Conjugated protein domains as engineered scaffold proteins

Assembly of proteins into higher-order complexes generates specificity and selectivity in cellular signaling. Signaling complex formation is facilitated by scaffold proteins that use modular scaffolding domains, which recruit specific pathway enzymes. Multimerization and recombination of these conjugated native domains allows the generation of, libraries of, engineered multi-domain scaffold proteins. Analysis of these engineered proteins has provided molecular insight into the regulatory mechanism of the native scaffold proteins and the applicability of these synthetic variants. This topical review highlights the use of engineered, conjugated multi-domain scaffold proteins on different length scales in the context of synthetic signaling pathways, metabolic engineering, liquid-liquid phase separation and hydrogel formation.