Codon Optimisation for Heterologous Gene Expression in Yeast

Heterologous protein production is used to amplify the yield of a desired protein target. To date, however, this is not a streamlined process: the factors defining an optimal protein production experiment are still poorly understood. This empirical exercise is particularly challenging for proteins of eukaryotic origin as well as those located in cellular membranes. The strong interest in structural and functional characterisation of eukaryotic membrane proteins—of which many are targets for different drugs—means that large amounts of pure protein, and hence high production levels in a suitable host, are required. On the genetic level, there are mainly two ways to positively influence the final yield of a desired protein target. First, the sequence surrounding the starting ATG can be altered and second the genetic code itself can be optimised to suit the selected host for production. The practical aspects of these two strategies will be discussed and exemplified in further detail in this chapter together with some hints and troubleshooting around different stages of the procedure.