Cell cycle-regulated association of E2F1 and Sp1 is related to their functional interaction

Shiaw Yih Lin, Adrian R Black, Dusan Kostic, Sanja Pajovic, Carol N. Hoover, Jane Clifford Azizkhan

Research output: Contribution to journalArticle

234 Citations (Scopus)

Abstract

Because of the large number of growth-regulated genes containing binding sites for the transcription factors Sp1 and E2F and the reported ability of E2F to mediate cell cycle (growth) regulation, we studied interactions between E2F1 and Sp1. In transient transfection assays using Drosophila melanogaster SL2 cells, transfection with both Sp1 and E2F1 expression vectors resulted in greater than 85-fold activation of transcription from a hamster dihydrofolate reductase reporter construct, whereas cotransfection with either the Sp1 or E2F1 expression vector resulted in 30- or <2-fold activation, respectively. Therefore, these transcription factors act synergistically in activation of dihydrofolate reductase transcription. Transient transfection studies demonstrated that E2F1 could superactivate Sp1-dependent transcription in a promoter containing only Sp1 sites and that Sp1 could superactivate transcription of promoters through E2F sites, further demonstrating that these factors functionally interact with one another. Coimmunoprecipitation studies revealed that Sp1 and E2F1 are physically associated in Drosophila cells transfected with Sp1 and E2F1 expression vectors and in human cells, with maximal interaction detected in mid- to late G1. Additionally, E2F1 and Sp1 interact in vitro through specific domains of each protein, and the physical interaction and functional synergism appear to require the same regions. Taken together, these data demonstrate that E2F1 and Sp1 both functionally and physically interact; therefore, through this interaction, Sp1 and E2F1 may regulate transcription of genes containing binding sites for either or both factors.

Original languageEnglish (US)
Pages (from-to)1668-1675
Number of pages8
JournalMolecular and cellular biology
Volume16
Issue number4
DOIs
StatePublished - Jan 1 1996

Fingerprint

Transfection
Cell Cycle
Tetrahydrofolate Dehydrogenase
Binding Sites
E2F Transcription Factors
Growth
Drosophila melanogaster
Cricetinae
Transcriptional Activation
Genes
Drosophila
Transcription Factors
In Vitro Techniques
Protein Domains

ASJC Scopus subject areas

  • Molecular Biology
  • Cell Biology

Cite this

Cell cycle-regulated association of E2F1 and Sp1 is related to their functional interaction. / Lin, Shiaw Yih; Black, Adrian R; Kostic, Dusan; Pajovic, Sanja; Hoover, Carol N.; Azizkhan, Jane Clifford.

In: Molecular and cellular biology, Vol. 16, No. 4, 01.01.1996, p. 1668-1675.

Research output: Contribution to journalArticle

Lin, Shiaw Yih ; Black, Adrian R ; Kostic, Dusan ; Pajovic, Sanja ; Hoover, Carol N. ; Azizkhan, Jane Clifford. / Cell cycle-regulated association of E2F1 and Sp1 is related to their functional interaction. In: Molecular and cellular biology. 1996 ; Vol. 16, No. 4. pp. 1668-1675.
@article{007b3f5a828347fc9b349e5437a727d5,
title = "Cell cycle-regulated association of E2F1 and Sp1 is related to their functional interaction",
abstract = "Because of the large number of growth-regulated genes containing binding sites for the transcription factors Sp1 and E2F and the reported ability of E2F to mediate cell cycle (growth) regulation, we studied interactions between E2F1 and Sp1. In transient transfection assays using Drosophila melanogaster SL2 cells, transfection with both Sp1 and E2F1 expression vectors resulted in greater than 85-fold activation of transcription from a hamster dihydrofolate reductase reporter construct, whereas cotransfection with either the Sp1 or E2F1 expression vector resulted in 30- or <2-fold activation, respectively. Therefore, these transcription factors act synergistically in activation of dihydrofolate reductase transcription. Transient transfection studies demonstrated that E2F1 could superactivate Sp1-dependent transcription in a promoter containing only Sp1 sites and that Sp1 could superactivate transcription of promoters through E2F sites, further demonstrating that these factors functionally interact with one another. Coimmunoprecipitation studies revealed that Sp1 and E2F1 are physically associated in Drosophila cells transfected with Sp1 and E2F1 expression vectors and in human cells, with maximal interaction detected in mid- to late G1. Additionally, E2F1 and Sp1 interact in vitro through specific domains of each protein, and the physical interaction and functional synergism appear to require the same regions. Taken together, these data demonstrate that E2F1 and Sp1 both functionally and physically interact; therefore, through this interaction, Sp1 and E2F1 may regulate transcription of genes containing binding sites for either or both factors.",
author = "Lin, {Shiaw Yih} and Black, {Adrian R} and Dusan Kostic and Sanja Pajovic and Hoover, {Carol N.} and Azizkhan, {Jane Clifford}",
year = "1996",
month = "1",
day = "1",
doi = "10.1128/MCB.16.4.1668",
language = "English (US)",
volume = "16",
pages = "1668--1675",
journal = "Molecular and Cellular Biology",
issn = "0270-7306",
publisher = "American Society for Microbiology",
number = "4",

