Distinct roles for Sp1 and E2F sites in the growth/cell cycle regulation of the DHFR promoter

David E. Jensen, Adrian R. Black, Andrew G. Swick, Jane Clifford Azizkhan

Research output: Contribution to journalArticle

53 Citations (Scopus)

Abstract

Dihydrofolate reductase activity is required for many biosynthetic pathways including nucleotide synthesis. Its expression is therefore central to cellular growth, and it has become a key target for cancer chemotherapy. Transcription of the dihydrofolate reductase gene is regulated with growth, being expressed maximally in late G1/early S phase following serum stimulation of quiescent cells. This regulation is directed by a promoter which contains binding sites for only the transcription factors Sp1 and E2F. In this study, the role of these promoter elements in growth/cell cycle regulation of dihydrofolate transcription was addressed directly by transient transfection of Balb/c 3T3 cells with mutant promoter-reporter gene constructs. The E2F sites were found to repress transcription in G0 and early G1 but did not contribute to the level of transcription in late G1/S phase. In contrast, Sp1 sites were able to mediate induction of transcription from the dihydrofolate reductase promoter, as well as a heterologous promoter, following serum stimulation of quiescent cells. These findings add dihydrofolate reductase to a growing list of genes at which E2F sites are primarily repressive elements and delineate a role for Sp1 sites in the growth/cell cycle regulation of transcription.

Original languageEnglish (US)
Pages (from-to)24-31
Number of pages8
JournalJournal of Cellular Biochemistry
Volume67
Issue number1
DOIs
StatePublished - Oct 1 1997

Fingerprint

Tetrahydrofolate Dehydrogenase
Cell growth
Transcription
Cell Cycle
Growth
S Phase
Genes
E2F Transcription Factors
3T3 Cells
Biosynthetic Pathways
G1 Phase
Serum
Reporter Genes
Transfection
Chemotherapy
Nucleotides
Binding Sites
Drug Therapy
Neoplasms

Keywords

  • Balb/c 3T3 cells
  • Dihydrofolate reductase
  • Gene expression
  • Growth control
  • Repression
  • Retinoblastoma
  • TATAA-less promoter
  • Transcription

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology

Cite this

Distinct roles for Sp1 and E2F sites in the growth/cell cycle regulation of the DHFR promoter. / Jensen, David E.; Black, Adrian R.; Swick, Andrew G.; Azizkhan, Jane Clifford.

In: Journal of Cellular Biochemistry, Vol. 67, No. 1, 01.10.1997, p. 24-31.

Research output: Contribution to journalArticle

Jensen, David E. ; Black, Adrian R. ; Swick, Andrew G. ; Azizkhan, Jane Clifford. / Distinct roles for Sp1 and E2F sites in the growth/cell cycle regulation of the DHFR promoter. In: Journal of Cellular Biochemistry. 1997 ; Vol. 67, No. 1. pp. 24-31.
@article{40359616fc63422f9369fdc3486ed355,
title = "Distinct roles for Sp1 and E2F sites in the growth/cell cycle regulation of the DHFR promoter",
abstract = "Dihydrofolate reductase activity is required for many biosynthetic pathways including nucleotide synthesis. Its expression is therefore central to cellular growth, and it has become a key target for cancer chemotherapy. Transcription of the dihydrofolate reductase gene is regulated with growth, being expressed maximally in late G1/early S phase following serum stimulation of quiescent cells. This regulation is directed by a promoter which contains binding sites for only the transcription factors Sp1 and E2F. In this study, the role of these promoter elements in growth/cell cycle regulation of dihydrofolate transcription was addressed directly by transient transfection of Balb/c 3T3 cells with mutant promoter-reporter gene constructs. The E2F sites were found to repress transcription in G0 and early G1 but did not contribute to the level of transcription in late G1/S phase. In contrast, Sp1 sites were able to mediate induction of transcription from the dihydrofolate reductase promoter, as well as a heterologous promoter, following serum stimulation of quiescent cells. These findings add dihydrofolate reductase to a growing list of genes at which E2F sites are primarily repressive elements and delineate a role for Sp1 sites in the growth/cell cycle regulation of transcription.",
keywords = "Balb/c 3T3 cells, Dihydrofolate reductase, Gene expression, Growth control, Repression, Retinoblastoma, TATAA-less promoter, Transcription",
author = "Jensen, {David E.} and Black, {Adrian R.} and Swick, {Andrew G.} and Azizkhan, {Jane Clifford}",
year = "1997",
month = "10",
day = "1",
doi = "10.1002/(SICI)1097-4644(19971001)67:1<24::AID-JCB3>3.0.CO;2-Y",
language = "English (US)",
volume = "67",
pages = "24--31",
journal = "Journal of Cellular Biochemistry",
issn = "0730-2312",
publisher = "Wiley-Liss Inc.",
number = "1",

