Open AccessSecretion of foreign proteins from Saccharomyces cerevisiae directed by alpha-factor gene fusions.
Author(s) -
Grant A. Bitter,
Kenneth K. Chen,
Allen R. Banks,
Por-Hsiung Lai
Publication year - 1984
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.81.17.5330
Subject(s) - amino acid , saccharomyces cerevisiae , biology , biochemistry , peptide sequence , gene , fusion protein , signal peptide , protein biosynthesis , peptide , microbiology and biotechnology , recombinant dna
Fusions between the cloned yeast alpha-factor structural gene and chemically synthesized DNA segments encoding human protein analogs have been constructed. The gene fusions encode hybrid proteins that include the first 89 amino acids of the native alpha-factor precursor fused to either a small (beta-endorphin, 31 amino acids) or large (alpha-interferon, 166 amino acids) foreign protein. Proteolytic cleavage sites involved in alpha-factor maturation from the native precursor immediately precede the foreign peptide in the hybrid protein. The alpha-factor promoter was utilized to express the gene fusions in Saccharomyces cerevisiae and resulted in the efficient secretion of the foreign proteins into the culture medium. The processing of the hybrid proteins has been characterized by amino acid sequence analysis of the secreted proteins. The proteolytic cleavages involved in the maturation of alpha-factor peptides from the native precursor also occur accurately in the hybrid protein. In addition, cleavages occurred on the carboxyl side of two lysines within the beta-endorphin peptide. Internal cleavages in the interferon protein were also detected. However, in this case, the cleavages occurred at a very low frequency such that greater than 95% of the secreted interferon remained intact.