Dataset Information

Aquaporin tetramer composition modifies the function of tobacco aquaporins.

ABSTRACT: Heterologous expression in yeast cells revealed that NtAQP1, a member of the so-called PIP1 aquaporin subfamily, did not display increased water transport activity in comparison with controls. Instead, an increased CO(2)-triggered intracellular acidification was observed. NtPIP2;1, which belongs to the PIP2 subfamily of plant aquaporins, behaved as a true aquaporin but lacked a CO(2)-related function. Results from split YFP experiments, protein chromatography, and gel electrophoresis indicated that the proteins form heterotetramers when coexpressed in yeast. Tetramer composition had effects on transport activity as demonstrated by analysis of artificial heterotetramers with a defined proportion of NtAQP1 to NtPIP2;1. A single NtPIP2;1 aquaporin in a tetramer was sufficient to significantly increase the water permeability of the respective yeast cells. With regard to CO(2)-triggered intracellular acidification, a cooperative effect was observed, where maximum rates were measured when the tetramer consisted of NtAQP1 aquaporins only. The results confirm the model of an aquaporin monomer as a functional unit for water transport and suggest that, for CO(2)-related transport processes, a structure built up by the tetramer is the basis of this function.

SUBMITTER: Otto B

PROVIDER: S-EPMC2951199 | biostudies-literature | 2010 Oct

REPOSITORIES: biostudies-literature

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Aquaporin tetramer composition modifies the function of tobacco aquaporins.

Otto Beate B Uehlein Norbert N Sdorra Sven S Fischer Matthias M Ayaz Muhammad M Belastegui-Macadam Xana X Heckwolf Marlies M Lachnit Magdalena M Pede Nadine N Priem Nadine N Reinhard André A Siegfart Sven S Urban Michael M Kaldenhoff Ralf R

The Journal of biological chemistry 20100725 41

Heterologous expression in yeast cells revealed that NtAQP1, a member of the so-called PIP1 aquaporin subfamily, did not display increased water transport activity in comparison with controls. Instead, an increased CO(2)-triggered intracellular acidification was observed. NtPIP2;1, which belongs to the PIP2 subfamily of plant aquaporins, behaved as a true aquaporin but lacked a CO(2)-related function. Results from split YFP experiments, protein chromatography, and gel electrophoresis indicated t ...[more]

PMID: 20657033

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Aquaporin tetramer composition modifies the function of tobacco aquaporins.

Publications

Aquaporin tetramer composition modifies the function of tobacco aquaporins.

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