GFP: the Green Revolution

Milestones

MILESTONE 18 GFP: the green revolution

aequorin to GFP by Morise and colleagues in 1974 provided insight This development into the fluorescent properties of GFP, which was shown to emit opened the floodgates green light on energy transfer from to countless uses of aequorin. GFP… Whether GFP would need Vladislav Verkhusha aequorin and possibly other factors from the jellyfish to fluoresce in het- erologous systems remained an open question for many years. In 1992, 30 years after its discovery, Prasher imaging experiments that could et al. cloned the gene encoding GFP, follow multiple tagged proteins in paving the way for experiments to cells and organisms. assess its utility as an in vivo tag for Almost half a century after GFP Cell bodies of two touch-receptor neurons from the worm Caenorhabditis elegans are labelled with green fluorescent protein expressed from the gene encoding proteins. Two years later, Chalfie was discovered, the 2008 Nobel Prize β-tubulin. Image is reproduced, with permission, from M. Chalfie et al. © (1994) et al. showed that GFP could fluo- in Chemistry was awarded to Osamu American Association for the Advancement of Science. resce when expressed in bacteria and Shimomura, Martin Chalfie and worm cells. In the worm, GFP was Roger Tsien “for the discovery and expressed from the promoter of a development of the green fluorescent In 1994, Chalfie et al. published a gene that encoded β-tubulin. Its protein, GFP”, acknowledging the report in Science showing that the spatial and temporal expression seminal nature of this discovery. green fluorescent protein (GFP) in specific neurons of the worm Sowmya Swaminathan, Senior Editor, from the jellyfish Aequorea victoria mimicked that of the endogenous Nature Cell Biology could be used as a marker for protein β-tubulin gene, thus proving that localization and expression in liv- GFP could be a faithful marker for PRIMARY REFERENCE Chalfie, M., Tu, Y., ing bacteria and worm cells, in the monitoring gene-expression pat- Euskirchen. G., Ward, W. W. & Prasher, D. C. absence of any auxiliary factors from terns. Soon thereafter, Roger Tsien’s Green fluorescent protein as a marker for gene A. victoria. This demonstration of laboratory engineered native GFP to expression. Science 263, 802–805 (1994) FURTHER READING Shimomura, O., GFP as a tool to study proteins in become brighter, more photostable Johnson, F. H. & Saiga, Y. Extraction, purification vivo fundamentally altered the nature and excitable at a wavelength that and properties of aequorin, a bioluminescent protein from the luminous hydromedusan and scope of the issues that could be matched that of conventional Aequorea. J. Cell. Comp. Physiol. 59, 223–239 addressed by cell biologists. microscope filter sets, increasing its (1962) | Morise, H., Shimomura, O., Johnson, F. H. GFP was first discovered fortui- practical usability (as summarized & Winant, J. Intermolecular energy transfer in the bioluminescent system of Aequorea. tously in 1962 by Shimomura and in his 1998 review). The next break- Biochemistry 13, 2656–2662 (1974) | Prasher, D. C., colleagues during the purification of through in GFP technology came Eckenrode, V. K., Ward, W. W., Prendergast, F. G. & the bioluminescent protein aequorin with the development of GFP vari- Cormier, M. J. Primary structure of the Aequorea victoria green-fluorescent protein. Gene 111, from A. victoria. Subsequent purifi- ants to produce blue, cyan and yellow 229–233 (1992) | Tsien, R. Y. The green fluorescent cation, crystallization and reconstitu- fluorescent proteins (also described protein. Annu. Rev. Biochem. 67, 509–544 (1998) tion of energy transfer in vitro from in Tsien’s review), thus enabling