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| Autor | Sapar Meredovich Saparov |
| Titel | Transient receptor potential channels (TRPs) |
| Ort | JKU Linz |
| Jahr | 2007 |
| Anmerkung | Online teaching material, removed from web as Saparov passed away 2007 : http://wayback.archive.org/web/20071213151607/http://www.bphys.uni-linz.ac.at/bioph/biophtit.htm, methods page is linked from http://wayback.archive.org/web/20070915214110/http://www.bphys.uni-linz.ac.at/bioph/res/icg/base.html |
| URL | http://wayback.archive.org/web/20071213100817/http://www.bphys.uni-linz.ac.at/bioph/res/icg/TRP_intro.html |
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| Fußnoten | no |
| Fragmente | 3 |
| [1.] Dsa/Fragment 042 01 - Diskussion Zuletzt bearbeitet: 2016-08-27 21:21:08 WiseWoman | Dsa, Fragment, Gesichtet, KomplettPlagiat, SMWFragment, Saparov 2007, Schutzlevel sysop |
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| Untersuchte Arbeit: Seite: 42, Zeilen: 1ff (entire page) |
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| Transient receptor potential channels (TRPs)
The mammalian TRP channels encode a family of about 30 ion channel proteins. This superfamily consists of seven diverse groups structurally similar to the originally found Drosophila TRP and they differ in ion selectivities, modes of activation and physiological functions.
Figure nr. 10 - TRP family with its subgroups. The vanilloids, the classical, the melastatin, the mucolipins (TRPML) and the polycystins (TRPP) (members of TRPN, TRPA not shown). TRP proteins are expressed predominantly in the nervous system and are of particular importance in sensory physiology. (Montell C. et al., (2005) Sci STKE). In each subfamily are three to eight members. (Hönderop JG. et al., (2005) Physiol Rev). The reason to identify mammalian TRPs is to characterize those channels that might account for highly Ca2+ selective Ca2+ entry mechanism in nonexcitable cells, referred to as store-operated Ca2+ entry (SOCE). SOCE is interesting, due to association of these modes of Ca2+ entry with processes ranging from T cell activation to apoptosis, cell proliferation, fluid secretion and cell migration.(Montell C. et al., (2005) Sci STKE.). The TRP superfamily can be divided into two structurally different groups (Clapham DE. et al., (2003) Pharmacol Rev): • Group 1: TRPC, TRPV, TRPM, TRPN, TRPA. They share substantial sequence identity in the transmembrane domains. • Group 2: TRPP and TRPML. They have low sequence similarity and a large extracellular loop between the first and the second transmembrane domains. |
Transient receptor potential channels (TRPs)
The mammalian TRP channels encode a family of about 30 ion channel proteins. This superfamily consists of seven diverse groups structurally similar to the originally found Drosophila TRP and they differ in ion selectivities, modes of activation and physiological functions. TRP proteins are expressed predominantly in the nervous system and are of particular importance in sensory physiology. (1) [Illustration] Summary of the different TRP family members TRP family with its subgroups: the vanilloids, the classical, the melastatin, the mucolipins (TRPML) and the polycystins (TRPP) (members of TRPN, TRPA not shown). In each subfamily are three to eight members. (2) The reason to identify mammalian TRPs is to characterize those channels that might account for highly Ca2+ selective Ca2+ entry mechanism in nonexcitable cells, referred to as store-operated Ca2+ entry (SOCE). SOCE is interesting, due to association of these modes of Ca2+ entry with processes ranging from T cell activation to apoptosis, cell proliferation, fluid secretion and cell migration.(1) The TRP superfamily can be divided into two structurally different groups(1,3): 1. Group 1: TRPC, TRPV, TRPM, TRPN, TRPA They share substantial sequence identity in the transmembrane domains. 2. Group 2: TRPP and TRPML They have low sequence similarity and a large extracellular loop between the first and the second transmembrane domains. 1. Montell, C. (2005) Sci STKE 2005, re3 2. Hoenderop, J. G., Nilius, B., and Bindels, R. J. (2005) Physiol Rev 85, 373-42 3. Clapham, D. E., Montell, C., Schultz, G., and Julius, D. (2003) Pharmacol Rev 55, 591-596 |
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| [2.] Dsa/Fragment 043 01 - Diskussion Zuletzt bearbeitet: 2016-08-27 21:21:45 WiseWoman | Dsa, Fragment, Gesichtet, KomplettPlagiat, SMWFragment, Saparov 2007, Schutzlevel sysop |
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| [Figure 11]
Figure nr. 11 - The seven TRP subfamilies. Representatives of the different subfamilies are indicated at the top and bottom, respectively. Several domains are indicated: ankyrin repeats (A), coiled coil domain (cc), protein kinase domain (TRPM6/7 only), transmembrane segments, and the TRP domain.
