TRPM5

TRPM5
Identifiers
Aliases	TRPM5, LTRPC5, MTR1, transient receptor potential cation channel subfamily M member 5
External IDs	OMIM: 604600 MGI: 1861718 HomoloGene: 22818 GeneCards: TRPM5
Gene location (Human) Chr. Chromosome 11 (human)[1] Band 11p15.5 Start 2,404,515 bp[1] End 2,444,514 bp[1]
Gene location (Mouse) Chr. Chromosome 7 (mouse)[2] Band 7|7 F5 Start 142,622,890 bp[2] End 142,648,379 bp[2]
RNA expression pattern Bgee Human Mouse (ortholog) Top expressed in seminal vesicula body of pancreas duodenum metanephros left lobe of thyroid gland epididymis right lobe of thyroid gland caput epididymis kidney islet of Langerhans Top expressed in islet of Langerhans internal carotid artery urethra female urethra male urethra external carotid artery vas deferens intestinal villus jejunum yolk sac More reference expression data BioGPS n/a
Gene ontology Molecular function voltage-gated ion channel activity ion channel activity potassium channel activity calcium activated cation channel activity sodium channel activity Cellular component plasma membrane membrane neuronal cell body dendrite integral component of membrane Biological process ion transport sodium ion transmembrane transport sensory perception of taste calcium ion transmembrane transport potassium ion transmembrane transport cation transport regulation of ion transmembrane transport ion transmembrane transport transmembrane transport Sources:Amigo / QuickGO
Orthologs Species Human Mouse Entrez 29850 56843 Ensembl ENSG00000070985 ENSMUSG00000009246 UniProt Q9NZQ8 Q9JJH7 RefSeq (mRNA) NM_014555 NM_020277 RefSeq (protein) NP_055370 NP_064673 Location (UCSC) Chr 11: 2.4 – 2.44 Mb Chr 7: 142.62 – 142.65 Mb PubMed search [3] [4]
Wikidata
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Transient receptor potential cation channel subfamily M member 5 (TRPM5), also known as long transient receptor potential channel 5 is a protein that in humans is encoded by the TRPM5 gene.^[5][6]

Function

TRPM5 is a calcium-activated non-selective cation channel that induces depolarization upon increases in intracellular calcium, it is a signal mediator in chemosensory cells. Channel activity is initiated by a rise in the intracellular calcium, and the channel permeates monovalent cations as K⁺ and Na⁺. TRPM5 is a key component of taste transduction in the gustatory system of bitter, sweet and umami tastes being activated by high levels of intracellular calcium. It has also been targeted as a possible contributor to fat taste signaling.^[7][8] The calcium dependent opening of TRPM5 produces a depolarizing generator potential which leads to an action potential.^[9]

TRPM5 is expressed in pancreatic β-cells^[10] where it is involved in the signaling mechanism for insulin secretion. The potentiation of TRPM5 in the β-cells leads to increased insulin secretion and protects against the development of type 2 diabetes in mice.^[11] Further expression of TRPM5 can be found in tuft cells,^[12] solitary chemosensory cells and several other cell types in the body that have a sensory role.

Drugs modulating TRPM5

The role of TRPM5 in the pancreatic β-cell makes it a target for the development of novel antidiabetic therapies.^[13]

Agonists

• Steviol glycosides, the sweet compounds in the leaves of the Stevia rebaudiana plant, potentiate the calcium-induced activity of TRPM5. In this way they stimulate the glucose-induced insulin secretion from the pancreatic β-cell.^[11]
• Rutamarin, a phytochemical found in Ruta graveolens has been identified as an activator of several TRP channels, including TRPM5 and TRPV1 and inhibits the activity of TRPM8.^[14]

Antagonists

Selective blocking agents of TRPM5 ion channels can be used to identify TRPM5 currents in primary cells. Most identified compounds show, however, a poor selectivity between TRPM4 and TRPM5 or other ion channels.

• TPPO or TriPhenylPhosphineOxide is the most selective blocker of TRPM5 however, its application suffers due to a poor solubility.^[15]
• Ketoconazole is an antifungal drug that inhibits TRPM5 activity.^[16]
• Flufenamic Acid is an NSAID drug that inhibits the activity of TRPM5 or TRPM4.^[17]
• Clotrimazole is an antifungal drug and reduces the currents through TRPM5.^[17]
• Nicotine inhibits the TRPM5 channel. Through the inhibition of TRPM5, the taste loss observed in people with a smoking habit can be explained.^[18]

See also

• TRPM

References

Further reading

External links

• TRPM5+protein,+human at the U.S. National Library of Medicine Medical Subject Headings (MeSH)
• IUPHAR
• HGNC Gene families
• Pfam

This article incorporates text from the United States National Library of Medicine, which is in the public domain.