Interaction between CCAAT/enhancer binding protein and cyclic AMP response element binding protein 1 regulates human immunodeficiency virus type 1 transcription in cells of the monocyte/macrophage lineage

Recent observations have shown two CCAAT/enhancer binding protein (C/EBP) binding sites to be critically important for efficient human immunodeficiency virus type 1 (HIV-1) replication within cells of the monocyte/macrophage lineage, a cell type likely involved in transport of the virus to the brain. Additionally, sequence variation at C/EBP site I, which lies immediately upstream of the distal nuclear factor kappa B site and immediately downstream of a binding site for activating transcription factor (ATF)/cyclic AMP response element binding protein (CREB), has been shown to affect HIV-1 long terminal repeat (LTR) activity. Given that C/EBP proteins have been shown to interact with many other transcription factors including members of the ATF/CREB family, we proceeded to determine whether an adjacent ATF/CREB binding site could affect C/EBP protein binding to C/EBP site I. Electrophoretic mobility shift analyses indicated that selected ATF/CREB site variants assisted in the recruitment of C/EBP proteins to an adjacent, naturally occurring, low-affinity C/EBP site. This biophysical interaction appears to occur via at least two mechanisms. First, low amounts of CREB-1 and C/EBP appear to heterodimerize and bind to a site consisting of a half site from both the ATF/CREB and C/EBP binding sites. In addition, CREB-1 homodimers bind to the ATF/CREB site and recruit C/EBP dimers to their cognate weak binding sites. This interaction is reciprocal, since C/EBP dimer binding to a strong C/EBP site leads to enhanced CREB-1 recruitment to ATF/CREB sites that are weakly bound by CREB. Sequence variation at both C/EBP and ATF/CREB sites affects the molecular interactions involved in mediating both of these mechanisms. Most importantly, sequence variation at the ATF/CREB binding site affected basal LTR activity as well as LTR function following interleukin-6 stimulation, a treatment that leads to increases in C/EBP activation. Thus, HIV-1 LTR ATF/CREB binding site sequence variation may modulate cellular signaling at the viral promoter through the C/EBP pathway.

Medienart:

Artikel

Erscheinungsjahr:

2001

Erschienen:

2001

Enthalten in:

Zur Gesamtaufnahme - volume:75

Enthalten in:

Journal of virology - 75(2001), 4 vom: Feb., Seite 1842-56

Sprache:

Englisch

Beteiligte Personen:

Ross, H L [VerfasserIn]
Nonnemacher, M R [VerfasserIn]
Hogan, T H [VerfasserIn]
Quiterio, S J [VerfasserIn]
Henderson, A [VerfasserIn]
McAllister, J J [VerfasserIn]
Krebs, F C [VerfasserIn]
Wigdahl, B [VerfasserIn]

Themen:

CCAAT-Enhancer-Binding Proteins
Cyclic AMP Response Element-Binding Protein
Journal Article
Research Support, U.S. Gov't, P.H.S.

Anmerkungen:

Date Completed 05.04.2001

Date Revised 13.11.2018

published: Print

Citation Status MEDLINE

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM110740491