A Versatile Nanotrap for Biochemical and Functional Studies with Fluorescent Fusion Proteins

Green fluorescent proteins (GFPs) and variants thereof are widely used to study protein localization and dynamics. We engineered a specific binder for fluorescent proteins based on a 13-kDa GFP binding fragment derived from a llama single chain antibody. This GFP-binding protein (GBP) can easily be produced in bacteria and coupled to a monovalent matrix. The GBP allows a fast and efficient (one-step) isolation of GFP fusion proteins and their interacting factors for biochemical analyses including mass spectroscopy and enzyme activity measurements. Moreover GBP is also suitable for chromatin immunoprecipitations from cells expressing fluorescent DNA-binding proteins. Most importantly, GBP can be fused with cellular proteins to ectopically recruit GFP fusion proteins allowing targeted manipulation of cellular structures and processes in living cells. Because of the high affinity capture of GFP fusion proteins in vitro and in vivo and a size in the lower nanometer range we refer to the immobilized GFP-binding protein as GFP-nanotrap. This versatile GFP-nanotrap enables a unique combination of microscopic, biochemical, and functional analyses with one and the same protein. Green fluorescent proteins (GFPs) and variants thereof are widely used to study protein localization and dynamics. We engineered a specific binder for fluorescent proteins based on a 13-kDa GFP binding fragment derived from a llama single chain antibody. This GFP-binding protein (GBP) can easily be produced in bacteria and coupled to a monovalent matrix. The GBP allows a fast and efficient (one-step) isolation of GFP fusion proteins and their interacting factors for biochemical analyses including mass spectroscopy and enzyme activity measurements. Moreover GBP is also suitable for chromatin immunoprecipitations from cells expressing fluorescent DNA-binding proteins. Most importantly, GBP can be fused with cellular proteins to ectopically recruit GFP fusion proteins allowing targeted manipulation of cellular structures and processes in living cells. Because of the high affinity capture of GFP fusion proteins in vitro and in vivo and a size in the lower nanometer range we refer to the immobilized GFP-binding protein as GFP-nanotrap. This versatile GFP-nanotrap enables a unique combination of microscopic, biochemical, and functional analyses with one and the same protein. After the identification of most components of the cell, further insights into their regulation and function require information on their abundance, localization, and dynamic interactions. Green fluorescent proteins (GFPs) 1The abbreviations used are: GFP, green fluorescent protein; GBP, GFP-binding protein; ChIP, chromatin immunoprecipitation; VHH, variable domain of heavy chain antibody; HEK, human embryonic kidney; IgG, immunoglobulin G; YFP, enhanced yellow fluorescent protein; CFP, enhanced cyan fluorescent protein; DsRed, Discosoma genus red fluorescent protein; mRFP, monomeric red fluorescent protein; PCNA, proliferating cell nuclear antigen; H2B, histone H2B; Dnmt1, DNA methyltransferase I; PBD, PCNA binding domain; HMGA1a, high mobility group protein A1a; Igf, insulin-like growth factor; PML, promyelocytic leukemia protein. 1The abbreviations used are: GFP, green fluorescent protein; GBP, GFP-binding protein; ChIP, chromatin immunoprecipitation; VHH, variable domain of heavy chain antibody; HEK, human embryonic kidney; IgG, immunoglobulin G; YFP, enhanced yellow fluorescent protein; CFP, enhanced cyan fluorescent protein; DsRed, Discosoma genus red fluorescent protein; mRFP, monomeric red fluorescent protein; PCNA, proliferating cell nuclear antigen; H2B, histone H2B; Dnmt1, DNA methyltransferase I; PBD, PCNA binding domain; HMGA1a, high mobility group protein A1a; Igf, insulin-like growth factor; PML, promyelocytic leukemia protein. and spectral variants thereof became popular tools to determine protein localization and, in combination with fluorescence photobleaching techniques, provided unique information on protein dynamics in living cells (1Chalfie M. Tu Y. Euskirchen G. Ward W.W. Prasher D.C. Green fluorescent protein as a marker for gene expression.Science. 