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Diverse TRPC heteromultimers form store‐operated channels in native vascular smooth muscle preparations
Author(s) -
Albert Anthony,
Saleh Sohag,
PeppiattWildman Claire,
Large William
Publication year - 2008
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.22.1_supplement.965.22
Subject(s) - trpc , trpc1 , transient receptor potential channel , vascular smooth muscle , trpc5 , chemistry , myocyte , trpc6 , microbiology and biotechnology , biophysics , receptor , biochemistry , biology , endocrinology , smooth muscle
Store‐operated channels (SOCs) are activated following depletion of intracellular Ca 2+ stores and the canonical transient receptor potential (TRPC) family of channels are possible molecular candidates of SOCs. Here we describe diverse properties and putative molecular identities of SOCs in different vascular preparations. In rabbit mesenteric (MA) and coronary artery (CA) myocytes SOCs were activated by the store depleting reagents BAPTA‐AM and cyclopiazonic acid and in 1.5mM [Ca 2+ ] o these SOCs had conductances of about 2pS (Saleh et al . 2006) and 3 pS and reversal potentials (E REV ) of about +20mV and −10mV respectively. In 0mM [Ca 2+ ] o the conductances were about 7pS in MA and 3pS in CA whilst E REV were both about −10mV respectively, highlighting different biophysical properties of SOCs in these two preparations. MA SOCs were selectively inhibited by anti‐TRPC1/C5 whilst SOCs from CA were specifically inhibited by anti‐TRPC1/C5/C6. SOCs recorded from portal vein myocytes had similar biophysical properties to MA SOCs (Albert & Large, 2002) but were blocked by anti‐TRPC1/C5/C7. These data suggest that TRPC channels can form alternative heteromultimers with a similar SOCE function in different vascular smooth muscle preparations. Moreover, these data show that anti‐TRPC antibodies can be used as ‘immunopharmacological’ reagents with a remarkable degree of selectivity to determine the composition of heteromultimeric ion channel proteins in native tissue. Funded by British Heart Foundation and The Wellcome Trust.