Importin alpha3 interacts with HIV-1 integrase and contributes to HIV-1 nuclear import and replication.

Abstract

HIV-1 employs the cellular nuclear import machinery to actively transport its preintegration complex (PIC) into the nucleus for integration of the viral DNA. Several viral karyophilic proteins and cellular import factors have been suggested to contribute to HIV-1 PIC nuclear import and replication. However, how HIV interacts with different cellular machineries to ensure efficient nuclear import of its preintegration complex in dividing and nondividing cells is still not fully understood. In this study, we have investigated different importin alpha (Impalpha) family members for their impacts on HIV-1 replication, and we demonstrate that short hairpin RNA (shRNA)-mediated Impalpha3 knockdown (KD) significantly impaired HIV infection in HeLa cells, CD4(+) C8166 T cells, and primary macrophages. Moreover, quantitative real-time PCR analysis revealed that Impalpha3-KD resulted in significantly reduced levels of viral 2-long-terminal repeat (2-LTR) circles but had no effect on HIV reverse transcription. All of these data indicate an important role for Impalpha3 in HIV nuclear import. In an attempt to understand how Impalpha3 participates in HIV nuclear import and replication, we first demonstrated that the HIV-1 karyophilic protein integrase (IN) was able to interact with Impalpha3 both in a 293T cell expression system and in HIV-infected CD4(+) C8166 T cells. Deletion analysis suggested that a region (amino acids [aa] 250 to 270) in the C-terminal domain of IN is involved in this viral-cellular protein interaction. Overall, this study demonstrates for the first time that Impalpha3 is an HIV integrase-interacting cofactor that is required for efficient HIV-1 nuclear import and replication in both dividing and nondividing cells.

• Authors: Zhujun Ao, Kallesh Danappa Jayappa, Binchen Wang, Yingfeng Zheng, Sam Kung, Eric Rassart, Reinhard Depping, Matthias Kohler, Eric A Cohen, Xiaojian Yao
• Journal: Journal of virology (J Virol) Vol. 84 Issue 17 Pg. 8650-63 (Sep 2010) ISSN: 1098-5514 [Electronic] United States
• PMID: 20554775 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• KPNA4 protein, human
• alpha Karyopherins
• HIV Integrase

Topics

• Active Transport, Cell Nucleus
• Cell Line
• Cell Nucleus (metabolism)
• HIV Infections (genetics, metabolism, virology)
• HIV Integrase (genetics, metabolism)
• HIV-1 (enzymology, genetics, physiology)
• HeLa Cells
• Humans
• Virus Replication
• alpha Karyopherins (genetics, metabolism)