Referenced in: none

Automatically associated channels: TRP , TRPM , TRPM4

Title: Depletion of 14-3-3γ reduces the surface expression of Transient Receptor Potential Melastatin 4b (TRPM4b) channels and attenuates TRPM4b-mediated glutamate-induced neuronal cell death.

Authors: Chang-Hoon Cho, Eunju Kim, Young-Sun Lee, Oleg Yarishkin, Jae Cheal Yoo, Jae-Yong Park, Seong-Geun Hong, Eun Mi Hwang

Journal, date & volume: Mol Brain, 2014 , 7, 52

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/25047048

Abstract
TRPM4 channels are Ca2+-activated nonselective cation channels which are deeply involved in physiological and pathological conditions. However, their trafficking mechanism and binding partners are still elusive.We have found the 14-3-3γ as a binding partner for TRPM4b using its N-terminal fragment from the yeast-two hybrid screening. Ser88 at the N-terminus of TRPM4b is critical for 14-3-3γ binding by showing GST pull-down and co-immunoprecipitation. Heterologous overexpression of 14-3-3γ in HEK293T cells increased TRPM4b expression on the plasma membrane which was measured by whole-cell recordings and cell surface biotinylation experiment. Surface expression of TRPM4b was greatly reduced by short hairpin RNA (shRNA) against 14-3-3γ. Next, endogenous TRPM4b-mediated currents were electrophysiologically characterized by application of glutamate and 9-phenanthrol, a TRPM4b specific antagonist in HT-22 cells which originated from mouse hippocampal neurons. Glutamate-induced TRPM4b currents were significantly attenuated by shRNAs against 14-3-3γ or TRPM4b in these cells. Finally, glutamate-induced cell death was greatly prevented by treatment of 9-phenanthrol or 14-3-3γ shRNA.These results showed that the cell surface expression of TRPM4 channels is mediated by 14-3-3γ binding, and the specific inhibition of this trafficking process can be a potential therapeutic target for glutamate-induced neuronal cell death.