Lecture 2: Split Inteins as Synthetic Biology Tool to Control Biological Processes
Biological processes are carried out by complex networks of interacting proteins that continuously adapt to cellular environment and external stimuli with structural changes, which lead to new functional properties and binding partners. Being able to control protein function to dissect or build cellular networks is one of the fundamental goals of synthetic biology. Expressing a genetically modified protein that carries either mutations that inhibit or activate a certain function or a “handle” that allows switching it on and off, is a powerful way to achieve control over it. Yet, this method implies that the protein is always modified, whenever expressed. In certain applications, it would be advantageous to have the unmodified protein expressed until a certain time-point, after which it should be post-translationally modified to perform new functions or interact with other partners. A universal toolbox that enables post-translational modifications of a protein of interest can be built based on inteins, proteins that excise themselves out of other (host) proteins and, in doing so, connect the flanking regions (exteins) with a peptide bond. In this lecture we will discuss how split inteins work and which methods are available to control the splicing reaction in space and/or time.