Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.5.1.18 (glutathione S-transferase)
 22,582 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The glutathione S-transferases (GST) (glutathione transferase; EC 2.5.1.18) are a family of enzymes responsible for the metabolism of a broad range of xenobiotics and carcinogens. A cDNA clone containing the entire amino acid coding sequence of a human GST-2 subunit has been isolated using a lambda gt11 expression library. The complete nucleotide sequence and a partial restriction map are presented. The subunit is composed of 221 amino acids with a molecular weight of 25,425 before posttranslational modification. The deduced amino acid sequence is rich in lysine, which is consistent with the relatively high pI of GST-2. The human sequence shows considerable homology with the rat Ya and Yc GST sequences but little homology with the rat GSTp and Yb subunit sequences. Southern blots of restriction digests of human DNA indicate that there may be multiple GST-2 genes. In situ hybridization of the cloned cDNA to human chromosomes produces intense labeling only over band p12 on the short arm of chromosome 6 near the centromere. This indicates that the GST-2 gene(s) are located only at this site.
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PMID:Isolation of a cDNA clone and localization of human glutathione S-transferase 2 genes to chromosome band 6p12. 303 80

Two isoforms of a bovine-brain-derived 12-kDa protein (designated p12a and p12b) whose N-termini have a high amino acid sequence similarity with the glycosylation-inhibiting factor (GIF) and macrophage migration-inhibitory factor (MIF) were purified to homogeneity. The complete amino acid sequence of bovine p12a (pI 9.5) was determined by Edman degradation of the intact molecule and overlapping fragments generated by proteolytic cleavage. The p12a isoform has nine and ten conservative substitutions versus human GIF (hGIF) and human MIF (hMIF), respectively. Molecular filtration revealed that both isoforms of p12 exist as monomers in aqueous solution. Circular dichroism spectra indicate that both isoforms of p12 consist of 39 +/- 3% alpha helix, 23 +/- 3% beta structure and 15 +/- 3% beta turns. Although the N-terminal parts of p12a and p12b have weak amino acid sequence similarity with that of glutathione S-transferase (GST) neither isoform of p12 was bound to a GST-affinity gel nor had GST activity. Despite a high amino acid sequence similarity with human MIF neither of the p12 isoforms inhibited migration of the mouse monocyte-macrophage cells P338D1.
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PMID:A diversified family of 12-kDa proteins with a high amino acid sequence similarity to macrophage migration-inhibitory factor (MIF). 792 55

A total of 33 polymorphic markers were analyzed to generate a high-resolution genetic linkage map of the locus PKHD1 (polycystic kidney and hepatic disease 1) for the autosomal recessive polycystic kidney disease (ARPKD), using a combination of recombination mapping and linkage analysis in 164 families. Recombinants narrowed the PKHD1 region from 3.8 cM to a 1-cM interval flanked by the markers D6S1024 and D6S1714. Linkage disequilibrium analysis in 13 Finnish ARPKD families identified two different highly conserved haplotypes with four distal flanking markers, suggesting the existence of at least two major mutations of Finnish origin. The genes MUT (methylmalonyl coenzyme A-mutase), RDS (retinal degeneration, slow), CSNK2 beta (casein kinase II, beta subunit), and GSTA1 (glutathione S-transferase alpha, type 1) were excluded as PKHD1 genes using both established and novel intragenic polymorphisms in families with key recombinants. These genetic data, combined with our YAC-based physical map of the 6p21-p12 region, will facilitate efforts to positionally clone the PKHD1 gene.
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PMID:Fine mapping of the autosomal recessive polycystic kidney disease locus (PKHD1) and the genes MUT, RDS, CSNK2 beta, and GSTA1 at 6p21.1-p12. 950 14

