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Title: Identification of poly(rC) binding protein 2 (PCBP2) as a target protein of immunosuppressive agent 15-deoxyspergualin

Abstract

15-Deoxyspergualin (DSG) is an immunosuppressive agent being clinically used. Unlike tacrolimus and cyclosporine A, it does not inhibit the calcineurin pathway, and its mechanism of action and target molecule have not been elucidated. Therefore, we previously prepared biotinylated derivative of DSG (BDSG) to fish up the target protein. In the present research, we identified poly(rC) binding protein 2 (PCBP2) as a DSG-binding protein using this probe. DSG was confirmed to bind to PCBP2 by pull-down assay. Intracellular localization of PCBP2 was changed from the nucleus to the cytoplasm by DSG treatment. DSG inhibited the cell growth, and over-expression of PCBP2 reduced the anti-proliferative activity of DSG. PCBP2 is known to regulate various proteins including STAT1/2. Thus, we found PCBP2 as the first target protein of DSG that can explain the immunosuppressive activity. -- Highlights: •Fifteen-deoxyspergualin (DSG) is an immunosuppressive agent clinically used. •We have identified PCBP2, an RNA-binding protein, as a molecular target of DSG. •Alteration of PCBP2 activity may explain the immunosuppressive activity of DSG.

Authors:
; ;  [1];  [2]
  1. Department of Applied Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522 (Japan)
  2. Department of Molecular Target Medicine, Aichi Medical University School of Medicine, 1-1 Yazako-Karimata, Nagakute 480-1195 (Japan)
Publication Date:
OSTI Identifier:
22598797
Resource Type:
Journal Article
Resource Relation:
Journal Name: Biochemical and Biophysical Research Communications; Journal Volume: 476; Journal Issue: 4; Other Information: Copyright (c) 2016 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
60 APPLIED LIFE SCIENCES; BIOTIN; CYCLOSPORINE; CYTOPLASM; HEAT-SHOCK PROTEINS; MOLECULES; RNA; TRANSCRIPTION; TRANSDUCERS

Citation Formats

Murahashi, Masataka, Simizu, Siro, Morioka, Masahiko, and Umezawa, Kazuo, E-mail: umezawa@aichi-med-u.ac.jp. Identification of poly(rC) binding protein 2 (PCBP2) as a target protein of immunosuppressive agent 15-deoxyspergualin. United States: N. p., 2016. Web. doi:10.1016/J.BBRC.2016.05.142.
Murahashi, Masataka, Simizu, Siro, Morioka, Masahiko, & Umezawa, Kazuo, E-mail: umezawa@aichi-med-u.ac.jp. Identification of poly(rC) binding protein 2 (PCBP2) as a target protein of immunosuppressive agent 15-deoxyspergualin. United States. doi:10.1016/J.BBRC.2016.05.142.
Murahashi, Masataka, Simizu, Siro, Morioka, Masahiko, and Umezawa, Kazuo, E-mail: umezawa@aichi-med-u.ac.jp. Fri . "Identification of poly(rC) binding protein 2 (PCBP2) as a target protein of immunosuppressive agent 15-deoxyspergualin". United States. doi:10.1016/J.BBRC.2016.05.142.
@article{osti_22598797,
title = {Identification of poly(rC) binding protein 2 (PCBP2) as a target protein of immunosuppressive agent 15-deoxyspergualin},
author = {Murahashi, Masataka and Simizu, Siro and Morioka, Masahiko and Umezawa, Kazuo, E-mail: umezawa@aichi-med-u.ac.jp},
abstractNote = {15-Deoxyspergualin (DSG) is an immunosuppressive agent being clinically used. Unlike tacrolimus and cyclosporine A, it does not inhibit the calcineurin pathway, and its mechanism of action and target molecule have not been elucidated. Therefore, we previously prepared biotinylated derivative of DSG (BDSG) to fish up the target protein. In the present research, we identified poly(rC) binding protein 2 (PCBP2) as a DSG-binding protein using this probe. DSG was confirmed to bind to PCBP2 by pull-down assay. Intracellular localization of PCBP2 was changed from the nucleus to the cytoplasm by DSG treatment. DSG inhibited the cell growth, and over-expression of PCBP2 reduced the anti-proliferative activity of DSG. PCBP2 is known to regulate various proteins including STAT1/2. Thus, we found PCBP2 as the first target protein of DSG that can explain the immunosuppressive activity. -- Highlights: •Fifteen-deoxyspergualin (DSG) is an immunosuppressive agent clinically used. •We have identified PCBP2, an RNA-binding protein, as a molecular target of DSG. •Alteration of PCBP2 activity may explain the immunosuppressive activity of DSG.},
doi = {10.1016/J.BBRC.2016.05.142},
journal = {Biochemical and Biophysical Research Communications},
number = 4,
volume = 476,
place = {United States},
year = {Fri Aug 05 00:00:00 EDT 2016},
month = {Fri Aug 05 00:00:00 EDT 2016}
}
  • Highlights: • PCBP2 expression is over-expressed in human glioma tissues and cell lines. • SIRT6 is decreased in glioma and correlated with PCBP2. • SIRT6 inhibits PCBP2 expression by deacetylating H3K9. • SIRT6 inhibits glioma growth in vitro and in vivo. - Abstract: More than 80% of tumors that occur in the brain are malignant gliomas. The prognosis of glioma patients is still poor, which makes glioma an urgent subject of cancer research. Previous evidence and our present data show that PCBP2 is over-expressed in human glioma tissues and predicts poor outcome. However, the mechanism by which PCBP2 is regulatedmore » in glioma remains elusive. We find that SIRT6, one of the NAD{sup +}-dependent class III deacetylase SIRTUINs, is down-regulated in human glioma tissues and that the level of SIRT6 is negatively correlated with PCBP2 level while H3K9ac enrichment on the promoter of PCBP2 is positively correlated with PCBP2 expression. Furthermore, we identify PCBP2 as a target of SIRT6. We demonstrate that PCBP2 expression is inhibited by SIRT6, which depends upon deacetylating H3K9ac. Finally, our results reveal that SIRT6 inhibits glioma cell proliferation and colony formation in vitro and glioma cell growth in vivo in a PCBP2 dependent manner. In summary, our findings implicate that SIRT6 inhibits PCBP2 expression through deacetylating H3K9ac and SIRT6 acts as a tumor suppressor in human glioma.« less
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  • A novel 2'-modification, 2'-O-[2-(methylthio)ethyl] or 2'-O-MTE, has been incorporated into oligonucleotides and evaluated for properties relevant to antisense activity. The results were compared with the previously characterized 2'-O-[2-(methoxy)ethyl] 2'-O-MOE modification. As expected, the 2'-O-MTE modified oligonucleotides exhibited improved binding to human serum albumin compared to the 2'-O-MOE modified oligonucleotides. The 2'-O-MTE oligonucleotides maintained high binding affinity to target RNA. Nuclease digestion of 2'-O-MTE oligonucleotides showed that they have limited resistance to exonuclease degradation. We analyzed the crystal structure of a decamer DNA duplex containing the 2'-O-MTE modifcation. Analysis of the crystal structure provides insight into the improved RNA binding affinity,more » protein binding affinity and limited resistance of 2'-O-MTE modified oligonucleotides to exonuclease degradation.« less
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