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11.
Shuji Nakamura David W. Stock Karen L. Wydner Jacques A. Bollekens Kenichi Takeshita Brian M. Nagai Shigeru Chiba Toshio Kitamura Thomas M. Freeland Zhiyong Zhao Jun Minowada Jeanne B. Lawrence Kenneth M. Weiss Frank H. Ruddle 《Genomics》1996,38(3):314
We have cloned a new Dlx gene (Dlx7) from human and mouse that may represent the mammalian orthologue of the newt geneNvHBox-5.The homeodomains of these genes are highly similar to all other vertebrate Dlx genes, and regions of similarity also exist between mammalian Dlx7 and a subset of vertebrate Dlx genes downstream of the homeodomain. The sequence divergence between human and mouse Dlx7 in these regions is greater than that predicted from comparisons of other vertebrate Dlx genes, however, and there is little sequence similarity upstream of the homeodomain both between these two genes and with other Dlx genes. We present evidence for alternative splicing of mouseDlx7upstream of the homeodomain that may account for some of this divergence. We have mapped humanDLX7distal to the 5′ end of the HOXB cluster at an estimated distance of between 1 and 2 Mb by FISH. Both the human and the mouse Dlx7 are shown to be closely linked to Dlx3 in a convergently transcribed orientation. These mapping results support the possibility that vertebrate distal-less genes have been duplicated in concert with the Hox clusters. 相似文献
12.
Calsequestrin is the major Ca2+-binding protein localized in the terminal cisternae of the sarcoplasmic reticulum (SR) of skeletal and cardiac muscle cells. Calsequestrin has been purified and cloned from both skeletal and cardiac muscle in mammalian, amphibian, and avian species. Two different calsequestrin gene products namely cardiac and fast have been identified. Fast and cardiac calsequestrin isoforms have a highly acidic amino acid composition. The amino acid composition of the cardiac form is very similar to the skeletal form except for the carboxyl terminal region of the protein which possess variable length of acidic residues and two phosphorylation sites. Circular dichroism and NMR studies have shown that calsequestrin increases its -helical content and the intrinsic fluorescence upon binding of Ca2+. Calsequestrin binds Ca2+ with high-capacity and with moderate affinity and it functions as a Ca2+ storage protein in the lumen of the SR. Calsequestrin has been found to be associated with the Ca2+ release channel protein complex of the SR through protein-protein interactions. The human and rabbit fast calsequestrin genes have been cloned. The fast gene is skeletal muscle specific and transcribed at different rates in fast and slow skeletal muscle but not in cardiac muscle. We have recently cloned the rabbit cardiac calsequestrin gene. Heart expresses exclusively the cardiac calsquestrin gene. This gene is also expressed in slow skeletal muscle. No change in calsequestrin mRNA expression has been detected in animal models of cardiac hypertrophy and in failing human heart. 相似文献
13.
Shinichi Kitamura Takashi Hirano Kenichi Takeo Mitsuru Mimura Kanji Kajiwara Bjrn T. Stokke Tsutomu Harada 《International journal of biological macromolecules》1994,16(6)
The conformation and dilute solution properties of (2→1)-β-d-fructan in aqueous solution were studied by gel permeation chromatography, low-angle laser light-scattering photometry, viscometry, small-angle X-ray scattering and electron microscopy. Fractions covering a broad range of weight-average molecular weights (Mw) from 1.49 × 104 to 5.29 × 106 were obtained from a native sample by ultrasonic degradation and fractional precipitation. For Mw < 4 × 104, the intrinsic viscosity [η] varies with Mw0.71, indicating that the fructan chain behaves as a random coil expanded by an excluded-volume effect in this molecular weight region. For Mw > 105, [η] exhibits an unusually weak dependence on Mw and finally becomes almost independent of molecular weight. This behaviour is interpreted in terms of a globular conformation of the high-molecular-weight fructan molecules. Small-angle X-ray-scattering measurements and electron microscopic observations support this interpretation of the values of [η] observed. 相似文献
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15.
Zenjiro Osawa Tsubura Morota Kenichi Hatanaka Toshihiro Akaike Kei Matsuzaki Hideki Nakashima Naoki Yamamoto Eiichiro Suzuki Hiroshi Miyano Tohru Mimura Yutaro Kaneko 《Carbohydrate polymers》1993,21(4):283-288
Sulfopropyl curdlan was synthesized, its structure was determined, and the anti-HIV activity was compared with that of standard curdlan sulfates obtained with piperidine N-sulfonic acid in dimethyl sulfoxide. It was shown that sulfopropyl curdlan exhibits weaker anti-HIV activity than curdlan sulfate. Curdlan sulfates were synthesized with a SO3-pyridine complex in a heterogeneous phase. It was shown from 13C-NMR spectra of acetylated curdlan sulfates that they had a different substituent distribution from standard curdlan sulfate. The cytotoxicity of the curdlan sulfates was attributed to their heterogeneous structure. 相似文献
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Detection and mapping of six miniF-encoded proteins by cloning analysis of dissected miniF segments 总被引:11,自引:0,他引:11
Nobuhisa Komai Tsutomu Nishizawa Yasuhiko Hayakawa Tomoaki Murotsu Kenichi Matsubara 《Molecular & general genetics : MGG》1982,186(2):193-203
Summary Various DNA subfragments were derived from miniF DNA by complete or partial PstI cleavage, and cloned in the plasmid vectors pBR322 or dv1. The recombinant plasmids obtained were introduced into an Escherichia coli minicell-producing strain, and the plasmid-coded proteins were radiolabeled and analyzed by gel electrophoresis. Six miniF-encoded proteins, larger than 11 000 daltons, were detected and their coding regions were mapped on the F plasmid genome. Three of them were assigned by taking into account the known nucleotide sequences (Murotsu et al. 1981; K. Yoshioka, personal communication). The coding directions of some proteins were determined by inserting the lac promotor into one of the recombinant plasmids and analyzing the increase in production of the proteins. The coding direction of the five proteins analyzed so far was uniform. Comparison of these results with a functional map of miniF suggested possible roles of the proteins. 相似文献
19.
Tomoaki Murotsu Hiroshi Tanaka Masami Imaji Hideo Koga Kenichi Matsubara Tadao Horiuchi 《Molecular & general genetics : MGG》1977,157(2):139-147
Summary In order to study the mode of action of the tof gene product, which is an autorepressor of the bacteriophage and plasmid dv, we have purified a DNA-binding protein which is specifically produced in bacteria carrying dv. This protein possesses characteristics expected for the product of the tof gene, since it is produced under conditions where cI-repressor is not made, and since it binds to oL and oR operators on the phage genome. The molecular weight of the native protein is 16,000–17,000 daltons, and the monomeric molecular weight as measured by gel electrophoresis in the presence of sodium dodecyl sulfate is about 10,000 daltons. Denaturation and renaturation experiments demonstrated that the native protein is a dimer of 10,000-dalton monomers. The DNA-specific binding protein is not produced in cells carrying i
21dv or 80dv. 相似文献
20.
To understand the incompatibility between two related plasmids, both of which replicate in an autonomous state under a common control mechanism, we have developed a model that assumes a random choice mechanism for replication of plasmid copies and their random assortment into daughter cells upon cell division. Segregation kinetics by this model is analyzed mathematically and the number of generations required for segregation is calculated as a function of plasmid copy number per cell. The results obtained offer enough quantitative data to make our model reasonably realistic. 相似文献