Functional identification of the glycerol permease activity of Arabidopsis thaliana NLM1 and NLM2 proteins by heterologous expression in Saccharomyces cerevisiae.
NLM proteins (NOD26-like major intrinsic proteins) from plants contain amino acid sequence signatures which can be found in aquaporins including plant plasma membrane intrinsic proteins and tonoplast intrinsic proteins and glycerol permeases such as the Escherichia coli GlpF and the yeast FPS1 proteins. Heterologous expression of two members of the NLM subgroup from Arabidopsis thaliana (AtNLM1 and AtNLM2) in baker's yeast demonstrated the glycerol permease activity in addition to the previously described aquaporin activity of AtNLM1. The transport was non-saturable up to 100 mM extracellular glycerol concentration. Longer-chain sugar alcohols did not compete with the transport of radiolabelled glycerol and hexoses were also not transported through the pore.
Weig
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AR
Institute of Plant Physiology, University of Bayreuth, Universitätsstrasse 30, D-95440, Bayreuth, Germany. alfons.weig@uni-bayreuth.de
Jakob
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C
D000595:Amino Acid Sequence; D020346:Aquaporins / Q000502:physiology*; D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics*; D029681:Arabidopsis Proteins; D001692:Biological Transport; D003001:Cloning, Molecular; D005656:Fungal Proteins / Q000235:genetics; D005816:Genetic Complementation Test; D005990:Glycerol / Q000378:metabolism; D006601:Hexoses / Q000378:metabolism; D007473:Ion Channels / Q000502:physiology*; D008565:Membrane Proteins / Q000235:genetics; D026901:Membrane Transport Proteins / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D008969:Molecular Sequence Data; D009995:Osmosis; D009997:Osmotic Pressure; D010641:Phenotype; D010940:Plant Proteins / Q000502:physiology*; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins; D017386:Sequence Homology, Amino Acid; D013402:Sugar Alcohols / Q000378:metabolism; D014170:Transformation, Genetic; D014882:Water-Electrolyte Balance
D020346:Aquaporins; D029681:Arabidopsis Proteins; C093263:FPS1 protein, S cerevisiae; D005656:Fungal Proteins; C488962:GlpT protein, E coli; D006601:Hexoses; D007473:Ion Channels; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; C488963:NLM1 protein, Arabidopsis; D010940:Plant Proteins; D029701:Saccharomyces cerevisiae Proteins; D013402:Sugar Alcohols; C110065:major intrinsic protein, plant; C045625:nodulin; C491680:plasma membrane intrinsic protein 2 Arabidopsis; D005990:Glycerol