Scientists in Southampton, UK, and Ulm and Karlsruhe in Germany have shown that a variant form of a fluorescent protein (FP) originally isolated from a reef coral has excellent properties as a marker protein for super-resolution microscopy in live cells. Their findings have been published online by Nature Methods and will appear in print in the upcoming August issue of that journal.
Fluorescent proteins produced by a range of marine animals glow with a rainbow of colours, adding to the visual spectacle of coral reefs. Over recent years, molecular biologists have isolated a number of FPs and their genes, and used them to create genetically engineered variant FPs with particular light-emission characteristics.
"Fluorescent pigments from corals and related animals have proved to be invaluable lead structures to produce advanced markers for biomedical research," said Dr Jrg Wiedenmann of the University of Southampton's School of Ocean and Earth Science (SOES) based at the National Oceanography Centre, Southampton: "They enable a plethora of exciting experiments, including non-invasive study of dynamical processes within live cells,"
Photoactivatable FPs (PA-FPs)can, as their name suggests, be switched on by light. When light of a particular wavelength is shone upon them they start to glow, emitting light of characteristic hue.
Wiedenmann and his collaborators previously described EosFP, a PA-FP from the reef-building coral Lobophyllia. Genetic engineering yielded the variant IrisFP with dual photoactivation capacity. In one mode it is irreversibly 'photo-converted' from a green- to a red-emitting form under violet light. In a second mode, these two light-emitting forms can be switched on and off more or less at will using light of different wavelengths ('photo-switching').
For use in cell biology experiments, PA-FPs are genetically fused to proteins of interest, and expressed in live cells. Small regions o
|Contact: Dr. Rory Howlett|
National Oceanography Centre, Southampton (UK)