Disease relevance of HIV2gp5

• The Tat protein of human immunodeficiency virus type 1 is a substrate and inhibitor of the interferon-induced, virally activated protein kinase, PKR [1].
• Replication of HIV-1 depends on the viral Tat protein, which functions via a target sequence, TAR, present in the proviral long terminal repeat (LTR) and at the 5' end of viral mRNAs [2].
• Structure of the equine infectious anemia virus Tat protein [3].
• We found that viruses in groups (i) and (ii), although tat(-), were fully complemented for viral gene expression based on quantitative measurements of viral protein synthesis and on the visualization by electron microscopy of the proper assembly of morphologically correct virions [4].
• To test this possibility, we performed protein interaction studies with RNA polymerase II and both the HIV-1 and the closely related HIV-2 Tat protein [5].

High impact information on HIV2gp5

• Tat protein of human immunodeficiency virus 1 is a potent trans-activator of viral gene expression [6].
• Human immunodeficiency virus gene expression is regulated transcriptionally and post-transcriptionally by the virally encoded tat protein (Tat) [7].
• Tat protein of HIV-1 stimulates growth of cells derived from Kaposi's sarcoma lesions of AIDS patients [8].
• A peptide that contained nine arginines (R9) also bound specifically to TAR, and a mutant Tat protein that contained R9 was fully active for transactivation [9].
• The purified human immunodeficiency virus type-l (HIV-l) Tat protein inhibited lymphocyte proliferation induced by tetanus toxoid or Candida antigens by 66 to 97% at nanomolar concentrations of Tat [10].

Chemical compound and disease context of HIV2gp5

• Analysis of arginine-rich peptides from the HIV Tat protein reveals unusual features of RNA-protein recognition [11].
• The Tat protein of human immunodeficiency virus type 1, a growth factor for AIDS Kaposi sarcoma and cytokine-activated vascular cells, induces adhesion of the same cell types by using integrin receptors recognizing the RGD amino acid sequence [12].
• Tat protein of human immunodeficiency virus type 1 represses expression of manganese superoxide dismutase in HeLa cells [13].
• Neuropathologies in transgenic mice expressing human immunodeficiency virus type 1 Tat protein under the regulation of the astrocyte-specific glial fibrillary acidic protein promoter and doxycycline [14].
• Multiple interactions of HIV-I Tat protein with size-defined heparin oligosaccharides [15].

Biological context of HIV2gp5

• The Tat protein of human immunodeficiency virus type 1 (HIV-1) activates transcription following binding to nascent trans-activation response (TAR) RNA downstream of the transcription start site [16].
• To combat this cellular defense, HIV-1 has evolved in its Tat protein a suppressor of RNA silencing (SRS) function [17].
• These results indicate that the Tat protein, in addition to regulating the level of gene expression, is also important for efficient HIV-1 reverse transcription [18].
• The removal of the second tat intron is regulated by a combination of a suboptimal 3' splice site and cis-acting splicing enhancers and silencers [19].
• Group (iii) viruses, although capable of producing intact Tat protein, also could not use Tat for transcription/gene expression because of the TAR(-) genotype [4].

Anatomical context of HIV2gp5

• Inhibition of antigen-induced lymphocyte proliferation by Tat protein from HIV-1 [10].
• We show here that depletion of protein kinase C (PKC), which is essential to the stimulation of T cells by several mitogens, dramatically reduces HIV-1 transactivation without affecting synthesis of tat protein [20].
• The tat protein was assayed for cell attachment activity by measuring the adhesion of monocytic, T lymphocytic, and skeletal muscle-derived cell lines to tat-coated substratum [21].
• A similar potentiation of TNF effects was observed in Jurkat T cells and HeLa cells treated with soluble Tat protein [22].
• This review focuses on the activities of extracellular Tat protein on endothelial cells, on angiogenesis, and on the pathogenesis of AIDS-associated angioproliferative diseases such as Kaposi's sarcoma [23].

Associations of HIV2gp5 with chemical compounds

• In contrast, a Tat protein that contained a deletion of the proline-rich domain promoted neuronal aggregation [24].
• A number of studies have documented the neurotoxic property of Tat protein, and Tat has therefore been proposed to contribute to AIDS-associated neurological diseases [14].
• The percentage of the responders and the Ab titers continued to increase after three additional DNA boosts and pretreatment with bupivacaine at the site of inoculation, without a significant difference (p > 0.05) among the three groups of mice immunized with mutant and wild-type tat genes [25].
• Tat protein induced a rapid and transient Ca(2+) influx in basophils and mast cells, analogous to beta-chemokines [26].
• Tat protein neither induced histamine release from human basophils and mast cells nor increased IL-3-stimulated histamine secretion from basophils [26].

Other interactions of HIV2gp5

• Overexpression of Rev protein did not rescue the synthesis of HIV-1 proteins in these cells; however, the observed inhibition of HIV-1 RNA translation was efficiently overcome in the presence of Tat protein or TNF-alpha [27].

Analytical, diagnostic and therapeutic context of HIV2gp5

• The effect of Tat was completely blocked, however, by immunization with inactivated Tat protein before vaccination with the bicistronic gp120-Tat DNA vaccine [28].
• The purified Tat protein was biochemically analyzed and tested for activity upon electroporation into human cell lines [29].
• The chain length and the identity of the TAR-RNA were established by RNase protection assays while the Tat protein was confirmed by Western blotting technique [30].
• Using deletion mutations from the 5' end of the JCVL promoter, we demonstrated that different regions within the JCV enhancer/promoter are important for T-antigen and tat induction, implying that these activators function through distinct targets to increase JCVL promoter activity [31].
• We have used site-directed mutagenesis to delineate sequence specific domains within the human immunodeficiency virus type 1 (HIV-1) trans-acting-responsive (TAR) RNA element that are required for trans activation by the viral Tat protein [32].

References