• Biomedical Science Letters
• /
• v.12 no.4
• /
• pp.399-403
• /
• 2006

Cervical cancer is one of the most prevalent cancers developed in women worldwide, and human papillomavirus (HPV) type 16 is the most common agent linked to human cerivical carcinoma. Viral oncogenes E6 and E7 are selectively ratined and expressed in carcinoma cells infected with human papillomavirus type 16 and cooperated with each other in immortalization and transformation of primary keratinocytes. Because of HPV oncogenesis mechanism was not completely solved, the more studies be required thoroughly. In the present study, to investigate the telomere independent role of telomerase in HPV oncogenesis, we constructed the E6 mutant, E7, E6/E7 and hTERT over-expressed stable cells with a telomerase negative cell line, SW13. Expressions of Inserted genes were measured by RT-PCR. E6, E7 and hTERT genes were well expressed in each cell lines comparing with the control groups. By analyzing the cell morphology under the microscope, hTERT clone size was a more smaller than the mock control but oncogene expressed clones were slightly lengthened the marginal region. In addition, hTERT cells has also, a tendency of brief dividing time compared to the mock control. To determine whether telomerase activity associated with a HPV oncogenesis by oncoprotein expression, we performed the PCR based TRAP assay and Northern blot analysis. In TRAP assay data, telomerase activities in hTERT and oncogene clones were more increased than the mock control. In addition, SW13/ E6/E7 cells appeared a extremely increased activity than any other clones. Induced TERT mRNA by E6/E7 wasn't, however, detected in Northern blotting. In conclusion, these findings suggest that telomerase activity closely associated the HPV oncogenesis and E6/E7 co-expression is a most important factor of telomerase activity.

• Korean Journal of Clinical Laboratory Science
• /
• v.39 no.1
• /
• pp.1-6
• /
• 2007

Cervical cancer is one of the most prevalent cancers developed in women worldwide, and human papillomavirus(HPV) type 16 is the most common agent linked to human cerivical carcinoma. Viral oncogenes E6 and E7 are selectively retained and expressed in carcinoma cells infected with human papillomavirus type 16 and cooperate with each other in the immortalization and transformation of primary keratinocytes. Because the HPV oncogenesis mechanism was not completely solved, more thorough studies are required. ln the present study, we investigated the telomere independent role of telomerase in HPV oncogenesis, we constructed the E6 mutant, E7, E6/E7 and hTERT over-expressed stable cells with a telomerase negative cell line, SW13. Expressions of inserted genes were measured by RT-PCR. E6, E7 and hTERT genes were well expressed in each cell lines when compared with the control groups. By analyzing the cell morphology under the microscope, hTERT clone size was a smaller than the mock control but oncogene expressed clones had a slightly lengthened marginal region. In addition, hTERT cells also has a tendency of brief dividing time compared to the mock control. To determine whether telomerase activity was associated with a HPV oncogenesis by oncoprotein expression, we performed the PCR based TRAP assay and a Northern blot analysis. In TRAP assay data, telomerase activities in hTERT and oncogene clones increased compared to the mock control. In addition, SW13/E6/E7 cells showed an extremely increased activity compared to the other clones. Induced hTERT mRNA by E6/E7 wasn't, however, detected in Northern blotting. In conclusion, these findings suggest that telomerase activity is closely associated with the HPV oncogenesis and E6/E7 co-expression is a most important factor of telomerase activity.

• Molecules and Cells
• /
• v.19 no.2
• /
• pp.294-299
• /
• 2005

A cDNA encoding farnesyl diphosphate synthase (FPS; EC2.5.1.1/EC2.5.1.10) was isolated from Centella asiacita (L.) Urban, using degenerate primers based on two highly conserved domains. A full-length cDNA clone was subsequently isolated by rapid amplification of cDNA ends (RACE) PCR. The sequence of the CaFPS (C. asiatica farnesyl diphosphate synthase) cDNA contains an open reading frame of 1029 nucleotides encoding 343 amino acids with a molecular mass of 39.6 kDa. The deduced CaFPS amino acid sequence exhibits 84, 79, and 72%, identity to the FPSs of Artemisia annua, Arabidopsis thaliana, and Oryza sativa, respectively. Southern blot analysis suggested that the C. asiatica genome contains only one FPS gene. An artificially expressed soluble form of the CaFPS was identified by SDS-PAGE. It had high specific activity and produced farnesyl diphosphate as the major isoprenoid.

