| Title: | Single-amino-acid substitutions within the signal sequence of yeast prepro-alpha-factor affect membrane translocation |
| Address: | "Department of Biochemistry, University of Washington, Seattle 98195" |
| DOI: | 10.1128/mcb.8.5.1915-1922.1988 |
| ISSN/ISBN: | 0270-7306 (Print) 1098-5549 (Electronic) 0270-7306 (Linking) |
| Abstract: | "We used a genetic approach to identify point mutations in the signal sequence of a secreted eucaryotic protein, yeast alpha-factor. Signal sequence mutants were obtained by selecting for cells that partially mistargeted into mitochondria a fusion protein consisting of the alpha-factor signal sequence fused to the mature portion of an imported mitochondrial protein (Cox IV). The mutations resulted in replacement of a residue in the hydrophobic core of the signal sequence with either a hydrophilic amino acid or a proline. After reassembly into an intact alpha-factor gene, the substitutions were found to decrease up to 50-fold the rate of translocation of prepro-alpha-factor across microsomal membranes in vitro. Two of three mutants tested produced lower steady-state levels of alpha-factor in intact yeast cells, although the magnitude of the effect was less than that in the cell-free system" |
| Keywords: | Amino Acid Sequence Base Sequence Biological Transport Fungal Proteins/*genetics Intracellular Membranes/metabolism Mating Factor Microsomes/metabolism Mitochondria/metabolism Molecular Sequence Data Peptides/*genetics/metabolism Protein Precursors/*genet; |
| Notes: | "MedlineAllison, D S Young, E T eng GM-33779/GM/NIGMS NIH HHS/ Research Support, U.S. Gov't, P.H.S. 1988/05/01 Mol Cell Biol. 1988 May; 8(5):1915-22. doi: 10.1128/mcb.8.5.1915-1922.1988" |
