Recombinant production of human Aquaporin-1 to an exceptional high membrane density in Saccharomyces cerevisiae

PLoS One. 2013;8(2):e56431. doi: 10.1371/journal.pone.0056431. Epub 2013 Feb 11.

Abstract

In the present paper we explored the capacity of yeast Saccharomyces cerevisiae as host for heterologous expression of human Aquaporin-1. Aquaporin-1 cDNA was expressed from a galactose inducible promoter situated on a plasmid with an adjustable copy number. Human Aquaporin-1 was C-terminally tagged with yeast enhanced GFP for quantification of functional expression, determination of sub-cellular localization, estimation of in vivo folding efficiency and establishment of a purification protocol. Aquaporin-1 was found to constitute 8.5 percent of total membrane protein content after expression at 15°C in a yeast host over-producing the Gal4p transcriptional activator and growth in amino acid supplemented minimal medium. In-gel fluorescence combined with western blotting showed that low accumulation of correctly folded recombinant Aquaporin-1 at 30°C was due to in vivo mal-folding. Reduction of the expression temperature to 15°C almost completely prevented Aquaporin-1 mal-folding. Bioimaging of live yeast cells revealed that recombinant Aquaporin-1 accumulated in the yeast plasma membrane. A detergent screen for solubilization revealed that CYMAL-5 was superior in solubilizing recombinant Aquaporin-1 and generated a monodisperse protein preparation. A single Ni-affinity chromatography step was used to obtain almost pure Aquaporin-1. Recombinant Aquaporin-1 produced in S. cerevisiae was not N-glycosylated in contrast to the protein found in human erythrocytes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aquaporin 1 / biosynthesis*
  • Aquaporin 1 / chemistry
  • Aquaporin 1 / genetics
  • Aquaporin 1 / metabolism*
  • Cell Membrane / metabolism*
  • Detergents / chemistry
  • Genetic Engineering
  • Glucosides / chemistry
  • Humans
  • Nickel / chemistry
  • Protein Folding
  • Protein Multimerization
  • Protein Structure, Quaternary
  • Protein Transport
  • Recombinant Proteins / biosynthesis*
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / isolation & purification
  • Recombinant Proteins / metabolism*
  • Saccharomyces cerevisiae / cytology*
  • Saccharomyces cerevisiae / genetics*
  • Solubility
  • Temperature
  • Time Factors

Substances

  • Detergents
  • Glucosides
  • Recombinant Proteins
  • cyclohexyl-pentyl-maltoside
  • Aquaporin 1
  • Nickel

Grants and funding

The present work was supported by the Danish Research Council and Aquaporin A/S. The funders had no role on study design, data collection, decision to publish, or preparation of the manuscript.