Effects of XXXX on the kinetics of voltage-gated proton channels heterologously expressed in cultured cells.

@entity19 @entity26 @entity1426 @entity1474 @entity3900 @entity5031 @entity73324
UNASSIGNED: @entity1474 are key components of the biological membranes of all cells, and precursors of mediators for cell signalling. @entity1426 (AA) is an @entity5031 known to modulate the activities of various ion channels, including the voltage-gated proton (Hv) channel, which supports the rapid production of reactive @entity26 species (ROS) in phagocytes through regulation of pH and membrane potential. However, the molecular mechanisms and physiological functions of the effects of AA on Hv channels remain unclear. Here we report an electrophysiological analysis of the effects of AA on the @entity19 Hv channel ( @entity73324 ) heterologously expressed in HEK293T cells. Application of AA to excised inside-out patch membranes rapidly induced a robust increase in the amplitude of the proton current through @entity73324 . The current increase was accompanied by accelerated activation kinetics and a small leftward shift of the current-voltage relationship. In monomeric channels lacking the coiled-coil region of the channel protein, the shift in the current-voltage relationship was diminished but activation and deactivation remained accelerated. Studies with several AA derivatives showed that double bonds and hydrophilic head groups are essential for the effect of AA, but charge was not important. The application of @entity3900 ( @entity3900 ), which generates AA from cell membrane phospholipids, stimulated @entity73324 activity to a similar extent as direct application of approximately 20  M AA, suggesting endogenous AA may regulate Hv channel activity. This article is protected by copyright. All rights reserved.
