Conclusions
We conclude that despite a role for PIP2 in modulation of a wide variety of ion channels, PIP2 does not affect modulation of GABAARs by neurosteroids or related compounds.
Methods
We used Xenopus oocytes expressing the ascidian voltage-sensitive phosphatase (Ci-VSP) to deplete PIP2. Voltage pulses to positive membrane potentials were used to deplete PIP2 in Ci-VSP-expressing cells. GABAARs composed of α1β2γ2L and α4β2δ subunits were challenged with GABA and 3α5αP or other modulators before and after PIP2 depletion. KV7.1 channels and NMDA receptors (NMDARs) were used as positive controls to verify PIP2 depletion.
Results
We found no evidence that PIP2 depletion affected modulation of GABAARs by positive or negative allosteric modulators. By contrast, Ci-VSP-induced PIP2 depletion depressed KV7.1 activation and NMDAR activity. Conclusions: We conclude that despite a role for PIP2 in modulation of a wide variety of ion channels, PIP2 does not affect modulation of GABAARs by neurosteroids or related compounds.