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)

In order to investigate the mechanism of carbon catabolite repression in the industrially important fungus Trichoderma reesei, degenerated PCR-primers were designed to amplify a 0.7-bp fragment of the cre1 gene, which was used to clone the entire gene. It encodes a 402-amino acid protein with a calculated M(r) of 43.6 kDa. Its aa-sequence shows 55.6% and 54.7% overall similarity to the corresponding genes of Aspergillus nidulans and A. niger, respectively. Similarity was restricted to the aa-region containing the C2H2 zinc finger and several aa-regions rich in proline and basic amino acids, which may be involved in the interaction with other proteins. Another aa-region rich in the SPXX-motif that has been considered analogous to a region of yeast RGR1p, was instead identified as a domain occurring in several eucaryotic transcription factors. The presence of the cre1 translation product was demonstrated with polyclonal antibodies against Cre1, which identified a protein of 43 (+/- 2) kDa in cell-free extracts from T. reesei. A Cre1 protein fragment from the two zinc fingers to the region similar to the aa-sequence of eucaryotic transcription factors, was expressed in Escherichia coli as a fusion protein with glutathione S-transferase. EMSA and in vitro footprinting revealed binding of the fusion protein to the sequence 5'-GCGGAG-3', which matches well with the A. nidulans consensus sequence for CreA binding (5'-SYGGRG-3'). Cell-free extracts of T. reesei formed different complexes with DNA-fragments carrying this binding sites, and the presence of Cre1 and additional proteins in these complexes was demonstrated. We conclude that T. reesei Cre1 is the functional homologue of Aspergillus CreA and that it binds to its target sequence probably as a protein complex.
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PMID:Cre1, the carbon catabolite repressor protein from Trichoderma reesei. 852 52

The Gfi-1 proto-oncogene encodes a zinc finger protein with six C2H2-type, C-terminal zinc finger motifs and is activated by provirus integration in T-cell lymphoma lines selected for interleukin-2 independence in culture and in primary retrovirus-induced thymomas. Gfi-1 expression in adult animals is restricted to the thymus, spleen, and testis and is enhanced in mitogen-stimulated splenocytes. In this report, we show that Gfi-1 is a 55-kDa nuclear protein that binds DNA in a sequence-specific manner. The Gfi-1 binding site, TAAATCAC(A/T)GCA, was defined via random oligonucleotide selection utilizing a bacterially expressed glutathione S-transferase-Gfi-1 fusion protein. Binding to this site was confirmed by electrophoretic mobility shift assays and DNase I footprinting. Methylation interference analysis and electrophoretic mobility shift assays with mutant oliginucleotides defined the relative importance of specific bases at the consensus binding site. Deletion of individual zinc fingers demonstrated that only zinc fingers 3, 4, and 5 are required for sequence-specific DNA binding. Potential Gfi-1 binding sites were detected in a large number of eukaryotic promoter-enhancers, including the enhancers of several proto-oncogenes and cytokine genes and the enhancer of the human cytomegalovirus (HCMV) major immediate-early promoter, which contains two such sites. HCMV major immediate-early-chloramphenicol acetyltransferase reporter constructs, transfected into NIH 3T3 fibroblasts, were repressed by Gfi-1, and the repression was abrogated by mutation of critical residues in the two Gfi-1 binding sites. These results suggest that Gfi-1 may play a role in HCMV biology and may contribute to oncogenesis and T-cell activation by repressing the expression of genes that inhibit these processes.
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PMID:Gfi-1 encodes a nuclear zinc finger protein that binds DNA and functions as a transcriptional repressor. 875

The pr1 gene of the entomopathogenic fungus Metarhizium anisopliae encodes a serine protease that is highly active towards the insect cuticle and whose synthesis is subject to both carbon and nitrogen repression. The pr1 promoter region was sequenced revealing the presence of putative CREA- and AREA-binding sites. In vitro bandshift experiments demonstrated that an Aspergillus nidulans GST-CREA fusion protein was capable of binding to two of the three putative CREA sites. Using a PCR-based strategy the M. anisopliae crr1 gene was identified; it encodes a putative C2H2-type DNA-binding protein with significant sequence similarity to A. nidulans CREA. Complementation experiments with an A. nidulans strain carrying creA204 demonstrated that CRR1 can partially substitute for CREA function.
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PMID:Carbon regulation of the cuticle-degrading enzyme PR1 from Metarhizium anisopliae may involve a trans-acting DNA-binding protein CRR1, a functional equivalent of the Aspergillus nidulans CREA protein. 921 95

