• Bulletin of the Korean Chemical Society
• /
• v.14 no.6
• /
• pp.669-673
• /
• 1993

The CO substitution reactions of the complex, $Cp(S-2,4-Me_2C_5H_5)CrCo$ with $PR_3(PR_3=PMePh_2,\;P(OCH_3)_3,\;PMe_2Ph)$ were investigated spectrophotometrically at various temperatures. From the reaction rates, it was suggested that the CO substitution reaction took place by first-order (dissociative) pathway. Activation parameters in decaline were ${\Delta}H^{\neq}\;=\;22.0\;kcal{\cdot}mol^{-1}$, ${\Delta}S^{\neq}=\;-3.8cal{\cdot}mol^{-1}{\cdot}K^{-1}$. Unusually low value of ${\Delta}S{\neq}$ suggests an ${\eta}^5-S{\to}{\eta}^5-U$ conversion of the pentadienyl ligand. This suggestion was confirmed by the Extended-Huckel molecular orbital (EHMO) calculations, which revealed that the total energy of $Cp(S-2,4-Me_2C_5H_5$)CrCO is about 0.42 kcal/mol more lower than that of $Cp(U-2,4-Me_2C_5H_5)CrCO$ and the energy of $[Cp(U-2,4-Me_2C_5H_5)Cr{\cdots}CO]^{\neq} $ transition state is about 2.43 kcal/mol lower than that of $[Cp(S-2,4-Me_2C_5H_5)Cr{\cdots}CO]^{\neq}$ transition state.

• Development and Reproduction
• /
• v.10 no.2
• /
• pp.85-92
• /
• 2006

Progesterone(P4) is an important intermediate in the synthesis of androgens and estrogens. Furthermore, P4 itself plays a crucial role in ovulation, atresia and luteinization, and is essential for the continuation of early pregnancy in all mammalian species. In spite of the hormone's physiological importance, the exact action mechanism(s) of P4 in mammalian ovary has not been fully understood yet. In this context, a decades-long controversy regarding the identity of receptors that mediate non-genomic, transcription-independent cellular responses to P4 is presently attracting huge scientific interests. P4 may exert its action in mammalian ovary by several ways: 1) the well-documented genomic pathway, involving hormone binding to so-called classic cytosolic receptor(PGR) and subsequent modulation of gene expression by the ligand-receptor complex as transcription factor. 2) pathways are operating that do not act on the genome, therefore refered to as non-genomic actions. The prominent characteristics of the non-genomic P4 actions are: (i) rapid, (ii) insensitive to transcription inhibitors, (iii) transduced by membrane associated molecules. In particular, the non-genomic P4 actions could be mediated by: (a) classic genomic P4 receptor(PGR) that localizes at or near the plasma membrane, (b) a family of membrane progestin receptors(MPR $\alpha$, MPR $\beta$ and MPR $\gamma$), (c) progesterone receptor membrane component I(PGRMC1), and (d) a membrane complex composed of serpine I mRNA binding protein(SERBP1). The present review summarized these rapid signaling pathways of P4 in the mammalian ovary.

• Molecular & Cellular Toxicology
• /
• v.4 no.3
• /
• pp.205-210
• /
• 2008

Recent studies suggest that activated microglial cells play an essential role in the inflammatory responses and neurodegenerative disorders such as Alzheimer’s and Parkinson’s disease. This study was conducted to evaluate the protective mechanisms of Asiasarum sieboldi (AS) on LPS-induced activation of BV-2 microglial cells. The effects of AS on gene expression profiles in activated BV-2 microglial cells were evaluated using microarray analysis. BV-2 microglial cells were cultured in a 100 mm dish ($1{\times}10^7$/mL) for 24 h and then pretreated with 1 ${\mu}g$/mL AS or left untreated for 30 min. Next, 1 ${\mu}g$/mL LPS was added to the samples and the cells were reincubated at $37^{\circ}C$ for 30 min and 1 hr. The gene expression profiles of the BV-2 microglial cells varied depending on the AS. The microarray analysis revealed that MAPK signaling pathway-related genes were downregulated in AS-treated BV-2 microglial cells. AS can affect the neuroinflammatory-related pathway such as MAPK signaling pathway in activated BV-2 microglial cells.

