Yellow fluorescent protein (YFP) is a genetic mutant of

green fluorescent protein The green fluorescent protein (GFP) is a protein that exhibits bright green fluorescence when exposed to light in the blue to ultraviolet range. The label ''GFP'' traditionally refers to the protein first isolated from the jellyfish ''Aequorea ...

(GFP) originally derived from the

jellyfish Jellyfish and sea jellies are the informal common names given to the medusa-phase of certain gelatinous members of the subphylum Medusozoa, a major part of the phylum Cnidaria. Jellyfish are mainly free-swimming marine animals with umbrella- ...

Aequorea victoria ''Aequorea victoria'', also sometimes called the crystal jelly, is a bioluminescent hydrozoan jellyfish, or hydromedusa, that is found off the west coast of North America. The species is best known as the source of two proteins involved in biolu ...

''. Its excitation peak is 513 nm and its emission peak is 527 nm. Like the parent GFP, YFP is a useful tool in

cell Cell most often refers to: * Cell (biology), the functional basic unit of life Cell may also refer to: Locations * Monastic cell, a small room, hut, or cave in which a religious recluse lives, alternatively the small precursor of a monastery ...

and

molecular biology Molecular biology is the branch of biology that seeks to understand the molecular basis of biological activity in and between cells, including biomolecular synthesis, modification, mechanisms, and interactions. The study of chemical and physi ...

because the excitation and emission peaks of YFP are distinguishable from GFP which allows for the study of multiple processes/proteins within the same experiment. Three improved versions of YFP are Citrine, Venus, and Ypet. They have reduced chloride sensitivity, faster maturation, and increased brightness (defined as the product of the extinction coefficient and

quantum yield The quantum yield (Φ) of a radiation-induced process is the number of times a specific event occurs per photon absorbed by the system. Applications Fluorescence spectroscopy The fluorescence quantum yield is defined as the ratio of the numb ...

). Typically, YFP serves as the acceptor for genetically-encoded

FRET A fret is any of the thin strips of material, usually metal wire, inserted laterally at specific positions along the neck or fretboard of a stringed instrument. Frets usually extend across the full width of the neck. On some historical instrume ...

sensors of which the most likely donor FP is monomeric cyan fluorescent protein (mCFP). The red-shift relative to GFP is caused by a Pi-Pi stacking interaction as a result of the T203Y substitution introduced by mutation, which essentially increases the polarizability of the local

chromophore A chromophore is the part of a molecule responsible for its color. The color that is seen by our eyes is the one not absorbed by the reflecting object within a certain wavelength spectrum of visible light. The chromophore is a region in the molec ...

environment as well as providing additional electron density into the chromophore. "Venus" contains a novel amino acid substitution –F46L– which accelerates the oxidation of the chromophore at 37°C, the rate limiting step of maturation. The protein has other substitutions (F64L/ M153T/ V163A/ S175G), permitting Venus to fold well and giving it relative tolerance to acidosis and Cl⁻.

Evolution of YFP from GFP

Four protein mutations from the wild-type GFP found in Aequorea Victoria jellyfish were needed to create the YFP mutant. The most important mutation was the replacement of threonine with tyrosine at residue position 203 (the substitution is denoted by T203Y, where T and Y represent the single letter code for the amino acids threonine and tyrosine, respectively).

References

External links

Introduction to fluorescent proteinsEYFP
on FPbase * Fluorescent proteins {{protein-stub

Evolution of YFP from GFP

See also

References

External links