TRPM is a family of transient receptor potential

ion channel Ion channels are pore-forming membrane proteins that allow ions to pass through the channel pore. Their functions include establishing a resting membrane potential, shaping action potentials and other electrical signals by gating the flow of ...

s (''M'' standing for '' wikt:melastatin''). Functional TRPM channels are believed to form tetramers. The TRPM family consists of eight different channels, TRPM1–TRPM8. Unlike the TRPC and TRPV sub-families, TRPM subunits do not contain N-terminal

ankyrin repeat The ankyrin repeat is a 33-residue motif in proteins consisting of two alpha helices separated by loops, first discovered in signaling proteins in yeast Cdc10 and ''Drosophila'' Notch. Domains consisting of ankyrin tandem repeats mediate prot ...

motifs but, rather, contain entire functional proteins in their C-termini. TRPM6 and TRPM7, for example, contain functional α-kinase segments, which are a type of

serine/threonine-specific protein kinase A serine/threonine protein kinase () is a kinase enzyme, in particular a protein kinase, that phosphorylates the OH group of the amino-acid residues serine or threonine, which have similar side chains. At least 350 of the 500+ human prot ...

Permeability and activation

The relative permeability of calcium and magnesium varies widely among TRPM channels. *

TRPM4 Transient receptor potential cation channel subfamily M member 4 (hTRPM4), also known as melastatin-4, is a protein that in humans is encoded by the TRPM4 gene. TRPM4 Channel Blocker * 9-Phenanthrol * TRPM4-IN-5 See also * TRPM References ...

and TRPM5 are impermeable to calcium. * TRPM3, TRPM6 and TRPM7 are highly permeable to both calcium and magnesium. The mechanism of activation also varies greatly among TRPM channels. * TRPM2 is activated by ADP-ribose

adenosine 5'-diphosphoribose Adenosine diphosphate ribose (ADPR) is an ester molecule formed into chains by the enzyme poly ADP ribose polymerase. ADPR is created from cyclic ADP-ribose (cADPR) by the CD38 enzyme using nicotinamide adenine dinucleotide (NAD+) as a cofactor. ...

and functions as a sensor of redox status in cells. *

and TRPM5 are activated by intracellular calcium. * TRPM8 can be activated by low temperatures,

menthol Menthol is an organic compound, more specifically a monoterpenoid, made synthetically or obtained from the oils of corn mint, peppermint, or other mints. It is a waxy, clear or white crystalline substance, which is solid at room temperature and ...

, eucalyptol and icilin.

Functions

Among the functional responsibilities of the TRPM channels are: *regulation of calcium oscillations after T cell activation and prevention of cardiac conduction disorders (

). *modulation of

insulin Insulin (, from Latin ''insula'', 'island') is a peptide hormone produced by beta cells of the pancreatic islets encoded in humans by the ''INS'' gene. It is considered to be the main anabolic hormone of the body. It regulates the metabol ...

secretion and sensory transduction in taste cells ( TRPM5). *cold sensation ( TRPM8). *heat sensation and inflammatory pain ( TRPM3). *regulation of magnesium reabsorption in the kidneys and absorption in the intestines ( TRPM6). *regulation of cell adhesion ( TRPM7).

Genes

TRPM1 Transient receptor potential cation channel subfamily M member 1 is a protein that in humans is encoded by the ''TRPM1'' gene. Function The protein encoded by this gene is a member of the transient receptor potential (TRP) family of non-select ...

, TRPM2, TRPM3,

, TRPM5, TRPM6, TRPM7, TRPM8

References

External links

* * * {{Transient receptor potential channel modulators Membrane proteins Ion channels