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41.
Association of a regulatory gene, slyA with a mouse virulence of Salmonella serovar Choleraesuis 总被引:1,自引:0,他引:1
Kaneko A Mita M Sekiya K Matsui H Kawahara K Danbara H 《Microbiology and immunology》2002,46(2):109-113
The influence of slyA gene, originally found in Salmonella serovar Typhimurium as a regulatory gene for the expression of virulence genes, on a mouse virulence of S. serovar Choleraesuis was investigated by using an slyA-defective mutant. The defective mutant was constructed by the insertion of a kanamycin-resistance gene (aph) into the cloned slyA gene, and the homologous recombination with the intact slyA gene on the chromosome. The mutant strain showed the LD50 value for BALB/c mouse approximately 10(5) higher than that of the parent strain. The increase of the LD50 value was the same order as that shown by the mutation of the slyA gene of S. serovar Typhimurium, although LD50 of the wild-type strain of S. serovar Choleraesuis was 40-fold higher than that of S. serovar Typhimurium. The time course of infection observed in the mice organs also proved the clear difference of the virulence between the parent and the mutant strains. These results suggested that the slyA gene product functions as a virulence-associated regulator also in S. serovar Choleraesuis. 相似文献
42.
43.
Hirofumi Sato Yoji Nagashima George P. Chrousos Masamitsu Ichihashi Yoko Funasaka 《Pigment cell & melanoma research》2002,15(2):98-103
We previously demonstrated that advanced melanoma cells express high amounts of proopiomelanocortin (POMC) that correlate with tumor progression. We now investigated whether the high expression of POMC derives from increased expression of corticotropin‐releasing hormone (CRH) and the possible role of CRH as a melanoma growth factor. Forty‐five cases of melanoma [25 primary malignant melanoma; 20 metastatic melanoma (MetM)] were immunohistochemically analysed for coexpression of POMC and CRH peptides. The ability of CRH to induce POMC expression in cultured melanoma cells was examined using CRH and a CRH antagonist. In CRH positive melanomas, seven out of nine cases (78%) of primary melanoma, and 7 out of 12 cases (58%) of MetM showed colocalization of CRH and POMC peptides. CRH induced POMC mRNA expression, an effect that was inhibited by a CRH antagonist. These results provide evidence for the existence of the CRH/POMC axis in pigmented lesions. 相似文献
44.
Yoshihiro Ozeki Yoshio Ito Nobuhiro Sasaki Mikiko Oyanagi Hirofumi Akimoto Yukie Chikagawa Junko Takeda 《Journal of plant research》2000,113(3):319-326
D and is also induced rapidly and transiently by transfer of cells to fresh medium and lowering the cell density. From the
carrot genomic library, four clones of PAL genes, gDcPAL1,2,3 and 4, were obtained. Analyses of nucleotide sequences revealed that only the gDcPAL3 gene is responsible for the induction of anthocyanin synthesis by 2,4-D. Several cis-elements, boxes M, P, A, L, and G, exist in the proximal promoter region of gDcPAL3. Transient expression experiments in carrot protoplasts using deletion mutants of the proximal promoter region of gDcPAL3 gene showed that boxes M and L, both of which contain core sequences of the Myb binding sites, might play an important role
in gDcPAL3 promoter activity. Four myb cDNAs, Dcmyb8,10,12 and 14 were obtained from a carrot subtracted cDNA library and their structure
and expression patterns were analyzed. In addition to the analysis of the proximal region of gDcPAL3 promoter, the possibility of the regulation of gene expression by genomic DNA structure and chromatin modification in metabolic
differentiation is discussed.
Received 10 June 2000/ Accepted in revised form 1 July 2000 相似文献
45.
In vitro binding of nuclear proteins from wheat germ to the5'-upstream region of the rolC gene of Ri plasmid was investigated.The specific DNA sequences interacting with proteins were detectedby DNase I footprinting. (Received October 8, 1990; Accepted November 30, 1990) 相似文献
46.
Hirofumi Fukushima Shigenobu Umeki Takehito Watanabe Yoshinori Nozawa 《Biochemical and biophysical research communications》1982,105(2):502-508
With the use of detergents and successive column chromatographies, Tetrahymena b-type cytochrome was purified from microsomes to a specific content of 36.0 nmol per mg of protein. The purified form showed a single band on SDS-polyacrylamide gel with molecular weight of 22,000. The spectral properties of the reduced b-type cytochrome, the α-peak of which is situated at 560 nm and asymmetric with a shoulder at 556 nm, was different from that of rat liver microsomal cytochrome b5. However, it was reducible by NADH in the presence of NADH-cytochrome b5 reductase purified from rat liver microsomes.The results indicated that the microsomal b-type cytochrome should be designated as cytochrome b5 of a ciliated protozoan, Tetrahymena pyriformis. 相似文献
47.
