The Autodisplay Story, from Discovery to Biotechnical and Biomedical Applications

Abstract

SUMMARY Among the pathways used by gram-negative bacteria for protein secretion, the autotransporter pathway represents a solution of impressive simplicity. Proteins are transported, independent of their nature as recombinant or native passengers, as long as the coding nucleotide sequence is inserted in frame between those of an N-terminal signal peptide and a C-terminal domain, referred to as the β-barrel of the outer membrane translocation unit. The immunoglobulin A1 (IgA1) protease from Neisseria gonorrhoeae was the first identified member of the autotransporter family of secreted proteins. The IgA1 protease was employed in initial experiments investigating autotransporter-mediated surface display of recombinant proteins and to investigate structural and functional requirements. Various other autotransporter proteins have since been described, and the autodisplay system was developed on the basis of the natural Escherichia coli autotransporter protein AIDA-I (adhesin involved in diffuse adherence). Autodisplay has been used for the surface display of random peptide libraries to successfully screen for novel enzyme inhibitors. The autodisplay system was also used for the surface display of functional enzymes, including esterases, oxidoreductases, and electron transfer proteins. Whole E. coli cells displaying enzymes have been utilized to efficiently synthesize industrially important rare organic compounds with specific chirality. Autodisplay of epitopes on the surface of attenuated Salmonella carriers has also provided a novel way to induce immune protection after oral vaccination. This review summarizes the structural and functional features of the autodisplay system, illustrating its discovery and most recent applications. Autodisplay facilitates the export of more than 100,000 recombinant molecules per single cell and permits the oligomerization of subunits on the cell surface as well as the incorporation of inorganic prosthetic groups after transport of apoproteins onto the bacterial surface without disturbing bacterial integrity or viability. We discuss future biotechnical and biomedical applications in the light of these achievements.

Targeting acute myeloid leukemia with a small molecule inhibitor of the Myb/p300 interaction

“…46 Bacterial autodisplay provides a powerful experimental platform for the analysis of protein-protein interactions and the development of inhibitors. 47,48 Figure 3B shows that bacteria, which express the KIX domain on their surface, were able to bind GFP-Myb but not GFP. The interaction of Myb and the KIX domain is mediated by an LXXLL motif located in the transactivation domain of Myb.…”

Naphthol AS-E Phosphate Inhibits the Activity of the Transcription Factor Myb by Blocking the Interaction with the KIX Domain of the Coactivator p300

“…Bacterial Autodisplay is an efficient system for the expression of recombinant proteins on the outer membrane of Gram-negative bacteria (38,39). Autodisplay provides a powerful experimental platform for various biotechnologic applications, including the analysis of protein-protein interactions and the development of inhibitors (40,41).…”

Multiple Driving Forces Required for Efficient Secretion of Autotransporter Virulence Proteins

“…Moreover, the same secretion mechanism can be engineered to secrete other proteins of interest into the medium or display them on the cell surface (3,4). Although much work has been devoted to elucidating the AT (or Type Va) secretion mechanism, the dynamic nature of the process has hampered our understanding of what energy source(s) drives secretion of the passenger across the outer membrane (OM) given that there is no ATP available in the periplasm and no proton gradient across the OM (5).…”