Document 3303
 DOCN  M94A3303
 TI    HIV-1 Vpu liberates Golgi-targeted HIV-1 env gp160 from CD4-dependent
       retention in the endoplasmic reticulum.
 DT    9412
 AU    Nishikawa M; Kimura T; Department of Microbiology, Kansai Medical
       University, Osaka,; Japan.
 SO    Int Conf AIDS. 1994 Aug 7-12;10(1):107 (abstract no. PA0045). Unique
       Identifier : AIDSLINE ICA10/94369272
 AB    OBJECTIVE: The experiments were aimed to analyse the effects of HIV-1
       Vpu on subcellular localization and processing of HIV-1 env gp160 that
       had been complexed and retained with CD4 molecules in the Endoplasmic
       reticulum (ER). METHODS: COS-1 cells were transfected to express HIV-1
       env, vpu and rev, and CD4 genes. Analyses of oligosaccharides processing
       of gp160, and measurement of turn-over of CD4-gp160 complexes in the
       presence of and absence of Vpu were carried out on metabolically
       labelled COS-1 cells. In cycloheximide-treated cells a morphological
       chase was also performed to examine the effects of Vpu on the membrane
       traffic of gp160 coupled with CD4. RESULTS: When gp160 and Vpu were
       co-expressed from the singly spliced viral bicistronic mRNA, both
       molecules were independently targeted to the Golgi apparatus.
       Co-expression of CD4, however, resulted in the retention of gp160 in the
       ER but only observed in vpu-cells. Expression of Vpu selectively
       degraded CD4 and rendered the gp160 competent to translocate to the
       targeted Golgi complex. CONCLUSIONS: We concluded that Vpu prevents the
       formation of stable CD4-gp160 complexes in the ER, thereby, indirectly
       allows gp160 to accumulate in the Golgi apparatus where the protein is
       selectively retained to produce gp120-gp41.
 DE    Animal  Antigens, CD4/*METABOLISM  Cell Line  Endoplasmic
       Reticulum/METABOLISM/MICROBIOLOGY  Gene Expression  Gene Products,
       env/GENETICS/*METABOLISM  Gene Products, vpu/GENETICS/*METABOLISM
       Genes, env  Genes, rev  Genes, vpu  Golgi
       Apparatus/METABOLISM/MICROBIOLOGY  Human  HIV Envelope Protein
       gp120/METABOLISM  HIV Envelope Protein gp41/METABOLISM
       HIV-1/GENETICS/*METABOLISM  Protein Precursors/GENETICS/*METABOLISM
       Protein Processing, Post-Translational  Transfection  MEETING ABSTRACT

       SOURCE: National Library of Medicine.  NOTICE: This material may be
       protected by Copyright Law (Title 17, U.S.Code).