• Korean Journal of Microbiology
• /
• v.28 no.2
• /
• pp.104-108
• /
• 1990

The chromosomal DNA of Agrobacterium tumefaciens contains the genes required for bacterial attachment to plant cell which is an essential atage in crown gall tumorigenesis by Ti-plasmid. In order to clone the genes, Agrobacterium tumefaciens strain A5512 was mutagenized by transposon Tn5 and two Agrobacterium tumefaciens mutants which are attachment-defective and nontumorigenic were isolated. From one of the two mutants, a chromosomal virulence region which was required for attachment to the plant cells was cloned.

• Proceedings of the Korea Environmental Mutagen Society Conference
• /
• 2003.05a
• /
• pp.56-56
• /
• 2003

• Microbiology and Biotechnology Letters
• /
• v.28 no.1
• /
• pp.21-25
• /
• 2000

We have got several clones from Serratia marcescens which stimulated the cells to use maltose as a carbon source in Escherichia. coli TP2139 ( lac, crp). One of the cloned genes, pCKB17, was further analyzed. In order to find whether the increased expression of the gent was under the direction of maltose metabolism, we constructed several recombinant subclones. We have found that the clone, pCKB17AV, codes maltose metabolism stimulation(mms) gene. E. coli transformed with the cloned gene showed increase in the activity of maltose utilzation, The recombinant proteins expressed by multicopy and induction with IPTG, one polypeptide of 29-kDa, was confirmed by SDS-PAGE. The overexpression of maltose-binding proter protein in the presence of mms gene was confirmed by Western blot analysis. Southern hybridization analysis confirmed that the cloned DNA fragment was originated from S. marcescens chromosomal DNA.

• Korean Journal of Microbiology
• /
• v.13 no.3
• /
• pp.123-137
• /
• 1975

Sexual reproduction of paramecia have been accomplished through conjugation between individuals which have opposite mating type substances on their cilia when they were starved. Using selfing clone in which mating takes place, I examined whether a mating type change in indicidual cells required new protein and new mRNA synthesis or not and also shether there is a precursor relationship between both of the complementary mating type substances in their synthetic pathway. I found that 1. Mating type change needs new protein(s) and new mRNA synthesis. 2. Mating type substances are synthesized sequentially from mating type XIII to XIV 3. There might be a common precursor pool from which the mating type XIII substnace is synthesized and then complementary mating type XIV is fromed by addition of small group to the mating type XIII substance.

• Animal cells and systems
• /
• v.6 no.1
• /
• pp.81-84
• /
• 2002

SINE-R retroposons have been derived from human endogenous retrovirus HERV-K family and found to be hominoid specific. Both SINE-R retroposons and HERV_K family are potentially capable of affecting the expression of closely located genes. Using the genomic DNA from patients with schizophrenia, we identified 26 SINE-R retroposons and analyzed them with the sequences derived from the hominoid primates. The SINE-R retroposons from schizophrenia showed 89.7-96.6％ sequence similarities with the sequence of the schizo-cDNA clone that derived from postmortem tissue from the frontal cortex of an individual suffering from schizophrenial. Phylogenetic analysis using the neighbor-joining method revealed that the new SINE-R retroposons in schizophrenia have proliferated independently during hominid evolution. Such retroposons have great relevance to genomic change connected to human diseases. The data suggest that new SINE-R retroposons identified in schizophrenia deserve further investigation as potential leads on the understanding of neuropsychiatric diseases.

• Proceedings of the Korean Society of Toxicology Conference
• /
• 2003.05a
• /
• pp.56-56
• /
• 2003

The reactivity and toxicity of arsenic compounds depend on the their oxidative states. Exposure to arsenic causes many human health effects, including cardiovascular, hepatic and renal disease, in addition to cancer in kidney, liver, lung, urinary bladder and skin. The cytotoxic effects of arsenite on normal hepatocyte, which most of its biotranfomation takes place. (omitted)

• Genomics & Informatics
• /
• v.5 no.1
• /
• pp.6-9
• /
• 2007

An RNase P ribozyme library has been developed as a tool for functional genomics studies. Each clone of this library contains a random 18-mer and the sequence of M1 RNA, the catalytic subunit of RNase P. Repression of target gene expression is thus achieved by the complementary binding of mRNA to the random guide sequence and the successive target cleavage via M1 RNA. Cellular expression of the ribozyme expression was confirmed, and EGFP mRNA was used as a model to demonstrate that the RNase P ribozyme expression system can inhibit the target gene expression. The constructed RNase P ribozyme library has a complexity of $1.4\times10^7$. This novel library system should become a useful in functional genomics, to identify novel gene functions in mammalian cells.