The paper
C. Uttamapinant et al., “A fluorophore ligase for site-specific protein labeling inside living cells,” Proc Natl Acad Sci USA, 107:10914-19, 2010. Free F1000 Evaluation
The finding
Visualizing proteins is crucial for understanding normal cell function, yet current labeling methods are limited. Despite their remarkable specificity, GFP-type proteins are too bulky, often exceeding the size of their protein targets—thus interfering with their function and trafficking—and the only small peptide label in use is toxic to cells. To address this, Alice Ting from the Massachusetts Institute of Technology and colleagues developed an enzyme-mediated intracellular protein label that’s small, highly specific, and not toxic.
The feat
The researchers created a one-step labeling process whereby an engineered E. coli ligase attaches a blue fluorophore to a short amino acid tail engineered to be displayed by the protein of choice. The fluorophore-tag combo is small enough to allow proteins to pass through intracellular ...
