Human immunodeficiency virus 1 Vpu protein does not affect the conversion of influenza A virus hemagglutinin to its low-pH conformation in an acidic trans-Golgi compartment.
The 81-aa Vpu protein of Human immunodeficiency virus 1 (HIV-1) is a structural analogue of the M2 protein of influenza A virus (IAV). Expression of Vpu in Xenopus oocytes has showed that it can form a voltage-activated ion channel permeable to Na+ and K+ ions (Ewart et al., 1996). To investigate whether Vpu has a pH-modulating activity comparable to that of M2, Vpu was co-expressed with the pH-sensitive hemagglutinin (HA) from IAV. The results indicated that Vpu was unable to reduce the acidity of the exocytic pathway and reduce the conversion of the pH-sensitive HA to its low-pH conformation during transport to the cell surface. Despite these findings, we did not exclude the possibility that Vpu formed a weak ion channel with almost pore-like characteristics as was recently suggested.
Betáková
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Institute of Virology, Slovak Academy of Sciences, Bratislava, Slovak Republic. virubeta@savba.sk
D000818:Animals; D002460:Cell Line; D002462:Cell Membrane / Q000235:genetics / Q000378:metabolism; D002522:Chlorocebus aethiops; D006367:HeLa Cells; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D054298:Human Immunodeficiency Virus Proteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D011487:Protein Conformation; D021381:Protein Transport; D054334:Viral Regulatory and Accessory Proteins / Q000235:genetics / Q000378:metabolism*; D021601:trans-Golgi Network / Q000737:chemistry / Q000378:metabolism*; D000086082:Viroporin Proteins
D019267:Hemagglutinin Glycoproteins, Influenza Virus; D054298:Human Immunodeficiency Virus Proteins; D054334:Viral Regulatory and Accessory Proteins; C514859:vpu protein, Human immunodeficiency virus 1; D000086082:Viroporin Proteins