• Title/Summary/Keyword: Cellular metabolism

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A new function of glucocorticoid receptor: regulation of mRNA stability

  • Park, Ok Hyun;Do, Eunjin;Kim, Yoon Ki
    • BMB Reports
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    • v.48 no.7
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    • pp.367-368
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    • 2015
  • It has long been thought that glucocorticoid receptor (GR) functions as a DNA-binding transcription factor in response to its ligand (a glucocorticoid) and thus regulates various cellular and physiological processes. It is also known that GR can bind not only to DNA but also to mRNA; this observation points to the possible role of GR in mRNA metabolism. Recent data revealed a molecular mechanism by which binding of GR to target mRNA elicits rapid mRNA degradation. GR binds to specific RNA sequences regardless of the presence of a ligand. In the presence of a ligand, however, the mRNA-associated GR can recruit PNRC2 and UPF1, both of which are specific factors involved in nonsense-mediated mRNA decay (NMD). PNRC2 then recruits the decapping complex, consequently promoting mRNA degradation. This mode of mRNA decay is termed "GR-mediated mRNA decay" (GMD). Further research demonstrated that GMD plays a critical role in chemotaxis of immune cells by targeting CCL2 mRNA. All these observations provide molecular insights into a previously unappreciated function of GR in posttranscriptional regulation of gene expression. [BMB Reports 2015; 48(7): 367-368]

The gene encoding guanidinoacetate methyltransferase (GAMT) maps to mouse chromosome 10 near the locus of hesitant mutation affecting male fertility

  • Chae, Young-Jin;Chung, Chan-Ee;Kim, Byung-Jin;Lee, Mun-Han;Lee, Hang
    • Proceedings of the Korean Society of Developmental Biology Conference
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    • 1998.07a
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    • pp.50-51
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    • 1998
  • guanidinoacetate methyltransferase (GAMT) catalyzes the last step of creatine biosynthesis in mammals. Creatine plays an important role in cellular energy metabolism in variety of tissues including brain and male reproductive tract. Congenital deficiency of the enzyme leads to a neurologic disorder in humans. We used an interspecific backcross DNA panel to map Gamt to the central region of mouse Chromosome (Chr) 10 near the locus of hesitant mutation affecting male fertility. We assigned the human GAMT gene to Chr 19 by PCR analysis of a human/rodent somatic hybrid cell line DNA panel, and further localized the human gene to Chr 19 at band p13.3 by PCR analysis of a human radiation hybrid DNA panel. Human chr 19p13.3 is homologous to the central part of mouse Chr 10 where mouse Gamt is located. Furthermore, this part of mouse Chr 10 contains mutant loci the phenotype of which is similar to the GAMT deficiency in human.

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Human Glutathione S-Transferase P1 Suppresses MEKK1-mediated Apoptosis by Regulating MEKK1 Kinase Activity in HEK293 Cells

  • Zhao, Xin;Fan, Yumei;Shen, Jiayin;Wu, Yifan;Yin, Zhimin
    • Molecules and Cells
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    • v.21 no.3
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    • pp.395-400
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    • 2006
  • Glutathione S-transferase P1 (GSTP1) plays an important role in detoxification and the metabolism of xenobiotics. Here we show that GSTP1 also regulates the MEKK1-MKK7 signaling pathway. Over-expression of GSTP1 in HEK293 cells inhibited both ${\Delta}MEKK1$- and etoposide-induced apoptosis, and inhibited procaspase-3 activation and PARP cleavage. MEKK1- induced apoptosis requires both its kinase activity and proteolytic cleavage. ${\Delta}MEKK1$ activity was inhibited by over-expression of GSTP1 in vivo and MEKK1 kinase activity was also inhibited by GSTP1 in vitro when assayed with bacterially-expressed MKK7(KM) protein as substrate. GSTP1 inhibition of etoposide-induced cell apoptosis was mainly due to its ability to suppress MEKK1 kinase activity. The glutathione-conjugating activity of GSTP1 was essential for the above effects. These findings provide insight into the mechanism by which GSTP1 protects cells from genotoxin-induced apoptosis.