}

TY - JOUR

T1 - Cell cycle-regulated association of E2F1 and Sp1 is related to their functional interaction

AU - Lin, Shiaw Yih

AU - Black, Adrian R

AU - Kostic, Dusan

AU - Pajovic, Sanja

AU - Hoover, Carol N.

AU - Azizkhan, Jane Clifford

PY - 1996/1/1

Y1 - 1996/1/1

N2 - Because of the large number of growth-regulated genes containing binding sites for the transcription factors Sp1 and E2F and the reported ability of E2F to mediate cell cycle (growth) regulation, we studied interactions between E2F1 and Sp1. In transient transfection assays using Drosophila melanogaster SL2 cells, transfection with both Sp1 and E2F1 expression vectors resulted in greater than 85-fold activation of transcription from a hamster dihydrofolate reductase reporter construct, whereas cotransfection with either the Sp1 or E2F1 expression vector resulted in 30- or <2-fold activation, respectively. Therefore, these transcription factors act synergistically in activation of dihydrofolate reductase transcription. Transient transfection studies demonstrated that E2F1 could superactivate Sp1-dependent transcription in a promoter containing only Sp1 sites and that Sp1 could superactivate transcription of promoters through E2F sites, further demonstrating that these factors functionally interact with one another. Coimmunoprecipitation studies revealed that Sp1 and E2F1 are physically associated in Drosophila cells transfected with Sp1 and E2F1 expression vectors and in human cells, with maximal interaction detected in mid- to late G1. Additionally, E2F1 and Sp1 interact in vitro through specific domains of each protein, and the physical interaction and functional synergism appear to require the same regions. Taken together, these data demonstrate that E2F1 and Sp1 both functionally and physically interact; therefore, through this interaction, Sp1 and E2F1 may regulate transcription of genes containing binding sites for either or both factors.

AB - Because of the large number of growth-regulated genes containing binding sites for the transcription factors Sp1 and E2F and the reported ability of E2F to mediate cell cycle (growth) regulation, we studied interactions between E2F1 and Sp1. In transient transfection assays using Drosophila melanogaster SL2 cells, transfection with both Sp1 and E2F1 expression vectors resulted in greater than 85-fold activation of transcription from a hamster dihydrofolate reductase reporter construct, whereas cotransfection with either the Sp1 or E2F1 expression vector resulted in 30- or <2-fold activation, respectively. Therefore, these transcription factors act synergistically in activation of dihydrofolate reductase transcription. Transient transfection studies demonstrated that E2F1 could superactivate Sp1-dependent transcription in a promoter containing only Sp1 sites and that Sp1 could superactivate transcription of promoters through E2F sites, further demonstrating that these factors functionally interact with one another. Coimmunoprecipitation studies revealed that Sp1 and E2F1 are physically associated in Drosophila cells transfected with Sp1 and E2F1 expression vectors and in human cells, with maximal interaction detected in mid- to late G1. Additionally, E2F1 and Sp1 interact in vitro through specific domains of each protein, and the physical interaction and functional synergism appear to require the same regions. Taken together, these data demonstrate that E2F1 and Sp1 both functionally and physically interact; therefore, through this interaction, Sp1 and E2F1 may regulate transcription of genes containing binding sites for either or both factors.

UR - http://www.scopus.com/inward/record.url?scp=0029981560&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0029981560&partnerID=8YFLogxK

U2 - 10.1128/MCB.16.4.1668

DO - 10.1128/MCB.16.4.1668

M3 - Article

VL - 16

SP - 1668

EP - 1675

JO - Molecular and Cellular Biology

JF - Molecular and Cellular Biology

SN - 0270-7306

IS - 4

ER -