We generated and characterized novel antibodies specific for a cleavage site of human caspase-8/FLICE and its substrate, FLICE-like inhibitory protein (FLIP). The synthetic peptides used as immunogens were CQGDNYQKGIPVETD (#791) and VSEGQLEDSSLLEVD (#1342), which corresponded to cleaved regions of N-terminal fragments of caspase-8 and FLIP generated by active caspase-8, respectively. Each antibody purified from rabbit antiserum reacted specifically with the immunogen but not with the peptide corresponding to the unproteolyzed form, as assessed by ELISA. In vitro cleavage of GST-FLIP by active caspase-8 generated an N-terminal fragment (GST-p43) and a C-terminal one (p12). Consistent with other in vivo data, the FLIP cleavage site follows the Asp residue, LEVD(376)GPAMKNVEF, identified on N-terminal sequencing of the p12 fragment. #1342-antibody (#1342-Ab) recognized the GST-p43 fragment but not the uncleaved protein, thus confirming its specificity. When the antibodies were used for immunoblotting, flow cytometry, and confocal laser microscopy, the proteolysis of caspase-8 and FLIP, and the subcellular localization of their digests could be monitored in apoptotic U937 cells. Interestingly, a significant increase in the percentage of cells exhibiting caspase-8 and FLIP cleavage was observed upon Fas stimulation in interferon-gamma-treated U937 cells, in which the susceptibility to Fas is extremely enhanced. In contrast, U937 cells treated with vitamin D(3) or all-trans retinoic acid showed Fas-resistance, and caspase-8 processing and FLIP cleavage were strongly inhibited. In conclusion, we established a system based on the cleavage site-directed antibodies to monitor the dynamics of caspase-8 processing and activation during apoptosis. Using this system, we found that Fas-susceptibility changes during U937 differentiation occur upstream of caspase-8 processing/activation.
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PMID:Monitoring of caspase-8/FLICE processing and activation upon Fas stimulation with novel antibodies directed against a cleavage site for caspase-8 and its substrate, FLICE-like inhibitory protein (FLIP). 1209 60

The three human TACC genes encode a family of proteins that are suspected to play a role in carcinogenesis. Their function is not precisely known; a Xenopus TACC protein called Maskin is involved in translational control, while the Drosophila D-TACC associates with microtubules and centrosomes. We have characterized the human TACC1 gene and its products. The TACC1 gene is located in region p12 of chromosome 8; its mRNA is ubiquitously expressed and encodes a protein with an apparent molecular mass of 125 kDa, which is cytoplasmic and mainly perinuclear. We show that TACC1 mRNA gene expression is down-regulated in various types of tumors. Using immunohistochemistry of tumor tissue-microarrays and sections, we confirm that the level of TACC1 protein is down-regulated in breast cancer. Finally, using the two-hybrid screen in yeast, GST pull-downs and co-immunoprecipitations, we identified two potential binding partners for TACC1, LSM7 and SmG. They constitute a conserved subfamily of Sm-like small proteins that associate with U6 snRNPs and play a role in several aspects of mRNA processing. We speculate that down-regulation of TACC1 may alter the control of mRNA homeostasis in polarized cells and participates in the oncogenic processes.
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PMID:Carcinogenesis and translational controls: TACC1 is down-regulated in human cancers and associates with mRNA regulators. 1216 61

Human DOC-1/CDK2AP1 gene encodes a growth suppressor protein of 12kDa (p12(DOC-1/CDK2AP1)). Recently, p12(DOC-1/CDK2AP1) has been shown to associate with cell cycle proteins including CDK2 and DNA polymerase alpha/primase. It negatively regulates CDK2 activities and suppresses DNA replication. Therefore, identification of other p12(DOC-1/CDK2AP1) interacting proteins might clarify its role in the cell cycle regulation and carcinogenesis. The purpose of this study was to identify additional p12(DOC-1/CDK2AP1) interacting proteins using the yeast two-hybrid system. Using human p12(DOC-1/CDK2AP1) as a bait in a liver cDNA library screening, cDNA clones identical to human DOC-1R transcript were identified. The interaction between p12(DOC-1/CDK2AP1) and p14(DOC-1R) was verified in vitro and in cells. GST pull-down assay and immunoprecipitation experiments confirmed the interaction between the two proteins. The critical region for p12(DOC-1/CDK2AP1)'s interaction with p14(DOC-1R) was defined to amino acids 20-25 by using a series of deletion mutants as baits in the yeast two-hybrid system. Our data indicated that p12(DOC-1/CDK2AP1) could associate with its homologous protein, p14(DOC-1R).
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PMID:Interaction of the CDK2-associated protein-1, p12(DOC-1/CDK2AP1), with its homolog, p14(DOC-1R). 1498 11

