Abstract:
:The tat protein encoded by the human immunodeficiency virus type 1 is a potent trans-activator of gene expression from the viral long terminal repeat. The domains that are essential for trans-activation, a Pro-Xaa3-Pro triad, a cysteine-rich metal-binding sequence motif, and a cluster of basic residues, are present within the N-terminal 57 residues of tat. To determine the structural requirements for tat function and the role of metal binding at the transcription level alone, tat-(1-86) (full-length tat peptide), tat-(1-57), and tat-(1-47) were chemically synthesized. These peptides as well as the Cd2+ and Zn2+ complexes of tat-(1-86) and tat-(1-57) were evaluated for stimulation of transcription from the human immunodeficiency virus type 1 long terminal repeat by using cell-free in vitro methods. All three peptides produced a 7- to 9-fold increase over the basal level of transcription at a peptide concentration of 0.4 microM. Interestingly, at 4 microM, both tat-(1-57) and tat-(1-86) inhibited even the basal level of transcription. In contrast, tat-(1-47), which lacks the basic domain (residues 49-57), exhibited full stimulatory activity at 4 microM. Our data suggest, therefore, that the basic region may be responsible for the observed inhibitory activity of tat-(1-86) and tat-(1-57). Furthermore, binding to Zn2+ and not to Cd2+ ions only slightly augments (approximately 2-fold) the activity of the tat peptides.
journal_name
Proc Natl Acad Sci U S Aauthors
Jeyapaul J,Reddy MR,Khan SAdoi
10.1073/pnas.87.18.7030subject
Has Abstractpub_date
1990-09-01 00:00:00pages
7030-4issue
18eissn
0027-8424issn
1091-6490journal_volume
87pub_type
杂志文章abstract::Glucocorticoid hormones increase the level of hepatic tryptophan oxygenase (EC 1.13.11.11; L-tryptophan:oxygen 2,3-oxidoreductase (decyclizing) by increasing its rate of synthesis. Studies were performed to determine whether this induction is mediated by controlling the level of the mRNA for tryptophan oxygenase of by...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.72.3.1017
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.87.12.4413
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.88.2.458
更新日期:1991-01-15 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
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更新日期:1994-10-25 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.88.8.3065
更新日期:1991-04-15 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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更新日期:1982-01-01 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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更新日期:1989-03-01 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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更新日期:1996-11-12 00:00:00