Sequences in the rev-responsive element responsible for premature translational arrest in the human-immunodeficiency-virus-type-1 envelope.
Cell-free translation in the presence of pancreatic microsomal membranes of the full-length envelope transcript of the human immunodeficiency virus type 1 (HIV-1) yielded the expected extensively glycosylated and immunologically reactive gp160 envelope-protein precursor. In addition to this gp160, a shorter glycoprotein, which we designated gp120*, was produced due to a premature translation arrest. Utilizing kinetic experiments, pulse-chase analyses and various gp160 envelope RNA mutants, we demonstrated that the in-vitro-produced gp120* was not formed by cleavage of the gp160 precursor or by internal initiation of translation. A gp120 produced before gp160 synthesis was completed, and, independent of the gp160 proteolytic processing, has been shown to be produced and sequestered in the endoplasmic reticulum of HIV-1-infected cells [Willey, R. L., Klimkait, T., Frucht, D. M., Bonifacino, J. S. & Martin, M. A. (1991) Virology 184, 319-329]. The specific translational arrest shown to occur in vitro was found to be dependent on the Rev-responsive element, since deletion of this highly structured sequence abolished the production of gp120*. We found that the combination of two contiguous putative stem loops of the Rev-responsive element, located at nucleotides 7494-7522 and 7525-7550 of the HIV-1 Rev-responsive-element sequence, was responsible for the production of this truncated protein. To our knowledge, these stem-loop structures, distinct from that known to bind the Rev protein, represent the first example responsible for the production of alternative products by premature translational arrest in higher eukaryotes.
Oncologie Cellulaire et Moléculaire INSERM U363, Institut Cochin de Génétique Moléculaire, Paris, France.
H
H
Ellerbrok
N
N
Serpente
G
G
Pancino
C
C
Vanhée
L
L
D'Auriol
M
M
Sitbon
C
C
Vaquero
D001483:Base Sequence; D004279:DNA, Viral / Q000737:chemistry / Q000235:genetics; D015686:Gene Products, env / Q000096:biosynthesis / Q000235:genetics*; D015694:Gene Products, rev / Q000235:genetics*; D015752:Genes, env; D015699:HIV Envelope Protein gp120 / Q000096:biosynthesis / Q000235:genetics; D019302:HIV Envelope Protein gp160; D015497:HIV-1 / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D014176:Protein Biosynthesis; D011498:Protein Precursors / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism; D012367:RNA, Viral; D012045:Regulatory Sequences, Nucleic Acid; D013728:Terminator Regions, Genetic; D014158:Transcription, Genetic; D054321:rev Gene Products, Human Immunodeficiency Virus
D004279:DNA, Viral; D015686:Gene Products, env; D015694:Gene Products, rev; D015699:HIV Envelope Protein gp120; D019302:HIV Envelope Protein gp160; D011498:Protein Precursors; D012367:RNA, Viral; D054321:rev Gene Products, Human Immunodeficiency Virus