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Transferase Gene (transferase + gene)
Selected AbstractsExpression of the E. coli fpg protein in CHO cells lowers endogenous oxypurine clustered damage levels and decreases accumulation of endogenous Hprt mutations,ENVIRONMENTAL AND MOLECULAR MUTAGENESIS, Issue 5 2006Sunirmal Paul Abstract Endogenous DNA damage clusters,two or more oxidized bases, abasic sites, or strand breaks within about 20 base pairs on opposing strands,can accumulate in unirradiated mammalian cells, and may be significant origins of spontaneous detrimental biological effects. Factors determining the levels of such endogenous clusters are largely unknown. To determine if cellular repair genotype can affect endogenous cluster levels in mammalian cells, the authors examined cluster levels, growth rates, and mutant frequencies in Chinese hamster ovary cells expressing the Escherichia coli glycosylase fpg protein, whose principal substrates are oxidized purines. In cells expressing high levels of fpg protein, the levels of oxypurine clustered damages were decreased while those of oxypyrimidine clusters and abasic clusters were unchanged. Furthermore, in these cells, the growth rates were increased and the level of spontaneous background mutants in the hypoxanthine guanine phosphoribosyl transferase gene was decreased. These results suggest that endogenous clusters are potentially detrimental DNA damages, and that their levels,as well as the detrimental consequences of their presence,can be effectively reduced by increased cellular activity of specific DNA repair proteins. Environ. Mol. Mutagen., 2006. Published 2006 Wiley-Liss, Inc. [source] Identification of amplified and expressed genes in breast cancer by comparative hybridization onto microarrays of randomly selected cDNA clonesGENES, CHROMOSOMES AND CANCER, Issue 1 2002Jeremy Clark Microarray analysis using sets of known human genes provides a powerful platform for identifying candidate oncogenes involved in DNA amplification events but suffers from the disadvantage that information can be gained only on genes that have been preselected for inclusion on the array. To address this issue, we have performed comparative genome hybridization (CGH) and expression analyses on microarrays of clones, randomly selected from a cDNA library, prepared from a cancer containing the DNA amplicon under investigation. Application of this approach to the BT474 breast carcinoma cell line, which contains amplicons at 20q13, 17q11,21, and 17q22,23, identified 50 amplified and expressed genes, including genes from these regions previously proposed as candidate oncogenes. When considered together with data from microarray expression profiles and Northern analyses, we were able to propose five genes as new candidate oncogenes where amplification in breast cancer cell lines was consistently associated with higher levels of RNA expression. These included the HB01 histone acetyl transferase gene at 17q22,23 and the TRAP100 gene, which encodes a thyroid hormone receptor-associated protein coactivator, at 17q11,21. The results demonstrate the utility of this microarray-based CGH approach in hunting for candidate oncogenes within DNA amplicons. © 2002 Wiley-Liss, Inc. [source] Molecular cloning and characterization of alpha-class glutathione S -transferase gene from the liver of silver carp, bighead carp, and other major chinese freshwater fishesJOURNAL OF BIOCHEMICAL AND MOLECULAR TOXICOLOGY, Issue 3 2006Wan-Qin Liao Abstract Two full-length cDNAs encoding glutathione S -transferase (GST) were cloned and sequenced from the hepatopancreas of planktivorous silver carp (Hypophthalmichthys molitrix) and bighead carp (Aristichthys nobilis). The silver carp and bighead carp GST cDNA were 920 and 978 bp in length, respectively, and both contained an open reading frame that encoding 223 amino acids. Partial GST cDNA sequences were also obtained from the liver of grass carp (Ctenopharyngodon idellus), crucian carp (Carassius auratu), mud carp (Cirrhinus molitorella), and tilapia (Oreochromis nilotica). All these GSTs could be classified as alpha-class GSTs on the basis of their amino acid sequence identity with other species. The three-dimensional structure of the silver carp GST was predicted using a computer program, and was found to fit the classical two-domain GST structure. Using the genome walker method, a 875-bp 5,-flanking region of the silver carp GST gene was obtained, and several lipopolysaccharide (LPS) response elements were identified in the promoter region of the phytoplanktivorous fish GST gene, indicating that the GST gene expression of this fish might be regulated by LPS, released from the toxic blue-green algae producing microcystins. To compare the constitutive expression level of the liver GST gene among the six freshwater