Transient protonation changes in channelrhodopsin-2 and their relevance to channel gating

Lorenz-Fonfria VA, Resler T, Krause N, Nack M, Gossing M, Fischer von Mollard G, Bamann C, Bamberg E, Schlesinger R, Heberle J (2013)
Proceedings Of The National Academy Of Sciences 110(14): E1273-E1281.

Zeitschriftenaufsatz | Veröffentlicht | Englisch
 
Download
Es wurde kein Volltext hochgeladen. Nur Publikationsnachweis!
Autor/in
; ; ; ; ; ; ; ; ;
Abstract / Bemerkung
The discovery of the light-gated ion channel channelrhodopsin (ChR) set the stage for the novel field of optogenetics, where cellular processes are controlled by light. However, the underlying molecular mechanism of light-induced cation permeation in ChR2 remains unknown. Here, we have traced the structural changes of ChR2 by time-resolved FTIR spectroscopy, complemented by functional electrophysiological measurements. We have resolved the vibrational changes associated with the open states of the channel (P-2(390) and P-3(520)) and characterized several proton transfer events. Analysis of the amide I vibrations suggests a transient increase in hydration of transmembrane a-helices with a t(1/2) = 60 mu s, which tallies with the onset of cation permeation. Aspartate 253 accepts the proton released by the Schiff base (t(1/2) = 10 mu s), with the latter being reprotonated by aspartic acid 156 (t(1/2) = 2 ms). The internal proton acceptor and donor groups, corresponding to D212 and D115 in bacteriorhodopsin, are clearly different from other microbial rhodopsins, indicating that their spatial position in the protein was relocated during evolution. Previous conclusions on the involvement of glutamic acid 90 in channel opening are ruled out by demonstrating that E90 deprotonates exclusively in the nonconductive P-4(480) state. Our results merge into a mechanistic proposal that relates the observed proton transfer reactions and the protein conformational changes to the gating of the cation channel.
Stichworte
protein; photosensory; retinal; membrane protein; time-resolved IR; step scan
Erscheinungsjahr
2013
Zeitschriftentitel
Proceedings Of The National Academy Of Sciences
Band
110
Ausgabe
14
Seite(n)
E1273-E1281
ISSN
0027-8424
eISSN
1091-6490
Page URI
https://pub.uni-bielefeld.de/record/2584598

Zitieren

Lorenz-Fonfria VA, Resler T, Krause N, et al. Transient protonation changes in channelrhodopsin-2 and their relevance to channel gating. Proceedings Of The National Academy Of Sciences. 2013;110(14):E1273-E1281.
Lorenz-Fonfria, V. A., Resler, T., Krause, N., Nack, M., Gossing, M., Fischer von Mollard, G., Bamann, C., et al. (2013). Transient protonation changes in channelrhodopsin-2 and their relevance to channel gating. Proceedings Of The National Academy Of Sciences, 110(14), E1273-E1281. doi:10.1073/pnas.1219502110
Lorenz-Fonfria, V. A., Resler, T., Krause, N., Nack, M., Gossing, M., Fischer von Mollard, G., Bamann, C., Bamberg, E., Schlesinger, R., and Heberle, J. (2013). Transient protonation changes in channelrhodopsin-2 and their relevance to channel gating. Proceedings Of The National Academy Of Sciences 110, E1273-E1281.
Lorenz-Fonfria, V.A., et al., 2013. Transient protonation changes in channelrhodopsin-2 and their relevance to channel gating. Proceedings Of The National Academy Of Sciences, 110(14), p E1273-E1281.
V.A. Lorenz-Fonfria, et al., “Transient protonation changes in channelrhodopsin-2 and their relevance to channel gating”, Proceedings Of The National Academy Of Sciences, vol. 110, 2013, pp. E1273-E1281.
Lorenz-Fonfria, V.A., Resler, T., Krause, N., Nack, M., Gossing, M., Fischer von Mollard, G., Bamann, C., Bamberg, E., Schlesinger, R., Heberle, J.: Transient protonation changes in channelrhodopsin-2 and their relevance to channel gating. Proceedings Of The National Academy Of Sciences. 110, E1273-E1281 (2013).
Lorenz-Fonfria, Victor A., Resler, Tom, Krause, Nils, Nack, Melanie, Gossing, Michael, Fischer von Mollard, Gabriele, Bamann, Christian, Bamberg, Ernst, Schlesinger, Ramona, and Heberle, Joachim. “Transient protonation changes in channelrhodopsin-2 and their relevance to channel gating”. Proceedings Of The National Academy Of Sciences 110.14 (2013): E1273-E1281.

Export

Markieren/ Markierung löschen
Markierte Publikationen

Open Data PUB

Web of Science

Dieser Datensatz im Web of Science®

Quellen

PMID: 23509282
PubMed | Europe PMC

Suchen in

Google Scholar