• Title/Summary/Keyword: molecular genetics

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Microbial Rhodopsins: Genome-mining, Diversity, and Structure/Function

  • Jung, Kwang-Hwan;Vishwa Trivedi;Yang, Chii-Shen;Oleg A. Sineschekov;Elena N. Spudich;John L. Spudich
    • Journal of Photoscience
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    • v.9 no.3
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    • pp.45-48
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    • 2002
  • Microbial rhodopsins, photoactive 7-transmembrane helix proteins that use retinal as their chromophore, were observed initially in the Archaea and appeared to be restricted to extreme halophilic environments. Our understanding of the abundance and diversity of this family has been radically transformed by findings over the past three years. Genome sequencing of cultivated microbes as well as environmental genomics have unexpectedly revealed archaeal rhodopsin homologs in the other two domains of life as well, namely Bacteria and Eucarya. Organisms containing these homologs inhabit such diverse environments as salt flats, soil, freshwater, and surface and deep ocean waters, and they comprise a broad phylogenetic range of microbial life, including haloarchaea, proteobacteria, cyanobacteria, fungi, and algae. Analysis of the new microbial rhodopsins and their expression and structural and functional characterization reveal that they fulfill both ion transport and sensory functions in various organisms, and use a variety of signaling mechanisms. We have obtained the first crystallographic structure for a photosensory member of this family, the phototaxis receptor sensory rhodopsin II (SRII, also known as phoborhodopsin) that mediates blue-light avoidance by the haloarchaeon Natronobacterium pharaonis. The structure obtained from x-ray diffraction of 3D crystals prepared in a cubic lipid phase reveals key features responsible for its spectral tuning and its sensory function. The mechanism of SRII signaling fits a unified model for transport and signaling in this widespread family of phototransducers.

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Protoplast-Mediated Transformation of the Filamentous Fungus Cladosporium phlei: Evidence of Tandem Repeats of the Integrative Transforming Vector

  • Kim, Jung-Ae;Kim, Jung-Mi;Kim, Hwan-Gyu;Kim, Beom-Tae;Hwang, Ki-Jun;Park, Seung-Moon;Yang, Moon-Sik;Kim, Dae-Hyuk
    • The Plant Pathology Journal
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    • v.25 no.2
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    • pp.179-183
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    • 2009
  • To facilitate the genetic manipulation of Cladosporium phlei, a causal agent of leaf spot disease in timothy (Phleum pretense), protoplast-mediated transformation of C. phlei has been developed and the resulting transformants were characterized in this study. Hygromycin B resistance was applied as a dominant selection marker due to the sensitivity of C. phlei to this antibiotic. The transformation efficiency ranged from approximately 20-100 transformants per experiment. Southern blot analysis of stable transformants revealed that transformation occurred by way of stable integration of the vector DNA into the fungal chromosome. PCR analysis and plasmid rescuing of randomly selected transformants suggested that integration of tandem repeat copies of vector DNA was common. In addition, multiple integrations of the transforming vector at different chromosomal sites were also observed. The establishment of a transformation method for C. phlei facilitates strain improvement of this fungus and can be applied as an initial step in the molecular analysis of pigment production in this fungus.

Cooperative Activity of Subunits of Human Ferritin Heteropolymers in Escherichia coli

  • Lee, Jung;Seo, Hyang-Yun;Jeon, Eun-Soon;Park, Ok-Soon;Lee, Kang-Min;Park, Chung-Ung;Kim, Kyung-Suk
    • BMB Reports
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    • v.34 no.4
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    • pp.365-370
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    • 2001
  • We constructed a comparative expression system in order to produce recombinant human ferritin homo- and heteropolymers in Escherichia coli. Human ferritin H-(hfH) and L-chain (hfL) genes were expressed without amino acid changes under the control of a tac promoter. Ferritin heteropolymers of varying subunit composition were also produced by combining two different expression systems, a bicistronic expression system and a coplasmid expression system. As a result, recombinant H-chain ferritin and ferritin heteropolymers were catalytically active in forming iron core in vivo. In particular, the ferritin heteropolymer that is composed of 7% H-subunit and 93% L-subunit was capable of forming an iron core of the protein, while the L-chain ferritin homopolymer was inactive in vivo. This result indicates that the two H-subunits (i.e., 7% H-subunit content) are important to keep ferritin active in the cells. In addition, human ferritins were identified as the major iron binding proteins in the transformed cells. Also, the amount of iron bound to the recombinant ferritins was proportional to the H-subunit content in ferritin heteropolymers in vivo.

