Functional implications of mitochondrial reactive oxygen species generated by oncogenic viruses

Between 15% and 20% of human cancers are associated with infection by oncogenic viruses. Oncogenic viruses, including HPV, HBV, HCV and HTLV-1, target mitochondria to influence cell proliferation and survival. Oncogenic viral gene products also trigger the production of reactive oxygen species which can elicit oxidative DNA damage and potentiate oncogenic host signaling pathways. Viral oncogenes may also subvert mitochondria quality control mechanisms such as mitophagy and metabolic adaptation pathways to promote virus replication. Here, we will review recent progress on viral regulation of mitophagy and metabolic adaptation and their roles in viral oncogenesis.     

Role of BMP, betaig-h3, and chitosan in early bony consolidation in distraction osteogenesis in a dog model

The purpose of this investigation was to study the effect of bone morphogenetic protein (BMP), transforming growth factor beta-induced gene h3 (betaig-h3), and chitosan on early bony consolidation in distraction osteogenesis in a dog model. Sixteen dogs were used for this study. The lateral surface of the mandibular body was exposed in the subperiosteal plane and the vertical osteotomy on the mandibular body was extended downward. An external distraction device was applied to the mandibular body, and the mandibular distraction was started 5 days after the operation at a rate of 2 mm/day up to a 10-mm distraction after 5 days. The experimental group was then divided into a control group, a BMP group, a betaig-h3 group, and a chitosan group, depending on the type of implantation material used in the distracted area. On the same day after completing the distraction, BMP, betaig-h3, or chitosan was implanted into the distracted area. No material was implanted into the distracted area in the control group. After implanting the materials, the distraction device was left in place for 7 weeks to allow for bony consolidation. Four dogs were allocated to each group. Two dogs in each group, a total of eight dogs, were killed 4 weeks after completing the distraction and the other eight dogs were killed after 7 weeks. Serial radiographs were obtained every week after completing the distraction. New bone was generated in the distracted zone in all groups. In the BMP group, the formation of active woven bone was observed throughout the distracted zone, and the new bone appeared to be nearly normal cortical bone 7 weeks after implantation. In the betaig-h3 and chitosan groups, the development of new bone was observed in the distracted zone after 7 weeks; however, the amount was less than that in the BMP group. In the control group, the new bone was observed at the edges of the distracted zone. These findings suggest that BMP seems to be very effective in early bony consolidation in distraction osteogenesis.     

High Temperature Stress Resistance of Escherichia coli Induced by a Tobacco Class I Low Molecular Weight Heat-Shock Protein

TLHS1 is a class I low molecular weight heat-shock protein (LMW HSP) of tobacco (Nicotiana tabacum). For a functional study of TLHS1, a recombinant DNA coding for TLHS1 with a hexahistidine tag at the aminoterminus was constructed and expressed in Escherichia coli. An expressed fusion protein, H₆TLHS1, was purified using a Ni²⁺ affinity column and a Sephacryl S400 HR column. A polyclonal antibody against H₆TLHS1 was produced to follow the fate of H₆TLHS1 in E. coli. The fusion protein in E. coli maintained its solubility at a temperature of up to 90°C and most of the proteins in the E. coli cell lysate with H₆TLHS1 were prevented from thermally induced aggregation at up to 90°C. We compared the viability of E. coli cells expressing H₆TLHS1 to the E. coli cells without H₆TLHS1 at a temperature of 50°C. After 8 h of high temperature treatment, E. coli cells with H₆TLHS1 survived about three thousand times more than the bacterial cells without H₆TLHS1. These results showed that a plant class I LMW HSP, TLHS1, can protect proteins of E. coli from heat denaturation, which could lead to a higher survival rate of the bacterial cells at high temperature.     

Insect diversity in Gonggeom‐ji,the first protected paddy field wetland in Korea

Gonggeom‐ji pond is the first protected paddy field wetland area, designated by the Ministry of Environment of Korea in 2011, because of its high biodiversity and historic value. It contains reservoirs, paddy fields, and a forest site that provides diverse niches for insects. Quantitative methods were used in this study to estimate the insect diversity of this region. A transect of 50 m was designated in each site (reservoirs, paddy fields, and a forest site). Data were collected using sweeping and pitfall traps along each transect in May, August, and November 2017, representative of the seasons—spring, summer, and autumn, respectively. As a result, a total of 1079 individual insects representing 170 species from 60 families within nine orders were collected. Diversity, richness, and evenness indices were the highest in the forest site in May (4.77, 8.6, and 0.91, respectively). The dominance index was the highest in the forest site in November (0.64). Similarity index was the highest in the reservoir in May and August (0.519). These results would help compare different sites and their vegetation to assess relationships between insects and habitats.     