Noriko Osumi-Yamashita Youichirou Ninomiya Hirofumi Doi Kazuhiro Eto 《Development, growth & differentiation》1996,38(1):107-118
Prior to rhombomere development, structures called prorhombomeres appear in the mammalian hindbrain. This study clarifies the developmental relationship between prorhombomeres and their descendent rhombomeres and hindbrain crest cells in mouse embryos by focal dye injections at various levels of prorhombomere A (proRhA), proRhB, and proRhC, as well as at their boundaries. ProRhA gives rise to two rhombomeres, rhombomeres 1 and 2 (r1 and r2), as well as to crest cells that migrate into the first pharyngeal arch, including the trigeminal ganglion. ProRhB develops into r3 and r4 and produces crest cells populating the second arch and acousticofacial ganglion. The anterior portion of proRhC gives rise to r5 and r6 and to crest cells migrating into the third pharyngeal arch and the IXth ganglion; its posterior portion develops into r7 and releases crest cells into the fourth pharyngeal arch region as well as the Xth ganglion. These results suggest that the boundaries between prorhombomeres serve as lineage restrictions for both hind-brain neuroepithelial cells and for segmental origins of crest cell populations in mouse embryos. The Hox code of the mouse head can be schematized in a much simpler way based on this prorhombomeric organization of the hind-brain, suggesting that prorhombomeres primarily underlie mammalian hind-brain segmentation. 相似文献
48.
Four types of DNA polymerase (Pol beta, Pol lambda, Pol mu and TdT) have been identified in eukaryotes as members of the polymerase X-family. Only vertebrates have all four types of enzyme. Plants and fungi have one or two X-family polymerases, while protostomes, such as fruit flies and nematodes, do not appear to have any. It is possible that the well-known metabolic pathways in which these enzymes are involved are restricted to the vertebrate world. The distribution of the DNA polymerases involved in DNA repair across the various biological kingdoms differs from that of the DNA polymerases involved in chromosomal DNA replication. In this review, we focus on the interesting pattern of distribution of the X-family enzymes across biological kingdoms and speculate on their roles. 相似文献
49.
Proteolysis by sequence-specific proteases is the key step for positive sequencing in proteomic studies integrated with mass spectrometry (MS). The conventional method of in-solution digestion of protein is a time-consuming procedure and has limited sensitivity. In this study, we report a simple and rapid system for the analysis of protein sequence and protein posttranslational modification by multienzymatic reaction in a continuous flow using the enzyme (trypsin, chymotrypsin, or alkaline phosphatase)-immobilized microreactor. The feasibility and performance of the single microreactor and tandem microreactors that were connected by the different microreactors were determined by the digestion of nonphosphoprotein (cytochrome c) and phosphoproteins (β-casein and pepsin A). The single microreactor showed rapid digestion compared with that of in-solution digestions. Multiple digestion by the tandem microreactors showed higher sequence coverage compared with that by in-solution or the single microreactor. Moreover, the tandem microreactor that was made by using the combination of protease-immobilized microreactor and phosphatase-immobilized microreactor showed the capability for phosphorylation site analysis in phosphoproteins without the use of any enrichment strategies or radioisotope labeling techniques. This approach provides a strategy that can be applied to various types of linking microreactor-based multienzymatic reaction systems for proteomic analysis. 相似文献
50.
Rahman A Nakasone A Chhun T Ooura C Biswas KK Uchimiya H Tsurumi S Baskin TI Tanaka A Oono Y 《The Plant journal : for cell and molecular biology》2006,47(5):788-801
2,4-dichlorophenoxyacetic acid (2,4-D), a chemical analogue of indole-3-acetic acid (IAA), is widely used as a growth regulator and exogenous source of auxin. Because 2,4-D evokes physiological and molecular responses similar to those evoked by IAA, it is believed that they share a common response pathway. Here, we show that a mutant, antiauxin resistant1 (aar1), identified in a screen for resistance to the anti-auxin p-chlorophenoxy-isobutyric acid (PCIB), is resistant to 2,4-D, yet nevertheless responds like the wild-type to IAA and 1-napthaleneacetic acid in root elongation and lateral root induction assays. That the aar1 mutation alters 2,4-D responsiveness specifically was confirmed by analysis of GUS expression in the DR5:GUS and HS:AXR3NT-GUS backgrounds, as well as by real-time PCR quantification of IAA11 expression. The two characterized aar1 alleles both harbor multi-gene deletions; however, 2,4-D responsiveness was restored by transformation with one of the genes missing in both alleles, and the 2,4-D-resistant phenotype was reproduced by decreasing the expression of the same gene in the wild-type using an RNAi construct. The gene encodes a small, acidic protein (SMAP1) with unknown function and present in plants, animals and invertebrates but not in fungi or prokaryotes. Taken together, these results suggest that SMAP1 is a regulatory component that mediates responses to 2,4-D, and that responses to 2,4-D and IAA are partially distinct. 相似文献