8-Hydroxyguanine (7,8-dihydro-8-oxoguanine: oh8Gua) is a damaged form of guanine induced by oxygen-free radicals and causes GC to TA transversions. Previously we isolated the hOGG1 gene, a human homolog of the yeast OGG1 gene, which encodes a DNA glycosylase and lyase to excise oh8Gua in DNA. In this study, we isolated a mouse homolog (Ogg1) of the OGG1 gene, characterized oh8Gua-specific DNA glycosylase/AP lyase activities of its product, and determined chromosomal localization and exon-intron organization of this gene. A predicted protein possessed five domains homologous to human and yeast OGG1 proteins. Helix-hairpin-helix and C2H2 zinc finger-like DNA-binding motifs found in human and yeast OGG1 proteins were also retained in mouse Ogg1 protein. The properties of a GST fusion protein were identical to human and yeast OGG1 proteins in glycosylase/lyase activities, their substrate specificities, and suppressive activities against the spontaneous mutagenesis of an Escherichia coli mutM mutY double mutant. The mouse Ogg1 gene was mapped to Chromosome (Chr) 6, and consisted of 7 exons approximately 6 kb long. Two DNA-binding motifs were encoded in exons 4 through 5. These data will facilitate the investigation of the OGG1 gene to elucidate the relationship between oxidative DNA damage and carcinogenesis.
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PMID:Genomic structure and chromosomal localization of the mouse Ogg1 gene that is involved in the repair of 8-hydroxyguanine in DNA damage. 943 42

Active transport of proteins into the nucleus is mediated by interaction between the classical nuclear localization signals (NLSs) of the targeted proteins and the NLS receptor (importin) complex. This nuclear transport system is highly regulated and conserved in eukaryotes and is essential for cell survival. Using a fragment of BRCA1 containing the two NLS motifs as a bait for yeast two-hybrid screening, we have isolated four clones, one of which is importin alpha. Here we characterize one of the other clones identified, BRAP2, which is a novel gene and expressed as a 2-kilobase mRNA in human mammary epithelial cells and some but not all tissues of mice. The isolated full-length cDNA encodes a novel protein containing 600 amino acid residues with pI 6.04. Characteristic motifs of C2H2 zinc fingers and leucine heptad repeats are present in the middle and C-terminal regions of the protein, respectively. BRAP2 also shares significant homology with a hypothetical protein from yeast Saccharomyces cerevisiae, especially in the zinc finger region. Antibodies prepared against the C-terminal region of BRAP2 fused to glutathione S-transferase specifically recognize a cellular protein with a molecular size of 68 kDa, consistent with the size of the in vitro translated protein. Cellular BRAP2 is mainly cytoplasmic and binds to the NLS motifs of BRCA1 with similar specificity to that of importin alpha in both two-hybrid assays in yeast and glutathione S-transferase pull-down assays in vitro. Other motifs such as the SV40 large T antigen NLS motif and the bipartite NLS motif found in mitosin are also recognized by BRAP2. Similarly, the yeast homolog of BRAP2 also binds to these NLS motifs in vitro. These results imply that BRAP2 may function as a cytoplasmic retention protein and play a role in regulating transport of nuclear proteins.
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PMID:Identification of a novel cytoplasmic protein that specifically binds to nuclear localization signal motifs. 949 40

In order to identify genes that are differentially expressed as a consequence of oxidative stress due to paraquat we used the differential display technique to compare mRNA expression patterns in Caenorhabditis elegans . A C.elegans mixed stage worm population and a homogeneous larval population were treated with 100 mM paraquat, in parallel with controls. Induction of four cDNA fragments, designated L-1, M-47, M-96 and M-132, was confirmed by Northern blot analysis with RNA from stressed and unstressed worm populations. A 40-fold increase in the steady-state mRNA level in the larval population was observed for the L-1/M-47 gene, which encodes the detoxification enzyme glutathione S-transferase. A potential stress-responsive transcription factor (M-132) with C2H2-type zinc finger motifs and an N-terminal leucine zipper domain was identified. The M-96 gene encodes a novel stress-responsive protein. Since paraquat is known to generate superoxide radicals in vivo , the response of the C.elegans superoxide dismutase (SOD) genes to paraquat was also investigated in this study. The steady-state mRNA levels of the manganese-type and the copper/zinc-type SODs increased 2-fold in the larval population in response to paraquat, whereas mixed stage populations did not show any apparent increase in the levels of these SOD mRNAs.
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PMID:Identification of stress-responsive genes in Caenorhabditis elegans using RT-PCR differential display. 951 31

PRMT3 (protein arginine methyltransferase 3) is one of four type I arginine methyltransferases that catalyse the formation of asymmetric dimethylarginine. PRMT3 is unique in that its N-terminus harbours a C2H2 zinc-finger domain that is proposed to confer substrate specificity. In addition, PRMT3 is the only type I enzyme that is restricted to the cytoplasm. Known in vitro substrates for PRMT3 include GST-GAR (a glutathione S-transferase fusion protein containing the glycine- and arginine-rich N-terminal region of fibrillarin), Sam68 (Src-associated substrate during mitosis 68 kDa) and PABP-N1 [poly(A)-binding protein-N1; PABP2]. Here we report the identification of an in vivo substrate for mammalian PRMT3. We found that FLAG-tagged PRMT3 can 'pull down' a protein with a molecular mass of 30 kDa from HeLa cell extracts. MS identified this PRMT3-interacting protein as rpS2 (ribosomal protein S2). In vitro studies showed that the zinc-finger domain of PRMT3 is necessary and sufficient for binding to rpS2. In addition, rpS2 is methylated by PRMT3 in vitro and is also methylated in cell lines. Deletion analysis of the rpS2 amino acid sequence identified a N-terminal Arg-Gly repeat as the methylation site. Furthermore, both PRMT3 and rpS2 co-sediment with free ribosomal subunits. These studies implicate PRMT3 in ribosomal function and in the regulation of protein synthesis.
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PMID:Ribosomal protein S2 is a substrate for mammalian PRMT3 (protein arginine methyltransferase 3). 1547 65

