Yellow fluorescent protein (YFP) is a genetic mutant of
green fluorescent protein
The green fluorescent protein (GFP) is a protein that exhibits 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 victo ...
(GFP) originally derived from the
jellyfish
Jellyfish, also known as sea jellies or simply jellies, are the #Life cycle, medusa-phase of certain gelatinous members of the subphylum Medusozoa, which is a major part of the phylum Cnidaria. Jellyfish are mainly free-swimming marine animal ...
''
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 aequorin (a photoprotein), and ...
''.
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
* Cellphone, a phone connected to a cellular network
* Clandestine cell, a penetration-resistant form of a secret or outlawed organization
* Electrochemical cell, a de ...
and
molecular biology
Molecular biology is a branch of biology that seeks to understand the molecule, molecular basis of biological activity in and between Cell (biology), cells, including biomolecule, biomolecular synthesis, modification, mechanisms, and interactio ...
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
In particle physics, the quantum yield (denoted ) of a radiation-induced process is the number of times a specific event occurs per photon absorbed by the system.
\Phi(\lambda)=\frac
Applications
Fluorescence spectroscopy
The fluorescence ...
). 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 inst ...
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 word is derived .
The color that is seen by our eyes is that of the light not Absorption (electromagnetic radiation), absorbed by the reflecting object within a certain wavele ...
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).
See also
*
Red fluorescent protein
Red fluorescent protein (RFP) is a protein which acts as a fluorophore, fluorescing red-orange when excited. The original variant occurs naturally in the coral genus ''Discosoma'', and is named DsRed. Several new variants have been developed usin ...
References
External links
Introduction to fluorescent proteinsEYFP
on FPbase
*
Fluorescent proteins
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