cis-acting regulatory regions in the long terminal repeat of simian foamy virus type 1

Ayalew Mergia, Elissa Pratt-Lowe, Karen E S Shaw, Lisa W. Renshaw-Gegg, Paul A Luciw

Research output: Contribution to journalArticle

33 Citations (Scopus)

Abstract

Simian foamy virus type 1 (SFV-1), a member of the Spumavirinae subfamily of retroviruses, encodes a transcriptional transactivator (taf) that strongly augments gene expression directed by the viral long terminal repeat (LTR) (A. Mergia, K. E. S. Shaw, E. Pratt-Lowe, P. A. Barry, and P. A. Luciw, J. Virol. 65:2903-2909, 1991). This report describes cis-acting regulatory elements in the LTR that control viral gene expression. A series of LTR mutants and hybrid promoter constructs have been analyzed in transient expression assays for responsiveness to Taf. The targets for transactivation have been mapped to two regions of the U3 domain of the LTR, between positions -1196 and -880 and between positions -403 and -125 (+1 represents the transcription initiation site). No significant nucleotide sequence homology between these two regions is noted; thus, the SFV-1 taf gene acts through at least two distinct sequence elements in the LTR. The target contained between positions -403 and -125 acts independently of orientation, in different cell types and species, and in the context of a heterologous promoter. Thus, the target element between positions -403 and -125 has properties of a transcriptional enhancer. The observation that two distinct elements in the SFV-1 LTR are targets for transcriptional transactivation is novel with respect to observations for other retroviral systems. The R-U5 region of the SFV-1 LTR down-regulates transactivation by severalfold. Computer analysis of the R-U5 region revealed a secondary structure with a free-energy level of -74 kcal (ca. -310,000 J); this structural feature may account for the inhibitory effect on gene expression directed by the LTR. Taf of SFV-1 had no effect on gene expression directed by the LTR of the related human foamy virus, whereas Taf transactivates gene expression directed by the LTRs of the human and simian immunodeficiency viruses. Comparative functional analysis of Taf on homologous and heterologous LTRs may facilitate elucidation of the mechanism of transactivation of foamy viruses.

Original languageEnglish (US)
Pages (from-to)251-257
Number of pages7
JournalJournal of Virology
Volume66
Issue number1
StatePublished - Jan 1992

Fingerprint

Simian foamy virus
Spumavirus
terminal repeat sequences
Terminal Repeat Sequences
Nucleic Acid Regulatory Sequences
transcriptional activation
Transcriptional Activation
Gene Expression
gene expression
Retroviridae
promoter regions
Simian immunodeficiency virus
computer analysis
Simian Immunodeficiency Virus
regulatory sequences
Trans-Activators
Viral Genes
Transcription Initiation Site
Human immunodeficiency virus
Sequence Homology

ASJC Scopus subject areas

  • Immunology

Cite this

Mergia, A., Pratt-Lowe, E., Shaw, K. E. S., Renshaw-Gegg, L. W., & Luciw, P. A. (1992). cis-acting regulatory regions in the long terminal repeat of simian foamy virus type 1. Journal of Virology, 66(1), 251-257.

cis-acting regulatory regions in the long terminal repeat of simian foamy virus type 1. / Mergia, Ayalew; Pratt-Lowe, Elissa; Shaw, Karen E S; Renshaw-Gegg, Lisa W.; Luciw, Paul A.

In: Journal of Virology, Vol. 66, No. 1, 01.1992, p. 251-257.

Research output: Contribution to journalArticle

Mergia, A, Pratt-Lowe, E, Shaw, KES, Renshaw-Gegg, LW & Luciw, PA 1992, 'cis-acting regulatory regions in the long terminal repeat of simian foamy virus type 1', Journal of Virology, vol. 66, no. 1, pp. 251-257.
Mergia A, Pratt-Lowe E, Shaw KES, Renshaw-Gegg LW, Luciw PA. cis-acting regulatory regions in the long terminal repeat of simian foamy virus type 1. Journal of Virology. 1992 Jan;66(1):251-257.
Mergia, Ayalew ; Pratt-Lowe, Elissa ; Shaw, Karen E S ; Renshaw-Gegg, Lisa W. ; Luciw, Paul A. / cis-acting regulatory regions in the long terminal repeat of simian foamy virus type 1. In: Journal of Virology. 1992 ; Vol. 66, No. 1. pp. 251-257.
@article{41b52ae12ee24ecd856169c01e193db6,
title = "cis-acting regulatory regions in the long terminal repeat of simian foamy virus type 1",
abstract = "Simian foamy virus type 1 (SFV-1), a member of the Spumavirinae subfamily of retroviruses, encodes a transcriptional transactivator (taf) that strongly augments gene expression directed by the viral long terminal repeat (LTR) (A. Mergia, K. E. S. Shaw, E. Pratt-Lowe, P. A. Barry, and P. A. Luciw, J. Virol. 65:2903-2909, 1991). This report describes cis-acting regulatory elements in the LTR that control viral gene expression. A series of LTR mutants and hybrid promoter constructs have been analyzed in transient expression assays for responsiveness to Taf. The targets for transactivation have been mapped to two regions of the U3 domain of the LTR, between positions -1196 and -880 and between positions -403 and -125 (+1 represents the transcription initiation site). No significant nucleotide sequence homology between these two regions is noted; thus, the SFV-1 taf gene acts through at least two distinct sequence elements in the LTR. The target contained between positions -403 and -125 acts independently of orientation, in different cell types and species, and in the context of a heterologous promoter. Thus, the target element between positions -403 and -125 has properties of a transcriptional enhancer. The observation that two distinct elements in the SFV-1 LTR are targets for transcriptional transactivation is novel with respect to observations for other retroviral systems. The R-U5 region of the SFV-1 LTR down-regulates transactivation by severalfold. Computer analysis of the R-U5 region revealed a secondary structure with a free-energy level of -74 kcal (ca. -310,000 J); this structural feature may account for the inhibitory effect on gene expression directed by the LTR. Taf of SFV-1 had no effect on gene expression directed by the LTR of the related human foamy virus, whereas Taf transactivates gene expression directed by the LTRs of the human and simian immunodeficiency viruses. Comparative functional analysis of Taf on homologous and heterologous LTRs may facilitate elucidation of the mechanism of transactivation of foamy viruses.",
author = "Ayalew Mergia and Elissa Pratt-Lowe and Shaw, {Karen E S} and Renshaw-Gegg, {Lisa W.} and Luciw, {Paul A}",
year = "1992",
month = "1",
language = "English (US)",
volume = "66",
pages = "251--257",
journal = "Journal of Virology",
issn = "0022-538X",
publisher = "American Society for Microbiology",
number = "1",

