A tripartite DNA-binding element, comprised of the nuclear localization signal and two AT-hook motifs, mediates the association of LEDGF/p75 with chromatin in vivo
Author(s)
Turlure, F
Maertens, G
Rahman, S
Cherepanov, P
Engelman, A
Type
Journal Article
Abstract
Lens epithelium-derived growth factor p75 (LEDGF/p75) is a DNA-binding, transcriptional co-activator that participates in HIV-1 integration site targeting. Using complementary approaches, we determined the mechanisms of LEDGF/p75 DNA-binding in vitro and chromatin-association in living cells. The binding of highly-purified, recombinant protein was assayed by surface plasmon resonance (SPR) and electrophoretic mobility gel shift. Neither assay revealed evidence for sequence-specific DNA-binding. Residues 146–197 spanning the nuclear localization signal (NLS) and two AT-hook motifs mediated non-specific DNA-binding, and DNA-binding deficient mutants retained the ability to efficiently stimulate HIV-1 integrase activity in vitro. Chromatin-association was assessed by visualizing the localization of EGFP fusion proteins in interphase and mitotic cells. Although a conserved N-terminal PWWP domain was not required for binding to condensed mitotic chromosomes, its deletion subtly affected the nucleoplasmic distribution of the protein during interphase. A dual AT-hook mutant associated normally with chromatin, yet when the mutations were combined with NLS changes or deletion of the PWWP domain, chromatin-binding function was lost. As the PWWP domain did not readily bind free DNA in vitro, our results indicate that chromatin-association is primarily affected through DNA-binding, with the PWWP domain likely contributing a protein interaction to the overall affinity of LEDGF/p75 for human chromatin.
Date Issued
2006-03-20
Date Acceptance
2006-02-23
Citation
Nucleic Acids Research, 2006, 34 (5), pp.1653-1665
ISSN
1362-4962
Publisher
Oxford University Press
Start Page
1653
End Page
1665
Journal / Book Title
Nucleic Acids Research
Volume
34
Issue
5
Copyright Statement
© The Author 2006. Published by Oxford University Press. All rights reserved. The online version of this article has been published under an open access model. Users are entitled to use, reproduce, disseminate, or display the open access version of this article for non-commercial purposes provided that: the original authorship is properly and fully attributed; the Journal and Oxford University Press are attributed as the original place of publication with the correct citation details given; if an article is subsequently reproduced or disseminated not in its entirety but only in part or as a derivative work this must be clearly indicated.
Subjects
Science & Technology
Life Sciences & Biomedicine
Biochemistry & Molecular Biology
BIOCHEMISTRY & MOLECULAR BIOLOGY
IMMUNODEFICIENCY-VIRUS TYPE-1
STRESS-RELATED GENES
HIV-1 INTEGRASE
GROWTH-FACTOR
PWWP DOMAIN
TRANSCRIPTIONAL COACTIVATORS
PREINTEGRATION COMPLEXES
MYELOID-LEUKEMIA
CDNA INTEGRATION
HUMAN-CELLS
AT-Hook Motifs
Adaptor Proteins, Signal Transducing
Amino Acid Sequence
Binding Sites
Chromatin
Consensus Sequence
DNA
DNA-Binding Proteins
HIV Integrase
HeLa Cells
Humans
Molecular Sequence Data
Nuclear Localization Signals
Protein Structure, Tertiary
Transcription Factors
Hela Cells
Developmental Biology
05 Environmental Sciences
06 Biological Sciences
08 Information And Computing Sciences
Publication Status
Published