Transcription factor Sp3 antagonizes activation of the ornithine decarboxylase promoter by Sp1

Addanki P Kumar, Andrew P. Butler

Research output: Contribution to journalArticle

80 Citations (Scopus)

Abstract

Ornithine decarboxylase (ODC) expression is important for proliferation and is elevated in many tumor cells. We previously showed that Sp1 is a major positive regulator of ODC transcription. In this paper we have investigated transcriptional regulation of rat ODC by the closely related factor Sp3. White over-expression of Sp1 caused a dramatic activation of the ODC promoter, over-expression of Sp3 caused little or no activation in either Drosophila SL2 cells (lacking endogenous Sp1 or Sp3) or in H35 rat hepatoma cells. Furthermore, co-transfection studies demonstrated that Sp3 abolished transactivation of the ODC promoter by Sp1. DNase I footprint studies and electrophoretic mobility shift assays demonstrated that both recombinant Sp1 and Sp3 bind specifically to several sites within the ODC promoter also protected by nuclear extracts, including overlapping GC and CT motifs located between -116 and -104. This CT element is a site of negative ODC regulation. Mutation of either element reduced binding, but mutation of both sites was required to eliminate binding of either Sp1 or Sp3. These results demonstrate that ODC is positively regulated by Sp1 and negatively regulated by Sp3, suggesting that the ratio of these transcription factors may be an important determinant of ODC expression during development or transformation.

Original languageEnglish (US)
Pages (from-to)2012-2019
Number of pages8
JournalNucleic Acids Research
Volume25
Issue number10
DOIs
StatePublished - 1997
Externally publishedYes

Fingerprint

Sp3 Transcription Factor
Ornithine Decarboxylase
Mutation
Deoxyribonuclease I
Electrophoretic Mobility Shift Assay
Transcriptional Activation
Drosophila
Transfection
Hepatocellular Carcinoma
Transcription Factors

ASJC Scopus subject areas

  • Genetics

Cite this

Transcription factor Sp3 antagonizes activation of the ornithine decarboxylase promoter by Sp1. / Kumar, Addanki P; Butler, Andrew P.

In: Nucleic Acids Research, Vol. 25, No. 10, 1997, p. 2012-2019.

Research output: Contribution to journalArticle

@article{9e5af56b3ef94d609e97894dbf1cb619,
title = "Transcription factor Sp3 antagonizes activation of the ornithine decarboxylase promoter by Sp1",
abstract = "Ornithine decarboxylase (ODC) expression is important for proliferation and is elevated in many tumor cells. We previously showed that Sp1 is a major positive regulator of ODC transcription. In this paper we have investigated transcriptional regulation of rat ODC by the closely related factor Sp3. White over-expression of Sp1 caused a dramatic activation of the ODC promoter, over-expression of Sp3 caused little or no activation in either Drosophila SL2 cells (lacking endogenous Sp1 or Sp3) or in H35 rat hepatoma cells. Furthermore, co-transfection studies demonstrated that Sp3 abolished transactivation of the ODC promoter by Sp1. DNase I footprint studies and electrophoretic mobility shift assays demonstrated that both recombinant Sp1 and Sp3 bind specifically to several sites within the ODC promoter also protected by nuclear extracts, including overlapping GC and CT motifs located between -116 and -104. This CT element is a site of negative ODC regulation. Mutation of either element reduced binding, but mutation of both sites was required to eliminate binding of either Sp1 or Sp3. These results demonstrate that ODC is positively regulated by Sp1 and negatively regulated by Sp3, suggesting that the ratio of these transcription factors may be an important determinant of ODC expression during development or transformation.",
author = "Kumar, {Addanki P} and Butler, {Andrew P.}",
year = "1997",
doi = "10.1093/nar/25.10.2012",
language = "English (US)",
volume = "25",
pages = "2012--2019",
journal = "Nucleic Acids Research",
issn = "0305-1048",
publisher = "Oxford University Press",
number = "10",

}

TY - JOUR

T1 - Transcription factor Sp3 antagonizes activation of the ornithine decarboxylase promoter by Sp1

AU - Kumar, Addanki P

AU - Butler, Andrew P.

PY - 1997

Y1 - 1997

N2 - Ornithine decarboxylase (ODC) expression is important for proliferation and is elevated in many tumor cells. We previously showed that Sp1 is a major positive regulator of ODC transcription. In this paper we have investigated transcriptional regulation of rat ODC by the closely related factor Sp3. White over-expression of Sp1 caused a dramatic activation of the ODC promoter, over-expression of Sp3 caused little or no activation in either Drosophila SL2 cells (lacking endogenous Sp1 or Sp3) or in H35 rat hepatoma cells. Furthermore, co-transfection studies demonstrated that Sp3 abolished transactivation of the ODC promoter by Sp1. DNase I footprint studies and electrophoretic mobility shift assays demonstrated that both recombinant Sp1 and Sp3 bind specifically to several sites within the ODC promoter also protected by nuclear extracts, including overlapping GC and CT motifs located between -116 and -104. This CT element is a site of negative ODC regulation. Mutation of either element reduced binding, but mutation of both sites was required to eliminate binding of either Sp1 or Sp3. These results demonstrate that ODC is positively regulated by Sp1 and negatively regulated by Sp3, suggesting that the ratio of these transcription factors may be an important determinant of ODC expression during development or transformation.

AB - Ornithine decarboxylase (ODC) expression is important for proliferation and is elevated in many tumor cells. We previously showed that Sp1 is a major positive regulator of ODC transcription. In this paper we have investigated transcriptional regulation of rat ODC by the closely related factor Sp3. White over-expression of Sp1 caused a dramatic activation of the ODC promoter, over-expression of Sp3 caused little or no activation in either Drosophila SL2 cells (lacking endogenous Sp1 or Sp3) or in H35 rat hepatoma cells. Furthermore, co-transfection studies demonstrated that Sp3 abolished transactivation of the ODC promoter by Sp1. DNase I footprint studies and electrophoretic mobility shift assays demonstrated that both recombinant Sp1 and Sp3 bind specifically to several sites within the ODC promoter also protected by nuclear extracts, including overlapping GC and CT motifs located between -116 and -104. This CT element is a site of negative ODC regulation. Mutation of either element reduced binding, but mutation of both sites was required to eliminate binding of either Sp1 or Sp3. These results demonstrate that ODC is positively regulated by Sp1 and negatively regulated by Sp3, suggesting that the ratio of these transcription factors may be an important determinant of ODC expression during development or transformation.

UR - http://www.scopus.com/inward/record.url?scp=0030871232&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0030871232&partnerID=8YFLogxK

U2 - 10.1093/nar/25.10.2012

DO - 10.1093/nar/25.10.2012

M3 - Article

C2 - 9115370

AN - SCOPUS:0030871232

VL - 25

SP - 2012

EP - 2019

JO - Nucleic Acids Research

JF - Nucleic Acids Research

SN - 0305-1048

IS - 10

ER -