Open AccessEnhanced secretion of heterologous proteins in Kluyveromyces lactis by overexpression of the GDP‐mannose pyrophosphorylase, KlPsa1p
Author(s) -
Uccelletti Daniela,
Staneva Dessislava,
Rufini Silvia,
Venkov Pencho,
Palleschi Claudio
Publication year - 2005
Publication title -
fems yeast research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.991
H-Index - 92
eISSN - 1567-1364
pISSN - 1567-1356
DOI - 10.1016/j.femsyr.2005.01.004
Subject(s) - mannose , kluyveromyces lactis , biology , saccharomyces cerevisiae , biochemistry , glycosylation , heterologous , galactose , microbiology and biotechnology , gene
GDP‐mannose is the mannosyl donor for the glycosylation reactions and is synthesized by GDP‐mannose pyrophosphorylase from GTP and d ‐mannose‐1‐phosphate; in Saccharomyces cerevisiae this enzyme is encoded by the PSA1/VIG9/SRB1 gene. We isolated the Kluyveromyces lactis KlPSA1 gene by complementing the osmotic growth defects of S. cerevisiae srb1/psa1 mutants. KlPsa1p displayed a high degree of similarity with other GDP‐mannose pyrophosphorylases and was demonstrated to be the functional homologue of S. cerevisiae Psa1p. Phenotypic analysis of a K. lactis strain overexpressing the KlPSA1 gene revealed changes in the cell wall assembly. Increasing the KlPSA1 copy number restored the defects in O ‐glycosylation, but not those in N ‐glycosylation, that occur in K. lactis cells depleted for the hexokinase Rag5p. Overexpression of GDP‐mannose pyrophosphorylase also enhanced heterologous protein secretion in K. lactis as assayed by using the recombinant human serum albumin and the glucoamylase from Arxula adeninivorans .