Human immunodeficiency virus type 1 MA deletion mutants expressed in baculovirus-infected cells: cis and trans effects on the Gag precursor assembly pathway.
The role of the matrix protein (MA) of human immunodeficiency virus type 1 in intracellular transport, assembly, and extracellular release of Gag polyprotein precursor (Pr55gag) was investigated by deletion mutagenesis of the MA domain of recombinant Gag precursor expressed in baculovirus-infected cells. In addition, three carboxy-terminally truncated forms of the Gag precursor, representing mainly the MA, were constructed. One corresponded to an MA with a deletion of its last 12 residues (amb120), while the others corresponded to the entire MA with an additional sequence from the N-terminal portion of the CA (amb143 and och180). Deletions within the MA central region (residues 41 to 78) appeared to be detrimental to Gag particle assembly and budding from the plasma membrane. A slightly narrower domain, between amino acids 41 and 68, was found to be critical for soluble Gag secretion. Mutations which totally or partially deleted one or the other of the two polybasic signals altered the transport of N-myristylated Gag precursor to the plasma membrane. In coexpression with wild-type Gag precursor, a discrete trans-dominant negative effect on wild-type Gag particle assembly and release was observed with deletion mutants located in the central MA region (residues 41 to 78). A more significant negative effect was obtained with the two recombinant proteins of amb120 and och180, which redirected the Gag particle assembly pathway from the plasma membrane compartment to intracellular vesicles (amb120) and to the nuclear compartment (och180).
Chazal
N
N
Laboratoire de Virologie et Pathogénèse Moléculaires, CNRS URA-1487, Faculté de Médecine, Montpellier, France.
Gay
B
B
Carrière
C
C
Tournier
J
J
Boulanger
P
P
D000595:Amino Acid Sequence; D000818:Animals; D016367:Baculoviridae; D001483:Base Sequence; D002478:Cells, Cultured; D015683:Gene Products, gag / Q000235:genetics* / Q000378:metabolism*; D015488:HIV Antigens / Q000235:genetics / Q000378:metabolism*; D015497:HIV-1 / Q000235:genetics*; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides; D011485:Protein Binding; D011498:Protein Precursors / Q000235:genetics* / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D012367:RNA, Viral / Q000378:metabolism; D011995:Recombination, Genetic; D017384:Sequence Deletion; D018411:Spodoptera; D014763:Viral Matrix Proteins / Q000235:genetics / Q000378:metabolism; D014764:Viral Proteins; D054301:gag Gene Products, Human Immunodeficiency Virus
D015683:Gene Products, gag; D015488:HIV Antigens; D009838:Oligodeoxyribonucleotides; D011498:Protein Precursors; D012367:RNA, Viral; D014763:Viral Matrix Proteins; D014764:Viral Proteins; D054301:gag Gene Products, Human Immunodeficiency Virus; C054858:p17 protein, Human Immunodeficiency Virus Type 1; C059767:p55 gag precursor protein, Human immunodeficiency virus 1