}

TY - JOUR

T1 - cis-acting regulatory regions in the long terminal repeat of simian foamy virus type 1

AU - Mergia, Ayalew

AU - Pratt-Lowe, Elissa

AU - Shaw, Karen E S

AU - Renshaw-Gegg, Lisa W.

AU - Luciw, Paul A

PY - 1992/1

Y1 - 1992/1

N2 - Simian foamy virus type 1 (SFV-1), a member of the Spumavirinae subfamily of retroviruses, encodes a transcriptional transactivator (taf) that strongly augments gene expression directed by the viral long terminal repeat (LTR) (A. Mergia, K. E. S. Shaw, E. Pratt-Lowe, P. A. Barry, and P. A. Luciw, J. Virol. 65:2903-2909, 1991). This report describes cis-acting regulatory elements in the LTR that control viral gene expression. A series of LTR mutants and hybrid promoter constructs have been analyzed in transient expression assays for responsiveness to Taf. The targets for transactivation have been mapped to two regions of the U3 domain of the LTR, between positions -1196 and -880 and between positions -403 and -125 (+1 represents the transcription initiation site). No significant nucleotide sequence homology between these two regions is noted; thus, the SFV-1 taf gene acts through at least two distinct sequence elements in the LTR. The target contained between positions -403 and -125 acts independently of orientation, in different cell types and species, and in the context of a heterologous promoter. Thus, the target element between positions -403 and -125 has properties of a transcriptional enhancer. The observation that two distinct elements in the SFV-1 LTR are targets for transcriptional transactivation is novel with respect to observations for other retroviral systems. The R-U5 region of the SFV-1 LTR down-regulates transactivation by severalfold. Computer analysis of the R-U5 region revealed a secondary structure with a free-energy level of -74 kcal (ca. -310,000 J); this structural feature may account for the inhibitory effect on gene expression directed by the LTR. Taf of SFV-1 had no effect on gene expression directed by the LTR of the related human foamy virus, whereas Taf transactivates gene expression directed by the LTRs of the human and simian immunodeficiency viruses. Comparative functional analysis of Taf on homologous and heterologous LTRs may facilitate elucidation of the mechanism of transactivation of foamy viruses.

AB - Simian foamy virus type 1 (SFV-1), a member of the Spumavirinae subfamily of retroviruses, encodes a transcriptional transactivator (taf) that strongly augments gene expression directed by the viral long terminal repeat (LTR) (A. Mergia, K. E. S. Shaw, E. Pratt-Lowe, P. A. Barry, and P. A. Luciw, J. Virol. 65:2903-2909, 1991). This report describes cis-acting regulatory elements in the LTR that control viral gene expression. A series of LTR mutants and hybrid promoter constructs have been analyzed in transient expression assays for responsiveness to Taf. The targets for transactivation have been mapped to two regions of the U3 domain of the LTR, between positions -1196 and -880 and between positions -403 and -125 (+1 represents the transcription initiation site). No significant nucleotide sequence homology between these two regions is noted; thus, the SFV-1 taf gene acts through at least two distinct sequence elements in the LTR. The target contained between positions -403 and -125 acts independently of orientation, in different cell types and species, and in the context of a heterologous promoter. Thus, the target element between positions -403 and -125 has properties of a transcriptional enhancer. The observation that two distinct elements in the SFV-1 LTR are targets for transcriptional transactivation is novel with respect to observations for other retroviral systems. The R-U5 region of the SFV-1 LTR down-regulates transactivation by severalfold. Computer analysis of the R-U5 region revealed a secondary structure with a free-energy level of -74 kcal (ca. -310,000 J); this structural feature may account for the inhibitory effect on gene expression directed by the LTR. Taf of SFV-1 had no effect on gene expression directed by the LTR of the related human foamy virus, whereas Taf transactivates gene expression directed by the LTRs of the human and simian immunodeficiency viruses. Comparative functional analysis of Taf on homologous and heterologous LTRs may facilitate elucidation of the mechanism of transactivation of foamy viruses.

UR - http://www.scopus.com/inward/record.url?scp=0026540959&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0026540959&partnerID=8YFLogxK

M3 - Article

C2 - 1309244

AN - SCOPUS:0026540959

VL - 66

SP - 251

EP - 257

JO - Journal of Virology

JF - Journal of Virology

SN - 0022-538X

IS - 1

ER -