Transient receptor potential

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The phrase Transient receptor potential or TRP is appended to at least three classes of ion channels which mediate the response of a cell to external stimuli (electrical charge, substances, and forces) by increasing or decreasing its selective permeability to particular ions. The effect of this change is to modify the potential difference between inside and outside of the cell. Hence "receptor," for sensitivity to the environment, and "potential" for this difference.

Transient receptor potential ion channels are named after the role of the channels in Drosophila phototransduction.

Contents 1 Genes 2 TRPV 3 TRPM 4 References 5 External links

[edit] Genes

They are encoded by at least 21 channel subunit genes and divided in three subunits:

• TRPC (canonical): TRPC1, TRPC2, TRPC3, TRPC4, TRPC5, TRPC6, TRPC7
• TRPV (vanilloid): TRPV1, TRPV2, TRPV3, TRPV4, TRPV5, TRPV6
• TRPM (melastatin): TRPM1, TRPM2, TRPM3, TRPM4, TRPM5, TRPM6, TRPM7, TRPM8

[edit] TRPV

TRPV1 to TRPV4 can basically be seen as thermometers on a molecular level, and are activated by various means. TRPV1 is for example activated by noxious heat, acidic pH and capsaicin ^[1].

TRPV5 and TRPV6 are calcium entry channels responsible for calcium absorption in kidney and intestine. They were originally named ECaC ^[2] and CAT1 ^[3] and expression is regulated by the vitamin D endocrine system through the active metabolite calcitriol.

[edit] TRPM

TRPM5 is involved in the sensory transduction pathway of taste cells.

TRPM6 is a magnesium entry channel in epithelial tissues mediating magensium reabsorption in the kidney and absorption in the intestine ^[4]

ANKTM1 (or TRPA1) is a member of the TRP ion channel family responsible for the irritating effects of tetrahydrocannabinol, mustard oil, ^[5] and cinnamaldehyde.

TRPM8 is a Ca²⁺ permeable channel which can be activated by low temperatures, menthol, eucalyptol and icilin ^[6].

[edit] References

1. ^ TRPV3 is a temperature-sensitive vanilloid receptor-like protein G. D. Smith, M. J. Gunthorpe, R. E. Kelsell, P. D. Hayes, P. Reilly, P. Facer, J. E. Wright, J. C. Jerman, J.-P. Walhin, L. Ooi, J. Egerton, K. J. Charles, D. Smart, A. D. Nature 186 418 2002 abstract
2. ^ Molecular identification of the apical Ca2+ channel in 1, 25-dihydroxyvitamin D3-responsive epithelia Hoenderop JG, van der Kemp AW, Hartog A, van de Graaf SF, van Os CH, Willems PH, Bindels RJ. J Biol Chem 1999;274:8375-8. abstract
3. ^ Molecular cloning and characterization of a channel-like transporter mediating intestinal calcium absorption. Peng JB, Chen XZ, Berger UV, Vassilev PM, Tsukaguchi H, Brown EM, Hediger MA. J Biol Chem 1999;274:22739-46. abstract
4. ^ Hypomagnesemia with secondary hypocalcemia is caused by mutations in TRPM6, a new member of the TRPM gene family. Schlingmann KP, Weber S, Peters M, Niemann Nejsum L, Vitzthum H, Klingel K, Kratz M, Haddad E, Ristoff E, Dinour D, Syrrou M, Nielsen S, Sassen M, Waldegger S, Seyberth HW, Konrad M. Nat Genet 2002;31:166-70. abstract
5. ^ Mustard oils and cannabinoids excite sensory nerve fibres through the TRP channel ANKTM1 Sven-Eric Jordt, Diana M. Bautista, Huai-hu Chuang, David D. McKemy, Peter M. Zygmunt, Edward D. Högestätt, Ian D. Meng, David Julius Nature 260 427 2004 abstract
6. ^ Characterization of the mouse cold-menthol receptor TRPM8 and vanilloid receptor type-1 VR1 using a fluorometric imaging plate reader (FLIPR) assay H-J Behrendt, T Germann, C Gillen, H Hatt, R Jostock British Journal of Pharmacology 737 141 2004 abstract

[edit] External links

• IUPHAR
• MeSH Transient+Receptor+Potential+Channels