The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Oleg A Strelchyonok - One of the best experts on this subject based on the ideXlab platform.
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organization of the Transcortin binding domain on placental plasma membranes
Biochimica et Biophysica Acta, 1995Co-Authors: Sergey A Krupenko, Oleg I Kolesnik, Natalia I Krupenko, Oleg A StrelchyonokAbstract:Complex formation between Transcortin (corticosteroid-binding globulin) and 20 kDa sialoglycoprotein from human syncytiotrophoblast plasma membranes (presumably a Transcortin-recognizing subunit of the Transcortin membrane receptor) was studied using FPLC and cross-linking with bifunctional reagents. The action of 1,5-difluoro-2,4-dinitrobenzene (DFDNB) on a solution of the purified 20 kDa sialoglycoprotein and Transcortin resulted in formation of covalently linked complexes of 95 kDa and 140 kDa consisting of one Transcortin molecule and either two or four molecules of the membrane sialoglycoprotein (the molecular mass of Transcortin is 55 kDa). Additionally, cross-linking resulted in the appearance of a 43 kDa species which is the cross-linked dimer of the membrane protein. The dimer was also observed during chromatography on a Superose 12 column in the absence of DFDNB treatment. Treatment of intact syncytiotrophoblast membranes with DFDNB resulted in isolation of the Transcortin binding protein dimer as the major portion of total pool of the protein. Formation of the Transcortin complexes with two and four molecules of the membrane protein was also observed when the membranes were incubated with 125I-labeled Transcortin and treated with DFDNB, but formation of the latter complexes predominated. The results obtained suggest that the recognizing and binding domain for Transcortin in placental membranes is organized as dimers consisting of non-covalently linked sialoglycoprotein monomers of a 20 kDa each and that Transcortin has two sites for interaction with this dimer. Apparently, binding of two dimers results in the formation of the functional form of the Transcortin-receptor complex. The possible biological role of such a complex is discussed.
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testosterone destroys the Transcortin receptor complex
Biochemical and Biophysical Research Communications, 1992Co-Authors: Sergey A Krupenko, Oleg A StrelchyonokAbstract:Abstract Dissociation of the complex of Transcortin receptor with immobilized Transcortin in the presence of 10 −5 M testosterone has been shown with the use of affinity chromatography on Transcortin-Sepharose. The specificity of this effect is confirmed by its abrogation in the presence of cortisol. The testosterone effect has been used for the elution of Transcortin receptor from affinity column. The receptor retained Transcortin-binding capacity after the elution and removal of testosterone. Characteristics of the receptor obtained by testosterone elution were identical with those of the Transcortin eluted preparation.
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a Transcortin binding protein in the plasma membrane of human syncytiotrophoblast
Biochemical and Biophysical Research Communications, 1991Co-Authors: Sergey A Krupenko, George V Avvakumov, Oleg A StrelchyonokAbstract:Using affinity chromatography on immobilized Transcortin of 125I-labeled, cholate-solubilized plasma membranes of human syncytiotrophoblast, a Transcortin-binding protein with a minimal Mr of about 20 kDa has been isolated. It was found to be a sialoglycoprotein with an isoelectric point at pH 4.4 (about 5.0 after the treatment with neuraminidase). We assume that this protein is a component of membrane recognition system for Transcortin-steroid complexes.
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on the functional form of Transcortin recognizing subunit of Transcortin membrane receptor
FEBS Letters, 1991Co-Authors: Sergey A Krupenko, George V Avvakumov, Oleg A StrelchyonokAbstract:Abstract Complex formation between Transcortin and the 20 kDa sialoglycoprotein from the plasma membrane of human decidual endometrium (presumably a Transcortin-recognizing subunit of Transcortin membranes receptor) was studied using cross-linking reagents. The action of 1,5-difluoro-3,4-dinitrobenzene (DFDNB) on a solution of 125I-labelled 20 kDa sialoglycoprotein and unlabelled Transcortin resulted in the formation of two 125I-containing species that corresponded to covalently linked complexes of one Transcortin molecule and either 2 or 4 molecules of the labelled membrane sialoglycoprotein. Only the latter complex was observed when the endometrium membranes were incubated with [25I]Transcortin and treated with DFDNB. This suggests that the functional form of Transcortin-recognizing subunit of the membrane receptor is a tetramer.
