A Bright Future for Cell Research: The Development of mScarlet3
To accomplish this, they combined the properties of two existing mScarlet variants: one with fast folding but lower brightness, and another with slow folding but ultimately bright fluorescence. Through a series of targeted changes in...
Cell research has always been vital for understanding biological processes, and one technique that has proven particularly useful is attaching colored lights to proteins of interest. This allows scientists to observe the movements and interactions of these proteins in living cells under a microscope. The more colors available, the more processes can be followed simultaneously.
The journey of fluorescent proteins began in the 1990s when a green fluorescent protein was used for the first time as a colored marker in a cell. It was derived from a fluorescent jellyfish, and through modifications, blue, turquoise, and yellow variants were developed. In the 2000s, a red fluorescent protein was discovered in corals. However, turning this protein into a usable and bright red light for cell research proved to be challenging.
A breakthrough came in 2016 when a team of biologists led by Dorus Gadella at the University of Amsterdam created a bright red fluorescent protein called mScarlet. This development was quickly embraced by the scientific community, and the DNA encoding mScarlet has since been used in cell biology research worldwide.
However, there was room for improvement, as mScarlet folded more slowly and less completely than the green fluorescent proteins in mammalian cells, resulting in less-than-optimal brightness. The team continued working on the protein, aiming to accelerate and maximize the folding process.
To accomplish this, they combined the properties of two existing mScarlet variants: one with fast folding but lower brightness, and another with slow folding but ultimately bright fluorescence. Through a series of targeted changes in the protein structure, the team successfully created mScarlet3, which combines maximum brightness with fast and complete folding.
To test mScarlet3’s structure, the biologists collaborated with the Institut de Biologie Structurale in Grenoble, where structural biologist Antoine Royant utilized the European Synchrotron ESRF, the world’s brightest X-ray source, to map the protein’s molecular structure. Royant found that mScarlet3’s brightness is due to a unique hydrophobic (oily) local structure in the protein, which both accelerates and improves folding.
The development of mScarlet3 has significantly expanded the toolbox available to scientists in the lab. Gadella believes that mScarlet3 will quickly become the new global standard, as bright red fluorescent proteins are in high demand due to their less harmful excitation process and reduced scattering, allowing for deeper cell layer observation.
mScarlet3’s robustness, brightness, and rapid folding capabilities make it an ideal candidate for developing new red fluorescent biosensors for imaging specific cell functions. This advancement in cell research promises to unlock new discoveries and applications in the field of biology, further enhancing our understanding of the complex processes occurring within cells.