A method for the expression of hetero logical genes in the yeast pichia pastoris, expression method and transformed microorganisms

摘要

The present invention provides a highly efficient method for the expression of heterologous genes, using as the host an auxotrophic his3 mutant of strain BKM-90 of Pichia pastoris and as recombinant DNA for the transformation thereof an integrative vector which contains a functional selection marker of Saccharomyces cerevisiae, the promotor of the alcohol oxidase gene (AOX₁) of the yeast itself, as the transcription terminator that of glyceraldehyde 3-phosphate dehydrogenase (GAP) of S. cerevisiae, or that which is carried by the heterologous gene to be expressed, and another sequence homologous to the genome of Pichia pastoris which serves for the integration thereof. The expression vectors used further contain a heterologous gene bound to the signal peptide of the sucrose invertase gene (SUC2) of S. cerevisiae. This method guarantees that the polypeptide products are recoverable under controllable conditions and with high yields. The strains according to the present invention can be used for the large-scale production of pharmaceutical products or of enzymes of industrial interest.