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Caveolin‐1 scaffolding domain regulates store‐operated Ca 2+ influx by binding to TRPC1 in endothelial cells
Author(s) -
Kwiatek Angela M,
Minshall Richard D,
Malik Asrar B,
Tiruppathi Chinnaswamy
Publication year - 2006
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.20.4.a116-b
Subject(s) - trpc1 , chemistry , peptide , microbiology and biotechnology , caveolin , endothelial stem cell , biochemistry , biophysics , transient receptor potential channel , receptor , signal transduction , biology , caveolae , in vitro
Caveolin‐1 associates with store‐operated cation channels (SOC) in endothelial cells. We examined the importance of the caveolin‐1 scaffolding domain (CSD) in regulating the predominant SOC (i.e., transient receptor potential channel‐1 [TRPC1]) expressed in human pulmonary artery endothelial cells (HPAEC). We tested a cell permeable antennapedia (AP)‐CSD peptide effects on thrombin‐induced Ca 2+ influx via SOC. AP‐CSD peptide markedly reduced thrombin‐induced Ca 2+ influx via SOC in HPAEC. AP‐CSD also suppressed thapsigargin‐induced Ca 2+ influx. Control‐peptide had no effect on thrombin‐induced Ca 2+ influx. Streptavidin‐bead pull‐down assays indicated strong binding of biotin labeled AP‐CSD peptide to TRPC1. Immunoprecipitation studies further demonstrated the interaction between endogenous TRPC1 and ectopically expressed HA‐tagged‐CSD. Analysis of the deduced TRPC1 amino acid sequence revealed the presence of CSD binding consensus sequence in the TRPC1‐C‐terminus. Incubation of HPAEC with AP‐TRPC1 peptide containing the CSD binding sequence markedly reduced thrombin‐induced Ca 2+ influx. We also observed interaction between the biotin‐labeled AP‐TRPC1 C‐terminus peptide and cav‐1. These results indicate that the cav‐1 scaffolding domain interacts with TRPC1 to regulate SOC Ca 2+ influx and thus may regulate nitric oxide production and endothelial permeability.