TRPM is a family of transient receptor potential ( M standing for ).
Unlike the TRPC and TRPV sub-families, TRPM subunits do not contain N-terminal ankyrin repeat 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.
Permeability and activation
The relative permeability of calcium and magnesium varies widely among TRPM channels.
-
TRPM4 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 and functions as a sensor of redox status in cells.
-
TRPM4 and TRPM5 are activated by intracellular calcium.
-
TRPM8 can be activated by low temperatures, menthol, eucalyptol and icilin.
Functions
Among the functional responsibilities of the TRPM channels are:
-
regulation of calcium oscillations after T cell activation
-
modulation of insulin 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, TRPM2, TRPM3, TRPM4, TRPM5, TRPM6, TRPM7, TRPM8
External links
