Figure 4: Decreasing numbers of PANX1 C termini increase unitary conductance and open probability of PANX1 channel.
From: A quantized mechanism for activation of pannexin channels
(a,b) Single-channel I–V relationships from inside–out patches for PANX1 hexameric concatemers with different numbers of intact C termini recorded after TEVp exposure (a) and after removing remaining C termini with Casp3 (b). Unitary conductance indicated for each hexameric construct. Plotted data are mean±s.e.m., and numbers of recorded patches are provided in parenthesis; for Casp3-cleaved concatemeric hexamers, conductance was ∼95 pS (n=28). (c) Averaged unitary conductance (± s.e.m.) for each of the hexameric concatemers with different numbers of intact C termini (a,b), after TEVp exposure (blue) and from the same patches after Casp3 cleavage (red); data were fitted to a Hill equation, with coefficient -0.3 (blue dash line). The shaded area represents the 95% confidence interval for unitary conductance obtained from all fully cleaved concatemers (that is, after Casp3). (d) Open probability (NPO; from +80 mV) of PANX1 concatemers with different numbers of C termini (after TEVp) was normalized to that obtained from the same patches after Casp3 cleavage, averaged (±s.e.m.), and fitted by linear regression (blue dash line).
