Temperature dependence of protein-water interactions in a gated yeast aquaporin
Regulation of aquaporins is a key process of living organisms to counteract sudden osmotic changes. Aqy1, which is a water transporting aquaporin of the yeast Pichia pastoris, is suggested to be gated by chemo-mechanical stimuli as a protective regulatory-response against rapid freezing. Here, we te...
Saved in:
| Main Author: | |
|---|---|
| Format: | Article (Journal) |
| Language: | English |
| Published: |
21 June 2017
|
| In: |
Scientific reports
Year: 2017, Volume: 7 |
| ISSN: | 2045-2322 |
| DOI: | 10.1038/s41598-017-04180-z |
| Online Access: | Verlag, kostenfrei, Volltext: http://dx.doi.org/10.1038/s41598-017-04180-z
|
| Author Notes: | Camilo Aponte-Santamaría, Gerhard Fischer, Petra Båth, Richard Neutze & Bert L. de Groot |
| Summary: | Regulation of aquaporins is a key process of living organisms to counteract sudden osmotic changes. Aqy1, which is a water transporting aquaporin of the yeast Pichia pastoris, is suggested to be gated by chemo-mechanical stimuli as a protective regulatory-response against rapid freezing. Here, we tested the influence of temperature by determining the X-ray structure of Aqy1 at room temperature (RT) at 1.3 Å resolution, and by exploring the structural dynamics of Aqy1 during freezing through molecular dynamics simulations. At ambient temperature and in a lipid bilayer, Aqy1 adopts a closed conformation that is globally better described by the RT than by the low-temperature (LT) crystal structure. Locally, for the blocking-residue Tyr31 and the water molecules inside the pore, both LT and RT data sets are consistent with the positions observed in the simulations at room-temperature. Moreover, as the temperature was lowered, Tyr31 adopted a conformation that more effectively blocked the channel, and its motion was accompanied by a temperature-driven rearrangement of the water molecules inside the channel. We therefore speculate that temperature drives Aqy1 from a loosely- to a tightly-blocked state. This analysis provides high-resolution structural evidence of the influence of temperature on membrane-transport channels. |
|---|---|
| Item Description: | Gesehen am 02.07.2018 An author correction to this article was published on 05 December 2017 This error has now been corrected in the HTML and PDF versions of the article |
| Physical Description: | Online Resource |
| ISSN: | 2045-2322 |
| DOI: | 10.1038/s41598-017-04180-z |