The RNA-dependent RNA polymerase (RdRp) of SARS coronavirus (SARS-CoV) is essential for viral replication and a potential target for anti-SARS drugs. We report here the cloning, expression, and purification of the N-terminal GST-fused SARS-CoV RdRp and its polymerase catalytic domain in Escherichia coli. During purification, the full-length GST-RdRp was found to cleave into three main fragments: an N-terminal p12 fragment, a middle p30 fragment, and a C-terminal p64 fragment comprising the catalytic domain, presumably due to bacterial proteases. Biochemical assays show that the full-length GST-RdRp has RdRp activity and the p64 and p12 fragments form a complex that exhibits comparable RdRp activity, whereas the GST-p64 protein has no activity, suggesting that the p12 domain is required for polymerase activity possibly via involvement in template-primer binding. Nonnucleoside HIV-1 RT inhibitors are shown to have no evident inhibitory effect on SARS-CoV RdRp activity. This work provides a basis for biochemical and structural studies of SARS-CoV RdRp and for development of anti-SARS drugs.
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PMID:Expression, purification, and characterization of SARS coronavirus RNA polymerase. 1584 May 16

The histone fold is a structural element that facilitates heterodimerization, and histone fold heterodimers play crucial roles in gene regulation. Here, we investigated the nuclear import of two human histone fold pairs, which belong to the H2A/H2B family: CHRAC-15/CHRAC-17 and p12/CHRAC-17. Our results from in vitro nuclear import assays with permeabilized cells and in vivo cotransfection experiments reveal that importin 13 facilitates nuclear import of both histone fold heterodimers. Using glutathione S-transferase pulldown experiments, we provide evidence that heterodimers are required for efficient binding of importin 13 because the monomers alone do not significantly interact. Mutational analysis shows that stepwise substitution of basic amino acid residues conserved among the histone fold subunits leads to a progressive loss of importin 13 binding and nuclear accumulation of CHRAC-15/CHRAC-17 and p12/CHRAC-17. The distribution of basic amino acid residues among the histone fold subunits essential for nuclear uptake suggests that heterodimerization of the histone fold motif-containing proteins forms an importin 13-specific binding platform.
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PMID:Importin 13 mediates nuclear import of histone fold-containing chromatin accessibility complex heterodimers. 1921 65

The murine leukaemia virus (MLV) Gag cleavage product, p12, is essential for both early and late steps in viral replication. The N-terminal domain of p12 binds directly to capsid (CA) and stabilises the mature viral core, whereas defects in the C-terminal domain (CTD) of p12 can be rescued by addition of heterologous chromatin binding sequences (CBSs). We and others hypothesised that p12 tethers the pre-integration complex (PIC) to host chromatin ready for integration. Using confocal microscopy, we have observed for the first time that CA localises to mitotic chromatin in infected cells in a p12-dependent manner. GST-tagged p12 alone, however, did not localise to chromatin and mass-spectrometry analysis of its interactions identified only proteins known to bind the p12 region of Gag. Surprisingly, the ability to interact with chromatin was conferred by a single amino acid change, M63I, in the p12 CTD. Interestingly, GST-p12_M63I showed increased phosphorylation in mitosis relative to interphase, which correlated with an increased interaction with mitotic chromatin. Mass-spectrometry analysis of GST-p12_M63I revealed nucleosomal histones as primary interactants. Direct binding of MLV p12_M63I peptides to histones was confirmed by biolayer-interferometry (BLI) assays using highly-avid recombinant poly-nucleosomal arrays. Excitingly, using this method, we also observed binding between MLV p12_WT and nucleosomes. Nucleosome binding was additionally detected with p12 orthologs from feline and gibbon ape leukemia viruses using both pull-down and BLI assays, indicating that this a common feature of gammaretroviral p12 proteins. Importantly, p12 peptides were able to block the binding of the prototypic foamy virus CBS to nucleosomes and vice versa, implying that their docking sites overlap and suggesting a conserved mode of chromatin tethering for different retroviral genera. We propose that p12 is acting in a similar capacity to CPSF6 in HIV-1 infection by facilitating initial chromatin targeting of CA-containing PICs prior to integration.
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PMID:Murine leukemia virus p12 tethers the capsid-containing pre-integration complex to chromatin by binding directly to host nucleosomes in mitosis. 3017 8