Biophysical Society Conference | Tahoe 2022

Molecular Biophysics of Membranes

Poster Abstracts

2-POS Board 1 CALCIUM INHIBITION OF CALCIUM ACTIVATED TRPM4 CURRENT Abdullah A. Al Tekreeti 1 ; Jie Zheng 1 ; 1 University of California, Davis, Department of Physiology and Membrane Biology, Davis, CA, USA The TRPM4 channel is a voltage-dependent calcium-activated channel capable of sustaining membrane depolarization during cell activation. Paradoxically, TRPM4 current diminishes as calcium concentration continues to increases. We observed that, at the millimolar concentrations range, calcium application and wash-off produce two slow (in seconds) ON/OFF peaks that flank the calcium-activated current. We found that the prominent OFF response is caused by a rapid recovery from calcium inhibition in combination of a slow decline of TRPM4 current. This study examines the mechanistic and functional properties behind this calcium inhibitory effect, which may improve current understanding of the TRPM4 channel gating behavior during different cellular conditions.

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