[Figure 12] Figure nr. 12 - The quaternary structure of TRP channels allows homo- or heteromeric configurations. Left: TRP channel subunit, right: structure of functional TRP channel. |
[Representatives of the seven TRP subfamilies]
The seven TRP subfamilies. Representatives of the different subfamilies are indicated at the top and bottom, respectively. Several domains are indicated: ankyrin repeats (A), coiled coil domain (cc), protein kinase domain (TRPM6/7 only), transmembrane segments, and the TRP domain (1) TRP proteins are supposed to form 6 membrane-spanning segments whereas the pore region is formed by a hydrophilic region between S5 and S6 forms. The N- and C-termini are located intracellularly. The N-terminus often contains ankyrin repeats as well as a coiled-coil domain, which are suspected to bind with other proteins or the cytoskeleton. Especially they are thought to be needed for TRP protein interaction because a functional channel contains 4 TRP subunits, either similar or different ones, to form homo- or heteromers (4,5). [Scheme: Quaternary structure of TRP channels] The quartenary structure of TRP channels allows homo- or heteromeric configurations. Left: TRP channel subunit, right: structure of functional TRP channel 1. Montell, C. (2005) Sci STKE 2005, re3 4. Goel, M., Sinkins, W. G., and Schilling, W. P. (2002) J Biol Chem 277, 48303-48310 5. Hoenderop, J. G., Voets, T., Hoefs, S., Weidema, F., Prenen, J., Nilius, B., and Bindels, R. J. (2003) Embo J 22, 776-785 |
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| [3.] Dsa/Fragment 044 01 - Diskussion Zuletzt bearbeitet: 2016-08-27 21:16:16 WiseWoman | Dsa, Fragment, Gesichtet, KomplettPlagiat, SMWFragment, Saparov 2007, Schutzlevel sysop |
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| TRPV (vanilloid) family has six mammalian members grouped into three subfamilies. These proteins contain three to five ankyrin repeats and share ~25% amino acid identity to TRPC proteins (Montell C. et al, (2005) Sci STKE). TRPV1-TRPV4 form poor selective cation channels and are sensitive to heat (Hellwig N. et al., (2005) J Cell Sci). TRPV5 and TRPV6 are phylogenetically closely related Ca2+ selective channels (PCa: PNa > 100) expressed in epithelia of kidney and intestine and exhibit a constitutive activity (Clapham DE. et al., (2003) Pharmacol Rev). Both proteins become permeable to monovalent cations in the absence of divalent cations. It was proposed that TRPV6 may be the highly Ca2+-selective, store-operated channels, referred to CRAC but several biophysical properties of TRPV6 are distinct from those of ICRAC (Kahr H. et al., (2004) J Physiol). Nevertheless there remains still the option that TRPV5/ TRPV6 may be subunits of CRAC channels.
TRPM (long TRPC, melastatin) family is composed of eight members. They share ~20% identity, have a TRP domain and contain ankyrin repeats at the N-terminus which is longer than that of TRPCs and TRPVs (Fleig A. et al., (2004) Novartis Found Symp). |
TRPV (vanilloid) family has six mammalian members grouped into three subfamilies. These proteins contain three to five ankyrin repeats and share ~25% amino acid identity to TRPC proteins (1). TRPV1-TRPV4 form poor selective cation channels and are sensitive to heat (6,7). TRPV5 and TRPV6 are phylogenetically closely related Ca2+ selective channels (PCa:PNa > 100) expressed in epithelia of kidney and intestine and exhibit a constitutive activity. (3) Both proteins become permeable to monovalent cations in the absence of divalent cations. It was proposed that TRPV6 may be the highly Ca2+-selective, store-operated channels, referred to CRAC but several biophysical properties of TRPV6 are distinct from those of ICRAC (8). Nevertheless there remains still the option that TRPV5/ TRPV6 may be subunits of CRAC channels.(1)
TRPM (long TRPC, melastatin) family is composed of eight members. They share ~20% identity , have a TRP domain and contain ankyrin repeats at the N-terminus which is longer than that of TRPCs and TRPVs. (9) 1. Montell, C. (2005) Sci STKE 2005, re3 3. Clapham, D. E., Montell, C., Schultz, G., and Julius, D. (2003) Pharmacol Rev 55, 591-596 6. Hellwig, N., Albrecht, N., Harteneck, C., Schultz, G., and Schaefer, M. (2005) J Cell Sci 118, 917-928 7. Wang, H., and Woolf, C. J. (2005) Neuron 46, 9-12 8. Kahr, H., Schindl, R., Fritsch, R., Heinze, B., Hofbauer, M., Hack, M. E., Mortelmaier, M. A., Groschner, K., Peng, J. B., Takanaga, H., Hediger, M. A., and Romanin, C. (2004) J Physiol 557, 121-132 9. Fleig, A., and Penner, R. (2004) Novartis Found Symp 258, 248-258; discussion 258-266 |
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