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Effect of Leptin and IGFBP-3 Gene Polymorphisms on Serum IgG Level of Cattle Calves

  • Choudhary, Vivek;Kumar, Pushpendra;Saxena, V.K.;Bhattacharya, T.K.;Bhushan, Bharat;Sharma, Arjava;Ahmed, K.A.
    • Asian-Australasian Journal of Animal Sciences
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    • v.19 no.8
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    • pp.1095-1099
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    • 2006
  • Leptin and IGFBP-3 are two proteins that play an important role in growth and metabolism of the animals. They are also involved in the immune function of animals and, thus, are candidate genes for the study of association with immune functions. Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) of these two genes was done to screen 64 crossbred (Holstein Friesian${\times}$Hariana) female calves of one year of age. From each RFLPs (fragments) three genotypes were observed. In all the RFLPs the mutant homozygotes were very less in numbers and, hence, were excluded from the least squares analysis. The serum IgG level was estimated using SRID assay. The mean level of serum IgG was $28.83{\pm}2.73mg/ml$. The effect of these identified genotypes on serum IgG level of calves at one year of age was analysed using least squares analysis. The HaeIII RFLP-AB genotype had significantly (p<0.05) higher serum IgG level ($31.86{\pm}3.05$) than the HaeIII RFLP-AA ($25.62{\pm}2.96$) genotype. There was no significant effect of leptin genotypes on the IgG level. The present results indicated a role of the IGFBP-3 gene on serum IgG level of cattle calves.

Molecular approaches for improvement of medicinal and aromatic plants

  • Kumar, Jitendra;Gupta, Pushpendra Kumar
    • Plant Biotechnology Reports
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    • v.2 no.2
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    • pp.93-112
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    • 2008
  • Medicinal and aromatic plants (MAPs) are important sources for plant secondary metabolites, which are important for human healthcare. Improvement of the yield and quality of these natural plant products through conventional breeding is still a challenge. However, recent advances in plant genomics research has generated knowledge leading to a better understanding of the complex genetics and biochemistry involved in biosynthesis of these plant secondary metabolites. This genomics research also concerned identification and isolation of genes involved in different steps of a number of metabolic pathways. Progress has also been made in the development of functional genomics resources (EST databases and micro-arrays) in several medicinal plant species, which offer new opportunities for improvement of genotypes using perfect markers or genetic transformation. This review article presents an overview of the recent developments and future possibilities in genetics and genomics of MAP species including use of transgenic approach for their improvement.

Bag-1L is a Stress-withstand Molecule Prevents the Downregulation of Mcl-1 and c-Raf Under Control of Heat Shock Proteins in Cisplatin Treated HeLa Cervix Cancer Cells

  • Ozfiliz, Pelin;Arisan, Elif Damla;Coker-Gurkan, Ajda;Obakan, Pinar;Eralp, Tugce Nur;Dinler-Doganay, Gizem;Palavan-Unsal, Narcin
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.11
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    • pp.4475-4482
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    • 2014
  • Background: Cisplatin, a DNA damaging agent, induces apoptosis through increasing DNA fragmentation. However, identification of intrinsic resistance molecules against Cisplatin is vital to estimate the success of therapy. Bag-1 (Bcl-2-associated anthanogene) is one anti-apoptotic protein involved in drug resistance impacting on therapeutic efficiency. Elevated levels of this protein are related with increase cell proliferation rates, motility and also cancer development. For this reason, we aimed to understand the role of Bag-1 expression in Cisplatin-induced apoptosis in HeLa cervix cancer cells. Cisplatin decreased cell viability in time- and dose-dependent manner in wt and Bag-1L+HeLa cells. Although, $10{\mu}M$ Cisplatin treatment induced cell death within 24h by activating caspases in wt cells, Bag-1L stable transfection protected cells against Cisplatin treatment. To assess the potential protective role of Bag-1, we first checked the expression profile of interacting anti-apoptotic partners of Bag-1. We found that forced Bag-1L expression prevented Cisplatin-induced apoptosis through acting on Mcl-1 expression, which was reduced after Cisplatin treatment in wt HeLa cells. This mechanism was also supported by the regulation of heat shock protein (Hsp) family members, Hsp90 and Hsp40, which were involved in the regulation Bag-1 interactome including several anti-apoptotic Bcl-2 family members and c-Raf.

