• 제목/요약/키워드: metabolic regulation

검색결과 386건 처리시간 0.021초

Regulation of Gene Expression for Amino Acid Biosynthesis in the Yeast, Sacchromyces cerevisiae

  • Lea, Ho Zoo
    • 한국동물학회:학술대회논문집
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    • 한국동물학회 1995년도 한국생물과학협회 학술발표대회
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    • pp.82-82
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    • 1995
  • Regulation of enzyme synthesis by transcriptional and translational control systems provides rather stable adaptation to change of amino acid level in the growth medium, while manipulation of enzyme activity through endproduct feedback inhibition represents rather short-term and reversible ways of adjusting metabolic fluctuation of amino acid level. Various control mechanisms interplay to regulate genes encoding enzymes for amino acid biosynthesis in the yeast, Sacchromyces cerevisiae. When amino acids are in short supply, genes under a cross-pathway regulatory mechanism Or general amino acid control (general control) increase their action, in which Gcn4p is the major positive regulator of gene expression. When cells are cultured in minimal medium, basal level expression is also regulated by supplementary control elements, where inorganic phosphate level is additionally involved. Most of amino acid biosynthetic genes are also regulated by the level of endproduct of the pathway. This pathway-specific regulatory mechanism is called specific amino acid control (specific controD, under which gene expression is reduced when endproduct is present in the medium. Derepression of a gene through general control can be usually overridden by repression through specific control, where the endproduct level of that particular pathway is high and not limiting. In this presentation, regulatory factors for basal level expression and general control of yeast amino acid biosynthesis will be discussed, m addition to pathway-specific repression patterns and interaction between CrOSS- and specific-control mechanisms. Preliminary results are also presented from the investigation of the cloned genes in the threonine biosynthetic pathway of the yeast. yeast.

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젖소에서 epinephrine 및 insulin에 의한 대사 조절 (Roles of Epinephrine and Insulin in the Regulation of Metabolism in Dairy Cow)

  • 김진욱
    • 농업생명과학연구
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    • 제43권4호
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    • pp.15-20
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    • 2009
  • 젖소의 분만 전후기는 일반적으로 전환기라고 칭하며 분만후 유생산을 준비하기 위해 동물체내 대사 및 생리적 상태가 급격히 변화하는 시기라 할 수 있다. 젖소는 이 시기에 간조직에서 당신합성을 통해 유당합성을 위한 glucose의 생산을 촉진하고, 지방조직에서는 분만 전부터 지질을 축적하고 비유개시에 맞추어 혈중 NEFA (nonesterified fatty acid)의 농도를 증가시켜 유지방 합성을 준비 한다. 이러한 대사조절에 epinephrine 및 insulin이 조절 호르몬으로 작용하여 유생산을 위한 탄수화물 및 지질대사를 변화시키고 사료 섭취량의 부족에 기인한 전체 에너지의 감소를 체내 영양소의 재분배로 충족시킨다.

Development and Functions of Alveolar Macrophages

  • Woo, Yeon Duk;Jeong, Dongjin;Chung, Doo Hyun
    • Molecules and Cells
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    • 제44권5호
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    • pp.292-300
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    • 2021
  • Macrophages residing in various tissue types are unique in terms of their anatomical locations, ontogenies, developmental pathways, gene expression patterns, and immunological functions. Alveolar macrophages (AMs) reside in the alveolar lumen of the lungs and serve as the first line of defense for the respiratory tract. The immunological functions of AMs are implicated in the pathogenesis of various pulmonary diseases such as allergic asthma, chronic obstructive pulmonary disorder (COPD), pulmonary alveolar proteinosis (PAP), viral infection, and bacterial infection. Thus, the molecular mechanisms driving the development and function of AMs have been extensively investigated. In this review article, we discuss the roles of granulocyte-macrophage colony-stimulating factor (GM-CSF) and transforming growth factor (TGF)-β in AM development, and provide an overview of the anti-inflammatory and pro-inflammatory functions of AMs in various contexts. Notably, we examine the relationships between the metabolic status of AMs and their development processes and functions. We hope that this review will provide new information and insight into AM development and function.

