Yeast surface two-hybrid for quantitative in vivo detection of protein-protein interactions via the secretory pathway.
A quantitative in vivo method for detecting protein-protein interactions will enhance our understanding of protein interaction networks and facilitate affinity maturation as well as designing new interaction pairs. We have developed a novel platform, dubbed "yeast surface two-hybrid (YS2H)," to enable a quantitative measurement of pairwise protein interactions via the secretory pathway by expressing one protein (bait) anchored to the cell wall and the other (prey) in soluble form. In YS2H, the prey is released either outside of the cells or remains on the cell surface by virtue of its binding to the bait. The strength of their interaction is measured by antibody binding to the epitope tag appended to the prey or direct readout of split green fluorescence protein (GFP) complementation. When two alpha-helices forming coiled coils were expressed as a pair of prey and bait, the amount of the prey in complex with the bait progressively decreased as the affinity changes from 100 pM to 10 microM. With GFP complementation assay, we were able to discriminate a 6-log difference in binding affinities in the range of 100 pM to 100 microM. The affinity estimated from the level of antibody binding to fusion tags was in good agreement with that measured in solution using a surface plasmon resonance technique. In contrast, the level of GFP complementation linearly increased with the on-rate of coiled coil interactions, likely because of the irreversible nature of GFP reconstitution. Furthermore, we demonstrate the use of YS2H in exploring the nature of antigen recognition by antibodies and activation allostery in integrins and in isolating heavy chain-only antibodies against botulinum neurotoxin.
From the Department of Biomedical Engineering, Cornell University, Ithaca, New York 14853.
Xuebo
X
Hu
From the Department of Biomedical Engineering, Cornell University, Ithaca, New York 14853.
Sungkwon
S
Kang
From the Department of Biomedical Engineering, Cornell University, Ithaca, New York 14853.
Xiaoyue
X
Chen
Department of Biomedical Sciences, Tufts Cummings School of Veterinary Medicine, North Grafton, Massachusetts 01536.
Charles B
CB
Shoemaker
From the Department of Biomedical Engineering, Cornell University, Ithaca, New York 14853. Electronic address: mj227@cornell.edu.
Moonsoo M
MM
Jin
D000494:Allosteric Regulation; D000595:Amino Acid Sequence; D000906:Antibodies / Q000378:metabolism; D000937:Antigen-Antibody Reactions; D001905:Botulinum Toxins / Q000737:chemistry / Q000276:immunology / Q000378:metabolism; D049452:Green Fluorescent Proteins; D008969:Molecular Sequence Data; D040081:Protein Array Analysis; D025941:Protein Interaction Mapping / Q000379:methods* / Q000592:standards; D015203:Reproducibility of Results; D055571:Secretory Pathway / Q000502:physiology*; D020349:Surface Plasmon Resonance; D020798:Two-Hybrid System Techniques / Q000592:standards; D015003:Yeasts
D000906:Antibodies; D049452:Green Fluorescent Proteins; D001905:Botulinum Toxins