Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0019693 (HIV)
 170,526 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The protein kinase inhibitor 2-aminopurine (2-AP) greatly stimulated expression in human promonocytes-macrophages of plasmid constructs carrying various reporter genes (chloramphenicol acetyltransferase, lacZ, firefly luciferase [luc], and Salmonella typhimurium histidinol dehydrogenase [his]) driven by the human immunodeficiency virus type 1 (HIV-1) long terminal repeat. Adenine, adenosine, and caffeine were also effective inducers, but other purine or pyrimidine derivatives were ineffective. Experiments with mutant derivatives of the HIV-1 long terminal repeat revealed no specific eukaryotic promoter elements necessary for 2-AP induction but indicated the need for some minimum combination of such elements. Induction of HIV-1-directed gene expression appeared not to require action of the transcription factor NF-kappa B. The mechanism of induction was investigated by using the luc and his genes linked to the HIV-1 long terminal repeat. 2-AP induced marked, steady rises in mRNA accumulation from both transfected and chromosomally integrated HIV-1 constructs but no increases from an endogenous gene encoding gamma-actin or glucose 6-phosphate dehydrogenase. Thus, induction is selective and not an artifact induced by transfecting DNA into cells. In run-on transcription experiments, the rates of transcription initiation of both transfected and integrated copies of the his gene increased about sixfold in cells treated with 2-AP. Thus, while increased initiation accounted for a portion of 2-AP induction, it could not cause the far greater increase in steady-state mRNA levels. 2-AP induction did not change mRNA decay rates and differed from the phorbol ester (phorbol myristate acetate)-induced activation of the protein kinase C-NF-kappa B pathway in its time course and in its requirement for new protein synthesis. Gel retardation assays showed that unlike phorbol myristate acetate induction, 2-AP induction is enhancer independent. Whereas many previous studies have implicated the activation of various protein kinases in gene induction, we here describe a mechanism of gene activation that appears to involve protein kinase inhibition as a component of the induction response.
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PMID:Inducible transcriptional activation of the human immunodeficiency virus long terminal repeat by protein kinase inhibitors. 835 80

A novel recombinant marker virus assay (RMVA) has been developed to perform growth competition assays for assessing fitness of HIV-1. This assay allowed the generation of replication-competent viruses by homologous recombination of polymerase chain reaction (PCR)-derived reverse transcriptase (RT) coding sequences in RT-deleted proviral clones of HIV-1 in which the nef gene was replaced by the Salmonella typhimurium histidinol dehydrogenase (hisD) or human heat-stable placental alkaline phosphatase (PLAP) gene (pHIVDeltaRTBalIDeltanefhisD and pHIVDeltaRTBalIDeltanefPLAP, respectively). The proportion of a given RT species in a mixed culture was determined by quantifying the linked hisD or PLAP marker gene using real-time PCR. The RMVA was tested by comparing the relative fitness of wild-type and lamivudine-resistant recombinant viruses. The RMVA reproducibly detected differences in the fitness of these two viruses in growth competition assays. With appropriate modification of the recombination vectors, the RMVA should be useful for analyzing the fitness of viruses resistant to protease, integrase, or fusion inhibitors and should be applicable in clinical research.
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PMID:A novel recombinant marker virus assay for comparing the relative fitness of hiv-1 reverse transcriptase variants. 1140 14

The emergence of drug-resistant strains of Mycobacterium tuberculosis, the major causative agent of tuberculosis (TB), and the deadly HIV-TB co-infection have led to an urgent need for the development of new anti-TB drugs. The histidine biosynthetic pathway is present in bacteria, archaebacteria, lower eukaryotes and plants, but is absent in mammals. Disruption of the hisD gene has been shown to be essential for M. tuberculosis survival. Here we present cloning, expression and purification of recombinant hisD-encoded histidinol dehydrogenase (MtHisD). N-terminal amino acid sequencing and electrospray ionization mass spectrometry analyses confirmed the identity of homogeneous MtHisD. Analytical gel filtration, metal requirement analysis, steady-state kinetics and isothermal titration calorimetry data showed that homodimeric MtHisD is a metalloprotein that follows a Bi Uni Uni Bi Ping-Pong mechanism. pH-rate profiles and a three-dimensional model of MtHisD allowed proposal of amino acid residues involved in either catalysis or substrate(s) binding.
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PMID:Molecular, kinetic, thermodynamic, and structural analyses of Mycobacterium tuberculosis hisD-encoded metal-dependent dimeric histidinol dehydrogenase (EC 1.1.1.23). 2167 13