Structure-function analyses unravel distinct effects of allosteric inhibitors of HIV-1 integrase on viral maturation and integration.Bonnard, D., Le Rouzic, E., Eiler, S., Amadori, C., Orlov, I., Bruneau, J.M., Brias, J., Barbion, J., Chevreuil, F., Spehner, D., Chasset, S., Ledoussal, B., Moreau, F., Saib, A., Klaholz, B.P., Emiliani, S., Ruff, M., Zamborlini, A., Benarous, R.
(2018) J. Biol. Chem. 293: 6172-6186
- PubMed: 29507092
- DOI: 10.1074/jbc.M117.816793
- Primary Citation of Related Structures:
- PubMed Abstract:
Recently, a new class of HIV-1 integrase (IN) inhibitors with a dual mode of action, called IN-LEDGF/p75 allosteric inhibitors (INLAIs), was described. Designed to interfere with the INLEDGF/p75 interaction during viral integration, unexpectedly, the ...
Recently, a new class of HIV-1 integrase (IN) inhibitors with a dual mode of action, called IN-LEDGF/p75 allosteric inhibitors (INLAIs), was described. Designed to interfere with the INLEDGF/p75 interaction during viral integration, unexpectedly, their major impact was on virus maturation. This activity has been linked to induction of aberrant IN multimerization, while inhibition of the IN-LEDGF/p75 interaction accounts for weaker antiretroviral effect at integration. Since these dual activities result from INLAI binding to IN at a single binding site, we expected that these activities co-evolved together, driven by the affinity for IN. Using an original INLAI, MUT-A, and its activity on an Ala-125 (A125) IN variant, we found that these two activities on A125 IN can be fully dissociated: MUT-A-induced IN multimerization and the formation of eccentric condensates in viral particles, that are responsible for inhibition of virus maturation, were lost, while inhibition of the IN-LEDGF/p75 interaction and consequently integration, was fully retained. Hence the mere binding of INLAI to A125 IN is insufficient to promote the conformational changes of IN required for aberrant multimerization. By analyzing the X-ray structures of MUT-A bound to the IN catalytic core domain (CCD) with or without the A125 polymorphism, we discovered that the loss of IN multimerization is due to stabilization of the A125 IN variant CCD dimer, highlighting the importance of the CCD dimerization energy for IN multimerization. Our study reveals that affinity for the LEDGF/p75-binding pocket is not sufficient to induce INLAI-dependent IN multimerization and the associated inhibition of viral maturation.
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