TABLE 6

TRPC6 channel

Channel name TRPC61,2,3,4,5,6,7
Description DAG-activated channel
Other names None
Molecular information Human unigene: Hs0.159003, chr. 11q21-q22
Mouse unigene: Mm0.325086, chr. 9
Associated subunits TRPC3, TRPC7, calmodulin, FKBP12
Functional assays Patch-clamp, calcium imaging
Current Inwardly and outwardly rectifying, nonselective cation current
Conductance 35pS (symmetrical 120 Cs+)
Ion selectivity PNa/PCa ∼1:5
Activation Sensitive to intracellular Ca2+
Inactivation Not established
Activators DAGs
Gating inhibitors None
Blockers 0.25 mM Cd2+, 4 μM La3+, 2 μM Gd2+, 130 μM amiloride, 4 μM SKF96365, 100 μM 2-APB
Radioligands None
Channel distribution Lung, heart, brain, muscle
Physiological functions Cation influx in response to DAG generated by receptor-mediated activation of PLCβ and PLCγ
Mutations and pathophysiology Not established
Pharmacological Candidate for receptor-stimulated currents in smooth muscle significance cells
Comments The DAG response is PKC-independent
  • chr., chromosome.

  • 1. Hofmann T, Obukhov AG, Schaefer M, Harteneck C, Gudermann T, and Schultz G (1999) Direct activation of human TRPC6 and TRPC3 channels by diacylglycerol. Nature (Lond) 397:259-263

  • 2. Okada T, Inoue R, Yamazaki K, Maeda A, Kurosaki T, Yamakuni T, Tanaka I, Shimizu S, Ikenaka K, Imoto K, et al. (1999) Molecular and functional characterization of a novel mouse transient receptor potential protein homologue TRP7. Ca2+-permeable cation channel that is constitutively activated and enhanced by stimulation of G protein-coupled receptor. J Biol Chem 274:27359-27370

  • 3. Inoue R, Okada T, Onoue H, Hara Y, Shimizu S, Naitoh S, Ito Y, and Mori Y (2001) The transient receptor potential protein homologue TRP6 is the essential component of vascular alpha-1 adrenoceptor-activated Ca2+-permeable cation channel. Circ Res 88:325-332

  • 4. Corteling RL, Li S, Giddings J, Westwick J, Poll C, and Hall IP (2004) Expression of transient receptor potential C6 and related transient receptor potential family members in human airway smooth muscle and lung tissue. Am J Respir Cell Mol Biol 30:145-154

  • 5. Dietrich A, Mederos y Schnitzler M, Emmel J, Kalwa H, Hofmann T, and Gudermann T (2003) N-linked protein glycosylation is a major determinant for basal TRPC3 and TRPC6 channel activity. J Biol Chem 278:47842-47852

  • 6. Yu Y, Sweeney M, Zhang S, Platoshyn O, Landsberg J, Rothman A, and Yuan JX (2003) PDGF stimulates pulmonary vascular smooth muscle cell proliferation by upregulating TRPC6 expression. Am J Physiol Cell Physiol 284:C316-C330

  • 7. Shi J, Mori E, Mori Y, Mori M, Li J, Ito Y, and Inoue R (2004) Multiple regulation by calcium of murine homologues of transient receptor potential proteins TRPC6 and TRPC7 expressed in HEK293 cell. J Physiol 561:415-432