• Bulletin of the Korean Chemical Society
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• v.18 no.9
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• pp.998-1002
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• 1997

Irradiation of tert-butyl 9-anthroate and furan through a Uranium glass filter gave the [4+4] cyclodimer (21.8%) of tert-butyl 9-anthroate and furan and the 1,4-10',9' cyclodimer (4.2%) of tert-butyl 9-anthroate as well as the 9,10-10',9' cyclodimer (65.7%) of tert-butyl 9-anthroate. The [4+4] cyclodimer of tert-butyl 9-anthroate and furan was found to be thermally dissociated into their unit components with the activation enthalpy of 35.6 kcal/mole and the activation entropy of 7.6 eu, and photochemically dissociated to produce excited tert-butyl 9-anthroate. Quantum yields for the photodissociation to tert-butyl 9-anthroate and the formation of excited tert-butyl 9-anthroate in cyclohexane at room temperature were determined to be 0.56 and 0.19, respectively. The 1,4-10',9' cyclodimer of tert-butyl 9-anthroate in DMF was thermally dissociated into tert-butyl 9-anthroate with the activation enthalpy of 34.8 kcal/mole and the activation entropy of 16.4 eu. Upon irradiation, the [4+4] cyclodimers of tert-butyl 9-anthroate and the [4+4] cyclodimers of methyl 9-anthroate were quantitatively dissociated. However, no adiabatic photoreversion was observed from any of the cyclodimers. Quantum yields for the photodissociation in cyclohexane at room temperature were measured and compared.

• Molecules and Cells
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• v.38 no.9
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• pp.814-820
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• 2015

PinX1, a nucleolar protein of 328 amino acids, inhibits telomerase activity, which leads to the shortening of telomeres. The C-terminal region of PinX1 is responsible for its nucleolar localization and binding with TERT, a catalytic component of telomerase. A fraction of TERT localizes to the nucleolus, but the role of TERT in the nucleolus is largely unknown. Here, we report a functional connection between PinX1 and TERT regarding PinX1 stability. The C-terminal of $PinX1^{205-328}$, a nucleolar fragment, was much more stable than the N-terminal of $PinX1^{1-204}$, a nuclear fragment. Interestingly, PinX1 was less stable in TERT-depleted cells and more stable in TERT-myc expressing cells. Stability assays for PinX1 truncation forms showed that both $PinX1^{1-328}$ and $PinX1^{205-328}$, nucleolar forms, were more rapidly degraded in TERT-depleted cells, while they were more stably maintained in TERT-overexpressing cells, compared to each of the controls. However, $PinX1^{1-204}$ was degraded regardless of the TERT status. These results reveal that the stability of PinX1 is maintained in nucleolus in the presence of TERT and suggest a role of TERT in the regulation of PinX1 steady-state levels.

• Journal of Microbiology and Biotechnology
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• v.19 no.9
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• pp.1070-1076
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• 2009

Telomerase reverse transcriptase (TERT), which prolongs the replicative life span of cells, is highly upregulated in 85-90% of human cancers, whereas most normal somatic tissues in humans express limited levels of the telomerase activity. Therefore, TERT has been a potential target for anticancer therapy. Recently, we described a new approach to human cancer gene therapy, which is based on the group I intron of Tetrahymena thermophila. This ribozyme can specifically mediate RNA replacement of human TERT (hTERT) transcript with a new transcript harboring anticancer activity through a trans-splicing reaction, resulting in selective regression of hTERT-positive cancer cells. However, to validate the therapeutic potential of the ribozyme in animal models, ribozymes targeting inherent transcripts of the animal should be developed. In this study, we developed a Tetrahymena-based trans-splicing ribozyme that can specifically target and replace the mouse TERT (mTERT) RNA. This ribozyme can trigger transgene activity not only also in mTERT-expressing cells but hTERT-positive cancer cells. Importantly, the ribozyme could selectively induce activity of the suicide gene, a herpes simplex virus thymidine kinase gene, in cancer cells expressing the TERT RNA and thereby specifically hamper the survival of these cells when treated with ganciclovir. The mTERT-targeting ribozyme will be useful for evaluation of the RNA replacement approach as a cancer gene therapeutic tool in the mouse model with syngeneic tumors.

• Molecules and Cells
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• v.41 no.7
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• pp.684-694
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• 2018

Upregulation of human telomerase reverse transcriptase (hTERT) expression is an important factor in the cellular survival and cancer. Although growing evidence suggests that hTERT inhibits cellular apoptosis by telomere-independent functions, the mechanisms involved are not fully understood. Here, we show that hTERT contains a BH3-like motif, a short peptide sequence found in BCL-2 family proteins, and interacts with anti-apoptotic BCL-2 family proteins MCL-1 and BCL-xL, suggesting a functional link between hTERT and the mitochondrial pathway of apoptosis. Additionally, we propose that hTERT can be categorized into the atypical BH3-only proteins that promote cellular survival, possibly due to the non-canonical interaction between hTERT and antiapoptotic proteins. Although the detailed mechanisms underlying the hTERT BH3-like motif functions and interactions between hTERT and BCL-2 family proteins have not been elucidated, this work proposes a possible connection between hTERT and BCL-2 family members and reconsiders the role of the BH3-like motif as an interaction motif.

