The intracytoplasmic domain of gp41 mediates polarized budding of human immunodeficiency virus type 1 in MDCK cells.
Human immunodeficiency virus type 1 (HIV-1) has been shown to exhibit a specific basolateral release in polarized epithelial cells. Previous investigators have used vaccinia virus recombinants expressing HIV proteins to demonstrate that virus release is nonpolarized in the absence of viral envelope glycoproteins. In this study, we developed a transient expression system which allows the use of Madin-Darby canine kidney polarized epithelial cells directly grown on semipermeable membranes. This procedure allowed us to investigate polarized HIV viral budding following introduction of proviral DNA constructs. Expression of env gene products in trans demonstrated the ability to polarize env-negative viruses in a dose-dependent manner. The targeting signal for polarized virus release was shown to be present in the envelope gp41 transmembrane protein and absent from the gp120 portion of env. At least part of this signal is within the gp41 intracytoplasmic domain. Mutants of the p17gag matrix protein were shown to be nonpolarized only when unable to interact with the envelope glycoproteins. Together, these data are consistent with a model of polarized virus budding in which capsid proteins, lacking a targeting signal, are targeted for specific basolateral release via an interaction of p17 with the envelope glycoprotein containing the polarization signal in its intracytoplasmic domain.
Département de Microbiologie et Immunologie, Université de Montréal, Québec, Canada.
R
R
Lodge
H
H
Göttlinger
D
D
Gabuzda
E A
EA
Cohen
G
G
Lemay
D000818:Animals; D001692:Biological Transport; D002460:Cell Line; D003001:Cloning, Molecular; D003593:Cytoplasm / Q000378:metabolism; D004285:Dogs; D015686:Gene Products, env / Q000502:physiology; D015683:Gene Products, gag / Q000235:genetics / Q000378:metabolism; D015488:HIV Antigens / Q000235:genetics / Q000378:metabolism; D019302:HIV Envelope Protein gp160; D015700:HIV Envelope Protein gp41 / Q000235:genetics / Q000502:physiology*; D015497:HIV-1 / Q000502:physiology*; D009154:Mutation; D011498:Protein Precursors / Q000502:physiology; D021382:Protein Sorting Signals / Q000378:metabolism; D014764:Viral Proteins; D014779:Virus Replication; D054301:gag Gene Products, Human Immunodeficiency Virus
D015686:Gene Products, env; D015683:Gene Products, gag; D015488:HIV Antigens; D019302:HIV Envelope Protein gp160; D015700:HIV Envelope Protein gp41; D011498:Protein Precursors; D021382:Protein Sorting Signals; D014764:Viral Proteins; D054301:gag Gene Products, Human Immunodeficiency Virus; C054858:p17 protein, Human Immunodeficiency Virus Type 1