• Journal of Microbiology and Biotechnology
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• v.34 no.4
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• pp.804-811
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• 2024

Foamy viruses (FVs) are generally recognized as non-pathogenic, often causing asymptomatic or mild symptoms in infections. Leveraging these unique characteristics, FV vectors hold significant promise for applications in gene therapy. This study introduces a novel platform technology using a pseudo-virus with single-round infectivity. In contrast to previous vector approaches, we developed a technique employing only two vectors, pcHFV lacking Env and pCMV-Env, to introduce the desired genes into target cells. Our investigation demonstrated the efficacy of the prototype foamy virus (PFV) dual-vector system in producing viruses and delivering transgenes into host cells. To optimize viral production, we incorporated the codon-optimized Env (optEnv) gene in pCMV-Env and the Woodchuck Hepatitis Virus Posttranscriptional Regulatory Element (WPRE) at the 3' end of the transgene in the transfer vector. Consequently, the use of optEnv led to a significant enhancement in transgene expression in host cells. Additionally, the WPRE exhibited an enhancing effect. Furthermore, the introduced EGFP transgene was present in host cells for a month. In an effort to expand transgene capacity, we further streamlined the viral vector, anticipating the delivery of approximately 4.3 kbp of genes through our PFV dual-vector system. This study underscores the potential of PFVs as an alternative to lentiviruses or other retroviruses in the realm of gene therapy.

• Research in Plant Disease
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• v.30 no.3
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• pp.268-277
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• 2024

Erwinia pyrifoliae is a gram-negative bacterial pathogen that commonly causes black shoot blight in pear and apple tree. Although the pathogenicity of this bacterial species is very similar to E. amylovora, there is no specific explanation of its pathogenic genes and mechanisms. In this study, our investigation into E. pyrifoliae pathogenicity involved generating seven YKB12327 mutant strains using Tn5 transposon mutagenesis. Observations revealed weakened growth rate and loss of pathogenicity in these mutants. Whole-genome sequencing and alignment analysis identified transposon insertions within the coding sequences of five strains and in the intergenic region of two strains. Annotation analysis elucidated genes directly or indirectly associated with pathogenicity. Notably, mutant strain MT16 displayed a transposon insertion mutation in the cyclic-di-GMP phosphodiesterase (pdeF) gene, a key player in bacterial signaling, governing microbial behavior and adaptation to environmental changes. Our findings provide insights into the genetic regulation of E. pyrifoliae pathogenicity, suggesting potential avenues for further research aimed at understanding and controlling this bacterial pathogen by targeting pdeF to mitigate apple black shoot blight disease.

• Journal of Microbiology and Biotechnology
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• v.18 no.9
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• pp.1529-1536
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• 2008

Acetylation of lysine residues in proteins is a reversible and highly regulated posttranslational modification. However, it has not been systematically studied in prokaryotes. By affinity immunoseparation using an anti-acetyllysine antibody together with nano-HPLC/MS/MS, we identified 125 lysine-acetylated sites in 85 proteins among proteins derived from Escherichia coli. The lysine-acetylated proteins identified are involved in diverse cellular functions including protein synthesis, carbohydrate metabolism, the TCA cycle, nucleotide and amino acid metabolism, chaperones, and transcription. Interestingly, we found a higher level of acetylation during the stationary phase than in the exponential phase; proteins acetylated during the stationary phase were immediately deacetylated when the cells were transferred to fresh LB culture medium. These results demonstrate that lysine acetylation is abundant in E. coli and might be involved in modifying or regulating the activities of various enzymes involved in critical metabolic processes and the synthesis of building blocks in response to environmental changes.

• Proceedings of the PSK Conference
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• 2002.04a
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• pp.115.2-115.2
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• 2002

• Journal of Microbiology and Biotechnology
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• v.29 no.12
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• pp.2026-2026
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• 2019

• Molecules and Cells
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• v.41 no.11
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• pp.979-992
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• 2018

Potato (Solanum tuberosum L.) is the third most important food crop, and breeding drought-tolerant varieties is vital research goal. However, detailed molecular mechanisms in response to drought stress in potatoes are not well known. In this study, we developed EMS-mutagenized potatoes that showed significant tolerance to drought stress compared to the wild-type (WT) 'Desiree' cultivar. In addition, changes to transcripts as a result of drought stress in WT and drought-tolerant (DR) plants were investigated by de novo assembly using the Illumina platform. One-week-old WT and DR plants were treated with -1.8 Mpa polyethylene glycol-8000, and total RNA was prepared from plants harvested at 0, 6, 12, 24, and 48 h for subsequent RNA sequencing. In total, 61,100 transcripts and 5,118 differentially expressed genes (DEGs) displaying up- or down-regulation were identified in pairwise comparisons of WT and DR plants following drought conditions. Transcriptome profiling showed the number of DEGs with up-regulation and down-regulation at 909, 977, 1181, 1225 and 826 between WT and DR plants at 0, 6, 12, 24, and 48 h, respectively. Results of KEGG enrichment showed that the drought tolerance mechanism of the DR plant can mainly be explained by two aspects, the 'photosynthetic-antenna protein' and 'protein processing of the endoplasmic reticulum'. We also divided eight expression patterns in four pairwise comparisons of DR plants (DR0 vs DR6, DR12, DR24, DR48) under PEG treatment. Our comprehensive transcriptome data will further enhance our understanding of the mechanisms regulating drought tolerance in tetraploid potato cultivars.