• Bulletin of the Korean Chemical Society
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• v.21 no.7
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• pp.715-719
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• 2000

A ceramic powder of destructive adsorbent was synthesized by impregnating copper and manganese on the surface of silica aerosil@. In-site FTIR measurements on pulses of malodorant tert-butylmercaptan injected over the powder showed that rert-butylmercaptan dimerized into di-tert-hutyldisulfide on the surface of the adsorbent in an ambient condition. GC/MS measurement on the gas over the adsorbent showed no tert-butylmercaptan remaining, and showed only the dimerization product of di-tert-butyldisulfide. Most of the dimerization product, di-tert-butyldisulfide,remained on the surface of the adsorbent as physisorbed condense, and apparently Iowered the destruction efficiency by blocking the surface from the access by tert-butylmercaptan. Upon being heated above $100^{\circ}C$ it was observed that the physisorbed di-tert-butyldisulfide dissociated back into tert-butylmercaptan. tert-butylmercaptan physisorbed on the activated carbon, thereby no dimerization was occurring on the surface of the activated carbon. In an argn environment, the dimerization reaction was practically not occurring even on the surface of the adsorbent, indicating the free oxygen in air was also participating in the dimerization reaction. Water was identified as a by-product of the dimerization reaction. Possible reactions on the surface of the adsorbent were proposed.

• Fire Science and Engineering
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• v.31 no.3
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• pp.25-30
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• 2017

Because of the vertical combustion characteristics of combustible substances, accurate substance safety information for their safe use, handling and transportation is essential. The flash point, fire point, explosion limits and autoignition temperature (AIT) are important safety parameters which need special attention in chemical plants and laboratories that handle dangerous materials. In this study, tert-butylbenzene which is widely used as an intermediate material in the chemical industry was selected. For the reliability of the flammable properties of tert-butylbenzene, this study was investigated the explosion limits of tert-butylbenzene in the reference data. The flash points, fire points and AITs by the ignition delay time for tert-butylbenzene were experimented. The lower flash points of tert-butylbenzene by using the Setaflash and Pensky-Martens closed-cup testers measured $39^{\circ}C$ and $44^{\circ}C$, respectively. The flash points of tert-butylbenzene by using the Tag and Cleveland open cup testers are measured $51^{\circ}C$ and $54^{\circ}C$. And the fire points of tert-butylbenzene by the Tag and Cleveland open cup testers were $54^{\circ}C$ and $58^{\circ}C$ respectively. The AIT of tert-butylbenzene measured by the ASTM 659E tester was measured as $450^{\circ}C$. The lower explosion limit of $39^{\circ}C$ which measured by the Setaflash flash point tester was calculated to be 0.68 vol%.

• Environmental Analysis Health and Toxicology
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• v.23 no.2
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• pp.93-100
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• 2008

The ecotoxicological effects of 4-tert-octylphenol were observed on Harpacticoid copepoda Tigriopus japonicus s.l. gathered and cultured from tidal pool of Korean coast. There were no significant differences in survival rate (except 10 $\mu$g/L; 70.00%) and sex ratio (except 30 $\mu$g/L) on T. japonicus s.l. exposed to 4-tert-octylphenol. However, 4-tert-octylphenol induced developmental delay (copepodite emergence day and adult male mergence day) and retardation of first brooding day of adult female. Moreover the body size and biomass decreased at 4-tert-octylphenol exposure. As a result, detailed life-cycle research of T. japonicus s.l. may yield potential bioindicators for environmental monitoring and assessment.

• Environmental Analysis Health and Toxicology
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• v.23 no.4
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• pp.277-284
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• 2008

The ecotoxicological effects of 4-tert-octylphenol were observed on non-biting midge, Chironomus plumosus collected from Anyang stream in Seoul. The survival rate and adult emergence rate on C. plumosus exposed to octylphenol were not significantly affected. However, 4-tert-octylphenol induced developmental delay and disrupted sex ratio in high concentration of octylphenol. The mouth deformity such as tooth deletion or fusion in mentum, and tooth deletion in mandible were observed exposure to 4-tert-octylphenol. The deformity type of the mentum showed deletion (LT, 6.7%), and fusion (LT, 6.3%). Moreover, tooth deletion of mandible was observed in 4-tert-octylphenol treated groups (6.7%, 3 ppm).

• BMB Reports
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• v.47 no.1
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• pp.8-14
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• 2014

Telomerase plays a pivotal role in the pathology of aging and cancer by maintaining genome integrity, controlling cell proliferation, and regulating tissue homeostasis. Telomerase is essentially composed of an RNA component, Telomerase RNA or TERC, which serves as a template for telomeric DNA synthesis, and a catalytic subunit, telomerase reverse transcriptase (TERT). The canonical function of TERT is the synthesis of telomeric DNA repeats, and the maintenance of telomere length. However, accumulating evidence indicates that TERT may also have some fundamental functions that are independent of its enzymatic activity. Among these telomere-independent activities of hTERT, the role of hTERT in gene transcription has been investigated in detail. Transcriptional regulation is a fundamental process in biological systems. Several studies have shown a direct involvement of hTERT in gene transcription. This mini-review will focus on the role of hTERT in gene transcription regulation, and discuss its possible mechanisms.

• Journal of the Korean Chemical Society
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• v.12 no.4
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• pp.177-183
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• 1968

The rate equations for the nucleophilic addition reactions of n-propyl- and tert-buryl mercaptan to 3,4-methylenedioxy-$\beta$-nitrostyrene over wide pH range were obtained. From this equations, the rate constants for n-propyl-and tert-butylmercaptide ions at high pH were obtained numerically as $1.26{\times}10^8$ and $3.98{\times}10^6\;M^{-2},\;sec^{-1}$, and for n-propyl- and tert-butyl mercaptan at low pH, $7.07{\times}10^{-3}$ and $1.5{\times}10^3\;M^{-1},\;sec^{-1}$ respectively.