Biochemical and genetic analyses of integrase-interacting proteins lens epithelium-derived growth factor (LEDGF)/p75 and hepatoma-derived growth factor related protein 2 (HRP2) in preintegration complex function and HIV-1 replication

ABSTRACT We initially identified lens epithelium-derived growth factor/p75 (LEDGF/p75) as a binding partner of human immunodeficiency virus type 1 (HIV-1) integrase. To investigate the role of LEDGF/p75 in HIV replication and its potential as a new antiviral target, we stably overexpressed two different fragments containing the integrase binding domain (IBD) of LEDGF/p75 fused to enhanced green fluorescent protein (eGFP). HIV-1 replication was severely inhibited by overexpression of the eGFP-IBD fusion proteins, while no inhibition was observed in cell lines overexpressing the interaction-deficient D366A mutant. Quantitative PCR pinpointed the block to the integration step, whereas nuclear import was not affected. Competition of the IBD fusion proteins with endogenous LEDGF/p75 for binding to integrase led to a potent defect in HIV-1 replication in both HeLaP4- and MT-4-derived cell lines. A previously described diketo acid-resistant HIV-1 strain remained fully susceptible to inhibition, suggesting that this strategy will also work in patients who harbor strains resistant to the current experimental integrase inhibitors. These data support LEDGF/p75 as an important cofactor for HIV replication and provide proof of concept for the LEDGF/p75-integrase interaction as a novel target for treating HIV-1 infection.

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Structure-based virtual screening toward the discovery of novel inhibitors for impeding the protein-protein interaction between HIV-1 integrase and human lens epithelium-derived growth factor (LEDGF/p75)

Journal of Biomolecular Structure and Dynamics ◽

10.1080/07391102.2017.1384400 ◽

2017 ◽

Vol 36 (12) ◽

pp. 3199-3217 ◽

Cited By ~ 14

Author(s):

Umesh Panwar ◽

Sanjeev Kumar Singh

Keyword(s):

Growth Factor ◽

Virtual Screening ◽

Protein Interaction ◽

Lens Epithelium ◽

Human Lens ◽

Protein Protein Interaction ◽

Human Lens Epithelium ◽

Hiv 1

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Implication of Serine Residues 271, 273, and 275 in the Human Immunodeficiency Virus Type 1 Cofactor Activity of Lens Epithelium-Derived Growth Factor/p75

Journal of Virology ◽

10.1128/jvi.01043-09 ◽

2009 ◽

Vol 84 (2) ◽

pp. 740-752 ◽

Cited By ~ 19

Author(s):

Jose A. Garcia-Rivera ◽

Murilo T. D. Bueno ◽

Elisa Morales ◽

Jeffrey R. Kugelman ◽

Daniel F. Rodriguez ◽

...

Keyword(s):

Growth Factor ◽

Posttranslational Modifications ◽

Lens Epithelium ◽

Chromatin Binding ◽

Dna Integration ◽

Evolutionarily Conserved ◽

Cellular Cofactor ◽

Mouse Cells ◽

Cofactor Activity ◽

Hiv 1

ABSTRACT Lens epithelium-derived growth factor (LEDGF)/p75 is a cellular cofactor for HIV-1 DNA integration. It is well established that the simultaneous binding of LEDGF/p75 to chromatin and to HIV-1 integrase is required for its cofactor activity. However, the exact molecular mechanism of LEDGF/p75 in HIV-1 integration is not yet completely understood. Our hypothesis is that evolutionarily conserved regions in LEDGF/p75 exposed to solvent and harboring posttranslational modifications may be involved in its HIV-1 cofactor activity. Therefore, a panel of LEDGF/p75 deletion mutants targeting these protein regions were evaluated for their HIV-1 cofactor activity, chromatin binding, integrase interaction, and integrase-to-chromatin-tethering activity by using different cellular and biochemical approaches. The deletion of amino acids 267 to 281 reduced the cofactor activity of LEDGF/p75 to levels observed for chromatin-binding-defective mutants. This region contains a serine cluster (residues 271, 273, and 275) recurrently found to be phosphorylated in both human and mouse cells. Importantly, the conversion of these Ser residues to Ala was sufficient to impair the ability of LEDGF/p75 to mediate HIV-1 DNA integration, although these mutations did not alter chromatin binding, integrase binding, or the integrase-to-chromatin-tethering capability of LEDGF/p75. These results clearly indicated that serine residues 271, 273, and 275 influence the HIV-1 cofactor activity of integrase-to-chromatin-tethering-competent LEDGF/p75.

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