1994; 263: 802-805Crossref PubMed Scopus (5451) Google Scholar, 2Misteli T. Spector D.L. Applications of the green fluorescent protein in cell biology and biotechnology.Nat. Biotechnol. 1997; 15: 961-964Crossref PubMed Scopus (307) Google Scholar, 3Tsien R.Y. The green fluorescent protein.Annu. Rev. Biochem. 1998; 67: 509-544Crossref PubMed Scopus (4882) Google Scholar, 4van Roessel P. Brand A.H. Imaging into the future: visualizing gene expression and protein interactions with fluorescent proteins.Nat. Cell Biol. 2002; 4: E15-E20Crossref PubMed Scopus (211) Google Scholar). Necessary additional information on DNA binding, enzymatic activity, and complex formation can be obtained with various methods including chromatin immunoprecipitation (ChIP) and affinity and of 2002; PubMed Scopus Google Scholar, of chromatin in vivo 1997; PubMed Scopus Google Scholar). are the of specific are the protein of to specific protein including for PubMed Scopus Google Scholar, of protein from and biochemical to Biotechnol. PubMed Scopus Google Scholar). GFP, the most widely used in cell is used for biochemical various and of fluorescent protein to study nuclear of the in living Biol. 15: PubMed Scopus Google Scholar, proteins as 4: PubMed Scopus Google Scholar). This be in to and as as heavy and with to are variable single domain also to as VHH, derived from heavy chain of T. G. of PubMed Scopus Google Scholar). the with a mass of are and and can be produced in the Biol. PubMed Scopus Google Scholar, domain Biotechnol. Google Scholar). used for various P. in the of the human PubMed Scopus Google Scholar, of enzyme function in Biotechnol. PubMed Scopus Google Scholar, P. P. of specific for the domain in PubMed Scopus Google we a of a 13-kDa GFP binding fragment derived from a llama single chain and in cells with fluorescent PubMed Scopus Google Scholar). This GFP-binding protein (GBP) a and can easily be produced in We immobilized the GBP to a enables a fast and efficient isolation of GFP fusion proteins and their interacting factors for biochemical and Moreover we the GFP-binding protein can be fused with proteins to ectopically recruit GFP fusion proteins and interacting factors in living the localization and binding dynamics of fluorescent fusion proteins be with biochemical on interacting enzymatic activity, and DNA binding a for fast and efficient of GFP fusion proteins we used a 13-kDa GBP the domain of a heavy chain in GFP and in cells with fluorescent PubMed Scopus Google Scholar). The GBP fused with a produced in and a single the GBP can easily be produced and as a a functional we the binding of the GBP to of proteins and for the GBP and into a complex with a mass of We the of GBP to from cell and with and GBP and to protein of cells expressing proteins and After with GBP protein and the GBP additional to the and heavy of the as as proteins be in immunoprecipitations with the and The of GFP in to the GBP is efficient and and of fluorescent immunoprecipitation of of GBP with and of cells to immunoprecipitation with GBP, of and and GFP, heavy and of the and the GBP are with the GFP-nanotrap. protein on a GBP coupled to and proteins of GFP fusion proteins with the GFP-nanotrap. of cells are and GFP fusion proteins with the GFP-nanotrap. of GFP fusion proteins and interacting cells a of with the red fluorescent of PCNA cell of cells in are cells and to immunoprecipitation with the GFP-nanotrap. GBP can be immobilized and with protein to of the GBP and to with analyses we coupled GBP to a GFP-binding This GFP-nanotrap a fast of GFP from cell a single protein protein Moreover the a of the as of GFP from the the of GBP we immunoprecipitation with a of fluorescent proteins. GFP GBP the yellow of mRFP, further the binding of GBP we and we the of the binding from to and GBP high we and of GFP the and binding of we the of GFP in the range from to the to of GFP a fast and efficient to from the GFP-nanotrap GBP also GFP fusion proteins we from M. M. G. G. dynamics cell and a fusion Biol. 1997; PubMed Scopus Google G. and a in Cell Biol. PubMed Scopus Google P. T. of DNA in living Cell Biol. PubMed Scopus