Depletion of 14-3-3 gamma reduces the surface expression of Transient Receptor Potential Melastatin 4b (TRPM4b) Channels and attenuates TRPM4b-mediated glutamate-induced neuronal cell death

作者：Cho Chang Hoon; Kim Eunju; Lee Young Sun; Yarishkin Oleg; Yoo Jae Cheal; Park Jae Yong; Hong Seong Geun^*; Hwang Eun Mi

来源：Molecular Brain, 2014, 7(1): 52.

DOI：10.1186/s13041-014-0052-3

• TRPM4b
• 14-3-3
• Non-selective cation channels
• 9-phenanthrol
• HT-22
• Protein-protein interaction
• Surface expression
• Hippocampal neurons
• Calcium activated cation channels
• MTT assay

Background: 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. %26lt;br%26gt;Results: We have found the 14-3-3 gamma 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 14-3-3 gamma binding by showing GST pull-down and co-immunoprecipitation. Heterologous overexpression of 14-3-3 gamma 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 14-3-3 gamma. 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 14-3-3 gamma or TRPM4b in these cells. Finally, glutamate-induced cell death was greatly prevented by treatment of 9-phenanthrol or 14-3-3 gamma shRNA. %26lt;br%26gt;Conclusion: These results showed that the cell surface expression of TRPM4 channels is mediated by 14-3-3 gamma binding, and the specific inhibition of this trafficking process can be a potential therapeutic target for glutamate-induced neuronal cell death.

• 出版日期2014-7-22