Supriya Ghosh (Editor)

TRPM5

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Species
  
Human

Entrez
  
29850

Human
  
Mouse

Ensembl
  
ENSG00000070985

Aliases
  
TRPM5, LTRPC5, MTR1, transient receptor potential cation channel subfamily M member 5

External IDs
  
OMIM: 604600 MGI: 1861718 HomoloGene: 22818 GeneCards: TRPM5

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.

Contents

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. The calcium dependent opening of TRPM5 produces a depolarizing generator potential which leads to an action potential.

TPRM5 is expressed in pancreatic β-cells 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. Further expression of TRPM5 can be found in tuft cells, 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.

Agonists

  • Steviol glycosides, the sweet compounds in the leafs 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.
  • 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.
  • 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.
  • Flufenamic Acid is a NSAID drug that inhibits the activity of TRPM5 or TRPM4.
  • Clotrimazole is an antifungal drug and reduces the currents through TRPM5.
  • Nicotine inhibits the TRPM5 channel. Through the inhibition of TRPM5, the taste loss observed in people with a smoking habit can be explained.
  • References

    TRPM5 Wikipedia