Gideon Dreyfuss - One of the best experts on this subject based on the ideXlab platform.
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a novel receptor mediated nuclear protein import pathway
Cell, 1996Co-Authors: Victoria W Pollard, Matthew W Michael, Sara Nakielny, Mikiko C Siomi, Fan Wang, Gideon DreyfussAbstract:Abstract Targeting of most nuclear proteins to the cell nucleus is initiated by interaction between the classical nuclear localization signals (NLSs) contained within them and the importin NLS receptor complex. We have recently delineated a novel 38 amino acid transport signal in the hnRNP A1 protein, termed M9, which confers bidirectional transport across the nuclear envelope. We show here that M9-mediated nuclear import occurs by a novel pathway that is independent of the well-characterized, importin-mediated classical NLS pathway. Additionally, we have identified a specific M9-interacting protein, termed transportin, which binds to wild-type M9 but not to transport-defective M9 mutants. Transportin is a 90 kDa protein, distantly related to importin β, and we show that it mediates the nuclear import of M9-containing proteins. These findings demonstrate that there are at least two receptor-mediated nuclear protein import pathways. Furthermore, as hnRNP A1 likely participates in mRNA export, it raises the possibility that transportin is a mediator of this process as well.
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a novel receptor mediated nuclear protein import pathway
Cell, 1996Co-Authors: Victoria W Pollard, Matthew W Michael, Sara Nakielny, Mikiko C Siomi, Fan Wang, Gideon DreyfussAbstract:Targeting of most nuclear proteins to the cell nucleus is initiated by interaction between the classical nuclear localization signals (NLSs) contained within them and the importin NLS receptor complex. We have recently delineated a novel 38 amino acid transport signal in the hnRNP A1 protein, termed M9, which confers bidirectional transport across the nuclear envelope. We show here that M9-mediated nuclear import occurs by a novel pathway that is independent of the well-characterized, importin-mediated classical NLS pathway. Additionally, we have identified a specific M9-interacting protein, termed transportin, which binds to wild-type M9 but not to transport-defective M9 mutants. Transportin is a 90 kDa protein, distantly related to importin beta, and we show that it mediates the nuclear import of M9-containing proteins. These findings demonstrate that there are at least two receptor-mediated nuclear protein import pathways. Furthermore, as hnRNP A1 likely participates in mRNA export, it raises the possibility that transportin is a mediator of this process as well.
Sergey A Krupenko - One of the best experts on this subject based on the ideXlab platform.
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organization of the Transcortin binding domain on placental plasma membranes
Biochimica et Biophysica Acta, 1995Co-Authors: Sergey A Krupenko, Oleg I Kolesnik, Natalia I Krupenko, Oleg A StrelchyonokAbstract:Complex formation between Transcortin (corticosteroid-binding globulin) and 20 kDa sialoglycoprotein from human syncytiotrophoblast plasma membranes (presumably a Transcortin-recognizing subunit of the Transcortin membrane receptor) was studied using FPLC and cross-linking with bifunctional reagents. The action of 1,5-difluoro-2,4-dinitrobenzene (DFDNB) on a solution of the purified 20 kDa sialoglycoprotein and Transcortin resulted in formation of covalently linked complexes of 95 kDa and 140 kDa consisting of one Transcortin molecule and either two or four molecules of the membrane sialoglycoprotein (the molecular mass of Transcortin is 55 kDa). Additionally, cross-linking resulted in the appearance of a 43 kDa species which is the cross-linked dimer of the membrane protein. The dimer was also observed during chromatography on a Superose 12 column in the absence of DFDNB treatment. Treatment of intact syncytiotrophoblast membranes with DFDNB resulted in isolation of the Transcortin binding protein dimer as the major portion of total pool of the protein. Formation of the Transcortin complexes with two and four molecules of the membrane protein was also observed when the membranes were incubated with 125I-labeled Transcortin and treated with DFDNB, but formation of the latter complexes predominated. The results obtained suggest that the recognizing and binding domain for Transcortin in placental membranes is organized as dimers consisting of non-covalently linked sialoglycoprotein monomers of a 20 kDa each and that Transcortin has two sites for interaction with this dimer. Apparently, binding of two dimers results in the formation of the functional form of the Transcortin-receptor complex. The possible biological role of such a complex is discussed.
