title: A novel yeast secretion signal isolated from 28K killer precursor protein encoded on the linear DNA plasmid pGKL1.
abstract: Saccharomyces cerevisiae harboring linear dsDNA plasmids, pGKL1 and pGKL2, secretes a killer toxin consisting of 97, 31 and 28 kilodalton subunits (Nucleic Acids Res., 15, 1031-1046, 1987). We isolated the DNA encoding the N-terminal pre-sequence of the 28K precursor protein and constructed a new secretion vector in S. cerevisiae. Mouse alpha-amylase fused to the 28K signal sequence was secreted into the culture medium with a high efficiency similar to those fused to the mating factor alpha and 97K-31K killer signal sequences. This data clearly indicates that 28K presequence functions as a secretion signal. Glycosylated and nonglycosylated alpha-amylase molecules were detected in the culture medium. The secretion of alpha-amylase was blocked by sec18-1 mutation. The secreted alpha-amylase recovered from the medium was found to migrate faster in SDS-polyacrylamide gel than the precursor form of alpha-amylase synthesized in vitro. These lines of evidence suggest that mouse alpha-amylase fused to 28K killer signal sequence was processed, glycosylated and secreted through the normal secretion pathway of the yeast.
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D005800:Genes, Fungal; D005822:Genetic Vectors; D055646:Killer Factors, Yeast; D051379:Mice; D008969:Molecular Sequence Data; D009154:Mutation; D011499:Protein Processing, Post-Translational; D011506:Proteins / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D000516:alpha-Amylases / Q000235:genetics
chemical_list: D055646:Killer Factors, Yeast; D011506:Proteins; D000516:alpha-Amylases