• Microbiology and Biotechnology Letters
• /
• v.36 no.4
• /
• pp.353-359
• /
• 2008

Hepatitis C virus (HCV) is known as the causative agent of blood transmitted hepatitis. Two viral proteins, E2 and NS5A, are known to exert interferon resistance of HCV via PKR pathway. Here, we report a third protein, the RNA-dependent RNA polymerase (NS5B) of HCV, induced interferon resistance inhibiting p56 pathway. p56 was shown to interact with p48 subunit of eukaryotic initiation factor 3 (eIF3). This interaction inhibited formation of ternary complex in translation initiation. Using dual reporter assay system, we observed that the translation decreased when interferon alpha was added to the culture. But, in the presence of HCV NS5B, the translation partly recovered. NS5B and p48 subunit of eIF3 were shown to interact. This interaction seems to inhibit the interaction between p48 and p56. This is the first report that a virus exerts interferon resistance via p56 pathway.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2017.06a
• /
• pp.166-166
• /
• 2017

OsTAT encodes a twin-arginine translocator (TAT) pathway signal protein. It contains a TRANS membrane domain and a chloroplast transit peptide. mRNA transcription profiling of OsTAT1 revealed that it is highly overexpressed in the leaves corroborating reports on its role in chloroplast. Moreover, its level of expression is more pronounced during earlier stages (germination, 3-leaf stage, and maximum tillering) of growth in rice. A lower disease progress curve of bacterial blight is evident in transgenic lines compared with the wild type, Dongjin indicating its involvement in immunity to Xoo. Expression pattern following infection of Xoo strain K2 depicts highest levels at 4 and 8 hour post-inoculation which implies crucial induction of resistance during early response. This study initially reports a new overview on the biological functions of plant's TAT pathway. Further molecular and genetic analyses are underway to provide detailed involvement of OsTAT in disease resistance.

• Journal of Microbiology and Biotechnology
• /
• v.16 no.4
• /
• pp.543-549
• /
• 2006

DNA microarray was used to study the transcription profiling of Escherichia coli adapting to acetate as a sole carbon source. Bacteria grown in glucose minimal media were used as a reference. The dynamic expression levels of 3,497 genes were monitored at seven time points during this adaptation. Among the central metabolic genes, the glycolytic and glucose phosphotransferase genes were repressed as the bacteria entered stationary phase, whereas the glyoxylate pathway, TCA cycle, and gluconeogenic genes were induced. Distinct induction or repression patterns were recognized among different pathway genes. For example, the repression of glycolytic genes and the induction of gluconeogenic ones started immediately after glucose was depleted. On the other hand, the regulation of the pentose phosphate pathway genes and glyoxylate genes gradually responded to the glucose depletion or was more related to growth in acetate. When the whole genome was considered, many of the CRP, FadR, and Cra regulons were immediately responsive to the glucose depletion, whereas the $\sigma^s$, Lrp, and IHF regulons were gradually responsive to the glucose depletion. The expression profiling also provided differential regulations between isoenzymes; for example, malic enzymes A (sfcA) and B (maeB). The expression profiles of three genes were confirmed with RT-PCR.

• Biomolecules & Therapeutics
• /
• v.30 no.5
• /
• pp.435-446
• /
• 2022

The present study evaluated the anti-cancer activity of histone deacetylase (HDAC)-inhibiting CKD-581 in multiple myeloma (MM) and its pharmacological mechanisms. CKD-581 potently inhibited a broad spectrum of HDAC isozymes. It concentration-dependently inhibited proliferation of hematologic cancer cells including MM (MM.1S and RPMI8226) and T cell lymphoma (HH and MJ). It increased the expression of the dishevelled binding antagonist of β-catenin 3 (DACT3) in T cell lymphoma and MM cells, and decreased the expression of c-Myc and β-catenin in MM cells. Additionally, it enhanced phosphorylated p53, p21, cleaved caspase-3 and the subG1 population, and reversely, downregulated cyclin D1, CDK4 and the anti-apoptotic BCL-2 family. Finally, administration of CKD-581 exerted a significant anti-cancer activity in MM.1S-implanted xenografts. Overall, CKD-581 shows anticancer activity via inhibition of the Wnt/β-catenin signaling pathway in hematologic malignancies. This finding is evidence of the therapeutic potential and rationale of CKD-581 for treatment of MM.

