Fig. 7: HDAC6-mediated channel activation by deacetylation of Lys-140 on PANX1.
From: Deacetylation as a receptor-regulated direct activation switch for pannexin channels
a, b Basal and PE-stimulated whole-cell currents in α1D-AR-transfected HEK293T cells expressing the indicated Arg-substituted PANX1 constructs. c Summary data (mean ± s.e.m) reveal that Arg substitution at Lys-140, but not at Lys-409, increased basal PANX1 current and occluded PE effects. n = 9, 7, or 9 cells examined over 3 independent experiments. Two-way ANOVA (F2,22 = 9.924, p = 0.0008) with Bonferroni’s multiple comparisons test (p values from comparisons are shown). d, e Effect of HDAC6 on whole-cell current in HEK293T cells expressing hPANX1(TEV) or hPANX1(TEV)-K(140/409)Q. f, g Summary data reveal that HDAC6 (f) or DAD (g) did not activate basal whole-cell current in cells expressing Gln-substituted hPANX1(TEV) channels. n = 10 or 11 (f), 12 or 9 (g) cells examined over 6 independent experiments. Data are presented as mean ± s.e.m. Two-tailed unpaired t-test (f t = 6.425, df = 19; g t = 2.118, df = 19). h Grouped results showing tubacin (2 μM), but not DMSO, reduced basal whole-cell currents in cells expressing hPANX1(TEV) channels and wild-type HDAC6 proteins. n = 7 or 6 cells examined over 3 independent experiments. Data are presented as mean ± s.e.m. Two-tailed unpaired t-test (t = 3.858, df = 11). i Inside-out patch recordings of hPANX1(TEV) and hPANX1(TEV)-K(140/409)Q during exposure to HDAC6 and TEV protease. j Unitary I-Vs for each of the indicated PANX1 channel constructs after activation by C-terminal cleavage with caspase 3 or TEV protease; lines indicate fits by linear regression to estimate the unitary slope conductance (γ) for each group (green circles: hPANX1-eGFP, caspase: γ~101 pS; black triangles: hPANX1(TEV), TEVp: γ~91 pS; blue squares: hPANX1(TEV)-K(140/409)Q), TEVp: γ~94 pS; the n values provided are for biologically independent patches). PE phenylephrine, TEVp Tobacco Etch Virus protease.
