Single-amino-acid substitutions within the signal sequence of yeast prepro-alpha-factor affect membrane translocation.
Open Access
- 1 May 1988
- journal article
- research article
- Published by Taylor & Francis in Molecular and Cellular Biology
- Vol. 8 (5) , 1915-1922
- https://doi.org/10.1128/mcb.8.5.1915
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.This publication has 53 references indexed in Scilit:
- A signal sequence receptor in the endoplasmic reticulum membraneNature, 1987
- Two receptors act sequentiallyNature, 1987
- Protein translocation across the yeast microsomal membrane is stimulated by a soluble factor.The Journal of cell biology, 1986
- Mutations affecting the signal sequence alter synthesis and secretion of yeast invertase.Proceedings of the National Academy of Sciences, 1986
- In vitro protein translocation across the yeast endoplasmic reticulum: ATP-dependent post-translational translocation of the prepro-α-factorCell, 1986
- Secretion in yeast: Reconstitution of the translocation and glycosylation of α-factor and invertase in a homologous cell-free systemCell, 1986
- Signal sequencesJournal of Molecular Biology, 1985
- In Vivo Function and Membrane Binding Properties Are Correlated for Escherichia coli lamB Signal PeptidesScience, 1985
- Structure of a yeast pheromone gene (MFα): A putative α-factor precursor contains four tandem copies of mature α-factorCell, 1982
- Transfer of proteins across membranes. I. Presence of proteolytically processed and unprocessed nascent immunoglobulin light chains on membrane-bound ribosomes of murine myeloma.The Journal of cell biology, 1975