title: Efficiency and diversity of protein localization by random signal sequences.
abstract: Three randomly derived sequences that can substitute for the signal peptide of Saccharomyces cerevisiae invertase were tested for the efficiency with which they can translocate invertase or beta-galactosidase into the endoplasmic reticulum. The rate of translocation, as measured by glycosylation, was estimated in pulse-chase experiments to be less than 6 min. When fused to beta-galactosidase, these peptides, like the normal invertase signal sequence, direct the hybrid protein to a perinuclear region, consistent with localization to the endoplasmic reticulum. The diversity of function of random peptides was studied further by immunofluorescence localization of proteins fused to 28 random sequences: 4 directed the hybrid to the endoplasmic reticulum, 3 directed it to the mitochondria, and 1 directed it to the nucleus.
authors.affiliation: Department of Biology, Massachusetts Institute of Technology, Cambridge 02139.
authors.forename: C A
authors.initials: CA
authors.lastname: Kaiser
authors.forename: D
authors.initials: D
authors.lastname: Botstein
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D004247:DNA / Q000235:genetics; D004251:DNA Transposable Elements; D005455:Fluorescent Antibody Technique; D005696:Galactosidases / Q000235:genetics*; D015723:Gene Library; D006026:Glycoside Hydrolases / Q000032:analysis / Q000235:genetics*; D006031:Glycosylation; D006801:Humans; D008969:Molecular Sequence Data; D010957:Plasmids; D011499:Protein Processing, Post-Translational; D021382:Protein Sorting Signals / Q000235:genetics*; D011993:Recombinant Fusion Proteins / Q000032:analysis; D015183:Restriction Mapping; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics*; D012689:Sequence Homology, Nucleic Acid; D043324:beta-Fructofuranosidase; D001616:beta-Galactosidase / Q000032:analysis / Q000235:genetics*
chemical_list: D004251:DNA Transposable Elements; D021382:Protein Sorting Signals; D011993:Recombinant Fusion Proteins; D004247:DNA; D005696:Galactosidases; D006026:Glycoside Hydrolases; D001616:beta-Galactosidase; D043324:beta-Fructofuranosidase