Isolation, identification, and culture conditions of the strain producing antibacterial antibiotic (항세균성 항생물질을 생산하는 미생물의 분리, 동정 및 배양조건)

  • Yoo, Jae-Hong;Yoon, Sang-Hong;Koo, Bon-Sung;Yeo, Yun-Soo;Park, In-Cheol;Lee, Byung-Moo;Ryu, Jin-Chang
    • The Korean Journal of Pesticide Science
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    • v.3 no.2
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    • pp.1-7
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    • 1999
  • The strain with antibacterial activity was isolated among soil samples collected in Suwon area. The isolated strain was identified as Bacillus sp. YR-1 with respect to its morphological, cultural, and physiological characteristics. Optimal medium for the highest production of antibiotic was composed of sucrose 2.0%(w/v), peptone 2.0%(w/v) and NaCl 0.1%(w/v). The maximum production of antibiotic was shown at $35^{\circ}C$ for 48 hours with the initial pH 7.0.

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Changes in element accumulation, phenolic metabolism, and antioxidative enzyme activities in the red-skin roots of Panax ginseng

  • Zhou, Ying;Yang, Zhenming;Gao, Lingling;Liu, Wen;Liu, Rongkun;Zhao, Junting;You, Jiangfeng
    • Journal of Ginseng Research
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    • v.41 no.3
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    • pp.307-315
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    • 2017
  • Background: Red-skin root disease has seriously decreased the quality and production of Panax ginseng (ginseng). Methods: To explore the disease's origin, comparative analysis was performed in different parts of the plant, particularly the epidermis, cortex, and/or fibrous roots of 5-yr-old healthy and diseased red-skin ginseng. The inorganic element composition, phenolic compound concentration, reactive oxidation system, antioxidant concentrations such as ascorbate and glutathione, activities of enzymes related to phenolic metabolism and oxidation, and antioxidative system particularly the ascorbate-glutathione cycle were examined using conventional methods. Results: Aluminum (Al), iron (Fe), magnesium, and phosphorus were increased, whereas manganese was unchanged and calcium was decreased in the epidermis and fibrous root of red-skin ginseng, which also contained higher levels of phenolic compounds, higher activities of the phenolic compound-synthesizing enzyme phenylalanine ammonia-lyase and the phenolic compound oxidation-related enzymes guaiacol peroxidase and polyphenoloxidase. As the substrate of guaiacol peroxidase, higher levels of $H_2O_2$ and correspondingly higher activities of superoxide dismutase and catalase were found in red-skin ginseng. Increased levels of ascorbate and glutathione; increased activities of $\text\tiny L$-galactose 1-dehydrogenase, ascorbate peroxidase, ascorbic acid oxidase, and glutathione reductase; and lower activities of dehydroascorbate reductase, monodehydroascorbate reductase, and glutathione peroxidase were found in red-skin ginseng. Glutathione-S-transferase activity remained constant. Conclusion: Hence, higher element accumulation, particularly Al and Fe, activated multiple enzymes related to accumulation of phenolic compounds and their oxidation. This might contribute to red-skin symptoms in ginseng. It is proposed that antioxidant and antioxidative enzymes, especially those involved in ascorbate-glutathione cycles, are activated to protect against phenolic compound oxidation.