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Your search keyword '"Sylvia Eiler"' showing total 2 results
Start Over "Sylvia Eiler" Topic integrase Publisher biomed central
2 results on '"Sylvia Eiler"'

1. Structural and functional studies of HIV-1 pre-integration complexes

Author

Marc Ruff, Patrick Schultz, Corinne Crucifix, Sylvia Eiler, Vincent Parissi, Robert Drillien, Yves Mély, Stéphane Emiliani, Aurélie Schaetzel, Nicolas Lévy, and Karine Pradeau

Subjects
Functional analysis, biology, biology.organism_classification, Bioinformatics, Chromatin remodeling, Integrase, Turn (biochemistry), chemistry.chemical_compound, Infectious Diseases, Retrovirus, chemistry, Biophysics, biology.protein, Nucleosome, Oral Presentation, Function (biology), DNA
Abstract

HIV-1 integrase (IN) is a key component of the pre-integration complex (PIC) and is involved in several steps of retrovirus replication. IN cannot perform these functions on its own and need to recruit host cell proteins to efficiently carry out the different processes. Retroviral INs are flexible proteins showing high inter-domain flexibility. This intrinsic flexibility accounts for IN ability to interact with multiple partners, which in turn chaperones PIC formation and its multiple functions. Biochemical and structural studies have long been hampered due to the PIC dynamics and intrinsic flexibility. We demonstrated that the low solubility and inter-domain flexibility can be circumvented by forming stable and specific complexes with DNA or protein co-factors and by post-translational modifications. Hundreds of milligrams of stable complexes are needed for in vitro functional and structural studies. For this, we develop new technologies for high molecular weight transient complexes production as well as for functional and structural analysis (mammalian cell system for protein production, in vitro functional analysis and complexes characterization). Structures have been solved by Cryo-EM and X-ray crystallography. We reconstruct in vitro stable and soluble complexes around IN. We solved the cryo-EM structures of the IN/LEDGF/DNA (Michel et al. 2009) and IN/LEDGF/INI1/DNA (Maillot et al. 2013) complexes. Structures together with functional assays gave important hints on the functional role of LEDGF and INI1. Other sub-complexes of the PIC have been characterized. One of them is the IN/transportin-SR2/VBP1 complex (structure in progress). Our results suggest that the function of INI1 (core protein of the swi/snf chromatin remodeling complex) in HIV-1 replication is to stabilize the PIC in the host cell, by maintaining integrase in a stable constrained conformation which prevents non-specific interactions and auto integration on the route to its integration site within nucleosomes, while LEDGF (a transcriptional co-activator) organizes and stabilizes an active integrase tetramer suitable for specific vDNA integration.

Published
2014

2. Dual inhibition of HIV-1 replication by integrase-LEDGF allosteric inhibitors is predominant at the post-integration stage.

Author

Rouzic, Erwann Le, Bonnard, Damien, Chasset, Sophie, Bruneau, Jean-Michel, Chevreuil, Francis, Strat, Frédéric Le, Nguyen, Juliette, Beauvoir, Roxane, Amadori, Céline, Brias, Julie, Vomscheid, Sophie, Eiler, Sylvia, Levy, Nicolas, Delelis, Olivier, Deprez, Eric, Saïb, Ali, Zamborlini, Alessia, Emiliani, Stéphane, Ruff, Marc, and Ledoussal, Benoit

Subjects
HIV, ALLOSTERIC regulation, HIV infections, NUCLEOPROTEINS, ANTIRETROVIRAL agents
Abstract

Background LEDGF/p75 (LEDGF) is the main cellular cofactor of HIV-1 integrase (IN). It acts as a tethering factor for IN, and targets the integration of HIV in actively transcribed gene regions of chromatin. A recently developed class of IN allosteric inhibitors can inhibit the LEDGF-IN interaction. Results We describe a new series of IN-LEDGF allosteric inhibitors, the most active of which is Mut101. We determined the crystal structure of Mut101 in complex with IN and showed that the compound binds to the LEDGF-binding pocket, promoting conformational changes of IN which explain at the atomic level the allosteric effect of the IN/LEDGF interaction inhibitor on IN functions. In vitro, Mut101 inhibited both IN-LEDGF interaction and IN strand transfer activity while enhancing IN-IN interaction. Time of addition experiments indicated that Mut101 behaved as an integration inhibitor. Mut101 was fully active on HIV-1 mutants resistant to INSTIs and other classes of anti-HIV drugs, indicative that this compound has a new mode of action. However, we found that Mut101 also displayed a more potent antiretroviral activity at a post-integration step. Infectivity of viral particles produced in presence of Mut101 was severely decreased. This latter effect also required the binding of the compound to the LEDGF-binding pocket. Conclusion Mut101 has dual anti-HIV-1 activity, at integration and post-integration steps of the viral replication cycle, by binding to a unique target on IN (the LEDGF-binding pocket). The postintegration block of HIV-1 replication in virus-producer cells is the mechanism by which Mut101 is most active as an antiretroviral. To explain this difference between Mut101 antiretroviral activity at integration and post-integration stages, we propose the following model: LEDGF is a nuclear, chromatin-bound protein that is absent in the cytoplasm. Therefore, LEDGF can outcompete compound binding to IN in the nucleus of target cells lowering its antiretroviral activity at integration, but not in the cytoplasm where postintegration production of infectious viral particles takes place. [ABSTRACT FROM AUTHOR]

Published
2013
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