HTLV-III env gene products synthesized in E. coli are recognized by antibodies present in the sera of AIDS patients

Crowl, Robert M.; Ganguly, Kalyan; Gordon, M L; Conroy, Robert R.; Schaber, Michael D.; Kramer, R. Arjen; Shaw, GM; Wong‐Staal, Flossie; Reddy, E. S. P.

doi:10.1016/s0092-8674(85)80078-7

Cited by 77 publications

(44 citation statements)

References 17 publications

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“…The replication of equine infectious anemia virus, for example, progresses through cycles in infected horses, with each peak in virus replication reflecting a change in the antigenicity of its envelope glycoprotein (21). Similarly, five independent isolates of the acquired immune deficiency syndrome retrovirus all display striking sequence heterogeneity in the external region of the envelope glycoprotein, indicating that random mutation followed by a positive selection for varients which can escape immune detection may have occurred (9).…”

Section: Resultsmentioning

confidence: 99%

Neither arginine nor histidine can carry out the function of lysine-295 in the ATP-binding site of p60src.

Kamps¹,

Sefton²

1986

Mol. Cell. Biol.

152

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All 15 protein kinases whose amino acid sequence is known contain a lysine residue at a position homologous to that of lysine-295 in p60S, the transforming protein of Rous sarcoma virus. The ATP analog p-fluorosulfonyl 5'-benzoyl adenosine inactivates both p6(Y'= and the catalytic subunit of the cyclic AMP-dependent protein kinase by modification of this lysine. We used oligonucleotide-directed mutagenesis to examine the possible functions of this residue. Lysine-295 in p6(Y' was replaced with a glutamic acid, an arginine, or a histidine residue, and mutant p6(Wc proteins were characterized in chicken cells infected by mutant viruses. None of these three mutant p60(W proteins had tyrosine protein kinase activity in vitro, and none induced morphological transformation of infected cells. Since neither a histidine nor an arginine residue can replace the function of lysine-295, we suggest that it carries out the specialized function of proton transfer in the phosphotransferase reaction. All three mutant viruses underwent reversion to wild type during passage in tissue culture. Because the rate with which this occurred differed significantly among the mutants, reversion appears to have resulted from errors in transcription, rather than from recombination with the cellular src gene.Oncogenic transformation by Rous sarcoma virus (RSV) results from the expression of p60rc (22), a virally encoded phosphoprotein that possesses tyrosine-specific protein kinase activity (7,14). p605rc is one of 12 members of the tyrosine protein kinase family. Partial tryptic digestion has been used to isolate a 30-kilodalton (kDa) catalytic domain from the carboxy terminus of p60rc which functions autonomously as a tyrosine protein kinase, indicating that it contains all amino acids necessary for catalysis (19). The catalytic domain of serine protein kinases has both structural and functional homology with the kinase domain of tyrosine protein kinases. Direct sequence comparison of residues 259 to 485 of p605rc reveals 22% sequence homology with residues 33 to 258 of the cyclic AMP-dependent serine protein kinase (1). Functional homology within the active sites of these two kinases was recently established by demonstration that the ATP analog p-fluorosulfonyl 5'-benzoyl adenosine reacts with a lysine found in a homologous position in both p60rc (lysine-295) and the cyclic AMP-dependent protein kinase (lysine-72) (16, 29). This lysine is, in fact, 1 of 12 residues which are strictly conserved within the catalytic domains of every protein kinase sequenced to date (13).What is the exact function of this lysine? Lysine-295 of p60yc may have one of four functions. First, it could be present on the surface of p6Osrc and aid in orienting this region of the enzyme toward the hydrophilic cytosol. Second, lysine-295 might be the cationic half of a salt bridge which stabilizes the structure of p60srC in or near the ATPbinding site. A third possiblity is that lysine-295 is present within the ATP-binding site and stabilizes directly the negatively cha...

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Section: Resultsmentioning

confidence: 99%

Neither arginine nor histidine can carry out the function of lysine-295 in the ATP-binding site of p60src.

Kamps¹,

Sefton²

1986

Mol. Cell. Biol.

152

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“…Rather, the goal of this study was to localize T-cell sites from the HIV envelope that might be useful in vaccine development, as, to our knowledge, no T-cell epitopes have been identified in any AIDS virus protein. Studies with AIDS virus peptides have been directed at antibody specificities (1)(2)(3)(4)(5)(6)(7)(8)(9) or pharmacologic blocking of gpl20 binding to CD4 (51) and have dealt with sites distinct from those of the present study.…”

Section: Discussionmentioning

confidence: 99%

Helper T-cell antigenic site identification in the acquired immunodeficiency syndrome virus gp120 envelope protein and induction of immunity in mice to the native protein using a 16-residue synthetic peptide.

Cease¹,

Margalit²,

Cornette³

et al. 1987

Proc. Natl. Acad. Sci. U.S.A.