착상전 초기 배아에서 탄수화물 대사와 그 대사물의 역할 (Carbohydrate Metabolism in Preimplantation Stage Embryos and the Role of Metabolites)

  • 전용필
    • 한국발생생물학회지:발생과생식
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    • 제12권1호
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    • pp.19-30
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    • 2008
  • 수정란이 포배로 분화하는 것은 착상을 통하여 개체 발생이 성립되는 포유동물의 발생에 있어서 핵심적인 현상이다.. 초기 배아 발생 시기동안 배아는 생존을 위한 에너지원을 공급받아야 한다. 포유동물의 난자는 보통의 경우 난자 형성 동안 많은 양의 에니지원을 세포질에 비축하지 않기 때문에 발생 동안 수란관과 자궁으로부터 물질대사와 관련돼 여러 물질, 특히 에너지원을 획득해야 한다. 탄수화물은 착상전 배아의 주 에너지원으로 알려져 있다. 포도당, 젖산염, 피르브산염은 착상 전배아 배양액에서 없어서는 않될 성분으로, 초기 배아는 그 발생 단계에 따라 이들 물질에 대한 선호도를 각기 다르게 갖고 있다. 포도당수송체(glucose transporter)와 수소이온-단당류 동향수송체($H^+$-monocarboxylate cotransporter)는 탄수화물을 수송하는 주된 매개자로 이들의 발현 수준은 일차적으로 내인성 또는 인슐린이나 포도당과 같은 외인성 요인에 동시적으로 조절을 받는다. 비록 1960년대 이후 화학적으로 규명된 BWW와 같은 배양액을 이용하여 수정란이 성공적으로 포배로 발생되고 이식 후 정상적인 새끼가 태어났어도, 발생조절에 있어서 이들 탄수화물 물질대사 산물의 역할은 잘 알려져 있지 않다. 포도당은 밀착이 진행되는 상실배에서 물질대사 관련 효소와 수송체의 발현을 조절하고, 포배강 형성에 필요로 하는 에너지를 생산하는데 관련된 것으로 인식되고 있다. 다른 한편으로 cytokine은 배아에서 탄수화물의 대사율, 그리고 물질대사율 조절을 통하여 배아 발생을 조절할 수 있는 것으로 제안되어 왔다. 또한, 근래 들어 본인 등은 젖산염이 착상 전 배아의 발생을 조절할 수 있는 물질임을 밝히고 있다. 이러한 결과들은 탄수화물의 물질대사물이 초기 배아 시기에 에너지원으로서 뿐만이 아니라 생합성 경로 및 다른 조절경로에 참여하고 있음을 의미한다. 따라서 초기 배아 발생 동안 탄수화물 대사와 대사물질은 에너지원으로서 뿐만이 아니라 수정란이 착상할 수 있는 능력을 갖춘 포배로 발생하는 것을 조절하는 조절물질로 그 중요성이 있다.

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Carbon Source-Dependent Regulation of the Schizosaccharomyces pombe pbh1 Gene

  • Kim, Su-Jung;Cho, Nam-Chul;Ryu, In-Wang;Kim, Kyung-Hoon;Park, Eun-Hee;Lim, Chang-Jin
    • Journal of Microbiology
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    • 제44권6호
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    • pp.689-693
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    • 2006
  • Pbh1, from the fission yeast Schizosaccharomyces pombe, is a baculoviral inhibitor of apoptosis (IAP) repeat (BIR) domain-containing protein. Its unique encoding gene was previously found to be regulated by nitric oxide and nitrogen starvation. In the current work, the Pbh1-lacZ fusion gene was used to elucidate the transcriptional regulation of the pbh1 gene under various carbon sources. When fermentable carbon sources, such as glucose (at a low concentration of 0.2 %), sucrose (2.0 %) and lactose (2.0 %), were the sole carbon source, the synthesis of $\beta$-galactosidase from the Pbh1-lacZ fusion gene was reasonably enhanced. However, the induction by these fermentable carbon sources was abolished in the Pap1-negative S. pombe cells, implying that this type of induction of the pbh1 gene is mediated by Pap1. Ethanol (2.0%), a nonfermentable carbon source, was also able to enhance the synthesis of $\beta$-galactosidase from the fusion gene in wild-type cells but not in Pap1-negative cells. The results indicate that the S. pombe pbh1 gene is up-regulated under metabolic oxidative stress in a Pap1-dependent manner.

