[Establishment of suc2 signal sequence trap system]

Area of Science:

• Molecular Biology
• Yeast Genetics

Background:

• Protein secretion is directed by N-terminal signal peptides.
• Efficient screening methods for signal peptide sequences are essential for molecular biology research.

Purpose of the Study:

• To establish a novel yeast genetic system for screening cDNA libraries to identify signal peptide-encoding sequences.
• To validate the system's efficacy using known signal peptides.

Main Methods:

• A yeast strain (EGY48-delta suc) was created lacking invertase expression.
• A screening vector was constructed with the invertase gene (suc2) under the P-ADH1 promoter, incorporating a multiple cloning site for library insertion.
• The system's functionality was tested by fusing known signal peptides (from suc2 and human interleukin-2) to the reporter gene.

Main Results:

• The yeast strain grew on glucose but not raffinose without a functional signal peptide.
• Transformants expressing functional signal peptides, including those from suc2 and human interleukin-2, could grow on both glucose and raffinose media.
• The system demonstrated the ability to differentiate between sequences encoding functional signal peptides and those that do not.

Conclusions:

• A robust yeast-based genetic system for screening signal peptide sequences has been successfully developed.
• This system provides a valuable tool for identifying novel signal peptides from cDNA libraries.
• The findings have implications for understanding and manipulating protein secretion pathways.