title: Dependence of fluorescent protein brightness on protein concentration in solution and enhancement of it.
abstract: Fluorescent proteins have been widely used in biology because of their compatibility and varied applications in living specimens. Fluorescent proteins are often undesirably sensitive to intracellular conditions such as pH and ion concentration, generating considerable issues at times. However, harnessing these intrinsic sensitivities can help develop functional probes. In this study, we found that the fluorescence of yellow fluorescent protein (YFP) depends on the protein concentration in the solution and that this dependence can be enhanced by adding a glycine residue in to the YFP; we applied this finding to construct an intracellular protein-crowding sensor. A Förster resonance energy transfer (FRET) pair, involving a cyan fluorescent protein (CFP) insensitive to protein concentration and a glycine-inserted YFP, works as a genetically encoded probe to evaluate intracellular crowding. By measuring the fluorescence of the present FRET probe, we were able to detect dynamic changes in protein crowding in living cells.
authors.affiliation: Graduate School of Frontier Biosciences, Osaka University, 1-3 Yamadaoka, Suita,Osaka 565-0871, JAPAN.
authors.forename: Takamitsu J
authors.initials: TJ
authors.lastname: Morikawa
authors.affiliation: WPI, Immunology Frontier Research Center, Osaka University, 1-3 Yamadaoka, Suita, Osaka 565-0871, JAPAN.|RIKEN Quantitative Biology Center (QBiC), Suita, Osaka 565-0874, JAPAN.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Fujita
authors.affiliation: Faculty of Advanced Life Science, Hokkaido University, Sapporo 001-0021, JAPAN.
authors.forename: Akira
authors.initials: A
authors.lastname: Kitamura
authors.affiliation: Faculty of Advanced Life Science, Hokkaido University, Sapporo 001-0021, JAPAN.
authors.forename: Takashi
authors.initials: T
authors.lastname: Horio
authors.affiliation: Faculty of Advanced Life Science, Hokkaido University, Sapporo 001-0021, JAPAN.
authors.forename: Johtaro
authors.initials: J
authors.lastname: Yamamoto
authors.affiliation: Faculty of Advanced Life Science, Hokkaido University, Sapporo 001-0021, JAPAN.
authors.forename: Masataka
authors.initials: M
authors.lastname: Kinjo
authors.affiliation: Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8566, JAPAN.
authors.forename: Akira
authors.initials: A
authors.lastname: Sasaki
authors.affiliation: WPI, Immunology Frontier Research Center, Osaka University, 1-3 Yamadaoka, Suita, Osaka 565-0871, JAPAN.|RIKEN Quantitative Biology Center (QBiC), Suita, Osaka 565-0874, JAPAN.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Machiyama
authors.affiliation: RIKEN Quantitative Biology Center (QBiC), Suita, Osaka 565-0874, JAPAN.
authors.forename: Keiko
authors.initials: K
authors.lastname: Yoshizawa
authors.affiliation: RIKEN Quantitative Biology Center (QBiC), Suita, Osaka 565-0874, JAPAN.
authors.forename: Taro
authors.initials: T
authors.lastname: Ichimura
authors.affiliation: Department of Macromolecular Science, Graduate School of Science, Osaka University, Toyonaka, Osaka 565-0043, JAPAN.
authors.forename: Katsumi
authors.initials: K
authors.lastname: Imada
authors.affiliation: Graduate School of Frontier Biosciences, Osaka University, 1-3 Yamadaoka, Suita,Osaka 565-0871, JAPAN.|The Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Osaka 565-0873, JAPAN.|RIKEN Quantitative Biology Center (QBiC), Suita, Osaka 565-0874, JAPAN.
authors.forename: Takeharu
authors.initials: T
authors.lastname: Nagai
authors.affiliation: RIKEN Quantitative Biology Center (QBiC), Suita, Osaka 565-0874, JAPAN.|PRESTO, Japan Science and Technology Agency, 4-1-8 Honcho Kawaguchi, Saitama 332-0012, JAPAN.
authors.forename: Tomonobu M
authors.initials: TM
authors.lastname: Watanabe
mesh_terms: D031541:Fluorescence Resonance Energy Transfer; D005998:Glycine / Q000235:genetics; D008163:Luminescent Measurements / Q000379:methods*; D008164:Luminescent Proteins / Q000032:analysis* / Q000235:genetics; D011994:Recombinant Proteins / Q000032:analysis / Q000235:genetics; D012996:Solutions / Q000737:chemistry*
chemical_list: D008164:Luminescent Proteins; D011994:Recombinant Proteins; D012996:Solutions; D005998:Glycine