• Molecules and Cells
• /
• v.27 no.5
• /
• pp.539-546
• /
• 2009

In Saccharomyces cerevisiae, ribosomal protein L7, one of the ~46 ribosomal proteins of the 60S subunit, is encoded by paralogous RPL7A and RPL7B genes. The amino acid sequence identity between RPl7a and RPl7b is 97 percent; they differ by only 5 amino acid residues. Interestingly, despite the high sequence homology, Rpl7b is detected in both the cytoplasm and the nucleolus, whereas Rpl7a is detected exclusively in the cytoplasm. A site-directed mutagenesis experiment revealed that the change in the amino acid sequence of Rpl7b does not influence its subcellular localization. In addition, introns of RPL7A and RPL7B did not affect the subcellular localization of Rpl7a and Rpl7b. Remarkably, Rpl7b was detected exclusively in the cytoplasm in rpl7a knockout mutant, and overexpression of Rpl7a resulted in its accumulation in the nucleolus, indicating that the subcellular localization of Rpl7a and Rpl7b is influenced by the intracellular level of Rpl7a. Rpl7b showed a wide range of localization patterns, from exclusively cytoplasmic to exclusively nucleolar, in knockout mutants for some rRNA-processing factors, nuclear pore proteins, and large ribosomal subunit assembly factors. Rpl7a, however, was detected exclusively in the cytoplasm in these mutants. Taken together, these results suggest that although Rpl7a and Rpl7b are paralogous and functionally replaceable with each other, their precise physiological roles may not be identical.

• Korean Journal of Pharmacognosy
• /
• v.42 no.3
• /
• pp.218-222
• /
• 2011

The purpose of this research is to study of inhibitory activity of protostane type triterpens against farnesyl-protein transferase (FPTase). The ingredients of Alismatis Rhizoma, alisol B 23-acetate, C 23-acetate, alisols B and A 24-acetate, and thirteen synthetic analogues from alisol B 23-acetate exhibited inhibition activity against FPTase by scintillation proximity assay method. As a result, alisol C 23-acetate, one of the constituents of Alismatis Rhizoma, the synthetic analogues carboxylated and hydroxylated on branch chain of protostane exhibited a significant inhibitory activity. However, the compounds significantly lowered the inhibitory activity, when there is no 3 position keto on protostane skeletone.

• BMB Reports
• /
• v.41 no.12
• /
• pp.852-857
• /
• 2008

Little attention has been paid to the specificity between E2 and the target protein during ubiquitination, although RING-E3 induces a potential intra-molecular reaction by mediating the direct transfer of ubiquitin from E2 to the target protein. We have constructed artificial E2 fusion proteins in which a target protein (p27) is tethered to one of six E2s via a flexible linker. Interestingly, only three E2s (UbcH5b, hHR6b, and Cdc34) are able to ubiquitinate p27 via an intra-molecular reaction in this system. Although the first ubiquitination of p27 (p27-Ub) by Cdc34 is less efficient than that of UbcH5b and hHR6b, the additional ubiquitin attachment to p27-Ub by Cdc34 is highly efficient. The E2 core of Cdc34 provides specificity to p27, and the residues 184-196 are required for possessive ubiquitination by Cdc34. We demonstrate direct E2 specificity for p27 and also show that differential ubiquitin linkages can be dependent on E2 alone.

• Nutrition Research and Practice
• /
• v.14 no.2
• /
• pp.109-116
• /
• 2020

BACKGROUND/OBJECTIVES: Excessive intake of simple sugars induces obesity and increases the risk of inflammation. Thus, interest in alternative sweeteners as a sugar substitute is increasing. The purpose of this study was to determine the effect of saccharin on inflammation in 3T3-L1 adipocytes. MATERIALS/METHODS: 3T3-L1 preadipocytes were differentiated into adipocytes. The adipocytes were treated with saccharin (0, 50, 100, and 200 ㎍/mL) for 24 h. Inflammation was induced by exposure of treated adipocytes to lipopolysaccharide (LPS) for 18 h and cell proliferation was measured. The concentration of nitric oxide (NO) was measured by using Griess reagent. Protein expressions of nuclear factor kappa B (NF-κB) and inhibitor κB (IκB) were determined by western blot analysis. The mRNA expressions of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), interleukin 1β (IL-1β), interleukin 6 (IL-6), monocyte chemoattractant protein-1 (MCP-1), and tumor necrosis factor-α (TNF-α) were determined by real-time PCR. RESULTS: Compared with the control group, the amount of NO and the mRNA expression of iNOS in the LPS-treated group were increased by about 17.6% and 46.9%, respectively, (P < 0.05), and those parameter levels were significantly decreased by saccharin treatment (P < 0.05). Protein expression of NF-κB was decreased and that of IκB was increased by saccharin treatment (P < 0.05). Saccharin decreased the mRNA expression of COX-2 and the inflammation cytokines (IL-1β, IL-6, MCP-1, and TNF-α) (P < 0.05). CONCLUSIONS: The results of this study suggest that saccharin can inhibit LPS-induced inflammatory responses in 3T3-L1 adipocytes via the NF-κB pathway.

