LEDGF/p75 proteins with alternative chromatin tethers are functional HIV-1 cofactors.
LEDGF/p75 can tether over-expressed lentiviral integrase proteins to chromatin but how this underlies its integration cofactor role for these retroviruses is unclear. While a single integrase binding domain (IBD) binds integrase, a complex N-terminal domain ensemble (NDE) interacts with unknown chromatin ligands. Whether integration requires chromatin tethering per se, specific NDE-chromatin ligand interactions or other emergent properties of LEDGF/p75 has been elusive. Here we replaced the NDE with strongly divergent chromatin-binding modules. The chimeras rescued integrase tethering and HIV-1 integration in LEDGF/p75-deficient cells. Furthermore, chromatin ligands could reside inside or outside the nucleosome core, and could be protein or DNA. Remarkably, a short Kaposi's sarcoma virus peptide that binds the histone 2A/B dimer converted GFP-IBD from an integration blocker to an integration cofactor that rescues over two logs of infectivity. NDE mutants were corroborative. Chromatin tethering per se is a basic HIV-1 requirement and this rather than engagement of particular chromatin ligands is important for the LEDGF/p75 cofactor mechanism.
Meehan
Anne M
AM
Department of Molecular Medicine, Mayo Clinic College of Medicine, Rochester, Minnesota, USA.
Saenz
Dyana T
DT
Morrison
James H
JH
Garcia-Rivera
Jose A
JA
Peretz
Mary
M
Llano
Manuel
M
Poeschla
Eric M
EM
D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D000956:Antigens, Viral / Q000378:metabolism; D000998:Antiviral Agents / Q000378:metabolism; D001483:Base Sequence; D002460:Cell Line; D002478:Cells, Cultured; D002843:Chromatin / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism; D049452:Green Fluorescent Proteins; D015658:HIV Infections / Q000821:virology*; D019427:HIV Integrase / Q000378:metabolism; D015497:HIV-1 / Q000378:metabolism* / Q000502:physiology; D006657:Histones / Q000378:metabolism; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000378:metabolism; D010446:Peptide Fragments / Q000378:metabolism; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D034622:RNA Interference; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014779:Virus Replication
D048868:Adaptor Proteins, Signal Transducing; D000956:Antigens, Viral; D000998:Antiviral Agents; D002843:Chromatin; D004268:DNA-Binding Proteins; D006657:Histones; D009687:Nuclear Proteins; C504649:PSIP1 protein, human; D010446:Peptide Fragments; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; C109540:latency-associated nuclear antigen; D049452:Green Fluorescent Proteins; D019427:HIV Integrase; D046988:Proteasome Endopeptidase Complex