound to albumin, 8% to citrate, and 13% to other plasma proteins. The free calcium ions are prevented from precipitating by plasma pyrophosphate. Calcium ions are also stored in the endoplasmic reticulum (ER), mostly chelated to ER-resident proteins and phosphatidylser-ine. Free calcium ions may be released through transient receptor potential channels to the cytosol where it activates numerous physiological processes. If the free calcium ion concentration of blood plasma falls, parathyroid hormone (PTH) is secreted by the parathyroid gland cells. PTH speeds up the transport of demineralized bone products by osteoclasts. In the kidney, it increases the excretion of phosphate and decreases the excretion of calcium. PTH also acts on kidney cells to make calcitriol from vitamin D, which induces calcium transporters in the intestine and osteoclasts. PTH mediates these effects by activating G-protein-coupled receptors in the kidney and osteoclasts. 

Vitamin D is a fat soluble vitamin related to cholesterol. In the skin, sunlight spontaneously oxidizes cholesterol to 7-dehydrocholesterol. 7-Dehydrocholesterol spontaneously isomerizes to cholecalciferol (vitamin D3), which is oxidized in the liver to 25-hydroxy cholecalciferol and, under the influence of PTH in the kidney, to 1,25-dihy-droxy cholecalciferol (calcitriol), the active form of vitamin D. Vitamin D induces the expression of calcium ion transport proteins (calbindins) in intestinal epithelium, osteoclasts, and osteoblasts. Calbindins and transient receptor potential channels (TRPV) are responsible for the uptake of calcium from the diet. In children, the absence of sunlight provokes a deficiency of vitamin D, causing an absence of calbindins and inadequate blood calcium levels. Osteoid tissue cannot calcify, causing skeletal deformities (rickets). In the elderly, there is a loss of intestinal TRPV receptors and decreased calbindin expression by vitamin D. In both cases, the resultant low blood calcium levels cause poor mineralization during bone remodeling (osteomalacia). Rickets is the childhood expression of osteomalacia. Osteoclast activity is normal but the bone does not properly mineralize. In osteoporosis, the bone is properly mineralized but osteoclasts are overly active. 

Transient receptor potential channel TRPVl receptors Acetaminophen metabolite (inhibitor)... 

Okuhara, D. Y., Hsia, A. Y., Xie, M. Transient receptor potential channels as drug targets. Expert Opin. Ther. Tar. 2007,11, 391 01. 

The carboxyl-terminal 469 amino acids of NompC resemble a class of ion channel proteins called TRP (transient receptor potential) channels. This region includes six putative transmembrane helices with a pore-like region between the fifth and sixth helices. The amino-terminal 1150 amino acids consist almost exclu-... 

We also know of Ser/Thr-specific protein kinases that are an integral part of transmembrane receptors or of ion channels. The TGFyS-receptor contains a Ser/Thr-spe-cific protein kinase activity in the cytoplasmic part of its transmembrane polypeptide chain (see Chapter 12). Some members of a certain class of ion channels, named the transient receptor potential channels (TRP channels), carry a protein kinase activity on the cytoplasmic side of the channel protein that is essential for channel function. The TRP channels modulate Ca2+ entry into eukaryotic cells in response to external signals. The protein kinase activity is located on the cytoplasmic domain of the channel and can phosphorylate itself and other proteins on Ser/Thr residues (Runnels et ah, 2001). 

TRP —transient receptor potential channel TRPA—TRP ankyrin receptor subfamily TRPC—TRP canonical receptor subfamily TRPM—TRP melastatin receptor subfamily TRPML—TRP mucolipin receptor subfamily TRPN—TRP NOMPG receptor family TRPP—TRP polycystin receptor subfamily TRPV—TRP vanilloid receptor subfamily TTX—tetrodotoxin... 

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