Dynamic Behavior of Regulatory Elements in the Hierarchical Regulatory Network of Various Carbon Sources-Grown Escherichia coli

  • Lee, Sung-Gun;Hwang, Kyu-Suk;Kim, Cheol-Min
    • Journal of Microbiology and Biotechnology
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    • 제15권3호
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    • pp.551-559
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    • 2005
  • The recent rapid increase in genomic data related to many microorganisms and the development of computational tools to accurately analyze large amounts of data have enabled us to design several kinds of simulation approaches for the complex behaviors of cells. Among these approaches, dFBA (dynamic flux balance analysis), which utilizes FBA, differential equations, and regulatory events, has correctly predicted cellular behaviors under given environmental conditions. However, until now, dFBA has centered on substrate concentration, cell growth, and gene on/off, but a detailed hierarchical structure of a regulatory network has not been taken into account. The use of Boolean rules for regulatory events in dFBA has limited the representation of interactions between specific regulatory proteins and genes and the whole transcriptional regulation mechanism with environmental change. In this paper, we adopted the operon as the basic structure, constructed a hierarchical structure for a regulatory network with defined fundamental symbols, and introduced a weight between symbols in order to solve the above problems. Finally, the total control mechanism of regulatory elements (operons, genes, effectors, etc.) with time was simulated through the linkage of dFBA with regulatory network modeling. The lac operon, trp operon, and tna operon in the central metabolic network of E. coli were chosen as the basic models for control patterns. The suggested modeling method in this study can be adopted as a basic framework to describe other transcriptional regulations, and provide biologists and engineers with useful information on transcriptional regulation mechanisms under extracellular environmental change.

Low pH stress responsive transcriptome of seedling roots in wheat (Triticum aestivum L.)

  • Hu, Haiyan;He, Jie;Zhao, Junjie;Ou, Xingqi;Li, Hongmin;Ru, Zhengang
    • Genes and Genomics
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    • 제40권11호
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    • pp.1199-1211
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    • 2018
  • Soil acidification is one of major problems limiting crop growth and especially becoming increasingly serious in China owing to excessive use of nitrogen fertilizer. Only the STOP1 of Arabidopsis was identified clearly sensitive to proton rhizotoxicity and the molecular mechanism for proton toxicity tolerance of plants is still poorly understood. The main objective of this study was to investigate the transcriptomic change in plants under the low pH stress. The low pH as a single factor was employed to induce the response of the wheat seedling roots. Wheat cDNA microarray was used to identify differentially expressed genes (DEGs). A total of 1057 DEGs were identified, of which 761 genes were up-regulated and 296 were down-regulated. The greater percentage of up-regulated genes involved in developmental processes, immune system processes, multi-organism processes, positive regulation of biological processes and metabolic processes of the biological processes. The more proportion of down-regulation genes belong to the molecular function category including transporter activity, antioxidant activity and molecular transducer activity and to the extracellular region of the cellular components category. Moreover, most genes among 41 genes involved in ion binding, 17 WAKY transcription factor genes and 17 genes related to transport activity were up-regulated. KEGG analysis showed that the jasmonate signal transduction and flavonoid biosynthesis might play important roles in response to the low pH stress in wheat seedling roots. Based on the data, it is can be deduced that WRKY transcription factors might play a critical role in the transcriptional regulation, and the alkalifying of the rhizosphere might be the earliest response process to low pH stress in wheat seedling roots. These results provide a basis to reveal the molecular mechanism of proton toxicity tolerance in plants.

