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Updated: Jul 10, 2026
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Growth-based Determination and Biochemical Confirmation of Genetic Requirements for Protein Degradation in Saccharomyces cerevisiae
Published on: February 16, 2015
Changes in a mammalian signal sequence required for efficient protein secretion by yeasts
Gene
|February 14, 1990
Summary
Researchers engineered yeast to secrete invertase using a hybrid signal peptide. Modifying the signal peptide
Area of Science:
- Biochemistry
- Molecular Biology
- Yeast Genetics
Background:
- The yeast secretory pathway is crucial for producing and exporting proteins.
- Signal peptides direct proteins to the secretory pathway, but their efficiency can vary.
- Understanding signal peptide function is key to optimizing recombinant protein production in yeast.
Purpose of the Study:
- To investigate the efficiency of a hybrid signal peptide composed of bovine prolactin signal peptide (SpPRL) and yeast invertase (IVT).
- To identify modifications that enhance the secretion of IVT using the hybrid signal peptide in yeast.
- To elucidate the structural requirements of signal peptides for recognition by the yeast secretory apparatus.
Main Methods:
- Construction of a plasmid encoding a hybrid pre-protein (SpPRL-IVT).
- Expression and secretion analysis of the hybrid protein in yeast.
- Genetic modifications including mRNA truncation and amino acid substitutions within the signal peptide.
- Enzymatic assay of secreted invertase activity.
Main Results:
- The hybrid SpPRL-IVT construct showed a six-fold reduction in secreted invertase activity compared to the wild-type signal peptide (SpIVT).
- Truncating the 5'-untranslated region of the mRNA increased secreted IVT activity by 2.5-fold.
- Replacing the glycine residue at position 2 of SpPRL with alanine restored invertase activity to wild-type levels.
- Codon optimization of the SpPRL sequence did not improve secreted IVT levels.
Conclusions:
- The secondary structure of the signal peptide, specifically the region near the N-terminus, plays a critical role in its recognition by the yeast secretory machinery.
- Amino acid modifications, such as replacing Gly with Ala, can significantly enhance signal peptide function.
- This study provides insights into signal peptide design for improved heterologous protein secretion in yeast.
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