TRPM
TRPM is a family of transient receptor potential ion channels (M standing for wikt:melastatin).[1] Functional TRPM channels are believed to form tetramers.[2] The TRPM family consists of eight different channels, TRPM1–TRPM8.[3]
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.
- adenosine 5'-diphosphoribose and functions as a sensor of redox status in cells.[4]
- TRPM4 and TRPM5 are activated by intracellular calcium.
- TRPM8 can be activated by low temperatures, menthol, eucalyptol and icilin.[5][6]
Functions
Among the functional responsibilities of the TRPM channels are:
- regulation of calcium oscillations after T cell activation[7] and prevention of cardiac conduction disorders (TRPM4).[8]
- modulation of insulin secretion and sensory transduction in taste cells (TRPM5).[9]
- cold sensation (TRPM8).
- heat sensation and inflammatory pain (TRPM3).[10]
- regulation of magnesium reabsorption in the kidneys and absorption in the intestines (TRPM6).[11]
- regulation of cell adhesion (TRPM7).[12]
Genes
References
External links
- TRPM+Cation+Channels at the U.S. National Library of Medicine Medical Subject Headings (MeSH)
- "Transient Receptor Potential Channels". IUPHAR Database of Receptors and Ion Channels. International Union of Basic and Clinical Pharmacology.
- "TRIP Database". a manually curated database of protein-protein interactions for mammalian TRP channels.