Backbone 1H, 15N, and 13C resonance assignments of the Helicobacter pylori acyl carrier protein

One of the small proteins from Helicobacter pylori, acyl carrier protein (ACP), was investigated by NMR. ACP is related to various cellular processes, especially with the biosynthesis of fatty acid. The basic NMR resonance assignment is a prerequisite for the validation of a heterologous protein interaction with ACP in H. pylori. Here, the results of the backbone (1)H, (15)N, and (13)C resonance assignments of the H. pylori ACP are reported using double- and triple-resonance techniques. About 97% of all of the (1)HN, (15)N, (13)CO, (13)Calpha, and (13)Cbeta resonances that cover 76 of the 78 non-proline residues are clarified through sequential- and specific- assignments. In addition, four helical regions were clearly identified on the basis of the resonance assignments.     

Eleven new microsatellite markers in jack mackerel (Trachurus japonicus) derived from an enriched genomic library

Jack mackerel (Trachurus japonicus, Carangidae) are a commercially important fisheries resource in Korea. To understand patterns of genetic variation for conservation and management efforts, we developed microsatellite DNA markers fromT. japonicus. We report the isolation and characterization of eleven microsatellite loci isolated using an enrichment method based on magnetic/biotin capture of microsatellite sequences from a size-selected genomic library. To characterize each locus, 50 individuals from a naturalT. japonicus population in southern Korea were genotyped. All loci except one, KTJ38, were polymorphic with an average of 14 alleles per locus (range 6–23). The mean observed and expected heterozygosities were 0.70 (range 0.46–0.92) and 0.81 (range 0.49–1.00), respectively. Significant deviation from Hardy-Weinberg equilibrium was observed at three loci, KTj3, KTJ20 and KTJ28. Such high variability indicates that these microsatellites are useful markers for high-resolution analysis for population gemetic studies.     

Development of the Kranz structure during leaf growth in C4 Euphorbia maculate

The development of the Kranz structure was investigated in leaves of C₄ Euphorbia maculata using electron microscopy. Four leaf stages, i.e., primordial, immature, young, and mature, were examined, based on the photosynthetic tissue that surrounded the veins. The examination revealed how cells differentiated into distinct bundle sheath cells (BSCs) and mesophyll cells (MCs). Specialization of the BSCs was invariably associated with the development of the veins as well as the MCs. Precursors for BSC and MC were recognizable fairly early, at the immature stage, according to their position and differential enlargement Once these precursors were delimited from the procambial area, differentiation into each cell type occurred synchronously, in a coordinated manner. All cells enlarged as they were displaced from the Kranz precursor area, but the BSC precursors were initially larger and remained relatively larger than the other cell types throughout leaf development The developmental changes sharply distinguished BSCs from the adjacent MCs at the onset of Kranz formation and continued until maturity. Chloroplast enlargement also occurred during cell displacement, but the rate of enlargement was greater in BSCs, resulting in larger chloroplasts at later stages. However, no significant structural differences were detected among the chloroplasts of BSC and MC in the early stages. Most of the specialized features appeared at the young-leaf stage; structural dimorphism became prominent at the later stages. This enhanced development of the BSC chloroplasts was correlated with asymmetric distribution of cellular components. In addition, the BSC formed thin primary pit fields with numerous plasmodesmata. Peripheral reticulum was present, but generally was not conspicuous. We also discuss the characteristics of leaf anatomy and ultrastructure inE. maculata as they relate to the C₄ photosynthetic pathway.     

DNA microarrays on a dendron-modified surface improve significantly the detection of single nucleotide variations in the p53 gene

Selectivity and sensitivity in the detection of single nucleotide polymorphisms (SNPs) are among most important attributes to determine the performance of DNA microarrays. We previously reported the generation of a novel mesospaced surface prepared by applying dendron molecules on the solid surface. DNA microarrays that were fabricated on the dendron-modified surface exhibited outstanding performance for the detection of single nucleotide variation in the synthetic oligonucleotide DNA. DNA microarrays on the dendron-modified surface were subjected to the detection of single nucleotide variations in the exons 5–8 of the p53 gene in genomic DNAs from cancer cell lines. DNA microarrays on the dendron-modified surface clearly discriminated single nucleotide variations in hotspot codons with high selectivity and sensitivity. The ratio between the fluorescence intensity of perfectly matched duplexes and that of single nucleotide mismatched duplexes was >5–100 without sacrificing signal intensity. Our results showed that the outstanding performance of DNA microarrays fabricated on the dendron-modified surface is strongly related to novel properties of the dendron molecule, which has the conical structure allowing mesospacing between the capture probes. Our microarrays on the dendron-modified surface can reduce the steric hindrance not only between the solid surface and target DNA, but also among immobilized capture probes enabling the hybridization process on the surface to be very effective. Our DNA microarrays on the dendron-modified surface could be applied to various analyses that require accurate detection of SNPs.