title: Screening for novel genes of Saccharomyces cerevisiae involved in recombinant antibody production.
abstract: Cost-effective manufacturing of biopharmaceuticals in non-mammalian hosts still requires tremendous efforts in strain development. In order to expedite identification of novel leads for strain engineering, we used a transposon-mutagenized yeast genomic DNA library to create a collection of Saccharomyces cerevisiae deletion strains expressing a full-length IgG antibody. Using a high-throughput screening, transformants with either significantly higher or lower IgG expression were selected. The integration site of the transposon in three of the selected strains was located by DNA sequencing. The inserted DNA lay within the VPS30 and TAR1 open reading frame, and upstream of the HEM13 open reading frame. The complete coding sequence of these genes was deleted in the wild-type strain background to confirm the IgG expression phenotypes. Production of recombinant antibody was increased 2-fold in the Δvps30 strain, but only mildly affected secretion levels in the Δtar1 strain. Remarkably, expression of endogenous yeast acid phosphatase was increased 1.7- and 2.4-fold in Δvps30 and Δtar1 strains. The study confirmed the power of genome-wide high-throughput screens for strain development and highlights the importance of using the target molecule during the screening process.
authors.affiliation: Department of Biotechnology and Chemical Technology, Aalto University, 02150 Espoo, Finland.
authors.forename: Jorg C
authors.initials: JC
authors.lastname: de Ruijter
authors.affiliation: Alimetrics Oy, 02920 Espoo, Finland.
authors.forename: German
authors.initials: G
authors.lastname: Jurgens
authors.affiliation: Department of Biotechnology and Chemical Technology, Aalto University, 02150 Espoo, Finland alexander.frey@aalto.fi.
authors.forename: Alexander D
authors.initials: AD
authors.lastname: Frey
mesh_terms: D004251:DNA Transposable Elements; D017353:Gene Deletion; D005800:Genes, Fungal; D005820:Genetic Testing; D007074:Immunoglobulin G / Q000096:biosynthesis* / Q000235:genetics; D007218:Industrial Microbiology / Q000379:methods; D060847:Metabolic Engineering / Q000379:methods; D016254:Mutagenesis, Insertional; D011994:Recombinant Proteins / Q000096:biosynthesis* / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism*
chemical_list: D004251:DNA Transposable Elements; D007074:Immunoglobulin G; D011994:Recombinant Proteins
keywords: Saccharomyces cerevisiae; high-throughput screening; mitochondrial function; recombinant antibody expression; transposon mutagenized genomic DNA library; vacuolar protein sorting