TRPM5
Description
The TRPM5 (transient receptor potential cation channel subfamily M member 5) is a protein-coding gene located on chromosome 11.
TRPM5, also known as long transient receptor potential channel 5, is a protein encoded by the TRPM5 gene in humans. It is a calcium-activated non-selective cation channel that induces depolarization in response to increases in intracellular calcium, acting as a signal mediator in chemosensory cells. The channel is permeable to monovalent cations such as potassium and sodium, and its activation is triggered by rising intracellular calcium levels. TRPM5 plays a crucial role in taste transduction, specifically for bitter, sweet, and umami tastes, and it has been implicated in fat taste signaling. Its activation leads to a depolarizing generator potential, which triggers an action potential. TRPM5 is expressed in pancreatic β-cells and is involved in insulin secretion signaling. Potentiation of TRPM5 in β-cells leads to increased insulin secretion and helps protect against the development of type 2 diabetes in mice. Other locations for TRPM5 expression include tuft cells, solitary chemosensory cells, and other cell types with sensory roles. The involvement of TRPM5 in pancreatic β-cells makes it a target for developing novel antidiabetic therapies.
TRPM5 is a voltage-gated calcium-activated cation channel that plays a crucial role in taste perception. It is activated by increases in intracellular calcium and is permeable to monovalent cations like sodium, potassium, and cesium. Its activation is rapid and voltage-dependent, and it can be activated by both calcium increases and inositol 1,4,5-triphosphate-producing receptor agonists. While it is blocked by extracellular acidification, it is also highly sensitive to temperature, showing increased activity at temperatures between 15 and 35 degrees Celsius. This temperature sensitivity is due to a shift in the voltage-dependent activation curve towards negative potentials. TRPM5 is also activated by arachidonic acid in vitro and is thought to be involved in the perception of bitter, sweet, and umami tastes. It may also play a role in sensing semiochemicals.
TRPM5 is also known as LTRPC5, MTR1.
