8GDV

Structure of M66I mutant of disulfide stabilized HIV-1 CA hexamer in complex with CPSF6 peptide and IP6

8GDV の概要

• エントリーDOI: 10.2210/pdb8gdv/pdb
• 分子名称: Gag polyprotein, Cleavage and polyadenylation specificity factor subunit 6, INOSITOL HEXAKISPHOSPHATE (3 entities in total)
• 機能のキーワード: hiv-1 capsid, ip6, cpsf6, viral protein
• 由来する生物種: Human immunodeficiency virus 1; 詳細
• タンパク質・核酸の鎖数: 12
• 化学式量合計: 163284.25

構造登録者

Briganti, L.,Schope, L.,Kvaratskhelia, M. (登録日: 2023-03-06, 公開日: 2024-03-13, 最終更新日: 2025-04-30)

主引用文献

Briganti, L.,Annamalai, A.S.,Bester, S.M.,Wei, G.,Andino-Moncada, J.R.,Singh, S.P.,Kleinpeter, A.B.,Tripathi, M.,Nguyen, B.,Radhakrishnan, R.,Singh, P.K.,Greenwood, J.,Schope, L.I.,Haney, R.,Huang, S.-W.,Freed, E.O.,Engelman, A.N.,Francis, A.C.,Kvaratskhelia, M.
Structural and mechanistic bases for resistance of the M66I capsid variant to lenacapavir.
Mbio, :e0361324-e0361324, 2025

PubMed Abstract: Lenacapavir (LEN) is the first-in-class viral capsid protein (CA) targeting antiretroviral for treating multi-drug-resistant HIV-1 infection. Clinical trials and cell culture experiments have identified resistance-associated mutations (RAMs) in the vicinity of the hydrophobic CA pocket targeted by LEN. The M66I substitution conferred by far the highest level of resistance to the inhibitor compared to other RAMs. Here we investigated structural and mechanistic bases for how the M66I change affects LEN binding to CA and viral replication. The high-resolution X-ray structure of the CA(M66I) hexamer revealed that the β-branched side chain of Ile66 induces steric hindrance specifically to LEN, thereby markedly reducing the inhibitor binding affinity. By contrast, the M66I substitution did not affect the binding of Phe-Gly (FG)-motif-containing cellular cofactors CPSF6, NUP153, or SEC24C, which engage the same hydrophobic pocket of CA. In cell culture, the M66I variant did not acquire compensatory mutations. Analysis of viral replication intermediates revealed that HIV-1 predominantly formed correctly matured viral cores, which were more stable than their wild-type counterparts. The mutant cores stably bound to the nuclear envelope but failed to penetrate inside the nucleus. Furthermore, the M66I substitution markedly altered HIV-1 integration targeting. Taken together, our findings elucidate mechanistic insights into how the M66I change confers remarkable resistance to LEN and affects HIV-1 replication. Moreover, our structural findings provide a powerful means for future medicinal chemistry efforts to rationally develop second-generation inhibitors with a higher barrier to resistance.IMPORTANCELenacapavir (LEN) is a highly potent and long-acting antiretroviral that works by a unique mechanism of targeting the viral capsid protein. The inhibitor is used in combination with other antiretrovirals to treat multi-drug-resistant HIV-1 infection in heavily treatment-experienced adults. Furthermore, LEN is in clinical trials for preexposure prophylaxis (PrEP) with interim results indicating 100% efficacy to prevent HIV-1 infections. However, one notable shortcoming is a relatively low barrier of viral resistance to LEN. Clinical trials and cell culture experiments identified emergent resistance mutations near the inhibitor binding site on capsid. The M66I variant was the most prevalent capsid substitution identified in patients receiving LEN to treat multi-drug-resistant HIV-1 infections. The studies described here elucidate the underlying mechanism by which the M66I substitution confers a marked resistance to the inhibitor. Furthermore, our structural findings will aid future efforts to develop the next generation of capsid inhibitors with enhanced barriers to resistance.

PubMed: 40231850
DOI: 10.1128/mbio.03613-24

実験手法

X-RAY DIFFRACTION (3.3 Å)