Google and T. fusion protein enables of dynamics in living Biol. 1998; PubMed Scopus Google Scholar). expressing the fusion proteins to determine the localization of the GFP fusion protein cells and GFP fusion proteins with the GFP-nanotrap and lower The GBP GFP fusion proteins from and of the most of the GBP is the to localization, and complex formation of specific proteins and We a of the PCNA domain chromatin of and PubMed Scopus Google Scholar). with the fluorescent with the red fluorescent PCNA We from living cells with biochemical and to immunoprecipitation with the GFP-nanotrap. with with lower The the of the in of DNA methyltransferase activity in living PubMed Scopus Google Scholar). we also PCNA with with GBP can also interacting proteins. the GFP-nanotrap is suitable to interacting factors and cell of and specific binding we the GFP-nanotrap to interacting factors mass in cell is the fluorescent fusion proteins are and biochemical to their fast of enzymatic activity we fluorescent fusion of the Dnmt1, are in cell we the and After of the fluorescent in of cells proteins from cell with the GFP-nanotrap and for enzymatic measurements. a specific DNA methyltransferase activity to of lower The with the the DNA methyltransferase of cells the GFP-nanotrap is a efficient for and biochemical of fluorescent fusion fusion proteins their enzymatic activity with the GFP-nanotrap. of from cells the Dnmt1, protein one with the GFP-nanotrap and DNA methyltransferase activity of GFP fusion proteins and the GFP-nanotrap the to function in chromatin immunoprecipitations we a cell expressing a GFP fusion of the high mobility group protein and We the of the and protein are to M. components chromatin Biol. PubMed Google Scholar, nuclear and high mobility group proteins the of the insulin-like growth 1997; PubMed Scopus Google Scholar, G. M. of gene function embryonic cell PubMed Scopus Google Scholar, M. G. of the and in and PubMed Scopus Google Scholar). of to immunoprecipitation with the GFP-nanotrap and with the GFP-nanotrap a of This binding of the specific with The cells expressing specific of in with the the high and of the with the GFP-nanotrap. of cells to immunoprecipitation of of and of DNA of the and and obtained for the and are in the obtained in as the obtained with the GFP-nanotrap and in vitro of the GFP-binding protein. a we in vivo and the of the GFP-binding protein a the cell to a of the nuclear We fused the GBP with to a cellular the nuclear GBP and the in vitro biochemical with binding in living cells we cells with GFP, and and the of GFP and with to the GFP-nanotrap the nuclear GFP the nuclear a the cell of GFP, YFP, and from the fluorescent proteins the GBP we single to We the of to binding to the to a binding This the high and of the GBP in vitro and in vivo allowing of single we the GFP-nanotrap can be used to factors and cellular a we the The is in nuclear a in regulation of gene DNA and P. and of Biol. PubMed Scopus Google Scholar, the promyelocytic leukemia protein for nuclear Biol. 2002; PubMed Scopus Google Scholar). We of in cells are the cells are the green fluorescence of the is for protein and cell is for the formation of Google fusion protein and with a specific expression of green fluorescent the nuclear and the of from the nuclear the of the GFP-nanotrap to recruit GFP fusion proteins also interacting of the in cells expressing GFP, CFP, and GFP is the nuclear is of GFP, CFP, and are in The of GFP The of green fluorescent Biotechnol. PubMed Scopus Google is and the is as a protein of cells expressing GFP, CFP, and to with the GFP-nanotrap. and and and with manipulation of nuclear structures with the GFP-nanotrap. cells in combination with are are on the is into with antibody. of the with to a of from the nuclear the of in the nuclear with of the is the of biochemical, and cell This in the protein are used for we a GBP as a and versatile for biochemical analyses of GFP fusion proteins and functional in The and GBP the and the GBP can be produced in bacteria in and with and can easily be coupled to the high affinity of single chain GBP allows to fluorescent fusion proteins and factors from cellular size of binding and