• Journal of Nutrition and Health
• /
• v.27 no.9
• /
• pp.923-929
• /
• 1994

The effects of vitamin B6 deficiency on energy utilization during fasting or underfeeding were studied in rats. Fifteen rats were fed a vitamin B6 deficient(-B6) diet and another 15 rats wee fed a control (+B6) diet. These rats were fed for 5 weeks with respective diet, and then subdivided into 3 groups : non-fasted group, fasted group, underfed group. Rats of the fasted group were fasted for 3 days and those of underfed group for 6 days. At the respective time (non-fast, 3 day-fast, 6 day-underfeed at 5 weeks), animals were sacrificed. Feed efficiency ratio of - B6 rats was significantly lower than that of +B6 rats. In - B6 rats, the liver and kidney weights were significantly heavier than those of +B6 rats but spleen and heart weights were not. In non-fasted group, liver protein and triglyceride level of - B6 rats were significantly higher than that of +B6 rats. After - B6 rats were fasted for 3 days, plasma free fatty acid level was significantly lower but liver glycogen level was higher than that of +B6 rats and muscle protein level of +B6 was decreased while that of - B6 was not changed. Vitamin B6 deficiency had little effect on the energy utilization with 6 days underfeeding. These results suggest that vitamin B6 deficiency may impair the utilization of stored fuel during fasting.

• BMB Reports
• /
• v.35 no.3
• /
• pp.337-342
• /
• 2002

Many components that are derived from medicinal or dietary plants possess potential chemopreventive properties. Curcumin, a yellow coloring agent from turmeric (Curcuma longa Linn, Zingiberaceae), possesses strong antimutagenic and anticarcinogenic activities. In this study, we have found that curcumin inhibits the 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced nuclear factor ${\kappa}B$ (NF-${\kappa}B$) activation by preventing the degradation of the inhibitory protein $I{\kappa}B{\alpha}$ and the subsequent translocation of the p65 subunit in cultured human promyelocytic leukemia (HL-60) cells. Alternatively, curcumin repressed the TPA-induced activation of NF-${\kappa}B$ through direct interruption of the binding of NF-${\kappa}B$ to its consensus DNA sequences. Likewise, the TPA-induced DNA binding of the activator protein-1 (AP-1) was inhibited by curcumin pretreatment.

• BMB Reports
• /
• v.35 no.4
• /
• pp.371-376
• /
• 2002

The receptor activator of nuclear factor kappa B (RANK) is a member of the tumor necrosis factor (TNF) receptor superfamily. It plays a critical role in osteoclast differentiaion, lymph node organogenesis, and mammary gland development. The stimulation of RANK causes the activation of transcription factors NF-${\kappa}B$ and activator protein 1 (AP1), and the mitogen activated protein kinase (MAPK) c-Jun N-terminal kinase (JNK). In the signal transduction of RANK, the recruitment of the adaptor molecules, TNF receptor-associated factors (TRAFs), is and initial cytoplasmic event. Recently, the association of the MAPK kinase kinase, transforming growth factor-$\beta$-activated kinase 1 (TAK1), with TRAF6 was shown to mediate the IL-1 signaling to NF-${\kappa}B$ and JNK. We investigated whether or not TAK1 plays a role in RANK signaling. A dominant-negative form of TAK1 was discovered to abolish the RANK-induced activation of AP1 and JNK. The AP1 activation by TRAF2, TRAF5, and TRAF6 was also greatly suppressed by the dominant-negative TAK1. the inhibitory effect of the TAK1 mutant on RANK-and TRAF-induced NF-${\kappa}B$ activation was also observed, but less efficiently. Our findings indicate that TAK1 is involved in the MAPK cascade and NF-${\kappa}B$ pathway that is activated by RANK.

