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A stomatin dimer modulates the activity of acid‐sensing ion channels
Author(s) -
Brand Janko,
Smith Ewan St J,
Schwefel David,
Lapatsina Liudmila,
Poole Kate,
Omerbašić Damir,
Kozlenkov Alexey,
Behlke Joachim,
Lewin Gary R,
Daumke Oliver
Publication year - 2012
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1038/emboj.2012.203
Subject(s) - biology , biophysics , ion channel , oligomer , prohibitin , dimer , membrane , membrane protein , ligand (biochemistry) , plasma protein binding , biochemistry , microbiology and biotechnology , receptor , chemistry , apoptosis , organic chemistry
Stomatin proteins oligomerize at membranes and have been implicated in ion channel regulation and membrane trafficking. To obtain mechanistic insights into their function, we determined three crystal structures of the conserved stomatin domain of mouse stomatin that assembles into a banana‐shaped dimer. We show that dimerization is crucial for the repression of acid‐sensing ion channel 3 (ASIC3) activity. A hydrophobic pocket at the inside of the concave surface is open in the presence of an internal peptide ligand and closes in the absence of this ligand, and we demonstrate a function of this pocket in the inhibition of ASIC3 activity. In one crystal form, stomatin assembles via two conserved surfaces into a cylindrical oligomer, and these oligomerization surfaces are also essential for the inhibition of ASIC3‐mediated currents. The assembly mode of stomatin uncovered in this study might serve as a model to understand oligomerization processes of related membrane‐remodelling proteins, such as flotillin and prohibitin.