heavy and of and with of the GFP-nanotrap further with cells expressing a DNA binding gene with the GFP-nanotrap we a binding of the with versatile GFP-nanotrap with the of fluorescent fusion proteins enables a fast and of the localization and mobility of fluorescent fusion proteins with their enzymatic activity, interacting and DNA binding cell biology and with the GFP-nanotrap can also be used for functional in We GBP can be fused with cellular proteins to a GFP-nanotrap a to ectopically recruit GFP fusion proteins and their factors from their one we the GBP the nuclear to capture nuclear are GFP fusion protein can be with cellular The of GBP as a in living cells of of functional to and cellular processes and After the identification of most components of the cell, further insights into their regulation and function require information on their abundance, localization, and dynamic interactions. Green fluorescent proteins (GFPs) 1The abbreviations used are: GFP, green fluorescent protein; GBP, GFP-binding protein; ChIP, chromatin immunoprecipitation; VHH, variable domain of heavy chain antibody; HEK, human embryonic kidney; IgG, immunoglobulin G; YFP, enhanced yellow fluorescent protein; CFP, enhanced cyan fluorescent protein; DsRed, Discosoma genus red fluorescent protein; mRFP, monomeric red fluorescent protein; PCNA, proliferating cell nuclear antigen; H2B, histone H2B; Dnmt1, DNA methyltransferase I; PBD, PCNA binding domain; HMGA1a, high mobility group protein A1a; Igf, insulin-like growth factor; PML, promyelocytic leukemia protein. 1The abbreviations used are: GFP, green fluorescent protein; GBP, GFP-binding protein; ChIP, chromatin immunoprecipitation; VHH, variable domain of heavy chain antibody; HEK, human embryonic kidney; IgG, immunoglobulin G; YFP, enhanced yellow fluorescent protein; CFP, enhanced cyan fluorescent protein; DsRed, Discosoma genus red fluorescent protein; mRFP, monomeric red fluorescent protein; PCNA, proliferating cell nuclear antigen; H2B, histone H2B; Dnmt1, DNA methyltransferase I; PBD, PCNA binding domain; HMGA1a, high mobility group protein A1a; Igf, insulin-like growth factor; PML, promyelocytic leukemia protein. and spectral variants thereof became popular tools to determine protein localization and, in combination with fluorescence photobleaching techniques, provided unique information on protein dynamics in living cells (1Chalfie M. Tu Y. Euskirchen G. Ward W.W. Prasher D.C. Green fluorescent protein as a marker for gene expression.Science. 1994; 263: 802-805Crossref PubMed Scopus (5451) Google Scholar, 2Misteli T. Spector D.L. Applications of the green fluorescent protein in cell biology and biotechnology.Nat. Biotechnol. 1997; 15: 961-964Crossref PubMed Scopus (307) Google Scholar, 3Tsien R.Y. The green fluorescent protein.Annu. Rev. Biochem. 1998; 67: 509-544Crossref PubMed Scopus (4882) Google Scholar, 4van Roessel P. Brand A.H. Imaging into the future: visualizing gene expression and protein interactions with fluorescent proteins.Nat. Cell Biol. 2002; 4: E15-E20Crossref PubMed Scopus (211) Google Scholar). Necessary additional information on DNA binding, enzymatic activity, and complex formation can be obtained with various methods including chromatin immunoprecipitation (ChIP) and affinity and of 2002; PubMed Scopus Google Scholar, of chromatin in vivo 1997; PubMed Scopus Google Scholar). are the of specific are the protein of to specific protein including for PubMed Scopus Google Scholar, of protein from and biochemical to Biotechnol. PubMed Scopus Google Scholar). GFP, the most widely used in cell is used for biochemical various and of fluorescent protein to study nuclear of the in living Biol. 15: PubMed Scopus Google Scholar, proteins as 4: PubMed Scopus Google Scholar). This be in to and as as heavy and with to are variable single domain also to as VHH, derived from heavy chain of T. G. of PubMed Scopus Google Scholar). the with a mass of are and and can be produced in the Biol. PubMed Scopus Google Scholar, domain Biotechnol. Google Scholar). used for various P. in the of the human PubMed Scopus Google Scholar, of enzyme function in Biotechnol. PubMed Scopus Google Scholar, P. P. of specific