• Food Science of Animal Resources
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• v.30 no.6
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• pp.910-917
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• 2010

Makgeolli lees is a jigaemi by product produced by makgeolli brew processing. Jigaemi has high fiber content and therefore can potentially be used in the development of foods rich in dietary fiber. The effects of makgeolli lees fibers on the composition and physico-chemical properties of chicken emulsion systems were studied. The moisture and ash contents, yellowness, and viscosity of chicken meat emulsion systems with makgeolli lees fiber were all higher than those of control. Moreover, chicken batters supplemented with makgeolli lees fiber were characterized by lower cooking loss and better emulsion stability. Chicken emulsion systems with makgeolli lees fiber also had improved emulsion stability and emulsion viscosity, and the best results were obtained with meat batter containing 2% makgeolli lees fiber.

• Plant Biotechnology Reports
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• v.5 no.3
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• pp.289-295
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• 2011

The SpoU family of proteins catalyzes the methylation of transfer RNAs (tRNAs) and ribosomal RNAs (rRNAs). We characterized a putative tRNA/rRNA methyltransferase, VaSpoU1 of the SpoU family, from Viscum album (mistletoe). VaSpoU1 and other plant SpoU1s exhibit motifs of the SpoU methylase domain that are conserved with bacterial and yeast SpoU methyltransferases. VaSpoU1 transcripts were detected in the leaves and stems of V. album. VaSpoU1-GFP fusion proteins localized to both chloroplasts and mitochondria in Arabidopsis protoplasts. Sequence analysis similarly predicted that the plant SpoU1 proteins would localize to chloroplasts and mitochondria. Interestingly, mitochondrial localization of VaSpoU1 was inhibited by the deletion of a putative N-terminal presequence in Arabidopsis protoplasts. Therefore, VaSpoU1 may be involved in tRNA and/or rRNA methylation in both chloroplasts and mitochondria.

• Journal of Microbiology and Biotechnology
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• v.31 no.7
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• pp.903-911
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• 2021

Previous studies have modified microbial genomes by introducing gene cassettes containing selectable markers and homologous DNA fragments. However, this requires several steps including homologous recombination and excision of unnecessary DNA regions, such as selectable markers from the modified genome. Further, genomic manipulation often leaves scars and traces that interfere with downstream iterative genome engineering. A decade ago, the CRISPR/Cas system (also known as the bacterial adaptive immune system) revolutionized genome editing technology. Among the various CRISPR nucleases of numerous bacteria and archaea, the Cas9 and Cas12a (Cpf1) systems have been largely adopted for genome editing in all living organisms due to their simplicity, as they consist of a single polypeptide nuclease with a target-recognizing RNA. However, accurate and fine-tuned genome editing remains challenging due to mismatch tolerance and protospacer adjacent motif (PAM)-dependent target recognition. Therefore, this review describes how to overcome the aforementioned hurdles, which especially affect genome editing in higher organisms. Additionally, the biological significance of CRISPR-mediated microbial genome editing is discussed, and future research and development directions are also proposed.

• Journal of Microbiology and Biotechnology
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• v.34 no.8
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• pp.1551-1562
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• 2024

Fungi employ diverse mechanisms for iron uptake to ensure proliferation and survival in iron-limited environments. Siderophores are secondary metabolite small molecules with a high affinity specifically for ferric iron; these molecules play an essential role in iron acquisition in fungi and significantly influence fungal physiology and virulence. Fungal siderophores, which are primarily hydroxamate types, are synthesized via non-ribosomal peptide synthetases (NRPS) or NRPS-independent pathways. Following synthesis, siderophores are excreted, chelate iron, and are transported into the cell by specific cell membrane transporters. In several human pathogenic fungi, siderophores are pivotal for virulence, as inhibition of their synthesis or transport significantly reduces disease in murine models of infection. This review briefly highlights siderophore biosynthesis and transport mechanisms in fungal pathogens as well the model fungi Saccharomyces cerevisiae and Schizosaccharomyces pombe. Understanding siderophore biosynthesis and transport in pathogenic fungi provides valuable insights into fungal biology and illuminates potential therapeutic targets for combating fungal infections.