HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

J. Biol. Chem., Vol. 280, Issue 16, 16143-16150, April 22, 2005

This Article Full Text Full Text (PDF) All Versions of this Article: 280/16/16143    most recent M410175200v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Martic, G. Articles by Papamarcaki, T. Search for Related Content PubMed PubMed Citation Articles by Martic, G. Articles by Papamarcaki, T. Social Bookmarking                      What's this?

Parathymosin Affects the Binding of Linker Histone H1 to Nucleosomes and Remodels Chromatin Structure^*

Goran Martic, Zoe Karetsou, Katerina Kefala, Anastasia S. Politou, Cedric R. Clapier¶, Tobias Straub||, and Thomais Papamarcaki**

From the Laboratory of Biological Chemistry, Medical School, University of Ioannina, 451 10 Ioannina, Greece, the ^¶EMBL Grenoble Outstation, BP181 38042 Grenoble Cedex 9, France, the ^||Adolf-Butenandt-Institute, Molecular Biology, Schillerstrasse 44, 80336 Munich, Germany, and the ^**Foundation for Research and Technology-Hellas/Biomedical Research Institute, 451 10 Ioannina, Greece

Linker histone H1 is the major factor that stabilizes higher order chromatin structure and modulates the action of chromatin-remodeling enzymes. We have previously shown that parathymosin, an acidic, nuclear protein binds to histone H1 in vitro and in vivo. Confocal laser scanning microscopy reveals a nuclear punctuate staining of the endogenous protein in interphase cells, which is excluded from dense heterochromatic regions. Using an in vitro chromatin reconstitution system under physiological conditions, we show here that parathymosin (ParaT) inhibits the binding of H1 to chromatin in a dose-dependent manner. Consistent with these findings, H1-containing chromatin assembled in the presence of ParaT has reduced nucleosome spacing. These observations suggest that interaction of the two proteins might result in a conformational change of H1. Fluorescence spectroscopy and circular dichroism-based measurements on mixtures of H1 and ParaT confirm this hypothesis. Human sperm nuclei challenged with ParaT become highly decondensed, whereas overexpression of green fluorescent protein- or FLAG-tagged protein in HeLa cells induces global chromatin decondensation and increases the accessibility of chromatin to micrococcal nuclease digestion. Our data suggest a role of parathymosin in the remodeling of higher order chromatin structure through modulation of H1 interaction with nucleosomes and point to its involvement in chromatin-dependent functions.

Received for publication, September 3, 2004 , and in revised form, February 15, 2005.

^* This work was supported in part by a PENED 1999 Grant from the Greek Secretariat of Research and Technology. The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

Recipient of a predoctoral fellowship from the Greek State Scholarship Foundation.

To whom correspondence should be addressed: Tel.: 30-26510-97563; Fax: 30-26510-97868; E-mail: thpapama{at}cc.uoi.gr.

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				K. Okamoto and F. Isohashi Macromolecular Translocation Inhibitor II (Zn2+-binding Protein, Parathymosin) Interacts with the Glucocorticoid Receptor and Enhances Transcription in Vivo J. Biol. Chem., November 4, 2005; 280(44): 36986 - 36993. [Abstract] [Full Text] [PDF]

				J. F. Kepert, J. Mazurkiewicz, G. L. Heuvelman, K. F. Toth, and K. Rippe NAP1 Modulates Binding of Linker Histone H1 to Chromatin and Induces an Extended Chromatin Fiber Conformation J. Biol. Chem., October 7, 2005; 280(40): 34063 - 34072. [Abstract] [Full Text] [PDF]