• Food Science of Animal Resources
• /
• v.44 no.4
• /
• pp.885-898
• /
• 2024

Ovomucin (OM), which has insoluble fractions is a viscous glycoprotein, found in egg albumin. Enzymatic hydrolysates of OM have water solubility and bioactive properties. This study investigated that the immunostimulatory effects of OM hydrolysates (OMHs) obtained by using various proteolytic enzymes (Alcalase^®, bromelain, α-chymotrypsin, Neutrase^®, pancreatin, papain, Protamax^®, and trypsin) in RAW 264.7 cells. The results showed that OMH prepared with pancreatin (OMPA) produced the highest levels of nitrite oxide in RAW 264.7 cells, through upregulation of inducible nitric oxide synthase mRNA expression. The production of pro-inflammatory cytokines such as tumor necrosis factor-α and interleukin-6 were increased with the cytokines mRNA expression. The effect of OMPA on mitogen-activated protein kinase signaling pathway was increased the phosphorylation of p38, c-Jun NH2-terminal kinase, and extracellular signal-regulated kinase in a concentration-dependent manner. Therefore, OMPA could be used as a potential immune-stimulating agent in the functional food industry.

• The Plant Pathology Journal
• /
• v.30 no.3
• /
• pp.269-278
• /
• 2014

Remorins, a family of plant-specific proteins containing a variable N-terminal region and conserved C-terminal domain, play a role in various biotic and abiotic stresses, including host-microbe interactions. However, their functions remain to be completely elucidated, especially for the Arabidopsis thaliana remorin group 4 (AtREM4). To elucidate the role of remorins in Arabidopsis, we first showed that AtREM4s have typical molecular characteristics of the remorins, such as induction by various types of biotic and abiotic stresses, localization in plasma membrane and homo- and hetero-oligomeric interaction. Next, we showed that their loss-of-function mutants displayed reduced susceptibility to geminiviruses, Beet Curly Top Virus and Beet Severe Curly Top Virus, while overexpressors enhanced susceptibility. Moreover, we found that they interacted with SnRK1, which phosphorylated AtREM4.1, and were degraded by the 26S proteasome pathway. These results suggest that AtREM4s may be involved in the SnRK1-mediated signaling pathway and play a role as positive regulators of the cell cycle during geminivirus infection.

• Journal of Life Science
• /
• v.25 no.2
• /
• pp.223-230
• /
• 2015

Regulator of calcineurin 1 (RCAN1) is an endogenous calcineurin inhibitor that plays an important role in the pathogenesis of diseases related to the calcineurin-NFATc1 signaling pathway. The RCAN1-4 isoform is subject to NFATc1-dependent regulation. During receptor activator of nuclear factor kappa-B ligand (RANKL)-stimulated osteoclastogenesis, the calcineurin-NFATc1 pathway is critical. Because there is little information available on the role of RCAN1 in osteoclast differentiation, this study investigated whether changes in RCAN1 expression are related to the calcineurin-NFATc1 pathway and osteoclast differentiation. Mouse bone marrow monocytes (BMMs) were treated with 50 ng/ml of RANKL and M-CSF. Expression levels of NFATc1, calcineurin, and RCAN1 isoforms were determined using RT-PCR and Western blotting. Osteoclast differentiation was examined using tartrate-resistent acid phosphatase (TRAP) staining. To evaluate the effect of RCAN1 overexpression on osteoclastogenesis, cells were transfected with a mouse RCAN1-4 cDNA plasmid. After RANKL stimulation of BMMs, expression of NFATc1 and RCAN1 was increased at the mRNA and protein level, while calcineurin expression was unchanged. When the RCAN1-4 gene construct was transfected, the expression of RCAN1 protein was not increased despite several-fold increases in RCAN1-4 mRNA expression. Regardless of RANKL stimulation, over-expression of RCAN1-4 tended to reduce NFATc1 expression and knock-down of RCAN1 increase it. While BMMs transfected with the RCAN1-4 vector were differentiated into distinct osteoclasts, their phenotypes did not vary from those of mock controls. These results suggest that RCAN1 has a limited effect on the calcineurin-NFATc1 pathway during RANKL-stimulated osteoclast differentiation.