Sp1 activates the transcription of many cellular and viral genes with the GC-box in either the proximal promoter or the enhancer. Sp1 is composed of several functional domains, such as the inhibitory domain (ID), two serine/threonine-rich domains, two glutamine-rich domains, three C2H2-type zinc finger DNA binding domains (ZFDBD), and a C-terminal D domain. The ZDDBD is the most highly conserved domain among the Sp-family transcription factors and plays a critical role in GC-box recognition. In this study, we investigated the protein-protein interactions occurring at the Sp1ZFDBD and the Sp1ID, and the molecular mechanisms controlling the interaction. Our results found that Sp1ZFDBD and Sp1ID repressed transcription once they were targeted to the proximal promoter of the pGal4 UAS reporter fusion gene system, suggesting molecular interaction with the repressor molecules. Indeed, mammalian two-hybrid assays, GST fusion protein pull-down assays, and co-immunoprecipitation assays showed that Sp1ZFDBD and Sp1ID are able to interact with corepressor proteins such as SMRT, NcoR, and BCoR. The molecular interactions appear to be regulated by MAP kinase/Erk kinase kinase (MEK). The molecular interactions between Sp1ID and the corepressor might explain the role of Sp1 as a repressor under certain circumstances. The siRNA-induced degradation of the corepressors resulted in an up-regulation of Sp1-dependent transcription. The cellular context of the corepressors and the regulation of molecular interaction between corepressors and Sp1ZFDBD or Sp1ID might be important in controlling Sp1 activity.
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PMID:Transcriptional activity of Sp1 is regulated by molecular interactions between the zinc finger DNA binding domain and the inhibitory domain with corepressors, and this interaction is modulated by MEK. 1587 80

Toll-like receptors (TLRs) play an important role as a sensor of microbial pathogens in the innate immune response. TLRs transmit signals through the recruitment of adaptor proteins including tumor necrosis factor-associated factor 6 (TRAF6), which mediates the activation of IkappaB kinase (IKK). TIFA (TRAF-interacting protein with a forkhead-associated (FHA) domain) has been shown to bind to TRAF6 and activate IKK by promoting the oligomerization and ubiquitin-ligase activity of TRAF6. FHA domains preferentially bind to phospho-threonine residues in their targets. Here, we identified a novel zinc finger protein, ZCCHC11, that interacts with TIFA from phosphoproteins of a macrophage cell line, RAW 264.7, by using affinity purification with GST-TIFA and mass spectrometric analysis. By a search of the EST database, we found a 200kDa full-length form (ZCCHC11L). ZCCHC11L was mostly located to the nucleus, but translocated into the cytoplasm in response to LPS and bound to TIFA. Overexpression and knockdown by siRNA indicated that ZCCHC11 functions as a negative regulator of TLR-mediated NF-kappaB activation. The N-terminal region (ZCCHC11S) including C2H2-type [corrected] Zn-finger motif was sufficient for suppression of NF-kappaB. We propose that ZCCHC11 is a unique TLR signal regulator, which interacts with TIFA after LPS treatment and suppresses the TRAF6-dependent activation of NF-kappaB.
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PMID:A novel Zinc finger protein, ZCCHC11, interacts with TIFA and modulates TLR signaling. 1664 55

A novel rat gene, Mipu1, encodes a 608 amino acid protein with an amino-terminal KRAB domain and 14 carboxyl-terminal C2H2 zinc finger motifs. Mipu1 is localized to the nucleus through its KRAB domain or the linker adjacent to its zinc finger region. Using the GST-Mipu1 bound to glutathione-Sepharose beads, a consensus putative DNA binding site (5'-TGTCTTATCGAA-3') was extracted from a random oligonucleotide library. EMSA and target detection assay showed that the probe containing the putative site can bind to purified GST-Mipu1 fusion protein. The oligonucleotide containing the putative site was inserted into the pGL3-promotor vector to produce a reporter construct. The expression of reporter gene was repressed by overexpression of Mipu1 in a dose-dependent manner. Mutation analysis of the consensus sequence indicated that the repression mediated by Mipu1 is sequence-dependent. These results suggest that Mipu1 is a nuclear protein, which functions as a transcriptional repressor.
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PMID:Functional analysis of a novel KRAB/C2H2 zinc finger protein Mipu1. 1739 2


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