for the domain in PubMed Scopus Google Scholar). we a of a 13-kDa GFP binding fragment derived from a llama single chain and in cells with fluorescent PubMed Scopus Google Scholar). This GFP-binding protein (GBP) a and can easily be produced in We immobilized the GBP to a enables a fast and efficient isolation of GFP fusion proteins and their interacting factors for biochemical and Moreover we the GFP-binding protein can be fused with proteins to ectopically recruit GFP fusion proteins and interacting factors in living cells. the localization and binding dynamics of fluorescent fusion proteins be with biochemical on interacting enzymatic activity, and DNA binding a for fast and efficient of GFP fusion proteins we used a 13-kDa GBP the domain of a heavy chain in GFP and in cells with fluorescent PubMed Scopus Google Scholar). The GBP fused with a produced in and a single the GBP can easily be produced and as a a functional we the binding of the GBP to of proteins and for the GBP and into a complex with a mass of We the of GBP to from cell and with and GBP and to protein of cells expressing proteins and After with GBP protein and the GBP additional to the and heavy of the as as proteins be in immunoprecipitations with the and The of GFP in to the GBP is efficient and and GBP can be immobilized and with protein to of the GBP and to with analyses we coupled GBP to a GFP-binding This GFP-nanotrap a fast of GFP from cell a single protein protein Moreover the a of the as of GFP from the the of GBP we immunoprecipitation with a of fluorescent proteins. GFP GBP the yellow of mRFP, further the binding of GBP we and we the of the binding from to and GBP high we and of GFP the and binding of we the of GFP in the range from to the to of GFP a fast and efficient to from the GFP-nanotrap GBP also GFP fusion proteins we from M. M. G. G. dynamics cell and a fusion Biol. 1997; PubMed Scopus Google G. and a in Cell Biol. PubMed Scopus Google P. T. of DNA in living Cell Biol. PubMed Scopus Google and T. fusion protein enables of dynamics in living Biol. 1998; PubMed Scopus Google Scholar). expressing the fusion proteins to determine the localization of the GFP fusion protein cells and GFP fusion proteins with the GFP-nanotrap and lower The GBP GFP fusion proteins from and of the most of the GBP is the to localization, and complex formation of specific proteins and We a of the PCNA domain chromatin of and PubMed Scopus Google Scholar). with the fluorescent with the red fluorescent PCNA We from living cells with biochemical and to immunoprecipitation with the GFP-nanotrap. with with lower The the of the in of DNA methyltransferase activity in living PubMed Scopus Google Scholar). we also PCNA with with GBP can also interacting proteins. the GFP-nanotrap is suitable to interacting factors and cell of and specific binding we the GFP-nanotrap to interacting factors mass in cell is the fluorescent fusion proteins are and biochemical to their fast of enzymatic activity we fluorescent fusion of the Dnmt1, are in cell we the and After of the fluorescent in of cells proteins from cell with the GFP-nanotrap and for enzymatic measurements. a specific DNA methyltransferase activity to of lower The with the the DNA methyltransferase of cells the GFP-nanotrap is a efficient for and biochemical of fluorescent fusion fusion proteins their enzymatic activity with the GFP-nanotrap. of from cells the Dnmt1, protein one with the GFP-nanotrap and DNA methyltransferase activity of GFP fusion proteins and the GFP-nanotrap the to function in chromatin immunoprecipitations we a cell expressing a GFP fusion of the high mobility group protein and We the of the and protein are to M. components chromatin Biol. PubMed Google Scholar, nuclear and high mobility group proteins the of the insulin-like growth 1997; PubMed Scopus Google Scholar, G. M. of gene function embryonic cell PubMed Scopus Google Scholar, M. G. of the and in and PubMed Scopus Google Scholar). of to immunoprecipitation with the GFP-nanotrap and with the GFP-nanotrap a of This binding of the specific with The cells expressing specific of in with the the high and of the with the GFP-nanotrap. of cells to immunoprecipitation