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101.
Gene Transfer and Cloning of Flanking Chromosomal Regions Using the Medaka Fish Tol2 Transposable Element 总被引:1,自引:0,他引:1
For the ultimate purpose of developing genetic tools using the medaka fish Tol2 transposable element, we examined whether it can transfer a marker gene into the fish genome and also be applied for cloning
of chromosomal regions adjacent to insertion points. An internal region of Tol2 was removed and replaced with the green fluorescent protein (GFP) gene and a bacterial plasmid replication origin. This modified
Tol2 clone was microinjected into fertilized eggs together with messenger RNA for the Tol2 transposase. The GFP gene was found to be integrated into chromosomes and transmitted to subsequent generations. Restriction
enzyme digestion of genomic DNA of a transformant fish, followed by ligation and introduction into bacteria, produced a plasmid
containing the entire element and flanking chromosomal regions. Sequencing analysis of this clone demonstrated transposition
of the element in the germline of the first generation. Thus, the basic requirements for a gene transfer vector and gene tagging
system were fulfilled.
Received July 30, 2001; accepted October 4, 2001 相似文献
102.
Analysis of membrane stereochemistry with homology modeling of sn-glycerol-1-phosphate dehydrogenase
Different enantiomeric isomers, sn-glycerol-1-phosphate and sn-glycerol-3-phosphate, are used as the glycerophosphate backbones of phospholipids in the cellular membranes of Archaea and the remaining two kingdoms, respectively. In Archaea, sn-glycerol-1-phosphate dehydrogenase is involved in the generation of sn-glycerol-1-phosphate, while sn-glycerol-3-phosphate dehydrogenase synthesizes the enantiomer in Eukarya and Bacteria. The coordinates of sn-glycerol-3-phosphate dehydrogenase are available, although neither the tertiary structure nor the reaction mechanism of sn-glycerol-1-phosphate dehydrogenase is known. Database searching revealed that the archaeal enzyme shows sequence similarity to glycerol dehydrogenase, dehydroquinate synthase and alcohol dehydrogenase IV. The glycerol dehydrogenase, with coordinates that are available today, is closely related to the archaeal enzyme. Using the structure of glycerol dehydrogenase as the template, we built a model structure of the Methanothermobacter thermautotrophicus sn-glycerol-1-phosphate dehydrogenase, which could explain the chirality of the product. Based on the model structure, we determined the following: (1) the enzyme requires a Zn(2+) ion for its activity; (2) the enzyme selectively uses the pro-R hydrogen of the NAD(P)H; (3) the putative active site and the reaction mechanism were predicted; and (4) the archaeal enzyme does not share its evolutionary origin with sn-glycerol-3-phosphate dehydrogenase. 相似文献
103.
CPI17 and myosin binding subunit of type 1 protein phosphatase (MBS) are the regulators of myosin light chain phosphatase (MLCP). The function of both regulators is controlled by phosphorylation. The phosphorylation of CPI17 at Thr38 significantly enhances the inhibitory activity of CPI17 and the phosphorylation at Thr641 of MBS decreases the MLCP activity. Here, we found that p21-activated protein kinase (PAK) phosphorylates both CPI17 at Thr38 and MBS at Thr641. For CPI17, PAK specifically phosphorylated at Thr38, since the mutation of Thr38 to Ala completely abolished the phosphorylation. On the other hand, PAK phosphorylated Thr641 but not Thr799 of MBS, the site phosphorylated by Rho kinase. Because PAK phosphorylates MBS more than 1 mol/mol, it is anticipated that PAK also phosphorylates other sites in addition to Thr641. CPI17 phosphorylation induced by PAK significantly enhanced the inhibitory activity of CPI17. On the other hand, the phosphorylation of MBS by PAK also decreased the MLCP activity. These results raise the possibility that the PAK pathway plays a role in MLCP regulation. 相似文献
104.
105.
Kimura K Tsuda K Moriwaki C Kawabe T Hamada M Obana M Baba A Hano T Nishio I 《Biochemical and biophysical research communications》2002,294(2):359-362
Leukemia inhibitory factor (LIF) is a cytokine, which inhibits angiogenesis and decreases endothelial cell proliferation and migration, suggesting that LIF may modulate vascular tone. In this study, we examined the effects of LIF on the tone of rat arteries. The isometric tension of ring preparations from rat superior mesenteric arteries was continuously measured. LIF relaxed the mesenteric arteries in a dose-dependent manner, when the arterial rings were precontracted with phenylephrine. The relaxation was totally inhibited by mechanical removal of endothelium. N(G)-nitro-L-arginine methyl ester did not affect the relaxation by LIF. Ca(2+)-dependent K channel (KCa) blockers, apamin with charybdotoxin, inhibited the relaxation by LIF. Catalase, an enzyme which scavenges hydrogen peroxide, also inhibited the relaxation by LIF. Endothelium-derived hyperpolarizing factor relaxes smooth muscle cells and the effect is blocked by KCa and catalase. Our results suggest that LIF regulates vascular tone through the effect of this factor. 相似文献
106.
