Uncleaved env gp160 of human immunodeficiency virus type 1 is degraded within the Golgi apparatus but not lysosomes in COS-1 cells.
The fate of newly synthesized human immunodeficiency virus type 1 env gp160 was examined in COS-1 cells. The results of morphological chase experiments involving cycloheximide demonstrated that gp160 was retained in the Golgi apparatus for longer than the half-life of the molecule. The degradation of gp160 was insensitive to both bafilomycin A1 and leupeptin (< 0.2 mM), which block lysosomal proteolysis. However, degradation was effectively suppressed by leupeptin at higher concentrations, maximally at 1.7 mM. Furthermore, undegraded gp160 was accumulated in the Golgi apparatus, but was not detected in lysosomes. These results indicate that in COS-1 cells gp160 is not degraded in lysosomes, but rather that degradation takes place in the Golgi apparatus.
Kimura
T
T
Department of Microbiology, Kansai Medical University, Osaka, Japan.
Nishikawa
M
M
Fujisawa
J
J
D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002460:Cell Line; D002522:Chlorocebus aethiops; D004705:Endocytosis; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004815:Epidermal Growth Factor / Q000378:metabolism; D015686:Gene Products, env / Q000096:biosynthesis / Q000378:metabolism*; D015752:Genes, env; D006056:Golgi Apparatus / Q000378:metabolism*; D019302:HIV Envelope Protein gp160; D015497:HIV-1 / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007700:Kinetics; D007976:Leupeptins / Q000494:pharmacology; D008247:Lysosomes / Q000378:metabolism*; D018942:Macrolides; D011498:Protein Precursors / Q000096:biosynthesis / Q000378:metabolism*; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000378:metabolism; D013997:Time Factors; D014162:Transfection
D000900:Anti-Bacterial Agents; D004791:Enzyme Inhibitors; D015686:Gene Products, env; D019302:HIV Envelope Protein gp160; D007976:Leupeptins; D018942:Macrolides; D011498:Protein Precursors; D011994:Recombinant Proteins; D004815:Epidermal Growth Factor; C040929:bafilomycin A1; C032854:leupeptin