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ANO1 and TRPC6 Channels are Functionally Coupled in Cerebral Artery Smooth Muscle Cells
Author(s) -
Wang Qian,
Narayanan Damodran,
Neeb Zachary,
Jaggar Jonathan
Publication year - 2015
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.29.1_supplement.948.2
Subject(s) - trpc6 , myocyte , chemistry , bapta , patch clamp , chloride channel , biophysics , transient receptor potential channel , medicine , extracellular , biochemistry , biology , receptor
Activation of anoctamin 1 (ANO1 or TMEM16A), a calcium (Ca 2+ )‐activated chloride channel, in myocytes contributes to pressure‐induced vasoconstriction (the myogenic response) in small arteries. ANO1 is activated due to Ca 2+ influx through a stretch‐activated non‐selective cation channel that has not been identified. We used biochemical, fluorescence and patch‐clamp techniques to identify the cation channel associated with ANO1 in cerebral artery myocytes. ImmunoFRET experiments indicated that transient receptor potential channel 6 (TRPC6) and ANO1 were located in close spatial proximity in arterial myocytes. ANO1 antibodies co‐immunoprecipitated both ANO1 and TPRC6 protein from arterial lysate. A TRPC6 antibody that is a selective TRPC6 channel inhibitor blocked swelling‐activated ANO1 currents. HYP9, a TPRC6‐specific channel activator, activated Cl ‐ currents that were blocked by ANO1‐inh, a ANO1‐specific inhibitor. Substitution of EGTA with BAPTA, a fast Ca 2+ chelator in the patch pipette solution inhibited HYP9‐induced ANO1 current activation. ANO1 knockdown using siRNA, reduced both ANO1 protein and the amplitude of HYP9‐induced ANO1 currents. These data indicate that TRPC6 and ANO1 channels are spatially localized and that Ca 2+ influx via TRPC6 channels activates ANO1 currents in arterial myocytes.