Identification of a gp41 core-binding molecule with homologous sequence of human TNNI3K-like protein as a novel human immunodeficiency virus type 1 entry inhibitor.
Human immunodeficiency virus type 1 (HIV-1) gp41 plays a critical role in the viral fusion process, and its N- and C-terminal heptad repeat domains serve as important targets for developing anti-HIV-1 drugs, like T-20 (generic name, enfuvirtide; brand name, Fuzeon). Here, we conducted a yeast two-hybrid screening on a human bone marrow cDNA library using the recombinant soluble gp41 ectodomain as the bait and identified a novel gp41 core-binding molecule, designated P20. P20 showed no homology with a current HIV fusion inhibitor, T-20, but had sequence homology to a human protein, troponin I type 3 interacting kinase (TNNI3K)-like protein. While it could bind to the six-helix bundle core structure formed by the N- and C-terminal heptad repeats, P20 did not interrupt the formation of the six-helix bundle. P20 was effective in blocking HIV-1 Env-mediated syncytium formation and inhibiting infection by a broad spectrum of HIV-1 strains with distinct subtypes and coreceptor tropism, while it was ineffective against other enveloped viruses, such as vesicular stomatitis virus and influenza A virus. P20 exhibited no significant cytotoxicity to the CD4(+) cells that were used for testing antiviral activity. Among the 11 P20 mutants, four analogous peptides with a common motif (WGRLEGRRT) exhibited significantly reduced anti-HIV-1 activity, suggesting that this region is the critical active site of P20. Therefore, this peptide can be used as a lead for developing novel HIV fusion inhibitors and as a probe for studying the membrane-fusogenic mechanism of HIV.
Zhu
Yun
Y
Laboratory of Immunology, School of Life Sciences, Tsinghua University, Beijing, People's Republic of China.
Lu
Lu
L
Xu
Liling
L
Yang
Hengwen
H
Jiang
Shibo
S
Chen
Ying-Hua
YH
D000595:Amino Acid Sequence; D015496:CD4-Positive T-Lymphocytes / Q000821:virology; D002478:Cells, Cultured; D015700:HIV Envelope Protein gp41 / Q000378:metabolism*; D023581:HIV Fusion Inhibitors / Q000302:isolation & purification*; D015497:HIV-1 / Q000276:immunology / Q000502:physiology*; D054884:Host-Pathogen Interactions; D006801:Humans; D020930:MAP Kinase Kinase Kinases / Q000235:genetics*; D008969:Molecular Sequence Data; D010455:Peptides / Q000235:genetics / Q000302:isolation & purification*; D011485:Protein Binding; D017346:Protein Serine-Threonine Kinases; D017386:Sequence Homology, Amino Acid; D020798:Two-Hybrid System Techniques; D053586:Virus Internalization
D015700:HIV Envelope Protein gp41; D023581:HIV Fusion Inhibitors; D010455:Peptides; C514787:gp41 protein, Human immunodeficiency virus 1; D017346:Protein Serine-Threonine Kinases; C481078:TNNI3K protein, human; D020930:MAP Kinase Kinase Kinases