The term ‘Green Fluorescence Protein’, or the GFP, traditionally referred to a protein that was first isolated from the Jelly fish Aequorea victoria. This jelly fish produces glowing points of light around the edges of its umbrella, because of a process called bioluminescence. The components of this process include a calcium-activated photoprotein (aequorin) that emits blue-green light, and an accessory green fluorescent protein (GFP), which accepts energy from aequorin and re-emits it as green light. GFP has an excellent role in providing visual signals that have been exploited to tag a protein and to study a protein's activity, such as when and where are the proteins produced, and how these proteins or these parts move and interact within a cell.
In the 1960s, Osamu Shimomura, who was born in August 1928, Japan, took the initial steps in studying biological processes using GFP as a tool because GFP can be linked to other proteins through genetic engineering. It was he who isolated GFP from Aequorea victoria and came up with the actual regions from where this jelly fish produced green bioluminescence that were small photo-organs located on its umbrella. He tried to squeeze the rings of 20-30 jelly fishes through rayon gauze in order to obtain a liquid called ‘squeezate’, which was faintly luminescent. Shimomura collected over a million Aequorea specimens to produce squeezate for his study.
Later, Martin Chalfie, born on January 15, 1947 in Illinois, United States, was working on C.elegans in order to investigate nerve cell development and function needed for mechanosensation used GFP. Chalfie was attending a seminar on bioluminescent organisms at Columbia University where he first heard about GFP and got very excited to use this in his C.elegans work. Therefore, he used the GFP gene to demonstrate the value of GFP as a luminescent genetic tag for various biological phenomena by inserting this gene into C.elegans and successfully getting six individual cells colored, which could then be tracked.
Since the discovery of GFP many mutants of the gene had been tried and tested but the first mile stone was achieved by Roger Tsein in 1995. Tsein, born in New York in 1952, was a pioneer of calcium imaging. He made a single point mutation in the GFP gene, which enhanced its fluorescent and spectral characteristics. His work mainly contributed to our understanding of how GFP works and the generation of new mutants of GFP.
Nine years ago, these eminent scientists were awarded the 2008 Noble prize in Chemistry “For the discovery and development of the green fluorescent protein, GFP”. Their spectacular work has revolutionized the field of biochemistry and our understanding towards it, making it much more interesting and easier for the new age researchers to understand science, as it made microscopic imaging much easier.
Authors: Ms. Ibtisam Mumtaz and Dr. Shashi Singh, CSIR-Centre for Cellular and Molecular Biology.
Email: shashis@ccmb.res.in
(Image source: https://cdn.zmescience.com/wp-content/uploads/2016/02/ZSVIqEL.jpg)
Posted By : ScienceIndia Administrator
Please sign-in to post comments