Send to

Choose Destination
Chem Biol. 2005 Sep;12(9):999-1006.

Single-cell FRET imaging of transferrin receptor trafficking dynamics by Sfp-catalyzed, site-specific protein labeling.

Author information

Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115, USA.


Fluorescence imaging of living cells depends on an efficient and specific method for labeling the target cellular protein with fluorophores. Here we show that Sfp phosphopantetheinyl transferase-catalyzed protein labeling is suitable for fluorescence imaging of membrane proteins that spend at least part of their membrane trafficking cycle at the cell surface. In this study, transferrin receptor 1 (TfR1) was fused to peptide carrier protein (PCP), and the TfR1-PCP fusion protein was specifically labeled with fluorophore Alexa 488 by Sfp. The trafficking of transferrin-TfR1-PCP complex during the process of transferrin-mediated iron uptake was imaged by fluorescence resonance energy transfer between the fluorescently labeled transferrin ligand and TfR1 receptor. We thus demonstrated that Sfp-catalyzed small molecule labeling of the PCP tag represents a practical and efficient tool for molecular imaging studies in living cells.

[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Elsevier Science Icon for PubMed Central
Loading ...
Support Center