of of and of DNA of the and and obtained for the and are in the obtained in as the obtained with the GFP-nanotrap and in vitro of the GFP-binding protein. a we in vivo and the of the GFP-binding protein a the cell to a of the nuclear We fused the GBP with to a cellular the nuclear GBP and the in vitro biochemical with binding in living cells we cells with GFP, and and the of GFP and with to the GFP-nanotrap the nuclear GFP the nuclear a the cell of GFP, YFP, and from the fluorescent proteins the GBP we single to We the of to binding to the to a binding This the high and of the GBP in vitro and in vivo allowing of single we the GFP-nanotrap can be used to factors and cellular a we the The is in nuclear a in regulation of gene DNA and P. and of Biol. PubMed Scopus Google Scholar, the promyelocytic leukemia protein for nuclear Biol. 2002; PubMed Scopus Google Scholar). We of in cells are the cells are the green fluorescence of the is for protein and cell is for the formation of Google fusion protein and with a specific expression of green fluorescent the nuclear and the of from the nuclear the of the GFP-nanotrap to recruit GFP fusion proteins also interacting of the in cells expressing GFP, CFP, and GFP is the nuclear is of GFP, CFP, and are in The of GFP The of green fluorescent Biotechnol. PubMed Scopus Google is and the is as a protein of cells expressing GFP, CFP, and to with the GFP-nanotrap. and and and with manipulation of nuclear structures with the GFP-nanotrap. cells in combination with are are on the is into with antibody. of the with to a of from the nuclear the of in the nuclear with the localization and binding dynamics of fluorescent fusion proteins be with biochemical on interacting enzymatic activity, and DNA binding a for fast and efficient of GFP fusion proteins we used a 13-kDa GBP the domain of a heavy chain in GFP and in cells with fluorescent PubMed Scopus Google Scholar). The GBP fused with a produced in and a single the GBP can easily be produced and as a a functional we the binding of the GBP to of proteins and for the GBP and into a complex with a mass of We the of GBP to from cell and with and GBP and to protein of cells expressing proteins and After with GBP protein and the GBP additional to the and heavy of the as as proteins be in immunoprecipitations with the and The of GFP in to the GBP is efficient and and GBP can be immobilized and with protein to of the GBP and to with analyses we coupled GBP to a GFP-binding This GFP-nanotrap a fast of GFP from cell a single protein protein Moreover the a of the as of GFP from the the of GBP we immunoprecipitation with a of fluorescent proteins. GFP GBP the yellow of mRFP, further the binding of GBP we and we the of the binding from to and GBP high we and of GFP the and binding of we the of GFP in the range from to the to of GFP a fast and efficient to from the GFP-nanotrap GBP also GFP fusion proteins we from M. M. G. G. dynamics cell and a fusion Biol. 1997; PubMed Scopus Google G. and a in Cell Biol. PubMed Scopus Google P. T. of DNA in living Cell Biol. PubMed Scopus Google and T. fusion protein enables of dynamics in living Biol. 1998; PubMed Scopus Google Scholar). expressing the fusion proteins to determine the localization of the GFP fusion protein cells and GFP fusion proteins with the GFP-nanotrap and lower The GBP GFP fusion proteins from and of the most of the GBP is the to localization, and complex formation of specific proteins and We a of the PCNA domain chromatin of and PubMed Scopus Google Scholar). with the fluorescent with the red fluorescent PCNA We from living cells with biochemical and to immunoprecipitation with the GFP-nanotrap. with with lower The the of the in of DNA methyltransferase activity in living PubMed Scopus Google Scholar). we also PCNA with with GBP can also interacting proteins. the GFP-nanotrap is suitable to interacting factors and cell of and specific binding we the GFP-nanotrap to interacting factors mass in cell is the fluorescent fusion proteins are and biochemical to their fast of enzymatic activity we fluorescent fusion of the Dnmt1, are in cell we the and After of the fluorescent in of cells proteins from cell with the GFP-nanotrap