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Research article - Peer-reviewed, 2011

Increasing gene dosage greatly enhances recombinant expression of aquaporins in Pichia pastoris

Norden, Kristina; Agemark, Maria; Danielson, Jonas A H; Alexandersson, Erik; Kjellbom, Per; Johanson, Urban


Conclusions: We report a convenient and robust method based on qPCR to determine recombinant gene dosage. The method is generic for all constructs based on the pPICZ vectors and offers an inexpensive, quick and reliable means of characterising recombinant P. pastoris clones. By using this method we show that: (1) heterologous expression of all aquaporins investigated respond strongly to an increase in recombinant gene dosage (2) expression from a single recombinant gene copy varies in an isoform dependent manner (3) the poor expression observed for AtSIP1;1 is mainly caused by posttranscriptional limitations. The protein folding and membrane localisation seems to be unaffected by increased expression levels. Thus a screen for elevated gene dosage can routinely be performed for identification of P. pastoris clones with high expression levels of aquaporins and other classes of membrane proteins.


Pichia pastoris aquaporins; Major Intrinsic Proteins; qPCR

Published in

BMC Biotechnology
2011, volume: 11

Authors' information

Norden, Kristina
Agemark, Maria
Lund University
Danielson, Jonas A H
Lund University
Kjellbom, Per
Johanson, Urban

UKÄ Subject classification

Biochemistry and Molecular Biology

Publication Identifiers


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