Advanced glycation end products-induced apoptosis and overexpression of vascular endothelial growth factor in bovine retinal pericytes. 总被引:14,自引:0,他引:14
Sho-ichi Yamagishi Shinjiro Amano Yosuke Inagaki Tamami Okamoto Kohachiro Koga Nobuyuki Sasaki Hiroshi Yamamoto Masayoshi Takeuchi Zenji Makita 《Biochemical and biophysical research communications》2002,290(3):973-978
The influence of advanced glycation end products (AGEs) on apoptotic cell death and vascular endothelial growth factor (VEGF) gene expression in cultured bovine retinal pericytes was investigated. When pericytes were incubated with three immunochemically distinct AGEs, which were prepared in vitro by incubating bovine serum albumin with glucose, glyceraldehyde, or glycolaldehyde, apoptotic cell death and DNA ladder formation were significantly induced. The cytopathic effects of glyceraldehyde- or glycolaldehyde-derived AGEs were significantly enhanced in AGE receptor-transfected pericytes. Furthermore, all of these AGEs were found to upregulate the secretory forms of VEGF mRNA levels in retinal pericytes. These results suggest that AGEs disturbed retinal microvascular homeostasis by inducing pericyte apoptosis and VEGF overproduction and thus were involved in the pathogenesis of early phase diabetic retinopathy. 相似文献
107.
Microsomal omega-3 fatty acid desaturase is an essential enzyme in the production of the n-3 polyunsaturated fatty acid alpha-linolenic acid during the seed developing stage. We have constructed a chimeric gene consisting of a maize Ubi1-P-int and a soybean GmFAD3 cDNA, which was introduced into rice plants by Agrobacterium-mediated transformation. Ten transformants containing the chimeric gene were established and expression subsequently confirmed by Northern blotting. Furthermore, alpha-linolenic acid content of the T(1) seeds increased dramatically up to tenfold that of the control, and this phenotype was also stably inherited in the T(2) and T(3) progenies. These results demonstrate that the alpha-linolenic acid content of rice seed oil can easily be altered using the combination of a high-activity promoter and a GmFAD3 gene. 相似文献
108.
Tachibana T Takagi T Saito ES Tomonaga S Zhang R Koga Y Kido Y Michael Denbow D Furuse M 《Comparative biochemistry and physiology. Part A, Molecular & integrative physiology》2003,135(3):403-409
We examined whether the brain beta 3-adrenergic receptor (B3-AR) is involved in the feeding regulation of chicks. Intracerebroventricular (ICV) injection of BRL37344, a B3-AR agonist, reduced food intake of chicks under ad libitum, but not fasting, feeding conditions. The ICV injection of BRL37344 did not affect chick posture or locomotion activity suggesting that BRL37344 inhibited feeding without induction of sleep-like behavior as caused by norepinephrine. Furthermore, the rectal temperature increased following the ICV injection of BRL37344. Intraperitoneal administration of BRL37344 did not reduce food intake under ad libitum feeding condition. The present study demonstrated that the brain B3-AR is involved in the inhibition of feeding in chicks. We also suggested that activation of the brain affects the energy metabolism in chicks. 相似文献
109.
M Koga T Uchida M Ueda M Shigeta T Yamamuro K Tamai T Suzuki T Saeki 《Nucleic acids symposium series》2000,(44):117-118
Achiral carbocyclic "DL-like" 5'-nor nucleosides have been synthesized and analyzed by the chiral capillary electrophoresis to elucidate the "D-like" monomers. 相似文献
110.
Experiments were carried out in vitro to investigate whether the sera of several animals as well as albumins and peptides might act as attractants for larvae of Strongyloides ratti. Samples of sera from several mammal species were dialysed and the aliquots were further centrifuged using ultrafiltration cartridges to remove any remaining small molecules. Additional test substances included commercially obtained ovalbumin, rat and bovine serum albumins, polypeptides such as peptone, tryptone and tryptose, amino nitrogens, monosaccharides, and reduced glutathione (triaminopeptide). Larvae were strongly attracted to the dialysed mammalian sera, which mainly consisted of serum albumin and globulins. Ov- and serum albumins, and polypeptides also acted as attractants. On the other hand, reduced glutathione, 16 kinds of amino acids and four kinds of monosaccharides did not attract this nematode. 相似文献