and for enzymatic measurements. a specific DNA methyltransferase activity to of lower The with the the DNA methyltransferase of cells the GFP-nanotrap is a efficient for and biochemical of fluorescent fusion proteins. the GFP-nanotrap the to function in chromatin immunoprecipitations we a cell expressing a GFP fusion of the high mobility group protein and We the of the and protein are to M. components chromatin Biol. PubMed Google Scholar, nuclear and high mobility group proteins the of the insulin-like growth 1997; PubMed Scopus Google Scholar, G. M. of gene function embryonic cell PubMed Scopus Google Scholar, M. G. of the and in and PubMed Scopus Google Scholar). of to immunoprecipitation with the GFP-nanotrap and with the GFP-nanotrap a of This binding of the specific with The cells expressing specific of in with the the high and of the GFP-nanotrap. in vitro of the GFP-binding protein. a we in vivo and the of the GFP-binding protein a the cell to a of the nuclear We fused the GBP with to a cellular the nuclear GBP and the in vitro biochemical with binding in living cells we cells with GFP, and and the of GFP and with to the GFP-nanotrap the nuclear GFP the nuclear a the cell of GFP, YFP, and from the fluorescent proteins the GBP we single to We the of to binding to the to a binding This the high and of the GBP in vitro and in vivo allowing of single we the GFP-nanotrap can be used to factors and cellular a we the The is in nuclear a in regulation of gene DNA and P. and of Biol. PubMed Scopus Google Scholar, the promyelocytic leukemia protein for nuclear Biol. 2002; PubMed Scopus Google Scholar). We of in cells are the cells are the green fluorescence of the is for protein and cell is for the formation of Google fusion protein and with a specific expression of green fluorescent the nuclear and the of from the nuclear the of the GFP-nanotrap to recruit GFP fusion proteins also interacting of the is the of biochemical, and cell This in the protein are used for we a GBP as a and versatile for biochemical analyses of GFP fusion proteins and functional in The and GBP the and the GBP can be produced in bacteria in and with and can easily be coupled to the high affinity of single chain GBP allows to fluorescent fusion proteins and factors from cellular size of binding and heavy and of and with of the GFP-nanotrap further with cells expressing a DNA binding gene with the GFP-nanotrap we a binding of the with versatile GFP-nanotrap with the of fluorescent fusion proteins enables a fast and of the localization and mobility of fluorescent fusion proteins with their enzymatic activity, interacting and DNA binding cell biology and with the GFP-nanotrap can also be used for functional in We GBP can be fused with cellular proteins to a GFP-nanotrap a to ectopically recruit GFP fusion proteins and their factors from their one we the GBP the nuclear to capture nuclear are GFP fusion protein can be with cellular The of GBP as a in living cells of of functional to and cellular processes and of the is the of biochemical, and cell This in the protein are used for we a GBP as a and versatile for biochemical analyses of GFP fusion proteins and functional in The and GBP the and the GBP can be produced in bacteria in and with and can easily be coupled to the high affinity of single chain GBP allows to fluorescent fusion proteins and factors from cellular size of binding and heavy and of and with The of the GFP-nanotrap further with cells expressing a DNA binding gene with the GFP-nanotrap we a binding of the with versatile GFP-nanotrap with the of fluorescent fusion proteins enables a fast and of the localization and mobility of fluorescent fusion proteins with their enzymatic activity, interacting and DNA binding cell biology and with the GFP-nanotrap can also be used for functional in We GBP can be fused with cellular proteins to a GFP-nanotrap a to ectopically recruit GFP fusion proteins and their factors from their one we the GBP the nuclear to capture nuclear are GFP fusion protein can be with cellular The of GBP as a in living cells of of functional to and cellular processes and We and for and for G. and for enzyme activity and for the cell with with