Referenced in: none

Automatically associated channels: TRP , TRPM , TRPM7 , TRPV , TRPV3

Title: 2-Aminoethyl diphenyl borinate (2-APB) inhibits TRPM7 channels through an intracellular acidification mechanism.

Authors: Rikki Chokshi, Petronilla Fruasaha, J Ashot Kozak

Journal, date & volume: Channels (Austin), 2012 Aug 24 , 6,

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/22922232

Abstract
2-APB is a widely used compound in ion channel research. It affects numerous channels including inositol 1,4,5-trisphosphate receptors, store-operated calcium channels and TRP channels, TRPV3 and TRPM7 among them. A characteristic property of TRPM7 channels is their sensitivity to intracellular Mg ( 2+) and pH. Using patch clamp electrophysiology we find that in Jurkat T lymphocytes, 100-300 µM extracellular 2-APB reversibly inhibits TRPM7 channels when internal HEPES concentration is low (1 mM). Increasing the concentration to 140 mM abolishes the 2-APB effect. Using single-cell fluorescence pH video imaging, we show that at concentrations of 100 µM and higher, 2-APB potently acidifies the cytoplasm. We conclude that TRPM7 sensitivity to 2-APB is not direct but rather, can be explained by cytoplasmic acidification and a resulting channel inhibition.