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

J. Biol. Chem., Vol. 280, Issue 11, 9786-9795, March 18, 2005

This Article Full Text Full Text (PDF) All Versions of this Article: 280/11/9786    most recent M414006200v1 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 Arinze, I. J. Articles by Kawai, Y. Search for Related Content PubMed PubMed Citation Articles by Arinze, I. J. Articles by Kawai, Y. Social Bookmarking                      What's this?

Transcriptional Activation of the Human G_i2 Gene Promoter through Nuclear Factor-B and Antioxidant Response Elements^*

Ifeanyi J. Arinze and Yumiko Kawai

From the Department of Biochemistry, Meharry Medical College, Nashville, Tennessee 37208-3599

Very little is known regarding molecular mechanism(s) underlying transcriptional regulation of any G-protein gene despite the importance of G-protein expression in modulating cellular processes. Here we show that phorbol myristate acetate (PMA) and tert-butylhydroquinone (tBHQ), which induce oxidative stress in cells, up-regulate transcription of G_i2 in K562 cells. Redox-sensing chemicals abrogated this transcriptional effect. A dominant negative I-B double mutant (S32A/S36A) suppressed PMA-induced transcription by 54–62%, suggesting involvement of nuclear factor-B (NF-B). SN50, a cell-permeable peptide that inhibits nuclear import of stress-responsive transcription factors (such as NF-B), inhibited PMA- and tBHQ-induced transcription. Deletion of an NF-B-binding motif that maps at +10/+19 in the promoter resulted in 55–60% suppression of PMA-induced transcription, and 81% suppression of tBHQ-induced transcription. Mutation of an antioxidant response element (ARE) that maps at –84/–76 in the promoter resulted in 51 and 86% decrease in PMA- and tBHQ-induced transcription, respectively. In electrophoretic mobility shift assays, this element formed complexes with the transcription factors NF-E2p45 and Nrf2 that are prototypic for binding to the ARE, as well as with c-Fos, which can also interact with the ARE. Chromatin immunoprecipitation analysis demonstrated recruitment of these transcription factors to the promoter. Exogenously transfected Nrf2 transactivated the G_i2 gene promoter; the cytoskeleton-associated protein, Keap1, abrogated this effect. Taken together, the present studies reveal that transcription factors that bind NF-B and/or antioxidant response elements play an activating role in the transcription of the human G_i2 gene.

Received for publication, December 13, 2004 , and in revised form, January 7, 2005.

^* This work was supported by National Science Foundation Grant MCB-9905070 and by Grant S06-GM08037-32 from the NIGMS, National Institutes of Health. 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.

To whom correspondence should be addressed: Dept. of Biochemistry, Meharry Medical College, 1005 David B. Todd Jr., Blvd., Nashville, TN 37208-3599. Tel.: 615-327-6586; Fax: 615-327-6442; E-mail: iarinze{at}mmc.edu.

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

This article has been cited by other articles:

				M. Theodore, Y. Kawai, J. Yang, Y. Kleshchenko, S. P. Reddy, F. Villalta, and I. J. Arinze Multiple Nuclear Localization Signals Function in the Nuclear Import of the Transcription Factor Nrf2 J. Biol. Chem., April 4, 2008; 283(14): 8984 - 8994. [Abstract] [Full Text] [PDF]

				Y. Kawai and I. J. Arinze Valproic Acid-Induced Gene Expression through Production of Reactive Oxygen Species. Cancer Res., July 1, 2006; 66(13): 6563 - 6569. [Abstract] [Full Text] [PDF]

				N. R. Chapman, I. Smyrnias, D. O. C. Anumba, G. N. Europe-Finner, and S. C. Robson Expression of the GTP-Binding Protein (G{alpha}s) Is Repressed by the Nuclear Factor {kappa}B RelA Subunit in Human Myometrium Endocrinology, November 1, 2005; 146(11): 4994 - 5002. [Abstract] [Full Text] [PDF]