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Updated: May 29, 2026
10:34
Measurement of In Vitro Integration Activity of HIV-1 Preintegration Complexes
Published on: February 22, 2017
Transportin 3 promotes a nuclear maturation step required for efficient HIV-1 integration
Lihong Zhou1, Elena Sokolskaja, Clare Jolly
1Wohl Virion Centre, Division of Infection & Immunity, University College London, London, United Kingdom.
Plos Pathogens
|September 9, 2011
Summary
Transportin 3 (Tnp3) facilitates HIV-1 integration by binding viral capsid and tRNAs post-nuclear entry. This karyopherin
Area of Science:
- Molecular Virology
- Cell Biology
- Infectious Diseases
Background:
- HIV/AIDS remains a significant global health challenge, necessitating deeper understanding of viral replication mechanisms for new therapies.
- Key events in HIV-1 replication, particularly post-nuclear entry and pre-integration, are not fully understood.
- Nuclear transport pathways are crucial for viral lifecycle progression.
Purpose of the Study:
- To elucidate the role of karyopherin Transportin 3 (Tnp3) in HIV-1 replication.
- To investigate the interaction of Tnp3 with HIV-1 components and its impact on viral integration.
- To explore Tnp3's function in nucleocytoplasmic trafficking of viral and cellular RNAs.
Main Methods:
- Investigated Tnp3's role in HIV-1 integration across various cell types.
- Assessed Tnp3 binding to viral capsid proteins and incorporated tRNAs, analyzing interactions in the presence of RanGTP.
- Examined the effect of Tnp3 depletion on HIV-1 capsid protein localization and viral infectivity using wild-type and mutant viruses.
Main Results:
- Transportin 3 (Tnp3) was shown to promote HIV-1 integration.
- Tnp3 binds to HIV-1 capsid proteins and viral tRNAs, with stronger interaction in the presence of RanGTP, suggesting an export function.
- Tnp3 depletion caused redistribution of capsid proteins and impaired viral integration, while a Tnp3-insensitive mutant (N74D) was unaffected.
- Tnp3 mediates the RanGTP-dependent nuclear export of viral tRNAs and specific cellular tRNAs with defective 3'CCA ends.
Conclusions:
- Tnp3 plays a critical role in promoting HIV-1 infection by facilitating the dissociation of capsid and tRNA from the pre-integration complex after nuclear entry.
- Tnp3 acts as a nuclear export factor for viral tRNAs and certain cellular tRNAs, revealing a novel aspect of tRNA nucleocytoplasmic trafficking.
- Targeting Tnp3 could represent a novel therapeutic strategy against HIV/AIDS.
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