Abstract
Purpose: We developed a bimolecular fluorescence complementation (BiFC) strategy using Dronpa, a new fluorescent protein with reversible photoswitching activity and fast responsibility to light, to monitor protein-protein interactions in cells. Procedures: Dronpa was split at residue Glu164 in order to generate two Dronpa fragments [Dronpa N-terminal: DN (Met1-Glu164), Dronpa C-terminal: DC (Gly165-Lys224)]. DN or DC was separately fused with C terminus of hHus1 or N terminus of hRad1. Flexible linker [(GGGGS)×2] was introduced to enhance Dronpa complementation by hHus1-hRad1 interaction. Furthermore, we developed expression vectors to visualize the interaction between hMYH and hHus1. Gene fragments corresponding to the coding regions of hMYH and hHus1 were N-terminally or C-terminally fused with DN and DC coding region. Results: Complemented Dronpa fluorescence was only observed in HEK293 cells cotransfected with hHus1-LDN and DCL-hRad1 expression vectors, but not with hHus1-LDN or DCL-hRad1 expression vector alone. Western blot analysis of immunoprecipitated samples using anti-c-myc or anti-flag showed that DN-fused hHus1 interacted with DC-fused hRad1. Complemented Dronpa fluorescence was also observed in cells cotransfected with hMYH-LDN and DCL-hHus1 expression vectors or hMYH-LDN and hHus1-LDC expression vectors. Furthermore, complemented Dronpa, induced by the interaction between hMYH-LDN and DCL-hHus1, showed almost identical photoswitching activity as that of native Dronpa. Conclusion: These results demonstrate that BiFC using Dronpa can be successfully used to investigate protein-protein interaction in live cells. Furthermore, the fact that complemented Dronpa has a reversible photoswitching activity suggests that it can be used as a tool for tracking protein-protein interaction.
Original language | English |
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Pages (from-to) | 468-478 |
Number of pages | 11 |
Journal | Molecular Imaging and Biology |
Volume | 12 |
Issue number | 5 |
DOIs | |
Publication status | Published - 2010 Oct |
Bibliographical note
Funding Information:Acknowledgments. This work was supported by Real Time Molecular Imaging Project of the Korea Ministry of Science and Technology, National Research Foundation of Korea Grant funded by Korean Government (2009-0074848), Priority Research Centers Program through the National research Foundation of Korea (2009-0093824), and World Class University (WCU, R33-2008-000-1071) program through the Korea Science and Engineering Foundation funded by the Ministry of Education, Science and Technology.
Keywords
- Bimolecular fluorescence complementation
- Dronpa
- Human MutY homolog
- Protein-protein interaction
- Reversible photoswitching activity
- hHus1
- hRad1
ASJC Scopus subject areas
- Oncology
- Radiology Nuclear Medicine and imaging
- Cancer Research