165

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authors request that the following correction be noted. Mutant 49 of the Tac receptor subunit in which Thr-85, Thr-86 were replaced by Ala-85, Gly-86 was also modified at the C terminus of the polypeptide chain. The oligonucleotide used in the mutation reaction apparently hybridized with the single-stranded template at the correct location surrounding Thr-85, Thr-86 and also at a site after the codon for Gln-202. As a consequence, the C-terminal region of the mutant 49 protein differed markedly from that of the native molecule. The mutant protein bound to affinity supports coupled with interleukin 2 and the anti-Tac monoclonal antibody, but was defective for expression on the cell surface. Examination of a new mutant of the Tac protein in which Thr-85 and Thr-86 were replaced by Ala and Gly, respectively, but in which the remaining sequence was identical to that of the native protein, indicates that this substitution has no effect on cell-surface expression. Moreover Correction. In the article "Helper T-cell antigenic site identification in the acquired immunodeficiency syndrome virus gp120 envelope protein and induction of immunity in mice to the native protein using a 16-residue synthetic peptide" by

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“…Transcripts expressed from this vector possess a 90-nt poly(A) sequence near their 3Ј ends, followed by a 31-nt non-A extension. Plasmid pRSV-Rev contains the Rev coding region from HIV-1 and is driven by the Rous sarcoma virus long terminal repeat promoter (6). PyE is the entire polyomavirus genome cloned into pUC18 at the BamHI site.…”

Section: Methodsmentioning

confidence: 99%

Role of Polyadenylation in Nucleocytoplasmic Transport of mRNA

Huang

Carmichael

1996

Molecular and Cellular Biology

216

175

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To examine the role of polyadenylation in the nuclear export of mRNA, we have replaced the poly(A) signal in a Rev-responsive human immunodeficiency virus type 1-based reporter gene with a cis-acting hammerhead ribozyme. Transcripts from this gene thus acquire a 3 terminus by cis-ribozyme cleavage rather than by polyadenylation. The nuclear and cytoplasmic distribution of transcripts was investigated using transient gene expression and quantitative RNase protection assays. In the absence of Rev, a basal level of polyadenylated unspliced mRNA transcribed from a poly(A) signal-containing control reporter gene was detected in the cytoplasm of transfected COS7 cells. However, cytoplasmic ribozyme-cleaved unspliced RNA was only barely detectable. The nuclear/cytoplasmic (n/c) ratio of polyadenylated RNAs was 3.8, while the n/c ratio for ribozyme cis-cleaved RNAs was 33. The cytoplasmic localization of the polyadenylated unspliced mRNA was enhanced about 10-fold in the presence of Rev and the Rev-responsive element. In marked contrast to this, ribozymecleaved RNA accumulated almost exclusively (n/c ratio of 28) in the nucleus in the presence of Rev. Actinomycin D time course analysis suggested that the low levels of the cytoplasmic ribozyme-cleaved RNAs in both the presence and absence of Rev were due to severe export deficiency of ribozyme-cleaved RNA. Finally, by inserting a 90-nucleotide poly(A) stretch directly upstream of the ribozyme cassette, we have demonstrated that a long stretch of poly(A) near the 3 end of a ribozyme-cleaved transcript is not sufficient for directing mRNA export. Taken together, these results suggest that polyadenylation is required for the nucleocytoplasmic transport of mRNA and that Rev interaction with the Rev-responsive element cannot bypass this requirement.Messenger RNA precursors (pre-mRNAs) are synthesized in the nucleus by RNA polymerase II and then subjected to a series of processing reactions which include the addition of a 7-methylguanosine cap at the 5Ј end, the removal of introns by splicing, and the generation of mature 3Ј ends. With the exception of histone genes, whose transcripts end in a highly conserved stem-loop structure (for reviews see references 2 and 36), the 3Ј end is formed by cleavage and polyadenylation (recently reviewed; see reference 47). Mature RNA molecules are then translocated to the cytoplasm through the nuclear pore complex (see reference 12 for review). The mechanism of mRNA nuclear export is poorly understood, although this process is fundamental to eukaryotic gene expression. Recently, however, evidence has begun to accumulate that capping and subsequent processing of pre-mRNA to generate mature mRNA influence the efficiency of nuclear export (reviewed in references 12, 20, and 26).Evidence that the 5Ј monomethylguanosine cap structure may serve as a positive signal for mRNA nuclear export was derived from microinjection experiments carried out with Xenopus oocytes (9, 18, 21). It was shown that mRNAs carrying the normal 5Ј cap structure were rapid...

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HTLV-III env gene products synthesized in E. coli are recognized by antibodies present in the sera of AIDS patients

Cited by 77 publications

References 17 publications

Neither arginine nor histidine can carry out the function of lysine-295 in the ATP-binding site of p60src.

Neither arginine nor histidine can carry out the function of lysine-295 in the ATP-binding site of p60src.

Helper T-cell antigenic site identification in the acquired immunodeficiency syndrome virus gp120 envelope protein and induction of immunity in mice to the native protein using a 16-residue synthetic peptide.

Role of Polyadenylation in Nucleocytoplasmic Transport of mRNA

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