Estrogen Receptor α Regulates Dlx3-Mediated Osteoblast Differentiation

  • Lee, Sung Ho;Oh, Kyo-Nyeo;Han, Younho;Choi, You Hee;Lee, Kwang-Youl
    • Molecules and Cells
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    • v.39 no.2
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    • pp.156-162
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    • 2016
  • Estrogen receptor ${\alpha}$ (ER-${\alpha}$), which is involved in bone metabolism and breast cancer, has been shown to have transcriptional targets. Dlx3 is essential for the skeletal development and plays an important role in osteoblast differentiation. Various osteogenic stimulators and transcription factors can induce the protein expression of Dlx3. However, the regulatory function of ER-${\alpha}$ in the Dlx3 mediated osteogenic process remains unknown. Therefore, we investigated the regulation of Dlx3 and found that ER-${\alpha}$ is a positive regulator of Dlx3 transcription in BMP2-induced osteoblast differentiation. We also found that ER-${\alpha}$ interacts with Dlx3 and increases its transcriptional activity and DNA binding affinity. Furthermore, we demonstrated that the regulation of Dlx3 activity by ER-${\alpha}$ is independent of the ligand (estradiol) binding domain. These results indicate that Dlx3 is a novel target of ER-${\alpha}$, and that ER-${\alpha}$ regulates the osteoblast differentiation through modulation of Dlx3 expression and/or interaction with Dlx3.

Autophagy in Ischemic Livers: A Critical Role of Sirtuin 1/Mitofusin 2 Axis in Autophagy Induction

  • Chun, Sung Kook;Go, Kristina;Yang, Ming-Jim;Zendejas, Ivan;Behrns, Kevin E.;Kim, Jae-Sung
    • Toxicological Research
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    • v.32 no.1
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    • pp.35-46
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    • 2016
  • No-flow ischemia occurs during cardiac arrest, hemorrhagic shock, liver resection and transplantation. Recovery of blood flow and normal physiological pH, however, irreversibly injures the liver and other tissues. Although the liver has the powerful machinery for mitochondrial quality control, a process called mitophagy, mitochondrial dysfunction and subsequent cell death occur after reperfusion. Growing evidence indicates that reperfusion impairs mitophagy, leading to mitochondrial dysfunction, defective oxidative phosphorylation, accumulation of toxic metabolites, energy loss and ultimately cell death. The importance of acetylation/deacetylation cycle in the mitochondria and mitophagy has recently gained attention. Emerging data suggest that sirtuins, enzymes deacetylating a variety of target proteins in cellular metabolism, survival and longevity, may also act as an autophagy modulator. This review highlights recent advances of our understanding of a mechanistic correlation between sirtuin 1, mitophagy and ischemic liver injury.

비허(脾虛)(기허(氣虛).양허(陽虛))증(證)에 관(關)한 문헌적(文獻的) 고찰(考察)

  • Yun, Sang-Hyeop;Ryu, Bong-Ha;Park, Dong-Won;Jang, In-Gyu;Ryu, Gi-Won
    • The Journal of Internal Korean Medicine
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    • v.10 no.1
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    • pp.53-64
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    • 1989
  • In an attempt to investigate the current of clinical researches on spleen yang or vital energy deficiency syndrome, the results were as follows. 1. It is possible to occure spleen deficiency syndrome which come from genetic factor. 2. The absorption disturbance in spleen deficiency syndrome can be likely caused by gastrointestinal mucosa injury, disorder of vagus nerve funtion and impairment of excretion of exocrine gland in pancreas. 3. Owing to the failure of tansporting and converting funtion of spleen, minerals, hematogenic substance and nutritional substance are scanty and then imbalanced metabolism state which heat production is decreasing is appeared. 4. By the failure of vital energy and blood growth, decreasement of $O_2$ transportation ability of RBC, disoder of blood coagulation, immune system disturbance which humoral immunity is enhanced and cellular immunity is decreased, are noted. 5. While there is not still an attemt to study the spleen deficiency sydrome in muscle disease or disease of four extremities, but it is likely suggested that spleen-stomach supplyment thereapy is very excellent effect on muscle disease and disease of four extremities.

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Determination of the MYB Motif Interacting with WD40 and Basic Helix Loop Helix Proteins

  • Kim, Ji-Hye;Kim, Bong-Gyu;Ahn, Joong-Hoon
    • Journal of Applied Biological Chemistry
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    • v.55 no.1
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    • pp.67-70
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    • 2012
  • Plant MYB transcription factors regulate secondary metabolism, cellular morphogenesis, and plant hormone signaling pathway. MYB proteins in plants consist of two repeats of 50 amino acid residues, which are referred to as R2R3 and they interact with WD40 or basic helix loop helix (bHLH) proteins. Yeast two hybrid assay was determined whether rice MYB protein interacts with either OsTTG1, which contains a WD40 domain, or with OsGL3, which contains a bHLH domain. Among 30 OsMYB proteins, three interacted with OsTTG1 and five interacted with OsGL3. A series of MYB mutants were created to determine the MYB domain important for the interaction with OsTTG1 or OsGL3. By using the yeast two hybrid assay, we found that the R3 motif of OsMYB10 and the R2 motif of OsMYB16 were required for interaction with OsTTG1 and OsGL3 proteins, respectively.

