We study the basic properties of members of this subfamily including ion permeation and channel regulation in heterologous expression systems, and their properties and role in native tissues (e.g. central neurones).
In recent years, our work has concentrated on the characterization of some members of a relatively new family of cation channels, TRP channels, most of which are Ca2+ permeable and which perform a very wide variety of physiological roles. TRP channels were originally found in photoreceptors of the fruit fly Drosophila (which display a Transient Receptor Potential when the TRP protein is mutated). Subsequently, a large number of mammalian TRP channels were found by expression or homology cloning. These can be divided into a number of subfamilies, some of which are more closely related to Drosophila TRP (Group I including TRPC, TRPV, TRPM and TRPA subfamilies) and others which are more distantly related (Group II including TRPML and TRPP).
TRPC (classical or canonical) channels are nonselective Ca2+ permeable cation channels that belong to the group of receptor operated channels (ROCs) that are activated in a phospholipase C-dependent manner. This can occur following the activation of G protein-coupled receptors e.g. by hormones and neurotransmitters or following the activation of receptor tyrosine kinases e.g. by growth factors. We study the basic properties of members of this subfamily including ion permeation and channel regulation in heterologous expression systems, and their properties and role in native tissues (e.g. central neurones).
We also study members of the TRPV subfamily. TRPV4 is a Ca2+ permeable cation channel activated by a variety of stimuli including intracellular messengers, warm temperatures and mechanical stimulation of cells, and which is regulated by the intracellular Ca2+ concentration. TRPV1 is expressed in nociceptive primary sensory neurones, but also in other tissues, and is involved in sensory responses to heat and a variety of chemicals including capsaicin, the pungent component in chilli peppers. The activity of TRPV1 is modulated by a number of signalling molecules known to sensitize nociceptors to painful stimuli.
- Strotmann R, Semtner M, Kepura F, Plant TD, Schöneberg T. (2010)
Interdomain interactions control Ca2+-dependent potentiation in the cation channel TRPV4.
PLoS One. 5(5):e10580.
- Semtner M, Schaefer M, Pinkenburg O, Plant TD. (2007)
Potentiation of TRPC5 by protons.
J Biol Chem. 282, 33868-33878.
- Strotmann R, Schultz G, Plant TD. (2003)
Ca2+-dependent potentiation of the nonselective cation channel TRPV4 is mediated by a C-terminal calmodulin binding site.
J Biol Chem. 278:26541-26549.
- Jung S, Mühle A, Schaefer M, Strotmann R, Schultz G, Plant TD. (2003)
Lanthanides potentiate TRPC5 currents by an action at extracellular sites close to the pore mouth.
J Biol Chem. 278, 3562-3571.
- Strotmann R, Harteneck C, Nunnenmacher K, Schultz G, Plant TD. (2000)
OTRPC4, a nonselective cation channel that confers sensitivity to extracellular osmolarity.
Nat Cell Biol. 2, 695-702.