• Korean Journal of Clinical Laboratory Science
• /
• v.52 no.1
• /
• pp.69-77
• /
• 2020

The tumor suppressor gene, p53, is inactivated in the human hepatocellular carcinoma cells line, Hep3B. Berberine has been reported to inhibit the proliferation of cancer cells. This study examined whether apoptosis was induced in berberine-treated Hep3B cells and observed the association between apoptosis and the expression of p53 and DNA methyltransferase (DNMT). The cell viability was measured using an MTT assay. Apoptosis of Hep3B was measured using annexin V flow cytometry. Berberine-treated cells were examined for their DNMT enzymatic activity, mRNA expression, and protein synthesis. The p53 levels were examined by Western blot analysis. The berberine treatment resulted in increased Hep3B cell death and apoptosis in a time- and dose-dependent manner. The DNMT3b activity, mRNA expression, and protein levels all decreased after the berberine treatment. In contrast, the p53 protein levels increased with a concomitant decrease in DNMT3b. No change in the expression of ERK was observed, but the P-ERK levels decreased in a dose dependent manner. These results indicate that a treatment of Hep3B cells with berberine can reduce the expression of DNMT3b, leading to an increase in the tumor suppressant gene p53 and an increase in cell apoptosis. This shows that berberine can effectively suppress the proliferation of liver cancer cells.

• Journal of Korean Neurosurgical Society
• /
• v.49 no.1
• /
• pp.13-19
• /
• 2011

Objective: The purpose of this study is to investigate the combined effects of ginkgo biloba extract, ginkgolide A and B and aspirin on SK-N-MC, human neuroblastoma cell viability and mRNA expression of growth associated protein43 (GAP43), Microtubule-associated protein 2 (MAP2), B-cell lymphoma2 (Bcl2) and protein53 (p53) gene in hypoxia and reperfusion condition. Methods: SK-N-MC cells were cultured with Dulbecco's Modified Eagle's Medium (DMEM) media in $37^{\circ}C$, 5% $CO_2$ incubator. The cells were cultured for 8 hours in non-glucose media and hypoxic condition and for 12 hours in normal media and $O_2$ concentration. Cell survival rate was measured with Cell Counting Kit-8 (CCK-8) reagent assay. Reverse transcriptase polymerase chain reaction (RT-PCR) was used to estimate mRNA levels of GAP43, MAP2, Bcl2, and p53 genes. Results: The ginkgolide A and B increased viable cell number decreased in hypoxic and reperfused condition. The co-treatment of ginkgolide B with aspirin also increased the number of viable cells, however, there was no additive effect. Although there was no increase of mRNA expression of GAP43, MAP2, and Bcl2 in SK-N-MC cells with individual treatment of ginkgolide A, B or aspirin in hypoxic and reperfused condition, the co-treatment of ginkgolide A or B with aspirin significantly increased GAP43 and Bcl2 mRNA levels. In MAP2, only the co-treatment of ginkgolide A and aspirin showed increasing effect. The mRNA expression of p53 had no change in all treating conditions. Conclusion: This study suggests that the combined treatments of Ginkgo biloba extracts and aspirin increase the regeneration of neuroblastoma cells injured by hypoxia and reperfusion.

• Journal of Ginseng Research
• /
• v.38 no.1
• /
• pp.28-33
• /
• 2014

Background: Panax notoginseng has been used as a general tonic agent to invigorate human body for millennia in China and continued to be used until present. Methods: Some chromatographic methods were performed to isolate pure triterpenoids, and their structures were determined by nuclear magnetic resonance (NMR) experiments. Anti-diabetes activities of isolated compounds were evaluated through their inhibitory activity of protein tyrosine phosphatase 1B (PTP1B) enzyme. Results and Conclusion: Three new dammarane-type triterpenoids, notoginsenoside-LX (1), notoginsenoside-LY (2), and notoginsenoside-FZ (3) together with eighteen known compounds were isolated from the Panax notoginseng leaves. The structure-activity relationship of the compounds with dammaranetype triterpenoids and their PTP1B inhibitory activity were also reported. Results showed that compounds 2, 15, 20, and 21 can significantly inhibit the enzyme activity of PTP1B in a dose-dependent manner, with inhibitory concentration 50 ($IC_{50}$) values of $29.08{\mu}M$, $21.27{\mu}M$, $28.12{\mu}M$, and $26.59{\mu}M$, respectively. The results suggested that Panax notoginseng leaves might have potential as a new therapeutic agent for the treatment of diabetes.