Premium
The activation mode of the mechanosensitive ion channel, MscL, by lysophosphatidylcholine differs from tension‐induced gating
Author(s) -
Mukherjee Nobina,
Jose Mac Donald,
Birkner Jan Peter,
Walko Martin,
Ingólfsson Helgi I.,
Dimitrova Anna,
Arnarez Clément,
Marrink Siewert J.,
Koçer Armağan
Publication year - 2014
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fj.14-251579
Subject(s) - mechanosensitive channels , lysophosphatidylcholine , gating , biophysics , chemistry , conductance , ion channel , lipid bilayer , stretch activated ion channel , tension (geology) , membrane , biochemistry , materials science , biology , physics , phospholipid , receptor , condensed matter physics , phosphatidylcholine , ultimate tensile strength , metallurgy
One of the best‐studied mechanosensitive channels is the mechanosensitive channel of large conductance (MscL). MscL senses tension in the membrane evoked by an osmotic down shock and directly couples it to large conformational changes leading to the opening of the channel. Spectroscopic techniques offer unique possibilities to monitor these conformational changes if it were possible to generate tension in the lipid bilayer, the native environment of MscL, during the measurements. To this end, asymmetric insertion of L‐α‐lysophosphatidylcholine (LPC) into the lipid bilayer has been effective; however, how LPC activates MscL is not fully understood. Here, the effects of LPC on tension‐sensitive mutants of a bacterial MscL and on MscL homologs with different tension sensitivities are reported, leading to the conclusion that the mode of action of LPC is different from that of applied tension. Our results imply that LPC shifts the free energy of gating by interfering with MscL‐membrane coupling. Furthermore, we demonstrate that the fine‐tuned addition of LPC can be used for controlled activation of MscL in spectroscopic studies.—Mukherjee, N., Jose, M. D., Birkner, J. P., Walko, M., Ingólfsson, H. I., Dimitrova, A., Arnarez, C., Marrink, S. J., Koçer, A., The activation mode of the mechanosensitive ion channel, MscL, by lysophosphatidylcholine differs from tension‐induced gating. FASEB J. 28, 4292–4302 (2014). www.fasebj.org