fishes with completely different tolerance to microcystins, beta-actin was used as control and the ratio GST/beta-actin mRNA (%) was determined as 130.7 ± 6.6 (grass carp), 103.1 ± 8.9 (bighead carp), 92.6 ± 15.0 (crucian carp), 72.3 ± 7.8 (mud carp), 58.8 ± 11.5 (silver carp), and 33.6 ± 13.7 (tilapia). The constitutive expression level of the liver GST gene clearly shows that all the six freshwater fishes had a negative relationship with their tolerance to microcystins: high-resistant fishes (phytoplanktivorous silver carp and tilapia) had the lowest tolerance to microcystins and the high-sensitive fish (herbivorous grass carp) had the highest tolerance to microcystins. Taken together with the reciprocal relationship of constitutive and inducible liver GST expression level in some of the tested fish species to microcystin exposure, a molecular mechanism for different microcystin detoxification abilities of the warm freshwater fishes was discussed. © 2006 Wiley Periodicals, Inc. J Biochem Mol Toxicol 20:114,126, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20125 [source] Isolation of a porcine UDP-GalNAc transferase cDNA mapping to the region of the blood group EAA locus on pig chromosome 1ANIMAL GENETICS, Issue 3 2001E. Meijerink In our studies of the genes constituting the porcine A0 blood group system, we have characterized a cDNA, encoding an ,(1,3)N-acetylgalactosaminyltransferase, that putatively represents the blood group A transferase gene. The cDNA has a 1095-bp open reading frame and shares 76.9% nucleotide and 66.7% amino acid identity with the human ABO gene. Using a somatic cell hybrid panel, the cDNA was assigned to the q arm of pig chromosome 1, in the region of the erythrocyte antigen A locus (EAA), which represents the porcine blood group A transferase gene. The RNA corresponding to our cDNA was expressed in the small intestinal mucosae of pigs possessing EAA activity, whereas expression was absent in animals lacking this blood group antigen. The UDP-N-acetylgalactosamine (UDP-GalNAc) transferase activity of the gene product, expressed in Chinese hamster ovary (CHO) cells, was specific for the acceptor fucosyl- ,(1,2)galactopyranoside; the enzyme did not use phenyl- , - D -galactopyranoside (phenyl- , -D-Gal) as an acceptor. Because the ,(1,3)GalNAc transferase gene product requires an ,(1,2)fucosylated acceptor for UDP-GalNAc transferase activity, the ,(1,2)fucosyltransferase gene product is necessary for the functioning of the ,(1,3)GalNAc transferase gene product. This mechanism underlies the epistatic effect of the porcine S locus on expression of the blood group A antigen. Abbreviations: CDS: coding sequence; CHO: Chinese Hamster Ovary; EAA: erythrocyte antigen A; FCS: foetal calf serum; Fuc,(1,2)Gal: fucosyl- ,(1,2)galactopyranoside; Gal: galactopyranoside; GGTA1: Gal,(1,3)Gal transferase; PCR: polymerase chain reaction; phenyl- , -D-Gal: phenyl- , - D -galactopyranoside; R: Gal,1-4Glc,1-1Cer; UDP-GalNAc: uridine diphosphate N-acetylgalactosamine [source] The putative-farnesoic acid O -methyl transferase (FAMeT) gene of Ceratitis capitata: characterization and pre-imaginal life expressionARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY (ELECTRONIC), Issue 2 2010Laura Vannini Abstract Farnesoic acid O -methyl transferase (FAMeT) is the enzyme involved in the penultimate step of insect juvenile hormone (JH) biosynthesis and is thus a key regulator in insect development and reproduction. We report the characterization of the putative- FAMeT in the medfly or Mediterranean fruit fly, Ceratitis capitata. This gene was identified by suppressive subtractive hybridization and completely sequenced by the screening of a medfly cDNA library. The obtained sequence was analyzed for conserved protein domain identification and its expression profile was evaluated by quantitative Real-Time PCR in medfly pre-imaginal life. The tissue expression of the isolated gene was verified by in situ hybridization on third instar larvae sections. The characterization of the isolated gene pointed out several typical features of methyl transferase genes. The pre-imaginal putative- FAMeT expression levels were consistent with JH titer change in Diptera. As recognized in some crustaceans, this gene seems to be widely expressed in the medfly as well. Ceratitis capitata is one of the most relevant agricultural pests against which insecticides and the sterile insect technique (SIT) are extensively used in spite of the well-known limitations of these approaches. Although results are not conclusive for the physiological role of the isolated gene, they suggest the characterization of a new gene in the Mediterranean fruit fly potentially involved in JH biosynthesis and may, therefore, have implications for pest control. © 2010 Wiley Periodicals, Inc. [source] | |||||||||||||