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testosterone destroys the Transcortin receptor complex
Biochemical and Biophysical Research Communications, 1992Co-Authors: Sergey A Krupenko, Oleg A StrelchyonokAbstract:Abstract Dissociation of the complex of Transcortin receptor with immobilized Transcortin in the presence of 10 −5 M testosterone has been shown with the use of affinity chromatography on Transcortin-Sepharose. The specificity of this effect is confirmed by its abrogation in the presence of cortisol. The testosterone effect has been used for the elution of Transcortin receptor from affinity column. The receptor retained Transcortin-binding capacity after the elution and removal of testosterone. Characteristics of the receptor obtained by testosterone elution were identical with those of the Transcortin eluted preparation.
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a Transcortin binding protein in the plasma membrane of human syncytiotrophoblast
Biochemical and Biophysical Research Communications, 1991Co-Authors: Sergey A Krupenko, George V Avvakumov, Oleg A StrelchyonokAbstract:Using affinity chromatography on immobilized Transcortin of 125I-labeled, cholate-solubilized plasma membranes of human syncytiotrophoblast, a Transcortin-binding protein with a minimal Mr of about 20 kDa has been isolated. It was found to be a sialoglycoprotein with an isoelectric point at pH 4.4 (about 5.0 after the treatment with neuraminidase). We assume that this protein is a component of membrane recognition system for Transcortin-steroid complexes.
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on the functional form of Transcortin recognizing subunit of Transcortin membrane receptor
FEBS Letters, 1991Co-Authors: Sergey A Krupenko, George V Avvakumov, Oleg A StrelchyonokAbstract:Abstract Complex formation between Transcortin and the 20 kDa sialoglycoprotein from the plasma membrane of human decidual endometrium (presumably a Transcortin-recognizing subunit of Transcortin membranes receptor) was studied using cross-linking reagents. The action of 1,5-difluoro-3,4-dinitrobenzene (DFDNB) on a solution of 125I-labelled 20 kDa sialoglycoprotein and unlabelled Transcortin resulted in the formation of two 125I-containing species that corresponded to covalently linked complexes of one Transcortin molecule and either 2 or 4 molecules of the labelled membrane sialoglycoprotein. Only the latter complex was observed when the endometrium membranes were incubated with [25I]Transcortin and treated with DFDNB. This suggests that the functional form of Transcortin-recognizing subunit of the membrane receptor is a tetramer.
Victoria W Pollard - One of the best experts on this subject based on the ideXlab platform.
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a novel receptor mediated nuclear protein import pathway
Cell, 1996Co-Authors: Victoria W Pollard, Matthew W Michael, Sara Nakielny, Mikiko C Siomi, Fan Wang, Gideon DreyfussAbstract:Abstract Targeting of most nuclear proteins to the cell nucleus is initiated by interaction between the classical nuclear localization signals (NLSs) contained within them and the importin NLS receptor complex. We have recently delineated a novel 38 amino acid transport signal in the hnRNP A1 protein, termed M9, which confers bidirectional transport across the nuclear envelope. We show here that M9-mediated nuclear import occurs by a novel pathway that is independent of the well-characterized, importin-mediated classical NLS pathway. Additionally, we have identified a specific M9-interacting protein, termed transportin, which binds to wild-type M9 but not to transport-defective M9 mutants. Transportin is a 90 kDa protein, distantly related to importin β, and we show that it mediates the nuclear import of M9-containing proteins. These findings demonstrate that there are at least two receptor-mediated nuclear protein import pathways. Furthermore, as hnRNP A1 likely participates in mRNA export, it raises the possibility that transportin is a mediator of this process as well.
