This Article Full Text Full Text (PDF) An erratum has been published Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Woodward, C. L. Articles by Chow, S. A. Search for Related Content PubMed PubMed Citation Articles by Woodward, C. L. Articles by Chow, S. A.

Subcellular Localization of Feline Immunodeficiency Virus Integrase and Mapping of Its Karyophilic Determinant

Cora L. Woodward,^1,2,3 Yao Wang,^1, Wendy J. Dixon,⁴ Han Htun,^1,2,5 and Samson A. Chow^1,2,3*

Department of Molecular and Medical Pharmacology,¹ Molecular Biology Institute,² AIDS Institute,³ Department of Obstetrics and Gynecology, School of Medicine, University of California, Los Angeles, California 90095,⁵ Department of Biological Sciences, California State Polytechnic University, Pomona, California 91768⁴

Received 13 September 2002/ Accepted 16 January 2003

Feline immunodeficiency virus (FIV), like other members of the lentivirus subfamily, such as human immunodeficiency virus type 1 (HIV-1), can infect nondividing and terminally differentiated cells. The transport of the preintegration complex into the nucleus is cell cycle-independent, but the mechanism is not well understood. Integrase is a key component of the complex and has been suggested to play a role in nuclear import during HIV-1 replication. To determine its karyophilic property, FIV integrase fused with glutathione S-transferase and enhanced green fluorescent protein was expressed in various feline and human cells and the subcellular localization was visualized by fluorescence microscopy. Wild-type FIV integrase was karyophilic in all cell lines tested and capable of targeting the fusion protein to the nuclei of transfected cells. Analysis of deletion and point mutation variants of FIV integrase failed to reveal any canonical nuclear localization signal, and the karyophilic determinant was mapped to the highly conserved N-terminal zinc-binding HHCC motif. A region near the C-terminal domain enriched with basic amino acid residues also affected the nuclear import of integrase. However, the role of this region is only modulatory in comparison to that of the zinc-binding domain. The N-terminal zinc-binding domain does not bind DNA and instead is essential in integrase multimerization. We therefore postulate that the karyophilic property of FIV integrase requires subunit multimerization promoted by the HHCC motif. Alternatively, the HHCC motif may directly promote interaction between FIV integrase and cellular proteins involved in nuclear import.

Present address: Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN 38105.

This article has been cited by other articles:

• An, D. G., Hyun, U., Shin, C.-G. (2008). Characterization of nuclear localization signals of the prototype foamy virus integrase. J. Gen. Virol. 89: 1680-1684 [Abstract] [Full Text]  
• Lu, R., Ghory, H. Z., Engelman, A. (2005). Genetic Analyses of Conserved Residues in the Carboxyl-Terminal Domain of Human Immunodeficiency Virus Type 1 Integrase. J. Virol. 79: 10356-10368 [Abstract] [Full Text]  
• Vanegas, M., Llano, M., Delgado, S., Thompson, D., Peretz, M., Poeschla, E. (2005). Identification of the LEDGF/p75 HIV-1 integrase-interaction domain and NLS reveals NLS-independent chromatin tethering. J. Cell Sci. 118: 1733-1743 [Abstract] [Full Text]  
• Llano, M., Delgado, S., Vanegas, M., Poeschla, E. M. (2004). Lens Epithelium-derived Growth Factor/p75 Prevents Proteasomal Degradation of HIV-1 Integrase. J. Biol. Chem. 279: 55570-55577 [Abstract] [Full Text]  
• Llano, M., Vanegas, M., Fregoso, O., Saenz, D., Chung, S., Peretz, M., Poeschla, E. M. (2004). LEDGF/p75 Determines Cellular Trafficking of Diverse Lentiviral but Not Murine Oncoretroviral Integrase Proteins and Is a Component of Functional Lentiviral Preintegration Complexes. J. Virol. 78: 9524-9537 [Abstract] [Full Text]  
• Maertens, G., Cherepanov, P., Debyser, Z., Engelborghs, Y., Engelman, A. (2004). Identification and Characterization of a Functional Nuclear Localization Signal in the HIV-1 Integrase Interactor LEDGF/p75. J. Biol. Chem. 279: 33421-33429 [Abstract] [Full Text]  
• Maertens, G., Cherepanov, P., Pluymers, W., Busschots, K., De Clercq, E., Debyser, Z., Engelborghs, Y. (2003). LEDGF/p75 Is Essential for Nuclear and Chromosomal Targeting of HIV-1 Integrase in Human Cells. J. Biol. Chem. 278: 33528-33539 [Abstract] [Full Text]