The ability to express heterologous proteins in a variety of hosts – including the popular yeast - remains a matter of trial and error. While we do believe to know the molecular players involved in the expression and secretion processes, and how expression more or less comes about, little is known about the relative importance of each process and molecule for the expression of each protein of a proteome.
This is mostly because so far, studies in this field have focused their attention on a few well-studied model proteins.
Our goal is to develop a technology to determine which soluble protein fragments can be produced in the yeast secretory system, on a proteome-wide scale. With such a technology at hand, we will be able to study which protein fragments depend on particular secretory system processes, such as the range of (glyco)proteins depending on the ER chaperone calnexin for their folding.
The platform will also allow assessment of the secretory system modifications that can be brought about to expand the range of expressable protein fragments. We will illustrate this by analyzing the protein fragments influenced in their expression and secretion when the Unfolded Protein Response is induced.
Our project thereby enables novel basic research about the functioning of the eukaryotic secretory system, and its outcomes are of broad utility to anyone producing recombinant proteins for functional, structural or therapeutics studies.