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71.
Binding in vitro of multiple cellular proteins to immunoglobulin heavy-chain enhancer DNA. 总被引:33,自引:15,他引:18
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Seven protein-binding sites on the immunoglobulin heavy-chain (IgH) enhancer element have been identified by exonuclease III protection and gel retardation assays. It appears that the seven sites bind a minimum of four separate proteins. Three of these proteins also bind to other enhancers or promoters, but one protein seems to recognize exclusively IgH enhancer sequences. A complex of four binding sites, recognized by different proteins, is located within one 80-base-pair region of IgH enhancer DNA. Close juxtaposition of enhancer proteins may allow protein-protein interactions or be part of a mechanism for modulating enhancer protein activity. All IgH enhancer-binding proteins identified in this study were found in extracts from nonlymphoid as well as lymphoid cells. These data provide the first direct evidence that multiple proteins bind to enhancer elements and that while some of these proteins recognize common elements of many enhancers, others have more limited specificities. 相似文献
72.
73.
Preferential conservation of the globular domains of the beta A3/A1-crystallin polypeptide of the chicken eye lens 总被引:4,自引:0,他引:4
The primary structure of the beta 19/26-crystallin polypeptide of the chicken lens has been determined by cDNA sequencing and primer extension experiments. In addition, a primer extension experiment has corrected the sequence for the N-terminal arm of the murine beta 23 polypeptide, which is the homologue of the chicken beta 19/26 polypeptide. We also show that, in the chicken and mouse, the N-terminal arm of the polypeptide is encoded on two separate exons. For simplicity, we have changed the names of both chicken beta 19/26 and murine beta 23 to beta A3/A1, which is the name of the homologous bovine polypeptide. The deduced sequence of the chicken beta A3/A1 polypeptide fits the predicted three-dimensional structure involving two homologous domains, each folded into two 'Greek key' motifs, common to the beta gamma-crystallin superfamily of proteins. Comparison of the amino acid sequence of the chicken and mammalian beta A3/A1 polypeptides indicates that different regions of the protein, which are encoded on different exons, are diverging at different rates. The N-terminal extension is the fastest evolving region of the beta A3/A1 polypeptide. Hybrid-selected translation coupled with primer extension experiments suggest that a single chicken beta A3/A1 mRNA synthesizes two polypeptides, beta A3 (25 kDa) and beta A1 (23 kDa) by utilization of different translation initiation sites. 相似文献
74.
C K Kelling M J Van Rafelghem R L Drake L A Menahan R E Peterson 《Journal of biochemical toxicology》1986,1(3):23-37
Perfluorodecanoic acid (PFDA) administration to adult male rats increased both the activity of hepatic malic enzyme and liver weight in a dose-dependent manner. Hepatomegaly and augmented activity of malic enzyme in liver were apparent within one day following PFDA administration and reached a plateau by three days posttreatment. Malic enzyme quantity per liver in PFDA-treated rats was elevated within one day following dosing and increased continually throughout five days posttreatment. Administration of PFDA to rats in the fed state also led to an increase in the specific activity of hepatic malic enzyme that peaked at three days following dosing. When compared to the fed condition, rats fasted for 48 hours had a decrease in both relative liver weight and the quantity of supernatant protein per liver. The total activity (U/liver) and specific activity of malic enzyme in the liver were also reduced in the fasted state. During the 24 hours after treatment in rats fasted for 48 hours, the body weight as well as the absolute and relative liver weight of animals receiving vehicle declined continuously in the absence of feed. Following the administration of PFDA to fasted rats, body weight was maintained until eight hours posttreatment but then declined at a rate similar to that found with the vehicle-treated group. Absolute and relative liver weight in PFDA-treated rats were increased significantly at eight hours posttreatment when compared to those receiving vehicle, and this increment was maintained throughout the rest of the 24 hours following dosing. While the activity and enzyme content of hepatic malic enzyme decreased in the vehicle-treated group, administration of PFDA to rats fasted for 48 hours prevented their decline. The specific activity of hepatic malic enzyme in 48 hours fasted rats receiving PFDA was also elevated significantly at 16 hours posttreatment. Thus, the administration of PFDA to the adult male rat in both the fed and fasted nutritional states was found to regulate hepatic malic enzyme by not only increasing enzyme quantity but also by augmenting the specific activity, (ie, catalytic state) of the enzyme. 相似文献
75.
B Marczynska D A Peterson J D Ogden L G Wolfe 《Folia primatologica; international journal of primatology》1983,40(3):217-226
The karyotype of Saguinus labiatus labiatus was determined by the Giemsa-banding technique on leukocytes cultured from 10 marmosets. The diploid chromosome number (2n = 46) was the same and the chromosome complement similar to other marmosets of genus Saguinus. Small karyotypic differences were found between S. l. labiatus and white-lipped marmosets (Saguinus fuscicollis) in the size of the X chromosome and in the banding pattern of one pair of metacentric chromosomes. A karyotypic variant was detected in 1 S. l. labiatus, characterized by a diploid chromosome number of 45 with balanced autosomal translocation involving two pairs of acrocentric chromosomes (T 16/19). 相似文献
76.
77.
The complete nucleotide sequence of the I-E alpha d immune response gene. 总被引:12,自引:4,他引:8
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J J Hyldig-Nielsen L Schenning U Hammerling E Widmark E Heldin P Lind B Servenius T Lund R Flavell J S Lee J Trowsdale P H Schreier F Zablitzky D Larhammar P A Peterson L Rask 《Nucleic acids research》1983,11(15):5055-5071
We have isolated and sequenced the complete murine I-E alpha immune response gene of the H-2db haplotype. The I-E alpha d gene consists of 5300 basepairs and is organized into five or possibly six exons that correspond to different domains of the alpha chain. The amino acid sequence deduced from the I-E alpha gene shows 75% homology to its human counterpart, the HLA-DR alpha chain. The absence of I-E antigen in H-2 mice is due to lack of E alpha chain synthesis. We show here that this defect is caused by a deletion in the 5' end of the I-E alpha b gene. 相似文献
78.
Use of a New Buffer System with Formalinized Sheep Erythrocytes in the Rubella Hemagglutination-Inhibition Test 总被引:4,自引:1,他引:3
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The increased sensitivity and improved agglutination and settling patterns of formalinized sheep erythrocytes in a new buffer, HEPES (N-2-hydroxyethylpiperazine N'-2'-ethanesulfonic acid), make this system more suitable for use in the rubella hemagglutination-inhibition test. 相似文献
79.
D F Steiner S Cho P E Oyer S Terris J D Peterson A H Rubenstein 《The Journal of biological chemistry》1971,246(5):1365-1374
80.
Escherichia coli and Bacillus megaterium rendered permeable to ribonucleoside triphosphates by toluene treatment retain the capacity to synthesize discrete ribonucleic acid species. 相似文献