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

J. Biol. Chem., Vol. 279, Issue 25, 26433-26444, June 18, 2004

This Article Full Text Full Text (PDF) Supplemental Data All Versions of this Article: 279/25/26433    most recent M312842200v1 Submit a Letter to Editor Alert me when this article is cited Alert me when eLetters are posted 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 Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Bondos, S. E. Articles by Matthews, K. S. Search for Related Content PubMed PubMed Citation Articles by Bondos, S. E. Articles by Matthews, K. S. Social Bookmarking                      What's this?

Hox Transcription Factor Ultrabithorax Ib Physically and Genetically Interacts with Disconnected Interacting Protein 1, a Double-stranded RNA-binding Protein^*

Sarah E. Bondos, Daniel J. Catanese, Jr., Xin-Xing Tan¶, Alicia Bicknell||, Likun Li**, and Kathleen S. Matthews

From the Department of Biochemistry and Cell Biology, Rice University, Houston, Texas 77005

The Hox protein family consists of homeodomain-containing transcription factors that are primary determinants of cell fate during animal development. Specific Hox function appears to rely on protein-protein interactions; however, the partners involved in these interactions and their function are largely unknown. Disconnected Interacting Protein 1 (DIP1) was isolated in a yeast two-hybrid screen of a 0–12-h Drosophila embryo library designed to identify proteins that interact with Ultrabithorax (Ubx), a Drosophila Hox protein. The Ubx ·DIP1 physical interaction was confirmed using phage display, immunoprecipitation, pull-down assays, and gel retardation analysis. Ectopic expression of DIP1 in wing and haltere imaginal discs malforms the adult structures and enhances a decreased Ubx expression phenotype, establishing a genetic interaction. Ubx can generate a ternary complex by simultaneously binding its target DNA and DIP1. A large region of Ubx, including the repression domain, is required for interaction with DIP1. These more variable sequences may be key to the differential Hox function observed in vivo. The Ubx ·DIP1 interaction prevents transcriptional activation by Ubx in a modified yeast one-hybrid assay, suggesting that DIP1 may modulate transcriptional regulation by Ubx. The DIP1 sequence contains two dsRNA-binding domains, and DIP1 binds double-stranded RNA with a 1000-fold higher affinity than either single-stranded RNA or double-stranded DNA. The strong interaction of Ubx with an RNA-binding protein suggests a wider range of proteins may influence Ubx function than previously appreciated.

Received for publication, November 24, 2003 , and in revised form, March 4, 2004.

^* This work was supported by National Institutes of Health (NIH) Grant GM22441 (to K. S. M.) and Robert A. Welch Foundation Grant C-576. Spectroscopic facilities utilized were provided by the Keck Center for Computational Biology and the Lucille P. Markey Charitable Trust. 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.

The on-line version of this article (available at http://www.jbc.org) contains two additional figures.

These three authors contributed equally to this work.

Was supported in part by NIH Molecular Biophysics Training Grant 5T32-GM08208.

^¶ Present address: CytoGenix, Inc., 9881 S. Wilcrest, Houston, TX 77099.

^|| Present address: UCSD Biology Student Affairs 038, 9500 Gilman Dr., La Jolla, CA 92093-0348.

^** Present address: Scott Dept. of Urology, Baylor College of Medicine, 6560 Fannin, Suite 2100, Houston, TX 77030.

To whom correspondence should be addressed: Dept. of Biochemistry and Cell Biology, Rice University, 6100 S. Main Street, Houston, TX 77005. Tel.: 713-348-4871; Fax: 713-348-6149; E-mail: ksm{at}rice.edu.

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

This article has been cited by other articles:

				Y. Liu, K. S. Matthews, and S. E. Bondos Multiple Intrinsically Disordered Sequences Alter DNA Binding by the Homeodomain of the Drosophila Hox Protein Ultrabithorax J. Biol. Chem., July 25, 2008; 283(30): 20874 - 20887. [Abstract] [Full Text] [PDF]