Physiologic and epigenetic effects of nutrients on disease pathways

  • Soo-Hyun Park;Jaein Lee;Jin-Taek Hwang;Min-Yu Chung
    • Nutrition Research and Practice
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    • 제17권1호
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    • pp.13-31
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    • 2023
  • BACKGROUND/OBJECTIVES: Epigenetic regulation by nutrients can influence the development of specific diseases. This study sought to examine the effect of individual nutrients and nutrient families in the context of preventing chronic metabolic diseases via epigenetic regulation. The inhibition of lipid accumulation and inflammation by nutrients including proteins, lipids, vitamins, and minerals were observed, and histone acetylation by histone acetyltransferase (HAT) was measured. Correlative analyses were also performed. MATERIALS/METHODS: Nutrients were selected according to information from the Korean Ministry of Food and Drug Safety. Selected nutrient functionalities, including the attenuation of fatty acid-induced lipid accumulation and lipopolysaccharide-mediated acute inflammation were evaluated in mouse macrophage Raw264.7 and mouse hepatocyte AML-12 cells. Effects of the selected nutrients on in vitro HAT inhibition were also evaluated. RESULTS: Nitric oxide (NO) production correlated with HAT activity, which was regulated by the amino acids group, suggesting that amino acids potentially contribute to the attenuation of NO production via the inhibition of HAT activity. Unsaturated fatty acids tended to attenuate inflammation by inhibiting NO production, which may be attributable to the inhibition of in vitro HAT activity. In contrast to water-soluble vitamins, the lipid-soluble vitamins significantly decreased NO production. Water- and lipid-soluble vitamins both exhibited significant inhibitory activities against HAT. In addition, calcium and manganese significantly inhibited lipid accumulation, NO production, and HAT activity. CONCLUSIONS: Several candidate nutrients and their family members may have roles in the prevention of diseases, including hepatic steatosis and inflammation-related diseases (i.e., nonalcoholic steatohepatitis) via epigenetic regulation. Further studies are warranted to determine which specific amino acids, unsaturated fatty acids and lipid-soluble vitamins or specific minerals influence the development of steatosis and inflammatory-related diseases.

비만 환경 내 면역세포 활성화 표현형의 변화 (Phenotype Changes in Immune Cell Activation in Obesity)

  • 박주휘;남주옥
    • 생명과학회지
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    • 제33권3호
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    • pp.295-303
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    • 2023
  • 면역 체계와 대사 체계는 항상성을 유지하는데 중요한 요소이다. 면역 반응과 대사 조절은 연관성이 높아, 정상적인 대사가 교란되면 대사 질환이 발생하며, 면역 반응에도 변화가 발생하였다. 마찬가지로, 비만은 면역 반응과 높은 관련이 있다. 에너지 대사의 불균형으로 발생하는 비만은 인슐린 저항성, 제2형 당뇨병, 지방간 질환, 동맥경화증, 고혈압 등의 대사 질환과 관련이 있다. 알려진 바로는, 비만은 낮은 수준의 염증이 만성화된 상태가 특징이다. 비만 환경에서, 면역세포의 미세 환경은 대식세포, 자연살해세포, T세포 같은 면역세포의 독특한 활성화 표현형에 의해 염증성이 되었다. 또한, 면역 세포는 세포 간의 기전, 사이토카인을 매개하는 기전을 통해 상호작용하여 비만으로 인한 염증 반응을 강화한다. 이러한 현상은 기존의 췌장 리파아제나 알파-아밀라아제 같은 체내 효소의 억제나 지방전구세포의 분화를 억제를 표적으로 하는 일반적인 비만의 약리학적 치료 외에 면역세포 활성화 조절을 표적으로 하는 비만의 약리학적 치료 전략을 시사한다. 본 논문에서는 대식세포, 자연살해세포, T세포의 활성화 표현형과 비만 환경 내이들의 양상에 대해 정리하였다. 또한, 본 논문에서는 현재까지 확인된 면역세포의 활성화 조절을 통한 비만을 완화하는 약리학적 물질에 대해서 정리하였다.

Insulin Receptor Substrate Proteins and Diabetes

  • Lee Yong Hee;White Morris F.
    • Archives of Pharmacal Research
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    • 제27권4호
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    • pp.361-370
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    • 2004
  • The discovery of insulin receptor substrate (IRS) proteins and their role to link cell surface receptors to the intracellular signaling cascades is a key step to understanding insulin and insulin-like growth factor (IGF) action. Moreover, IRS-proteins coordinate signals from the insulin and IGF receptor tyrosine kinases with those generated by proinflammatory cytokines and nutrients. The IRS2-branch of the insulin/IGF signaling cascade has an important role in both peripheral insulin response and pancreatic $\beta$-cell growth and function. Dysregulation of IRS2 signaling in mice causes the failure of compensatory hyperinsulinemia during peripheral insulin resistance. IRS protein signaling is down regulated by serine phosphorylation or protea-some-mediated degradation, which might be an important mechanism of insulin resistance during acute injury and infection, or chronic stress associated with aging or obesity. Under-standing the regulation and signaling by IRS1 and IRS2 in cell growth, metabolism and survival will reveal new strategies to prevent or cure diabetes and other metabolic diseases.