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a novel receptor mediated nuclear protein import pathway
Cell, 1996Co-Authors: Victoria W Pollard, Matthew W Michael, Sara Nakielny, Mikiko C Siomi, Fan Wang, Gideon DreyfussAbstract:Targeting of most nuclear proteins to the cell nucleus is initiated by interaction between the classical nuclear localization signals (NLSs) contained within them and the importin NLS receptor complex. We have recently delineated a novel 38 amino acid transport signal in the hnRNP A1 protein, termed M9, which confers bidirectional transport across the nuclear envelope. We show here that M9-mediated nuclear import occurs by a novel pathway that is independent of the well-characterized, importin-mediated classical NLS pathway. Additionally, we have identified a specific M9-interacting protein, termed transportin, which binds to wild-type M9 but not to transport-defective M9 mutants. Transportin is a 90 kDa protein, distantly related to importin beta, and we show that it mediates the nuclear import of M9-containing proteins. These findings demonstrate that there are at least two receptor-mediated nuclear protein import pathways. Furthermore, as hnRNP A1 likely participates in mRNA export, it raises the possibility that transportin is a mediator of this process as well.
Fan Wang - One of the best experts on this subject based on the ideXlab platform.
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a novel receptor mediated nuclear protein import pathway
Cell, 1996Co-Authors: Victoria W Pollard, Matthew W Michael, Sara Nakielny, Mikiko C Siomi, Fan Wang, Gideon DreyfussAbstract:Abstract Targeting of most nuclear proteins to the cell nucleus is initiated by interaction between the classical nuclear localization signals (NLSs) contained within them and the importin NLS receptor complex. We have recently delineated a novel 38 amino acid transport signal in the hnRNP A1 protein, termed M9, which confers bidirectional transport across the nuclear envelope. We show here that M9-mediated nuclear import occurs by a novel pathway that is independent of the well-characterized, importin-mediated classical NLS pathway. Additionally, we have identified a specific M9-interacting protein, termed transportin, which binds to wild-type M9 but not to transport-defective M9 mutants. Transportin is a 90 kDa protein, distantly related to importin β, and we show that it mediates the nuclear import of M9-containing proteins. These findings demonstrate that there are at least two receptor-mediated nuclear protein import pathways. Furthermore, as hnRNP A1 likely participates in mRNA export, it raises the possibility that transportin is a mediator of this process as well.
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a novel receptor mediated nuclear protein import pathway
Cell, 1996Co-Authors: Victoria W Pollard, Matthew W Michael, Sara Nakielny, Mikiko C Siomi, Fan Wang, Gideon DreyfussAbstract:Targeting of most nuclear proteins to the cell nucleus is initiated by interaction between the classical nuclear localization signals (NLSs) contained within them and the importin NLS receptor complex. We have recently delineated a novel 38 amino acid transport signal in the hnRNP A1 protein, termed M9, which confers bidirectional transport across the nuclear envelope. We show here that M9-mediated nuclear import occurs by a novel pathway that is independent of the well-characterized, importin-mediated classical NLS pathway. Additionally, we have identified a specific M9-interacting protein, termed transportin, which binds to wild-type M9 but not to transport-defective M9 mutants. Transportin is a 90 kDa protein, distantly related to importin beta, and we show that it mediates the nuclear import of M9-containing proteins. These findings demonstrate that there are at least two receptor-mediated nuclear protein import pathways. Furthermore, as hnRNP A1 likely participates in mRNA export, it raises the possibility that transportin is a mediator of this process as well.
