• Molecules and Cells
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• v.19 no.2
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• pp.198-204
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• 2005

Both erythropoietin (EPO) and the short-form thrombopoietin (TPO) were expressed at low levels whereas the long-form TPO was expressed at high levels in transgenic animals. To elucidate the role of carboxy-terminal half of the long-form TPO which is absent in the short-form, we generated recombinant TPO or EPO expression vectors which contain or lack the carboxy-terminal half of TPO and examined their expression in the HC11 and 293 cells. The long-form TPO was expressed higher than the short-form regardless of the cell types, transfection modes, and promoters. When 3'-half of the long-form TPO cDNA was placed downstream of the EPO cDNA to act as a 3'-untranslated region, expression of EPO was moderately increased at the RNA level, however, no remarkable increase was observed at the protein level. These results suggest that the low expression of EPO, as like as the short-form TPO, is due to absence of the 3'-half in the full-length TPO that confers stability both at the RNA and protein levels.

• Korean Journal of Animal Reproduction
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• v.18 no.2
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• pp.133-139
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• 1994

Two human lactoferrin expression vectors(pCChcLf and pCChcLf-1) were constructed using rat $\beta$-casein gene and human lactoferrin cDNA. The recombinant DNAs containing human lactoferrin cDNA were microinjected into the fertilized eggs of hybrid mice (BDF1 : C57BL$\times$DBA) and the DNA-injected eggs were treansferred into the oviducts of foster mothers. Genomic DNAs were isolated from the tails of mice born from the microinjected eggs and analyzed by Southern blot analysis. As a result, 5 and 9 transgenic mice with CChcLf and CChcLf-1 gene were produced, respectively. To determine tissue-specificity of transgene expression, Northern blot analysis was performed. Female transgenic mice were killed at day 10 of lactation and total RNAs from various tissues were isolated. Based on Northern blot analysis, it was shown that transgene was mainly expressed in the mammary glands of transgenic mice. In addition, the human lactoferrin in milk was detected by enzyme-linked immunosorbent assay. For this study, milk was obtained from the mammary glands of the transgenic mice at day 10 of lactation. In line #2 of CChcLf and line #7 of CChcLf-1 transgenic mice, human lactoferrin was secreted into the milk at concentration levels of 340ng/ml and 60ng/ml, respectively.

• Microbiology and Biotechnology Letters
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• v.17 no.6
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• pp.574-579
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• 1989

Chromosomal DNA fragments of Bacillus sp. YA-14, isolated from soil as a potent $\beta$-xylosidase producing bacterium, were ligated to a vector plasmid pBR322 and used to transfer Escherichia coli HB101 cells. The recombinant plasmid pYXL22 was found to enable the transformants to produce $\beta$-xylosidase. pYXL22 was found to contain the 7.0 kb HindIII DNA fragment originated from the Bacillus sp. YA-14 chromosomal DNA by Southern hybridization. The optimum temperature for the reaction of $\beta$-xylosidase produced by E. coli HB101 (pYXL22) was appeared at 3$0^{\circ}C$. The enzyme was maintained stably up to 4$0^{\circ}C$ when stored 1hr at 4$0^{\circ}C$. The $\beta$-xylosidase was repressed completely by 0.4% (w/v) glucose concentration in E. coli HB101 (pYXL22). The optimum concentration of xylose for the $\beta$-xylosidase production in Bacillus sp. YA-14 was 0.2% (w/v).

• Journal of the Korean Magnetic Resonance Society
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• v.16 no.1
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• pp.22-33
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• 2012

Tid1, belonging to the Hsp40/DnaJ family of proteins, functions as a cochaperone of cytosolic and mitochondrial Hsp70 proteins. In particular, the N-terminal J-domain of Tid1 (Tid1-JD) constitutes the major binding sites for proteinprotein interactions with client proteins, including p53, as well as its partner chaperone, Hsp70. In the present study, soluble, recombinant protein of Tid1-JD could be obtained by using the pCold vector system, and backbone NMR assignments were completed using the isotope $[^{13}C/^{15}N]$-enriched protein. Far-UV CD result implied that Tid1-JD is an ${\alpha}$-helical protein and the secondary structure determined using chemical shift data sets indentified four ${\alpha}$-helices with a loop region containing the HPD (conserved tripeptide of His, Pro and Asp) motif. Additionally, NMR spectra under different conditions implied that the HPD motif, which is a critical region for protein-protein interactions of Tid1-JD, would possess dynamic properties.

• Microbiology and Biotechnology Letters
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• v.13 no.3
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• pp.297-302
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• 1985

The 7.1 Mdal Xbaf fragment of Bacillus pasteurii ATCC 11859 containing gene for urease was inserted into the Xbal site of bifunctional plasmid pGR71, and its urease gene was cloned and expressed in E. coil RRI. But the cloned gene was not expressed in Bacillus subtilis BR151 in consequence of deletion of inserted DNA fragment. The recombinant plasmid thus formed was named pGU66. The restriction map of the plasmid pGU66 was determined, and the size of the plasmid was estimated to be 12.6 Mdal by double digestion of restriction enzymes of the plasmid. The urease of the cloned strain was accumulated in periplasmic space and very similiar to that of donor strains in their enzymatic properties.

