Analysis of alternatively spliced human immunodeficiency virus type-1 mRNA species, one of which encodes a novel tat-env fusion protein.
A polymerase chain reaction-based analysis was used to define the structures of the mRNAs that encode human immunodeficiency virus type-1 (HIV-1) regulatory and structural proteins in infected H9 cells. Twenty alternatively spliced mRNAs encoding the vif, vpr, env, nef, tat, and rev proteins were characterized. An evaluation of the coding potentials of these transcripts recognized both leaky scanning and reinitiation at downstream initiation codons as mechanisms that may operate during translation of many of the polycistronic messages. Two new splice acceptor sites, one at nt 6018 defining a new mRNA coding for the env and vpu proteins and another at nt 8671 defining a novel tat-env fusion transcript, were characterized. The latter transcript expressed a novel protein p17tev that was immunoprecipitated by both polyclonal tat antibodies and monoclonals directed towards the C-terminal region of gp41. The p17tev protein was able to transactivate transcription from the HIV-1 LTR in transient transfection assays. The use of multiple alternative splice donor and acceptor sites and the generation of novel proteins may confer evolutionary advantages on the viral mutants encoding them and influence the course of clinical disease.
Department of Medicine, Northwestern University Medical School, Chicago, Illinois 60611.
M R
MR
Furtado
R
R
Balachandran
P
P
Gupta
S M
SM
Wolinsky
D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D003001:Cloning, Molecular; D004279:DNA, Viral / Q000235:genetics / Q000302:isolation & purification; D015686:Gene Products, env / Q000096:biosynthesis / Q000235:genetics*; D015696:Gene Products, tat / Q000096:biosynthesis / Q000235:genetics*; D005814:Genes, Viral; D015752:Genes, env; D015756:Genes, tat; D016325:HIV Long Terminal Repeat / Q000235:genetics*; D015497:HIV-1 / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides; D010957:Plasmids; D014176:Protein Biosynthesis; D012326:RNA Splicing; D012333:RNA, Messenger / Q000235:genetics*; D012367:RNA, Viral / Q000235:genetics*; D011817:Rabbits; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D015183:Restriction Mapping; D012156:Reticulocytes / Q000378:metabolism; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D015678:Viral Structural Proteins / Q000235:genetics*; D054322:tat Gene Products, Human Immunodeficiency Virus
D004279:DNA, Viral; D015686:Gene Products, env; D015696:Gene Products, tat; D009838:Oligodeoxyribonucleotides; D012333:RNA, Messenger; D012367:RNA, Viral; D011993:Recombinant Fusion Proteins; D015678:Viral Structural Proteins; D054322:tat Gene Products, Human Immunodeficiency Virus