1. State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan
2. National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute
of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
3. College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
Human immunodeficiency virus-1 (HIV-1) encodes 15 viral proteins. Protein-protein interactions play a large role in the function of these proteins. In this study, we attempted to identify novel interactions between the HIV-1 proteins to better understand the role played by viral protein-protein interactions in the life cycle of HIV-1. Genes encoding the 15 viral proteins from the HIV-1 strain AD8 were inserted into the plasmids of a yeast two-hybrid system. By screening 120 pairs of
proteins, interactions between seven pairs were found. This led to the discovery of an interaction between the HIV-1 proteins integrase (IN) and glycoprotein 41 (gp41), which was confirmed by both co-immunoprecipitation (Co-IP) assays and fluorescence resonance energy transfer (FRET) imaging in live cells. In addition, it was found that the amino acids at positions 76–100 of gp41 are required for it to bind to IN. Deletion of this region from gp41 prevented its interaction with IN and reduced the production of HIV-1 in 293T cells. This study provides new information on HIV-1 protein-protein interactions which improves the understanding of the biological functions of gp41 and IN during the virus life cycle.