Methods of synthesizing heteromultimeric polypeptides in yeast using a haploid mating strategy

Abstract

Methods are provided for the synthesis and secretion of recombinant proteins preferably large mammalian proteins or hetero-multimeric proteins at high levels and for prolonged time in polyploid, preferably diploid yeast. These methods use various mating competent yeast, including Pichia. In a preferred embodiment, a first expression vector is transformed into a first haploid cell; and a second expression vector is transformed into a second haploid cell. The transformed haploid cells, each individually synthesizing a non-identical polypeptide, are identified and then genetically crossed or fused. The resulting diploid strains are utilized to produce and secrete fully assembled and biologically functional hetero-multimeric protein.