The Oxidative Modification of COL6A1 in Membrane Proteins of Ovarian Cancer Patients

  • Yang, Hee-Young;Lee, Tae-Hoon
    • Reproductive and Developmental Biology
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    • v.36 no.1
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    • pp.39-47
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    • 2012
  • Ovarian cancer is the most lethal gynecological malignancy, and specific biomarkers are important needed to improve diagnosis, prognosis, and to forecast and monitor treatment efficiency. There are a lot of pathological factors, including reactive oxygen species (ROS), involved in the process of cancer initiation and progression. The oxidative modification of proteins by ROS is implicated in the etiology or progression of disorders and diseases. In this study, a labeling experiment with the thiol-modifying reagent biotinylated iodoacetamide (BIAM) revealed that a variety of proteins were differentially oxidized between normal and tumor tissues of ovarian cancer patients. To identify cysteine oxidation-sensitive proteins in ovarian cancer patients, we performed comparative analysis by nano-UPLC-$MS^E$ shotgun proteomics. We found oxidation-sensitive 22 proteins from 41 peptides containing cysteine oxidation. Using Ingenuity program, these proteins identified were established with canonical network related to cytoskeletal network, cellular organization and maintenance, and metabolism. Among oxidation-sensitive proteins, the modification pattern of Collagen alpha-1(VI) chain (COL6A1) was firstly confirmed between normal and tumor tissues of patients by 2-DE western blotting. This result suggested that COL6A1 might have cysteine oxidative modification in tumor tissue of ovarian cancer patients.

Hydrogen Peroxide Induces Apoptosis of BJAB Cells Due to Formation of Hydroxyl Radicals Via Intracellular Iron-mediated Fenton Chemistry in Glucose Oxidase-mediated Oxidative Stress

  • Lee, Jeong-Chae;Son, Young-Ok;Choi, Ki-Choon;Jang, Yong-Suk
    • Molecules and Cells
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    • v.22 no.1
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    • pp.21-29
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    • 2006
  • The aim of this study was to determine if hydrogen peroxide ($H_2O_2$) generated by glucose oxidase (GO) induces apoptosis or necrosis of BJAB cells and which radical is the direct mediator of cell death. We found that GO produced $H_2O_2$ continuously in low concentrations, similar to in vivo conditions, and decreased proliferation and cell viability in a dose-dependent manner. The GO-mediated cytotoxicity resulted from apoptosis, and was confirmed by monitoring the cells after H33342/Annexin V/propidium iodide staining. Decreases of mitochondrial membrane potential and intracellular glutathione level were found to be critical events in the $H_2O_2$-mediated apoptosis. Additional experiments revealed that $H_2O_2$ exerted its apoptotic action through the formation of hydroxyl radicals via the Fenton rather than the Haber-Weiss reaction. Moreover, intracellular redox-active iron, but not copper, participated in the $H_2O_2$-mediated apoptosis.

Satellite Cells Isolated from Adult Hanwoo Muscle Can Proliferate and Differentiate into Myoblasts and Adipose-like Cells

  • Kook, Sung-Ho;Choi, Ki-Choon;Son, Young-Ok;Lee, Kyung-Yeol;Hwang, In-Ho;Lee, Hyun-Jeong;Chang, Jong-Soo;Choi, In-Ho;Lee, Jeong-Chae
    • Molecules and Cells
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    • v.22 no.2
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    • pp.239-245
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    • 2006
  • This study examined whether adult bovine muscle satellite cells from 30-month-old Hanwoo cattle are multipotential. The satellite cells were found to have the potential to proliferate and differentiate into myoblasts with the formation of multinucleated cells. In addition, treatment with the peroxisome proliferator activating receptor-${\gamma}$ ($PPAR{\gamma}$) agonist, rosiglitazone, promoted their trans-differentiation into adipocytes with significant increases in glycerol accumulation and glycerol-3-phosphate dehydrogenase activity. Western blot analysis revealed that increased levels of the adipocyte fatty acid-binding protein, $PPAR{\gamma}$ and of CCAAT/enhancerbinding protein were closely related to rosiglitazoneinduced differentiation of the cells. These findings demonstrate that satellite cells from adult Hanwoo cattle are multipotent, and that their trans-differentiation into adipocytes can be induced by rosiglitazone.