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21.
SB subregion of the human major histocompatibility complex: gene organization, allelic polymorphism and expression in transformed cells 总被引:7,自引:0,他引:7
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K Okada H L Prentice J M Boss D J Levy D Kappes T Spies R Raghupathy R A Mengler C Auffray J L Strominger 《The EMBO journal》1985,4(3):739-748
The SB region of the human major histocompatibility complex (MHC) has been cloned from cosmid and lambda phage libraries made from the human B-lymphoblastoid cell line Priess (DR4/4, DC4/4, SB3/4). Two alpha genes and two beta genes are encoded in the 100 kb long SB region in the order SB alpha-SB beta-SX alpha-SX beta. The SB alpha and SB beta genes encode the alpha and beta subunits of the SB subset of class II MHC molecules. Both the SX alpha and the SX beta genes are pseudogenes in the haplotype examined. From the isolated clones, the two haplotypes of the Priess cell line, SB3 and SB4, are distinguished by nucleotide sequencing and blot hybridization analyses. Restriction site polymorphisms between the SB3 and SB4 clones were observed only in relatively small regions of the SB beta and SX beta genes. A mouse macrophage cell line was transfected with one of the cosmid clones containing both SB alpha and SB beta genes. Expression of the alpha and beta genes was detected by fluorescene-activated cell sorting (FACS) and two-dimensional gel electrophoresis using SB-specific monoclonal antibodies. 相似文献
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Irma van Die Ingrid van Megen Wiel Hoekstra Hans Bergmans 《Molecular & general genetics : MGG》1984,194(3):528-533
Summary The genes responsible for the formation of the F72 fimbriae of the uropathogenic E. coli strain AD110 (O6:K2:H1:F7) have been cloned on the recombinant plasmid pPIL110-35 (Van Die et al. 1983). The F72 fimbriae, like the F71 fimbriae of AD110, are responsible for mannose resistant haemagglutination (MRHA).The molecular organisation of the genes of pPIL110-35 involved in the expression of MRHA was studied by: (a) analysis of transposon and Tn5 insertion mutants. Mutations that cause an MRHA-deficient phenotype were located in discrete groups within an 11.5 kb restriction fragment of pPIL110-35, separated by insertion mutations that do not inactivate MRHA. (b) complementation experiments. Restriction fragments of pPIL110-35 subcloned in the vector pBR322 were tested for their ability to complement transposon insertion mutations in the corresponding regions of pPIL110-35. Five complementation groups were distinguished.Five genes (designated A-E) involved in the expression of MRHA can be distinguished by these results. The products of these genes were analysed in minicells. The results indicate that gene B codes for a 75 K dalton protein, gene C for a 23 K dalton protein and gene E for a 36 K dalton protein. No product of gene D was observed. Gene A probably codes for the 17 K dalton subunit polypeptide of the F72 fimbriae, as will be discussed. 相似文献
24.
Summary Trichoderma reesei was grown on sulfite pulp and the major cellobiohydrolase of the culture filtrate was purified to homogeneity. The distance distribution function p(r) measured by the small angle X-ray scattering technique indicates that the enzyme molecule has a rather unusual tadpole like shape with an isotropic head and a long tail. The maximum length is 18 nm and the largest diameter is 4.4 nm. 相似文献
25.
The DNA replication origins of herpes simplex virus type 1 strain Angelotti 总被引:3,自引:0,他引:3
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The nucleotide sequences of the origins of DNA replication (ori) of the S- and L-component (oriS, oriL) of the herpes simplex virus type 1 (HSV-1) standard genome were determined from HSV-1 strain Angelotti (ANG). In contrast to other HSV-1 strains, the ANG oriS sequence revealed an insertion of an TA-dinucleotide in an otherwise very conserved but imperfect palindromic sequence of 47 bp. The oriL sequence of the standard ANG genome was found to be identical to that of an ANG class II defective genome which exhibits a duplication of a 144 bp palindrome. A model is presented to explain the origination of the amplified ANG oriL sequences from the parental genome with a single copy of oriL via illegitimate recombination. Alignment of the ori sequences of HSV, adeno- and papovaviruses unveiled that the HSV ori region can be subdivided into two distinct sites of homology to the DNA initiation signals of papova- and adenoviruses, suggesting that the HSV origins of replication comprise elements for DNA replication by both, cellular and virus-encoded DNA polymerases. 相似文献
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Jana Pospíšilová Jiřina Slavíkovà J. Tupý Ingrid Tiohá T. Gichner 《Biologia Plantarum》1983,25(3):237-240
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U. Ingrid Richardson 《Life sciences》1983,33(20):1981-1988
Synthetic corticotropin-releasing factor (CRF) stimulates ACTH secretion in the clonal mouse pituitary cell strain AtT20/D16v (D16) in a dose-dependent manner with a half-maximal effect at 2×10?9M. A single dose of 5×10?9M CRF maximally stimulates the rate of ACTH secretion during the initial two hrs of treatment. During the period of maximal CRF stimulation intracellular hormone concentration declines progressively to a nadir at 4 hrs. During the ensuing 24 hrs of incubation intracellular hormone levels in CRF-stimulated cells increase gradually toward control values. Somatostatin (SRIF) inhibits the secretory response to CRF. This action of SRIF is dose-dependent with a half-maximal effect at 1×10?9M and results in decreased maximal ACTH secretion with little effect on the ED50 for CRF. 相似文献
30.
The copolymeric structure of pig skin dermatan sulphate. Isolation and characterization of l-idurono-sulphate-containing oligosaccharides from copolymeric chains 总被引:3,自引:3,他引:0
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Lars-?ke Fransson Lars C?ster Birgitta Havsmark Anders Malmstr?m Ingrid Sj?berg 《The Biochemical journal》1974,143(2):379-389
Dermatan sulphate was degraded by testicular hyaluronidase and an oversulphated fraction was isolated by ion-exchange chromatography. This preparation, which contained fairly long segments derived from the non-reducing terminal portion of the molecule, was subjected to periodate oxidation under acidic conditions. The oxidized iduronic acid residues were cleaved by reduction-hydrolysis (Smith-degradation) (Fransson & Carlstedt, 1974) or by alkaline elimination. The oligosaccharides so obtained contained both GlcUA (glucuronic acid) and IdUA-SO(4) (sulphated iduronic acid) residues. Copolymeric oligosaccharides obtained after alkaline elimination were cleaved by chondroitinase-AC into disaccharide and higher oligosaccharides. Since the corresponding oligosaccharides obtained by Smith-degradation were unaffected by this enzyme, it was concluded that the carbohydrate sequences were GalNAc-(IdUA-GalNAc)(n)-GlcUA-GalNAc. The iduronic acid-containing sequences were resistant to digestion with chondroitinase-ABC. It was demonstrated that the presence of unsulphated N-acetylgalactosamine residues in these sequences could be responsible for the observed effect. This information was obtained in an indirect way. Chemically desulphated dermatan sulphate was found to be a poor substrate for the chondroitinase-ABC enzyme. Moreover, digestion with chondroitinase-ABC of chondroitinase-AC-degraded dermatan sulphate released periodate-resistant iduronic acid-containing oligosaccharides. It is concluded that copolymeric sequences of the following structure are present in pig skin dermatan sulphate: [Formula: see text] N-acetylgalactosamine moieties surrounding IdUA-SO(4) residues are unsulphated to a large extent. 相似文献