Protein tagging and labeling systems for protein chemistry and cellular biology.

We have developed a number of small peptide tools for tagging and detecting proteins that (1) work without perturbing native protein folding (2) label and detect proteins in living cells or in cell lysates. Applications are diverse and span protein folding studies, protein expression and library screening methods, proteins as reagents, and in vivo cell biology. We show how these tools based on reassembly of 'split' fluorescent proteins can solve challenges in identifying folded proteins and domain boundaries, examine trafficking of pathogen effector proteins, and monitoring protein localization and interaction in living systems.