Green fluorescent protein

Abbreviated GFP.

A protein that glows green under fluorescent light.

Found naturally in the jellyfish Aequorea victoria, GFP fluoresces green when exposed to blue light.

It has a sequence of three amino acids (serine-tyrosine-glycine) which is responsible for its fluorescence.</P> GFP has been much used in molecular and cell biology research as: > >A reporter of gene expression -- The expression of a gene can be monitored in cells by linking the control sequences for a gene to the GFP structural gene, which serves as a reporter.

>A protein tag -- The GFP structural gene is fused to another gene, producing a fusion protein that is tagged by GFP.

The location of this tagged gene can be seen within living cells.

</LI></UL> Thus, the fluorescence produced by GFP can serve to reveal where a particular protein is expressed and to monitor protein-protein interactions.