}

TY - JOUR

T1 - Distinct roles for Sp1 and E2F sites in the growth/cell cycle regulation of the DHFR promoter

AU - Jensen, David E.

AU - Black, Adrian R.

AU - Swick, Andrew G.

AU - Azizkhan, Jane Clifford

PY - 1997/10/1

Y1 - 1997/10/1

N2 - Dihydrofolate reductase activity is required for many biosynthetic pathways including nucleotide synthesis. Its expression is therefore central to cellular growth, and it has become a key target for cancer chemotherapy. Transcription of the dihydrofolate reductase gene is regulated with growth, being expressed maximally in late G1/early S phase following serum stimulation of quiescent cells. This regulation is directed by a promoter which contains binding sites for only the transcription factors Sp1 and E2F. In this study, the role of these promoter elements in growth/cell cycle regulation of dihydrofolate transcription was addressed directly by transient transfection of Balb/c 3T3 cells with mutant promoter-reporter gene constructs. The E2F sites were found to repress transcription in G0 and early G1 but did not contribute to the level of transcription in late G1/S phase. In contrast, Sp1 sites were able to mediate induction of transcription from the dihydrofolate reductase promoter, as well as a heterologous promoter, following serum stimulation of quiescent cells. These findings add dihydrofolate reductase to a growing list of genes at which E2F sites are primarily repressive elements and delineate a role for Sp1 sites in the growth/cell cycle regulation of transcription.

AB - Dihydrofolate reductase activity is required for many biosynthetic pathways including nucleotide synthesis. Its expression is therefore central to cellular growth, and it has become a key target for cancer chemotherapy. Transcription of the dihydrofolate reductase gene is regulated with growth, being expressed maximally in late G1/early S phase following serum stimulation of quiescent cells. This regulation is directed by a promoter which contains binding sites for only the transcription factors Sp1 and E2F. In this study, the role of these promoter elements in growth/cell cycle regulation of dihydrofolate transcription was addressed directly by transient transfection of Balb/c 3T3 cells with mutant promoter-reporter gene constructs. The E2F sites were found to repress transcription in G0 and early G1 but did not contribute to the level of transcription in late G1/S phase. In contrast, Sp1 sites were able to mediate induction of transcription from the dihydrofolate reductase promoter, as well as a heterologous promoter, following serum stimulation of quiescent cells. These findings add dihydrofolate reductase to a growing list of genes at which E2F sites are primarily repressive elements and delineate a role for Sp1 sites in the growth/cell cycle regulation of transcription.

KW - Balb/c 3T3 cells

KW - Dihydrofolate reductase

KW - Gene expression

KW - Growth control

KW - Repression

KW - Retinoblastoma

KW - TATAA-less promoter

KW - Transcription

UR - http://www.scopus.com/inward/record.url?scp=0030931381&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0030931381&partnerID=8YFLogxK

U2 - 10.1002/(SICI)1097-4644(19971001)67:1<24::AID-JCB3>3.0.CO;2-Y

DO - 10.1002/(SICI)1097-4644(19971001)67:1<24::AID-JCB3>3.0.CO;2-Y

M3 - Article

C2 - 9328836

AN - SCOPUS:0030931381

VL - 67

SP - 24

EP - 31

JO - Journal of Cellular Biochemistry

JF - Journal of Cellular Biochemistry

SN - 0730-2312

IS - 1

ER -