title: Cyan-emitting and orange-emitting fluorescent proteins as a donor/acceptor pair for fluorescence resonance energy transfer.
abstract: GFP (green fluorescent protein)-based FRET (fluorescence resonance energy transfer) technology has facilitated the exploration of the spatio-temporal patterns of cellular signalling. While most studies have used cyan- and yellow-emitting FPs (fluorescent proteins) as FRET donors and acceptors respectively, this pair of proteins suffers from problems of pH-sensitivity and bleeding between channels. In the present paper, we demonstrate the use of an alternative additional donor/acceptor pair. We have cloned two genes encoding FPs from stony corals. We isolated a cyan-emitting FP from Acropara sp., whose tentacles exhibit cyan coloration. Similar to GFP from Renilla reniformis, the cyan FP forms a tight dimeric complex. We also discovered an orange-emitting FP from Fungia concinna. As the orange FP exists in a complex oligomeric structure, we converted this protein into a monomeric form through the introduction of three amino acid substitutions, recently reported to be effective for converting DsRed into a monomer (Clontech). We used the cyan FP and monomeric orange FP as a donor/acceptor pair to monitor the activity of caspase 3 during apoptosis. Due to the close spectral overlap of the donor emission and acceptor absorption (a large Förster distance), substantial pH-resistance of the donor fluorescence quantum yield and the acceptor absorbance, as well as good separation of the donor and acceptor signals, the new pair can be used for more effective quantitative FRET imaging.
authors.affiliation: Laboratory for Cell Function and Dynamics, Advanced Technology Development Group, Brain Science Institute, RIKEN, 2-1 Hirosawa, Wako-city, Saitama, 351-0198, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Karasawa
authors.forename: Toshio
authors.initials: T
authors.lastname: Araki
authors.forename: Takeharu
authors.initials: T
authors.lastname: Nagai
authors.forename: Hideaki
authors.initials: H
authors.lastname: Mizuno
authors.forename: Atsushi
authors.initials: A
authors.lastname: Miyawaki
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000737:chemistry / Q000235:genetics; D000818:Animals; D037421:Anthozoa / Q000737:chemistry; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D031541:Fluorescence Resonance Energy Transfer / Q000145:classification / Q000379:methods*; D005456:Fluorescent Dyes / Q000737:chemistry / Q000378:metabolism; D049452:Green Fluorescent Proteins; D006863:Hydrogen-Ion Concentration; D008164:Luminescent Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed / Q000235:genetics
chemical_list: D000596:Amino Acids; D001426:Bacterial Proteins; D005456:Fluorescent Dyes; D008164:Luminescent Proteins; C413663:fluorescent protein 583; C054562:yellow fluorescent protein, Bacteria; D049452:Green Fluorescent Proteins; D053148:Caspase 3; D020169:Caspases