Abstract

The bcl-3 proto-oncogene encodes a nuclear I kappa B-like molecule that preferentially interacts with NF-kappa B p50 and p52 in a phosphorylation-dependent manner. G P Nolan , T Fujita , K Bhatia , C Huppi , H C Liou , M L Scott and D Baltimore Rockefeller University, New York, New York 10021. ABSTRACT The product of the putative proto-oncogene bcl-3 is an I kappa B-like molecule with novel binding properties specific for a subset of the rel family of transcriptional regulators. In vitro, Bcl-3 protein specifically inhibited the DNA binding of both the homodimeric NF-kappa B p50 subunit and a closely related homolog, p52 (previously p49), to immunoglobulin kappa NF-kappa B DNA motifs. Bcl-3 could catalyze the removal of these proteins from DNA. At concentrations that significantly inhibited DNA binding by homodimeric p50, Bcl-3 did not inhibit binding of reconstituted heterodimeric NF-kappa B (p50:p65), a DNA-binding homodimeric form of p65, or homodimers of c-Rel. Phosphatase treatment of Bcl-3 partially inactivated its inhibitory properties, implicating a role for phosphorylation in the regulation of Bcl-3 activity. Bcl-3, like p50, localizes to the cell nucleus. In cells cotransduced with Bcl-3 and p50, both molecules could be found in the nucleus of the same cells. Interestingly, coexpression of Bcl-3 with a p50 mutant deleted for its nuclear-localizing signal resulted in the relocalization of Bcl-3 to the cytoplasm, showing that the proteins interact in the cell. These properties contrast Bcl-3 to classically defined I kappa B, which maintains heterodimeric NF-kappa B p50:p65 in the cytoplasm through specific interactions with the p65 subunit. Bcl-3 appears to be a nuclear, I kappa B-related molecule that regulates the activity of homodimeric nuclear p50 and its homolog p52. CiteULike Connotea Delicious Digg Facebook Google+ Mendeley Reddit StumbleUpon Twitter What's this? « Previous | Next Article » Table of Contents This Article doi: 10.1128/​MCB.13.6.3557 Mol. Cell. Biol. June 1993 vol. 13 no. 6 3557-3566 » Abstract PDF Classifications Research Article Services Email this article to a colleague Similar articles in ASM journals Alert me when this article is cited Alert me if a correction is posted Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of MCB Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Load citing article information Citing articles via Web of Science Citing articles via Google Scholar Google Scholar Articles by Nolan, G. P. Articles by Baltimore, D. Search for related content PubMed PubMed citation Articles by Nolan, G. P. Articles by Baltimore, D. Related Content Load related web page information Social Bookmarking CiteULike Connotea Delicious Digg Facebook Google+ Mendeley Reddit StumbleUpon Twitter What's this? current issue January 2012, volume 32, issue 1 Spotlights in the Current Issue Architecture of the Yeast RNA Polymerase II Open Complex State and Regulation by TFIIF GATA-1 Establishes Cell-Type-Specific Autophagy as a Developmental Program Prickle Phosphorylation Regulates Its Localization and β-Catenin-Independent Wnt Signaling Alert me to new issues of MCB About MCB Subscribers Authors Reviewers Advertisers Inquiries from the Press Permissions & Commercial Reprints ASM Journals Public Access Policy MCB RSS Feeds 1752 N Street N.W. • Washington DC 20036 202.737.3600 • 202.942.9355 fax • journals@asmusa.org Print ISSN: 0270-7306 Online ISSN: 1098-5549 Copyright © 2011 by the American Society for Microbiology. For an alternate route to MCB .asm.org, visit: http://intl- MCB .asm.org | More Info» var gaJsHost = (("https:" == document.location.protocol) ? "https://ssl." : "http://www."); document.write(unescape("%3Cscript src='" + gaJsHost + "google-analytics.com/ga.js' type='text/javascript'%3E%3C/script%3E")); var pageTracker = _gat._getTracker("UA-5821458-11"); pageTracker._trackPageview();