• Journal of Microbiology
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• v.40 no.3
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• pp.245-247
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• 2002

A genomic DNA library of the fungus Trametes versicolor was constructed in a yeast integration vector which contains the URA3 gene of the budding yeast Saccharomyces cerevisiae and the gene responsible for hygromycin B resistance, and fragments acting as autonomously replicating sequences (ARSes) in the budding yeast were identified from the genomic DNA library. Sixteen recombinant plasmids from the library transformed the budding yeast Saccharomyces cerevisiae to Ura+ at high frequencies. They were maintained stably under selective conditions, but were gradually lost from yeast cells at different rates under nonselective conditions, indicating that they contain eukaryotic origins of DNA replication and exist as extrachromosomal plasmids. Base sequences of four ARS DNAs among the 16 cloned fragments revealed that all or the four contain at least one 11 bp ［(A/T)TTTA(T/C)(A/G)TTT(A/T)］consensus sequence of the budding yeast ARS.

• Fisheries and Aquatic Sciences
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• v.6 no.3
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• pp.116-124
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• 2003

Isolation and cloning of seven-band grouper (Epinephelus septemfasciatus) growth hormone cDNA from pituitary gland revealed an open reading frame of 612 bp coding for a pre-growth hormone of 204 amino acids with a 17 amino acid putative signal peptide. Deduced amino acid sequence showed that there was one possible N-glycosylation site at $Asn^{l84}$ and four cysteine residues $(Cys^{52},\;Cys^{160},\;Cys^{177},\;Cys^{185})$ on t e same positions as in some other species where they were involved in the stabilization of the tertiary structure. The seven-band grouper growth hormone (sbgGH) presented a $99.5\%$ amino acid sequence identity with the growth hormone of Epinephelus coioides and contained the conserved hormone domain region. Comparison of growth hormone sequences from evolutionarily diverse species revealed 25 amino acid residues conserved in jawless fishes to modern mammals. It also revealed an evolutionary trend to retain the same polypeptide sequence even in the distantly related animals while allowing alterations to occur in polypeptides of the closely related species. In order to create a recombinant system to produce high levels of the growth hormone, it was expressed in Escherichia coli (BL21) cells. The gel analysis revealed theoretically expected molecular weights for both mature and pre-sbgGHs.

• Microbiology and Biotechnology Letters
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• v.20 no.2
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• pp.129-135
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• 1992

A chitinase gene of Serratia marcescens ATCC 27117 was cloned and expressed in Escherichiu di. A genomic library of S, marcescens was constructed with pUC 19 and screened using the swollen chitin agar plate for chitinolytic clones. A positive clone showing chitinclearance contains a recombinant pCHI 89, composed of 8.9 Kb chromosomal DNA fragment and pUC 19. Plasmid pCHI 89 produced 58 KD chitinase in E. coli, which was coincided with one of five extracellular chitinases produced by S. nzarccscens. Restriction endonuclease cleavage sites of the 8.9 Kb insert DNA fragment were mapped. E. coli JM109 harboring pCHI 89 inhibits the growth of a plant pathogenic fungus, Fusarium oxysporum.

• Journal of Microbiology and Biotechnology
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• v.16 no.2
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• pp.286-290
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• 2006

A genomic library of Streptococcus vestibularis ATCC49124 was constructed in an E. coli plasmid vector, and the urease-positive transformants harboring the urease gene cluster were isolated on Christensen-urea agar plates. The minimal DNA region required for urease activity was located in a 5.6 kb DNA fragment, and a DNA sequence analysis revealed the presence of a partial ureI gene and seven complete open reading frames, corresponding to ureA, B, C, E, F, G, and D, respectively. The nucleotide sequence over the entire ure gene cluster and 3'-end flanking region of S. vestibularis was up to 95% identical to that of S. salivarius, another closely related oral bacterium, and S. thermophilus, isolated from dairy products. The predicted amino acid sequences for the structural peptides were 98-100% identical to the corresponding peptides in S. salivarius and S. thermophilus, respectively, whereas those for the accessory proteins were 96-100% identical. The recombinant E. coli strain containing the S. vestibularis ure gene cluster expressed a high level of the functional urease holoenzyme when grown in a medium supplemented with 1 mM nickel chloride. The enzyme was purified over 49-fold by using DEAE-Sepharose FF, Superdex HR 200, and Mono-Q HR 5/5 column chromatography. The specific activity of the purified enzyme was 2,019 U/mg, and the Michaelis constant ($K_{m}$) of the enzyme was estimated to be 1.4 mM urea. A Superose 6HR gel filtration chromatography study demonstrated that the native molecular weight was about 196 kDa.

• Korean Journal of Veterinary Research
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• v.32 no.4
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• pp.555-567
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• 1992

In this study gene encoding structural proteins of a CPV isolate was cloned and sequenced to elucidate the molecular genetical properties of the canine parvoviruses isolated from the field. Six recombinant plasmids of pEP3, p1471, p2070, pEP069, pEP338 and p14711p were constructed from the map positions 22 to 98 of RF DNA to clone the VP1 and VP2 genes of CPV-V20. Sequentialy the gene comprising 3780 nucleotides were sequenced by dideoxy chain termination method. When nucleotide sequence of gene encoding the structural proteins of CPV-V20 was compared with those of other strains, CPV-N, CPV-d and CPV-780929 published previously, DNA, homologies to CPV-V20 were 99.87% with CPV-N, 99.73% with CPV-d, 96.85% with CPV-780929 and 98.4% with FPLV-Carl, respectively. The DNA sequence data of CPV-V20 showed seven point mutations and also deletion of 135 nucleotides from the nucleotide position 4745 to 4879 located in the 3'-noncoding region of CPV-N.