• IMMUNE NETWORK
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• 제14권1호
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• pp.7-13
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• 2014

Molecular mimicry is an attractive mechanism for triggering autoimmunity. In this review, we explore the potential role of evolutionary conserved bacterial proteins in the production of autoantibodies with focus on granulomatosis with polyangiitis (GPA) and rheumatoid arthritis (RA). Seven autoantigens characterized in GPA and RA were BLASTed against a bacterial protein database. Of the seven autoantigens, proteinase 3, type II collagen, binding immunoglobulin protein, glucose-6-phosphate isomerase, ${\alpha}$-enolase, and heterogeneous nuclear ribonuclear protein have well-conserved bacterial orthologs. Importantly, those bacterial orthologs are also found in human-associated bacteria. The wide distribution of the highly conserved stress proteins or enzymes among the members of the normal flora and common infectious microorganisms raises a new question on how cross-reactive autoantibodies are not produced during the immune response to these bacteria in most healthy people. Understanding the mechanisms that deselect auto-reactive B cell clones during the germinal center reaction to homologous foreign antigens may provide a novel strategy to treat autoimmune diseases.

• 생명과학회지
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• 제22권2호
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• pp.177-183
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• 2012

Ralstonia solanacearum (Rs)에 의해 유발되는 풋마름병은 감자 재배 시 발병하는 주요 병 중의 하나이다. 감자에서 풋마름병 저항성관련 유전자를 찾기 위해 기존에 기능이 알려진 다른 가지과 작물의 기능 유사 유전체를 이용하여 StACRE (HM749652) 유전자를 분리하고 염기서열을 분석하였다. 분리한 StACRE의 발현양상을 분석하기 위해 병 저항성 유도 신호전달 물질인 SA와 풋마름병원균 Rs (KACC10722)를 처리한 감자에서 RNA를 추출하여 RT-PCR을 실시한 결과 이 유전자는 SA 처리에 의해 3시간 후부터, Rs에 의해서는 12시간 후부터 발현이 현저하게 증가하였다. 따라서, 감자에서 이 유전자의 생물학적인 기능을 분석하기 위해 Gateway System을 이용하여 과발현용 vector를 만든 후 과발현 형질전환 감자를 제작하고 풋마름병균인 Rs를 접종하여 병 저항성 기능을 검정 한 결과 대조구인 수미 감자에 비해 병 저항성이 증대하였다.

• Fisheries and Aquatic Sciences
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• 제14권1호
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• pp.31-42
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• 2011

Three novel hepcidin isoforms were isolated and characterized from the perciform fish species Oplegnathus fasciatus. These hepcidin isoforms (designated rbhepc5, rbhepc6 and rbhepc7) were found to share a conserved, tripartite gene structure and a considerable sequence homology one another. A comparison of their mature peptide sequences with those of other perciform hepcidin orthologs indicated that these three hepcidin isoforms as well as four other isoforms previously identified in this species, appear to belong to the HAMP2 group of hepcidin genes. Analysis of the 5'-upstream sequences showed that the proximal non-coding regions of rbhepc5~7 do not possess canonical TATA signals; instead, they harbor several binding motifs for transcription factors involved in immune modulation. Reverse transcriptase-PCR analysis demonstrated that the rbhepc5~7 are expressed predominantly in the liver, and that the transcription of rbhepc5~7 is rapidly induced in the liver, but not in other tissues, by experimental challenge with any of three different bacterial species. However, transcription of rbhepc6 appeared to be negligible under both basal and stimulated conditions, as judged by the redundancy count of randomly chosen reverse transcriptase-PCR clones.

• Journal of Microbiology and Biotechnology
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• 제25권4호
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• pp.511-520
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• 2015

Triclosan, the widely used biocide, specifically targets enoyl-acyl carrier protein reductase (ENR) in the bacterial fatty acid synthesis system. Although the fish pathogen Aeromonas salmonicida subsp. salmonicida exhibits triclosan resistance, the nature of this resistance has not been elucidated. Here, we aimed to characterize the triclosan resistance of A. salmonicida subsp. salmonicida causing furunculosis. The fosmid library of triclosan-resistant A. salmonicida subsp. salmonicida was constructed to select a fosmid clone showing triclosan resistance. With the fosmid clone showing triclosan resistance, a subsequent secondary library search resulted in the selection of subclone pTSR-1. DNA sequence analysis of pTSR-1 revealed the presence of a chromosomal-borne fabV-encoding ENR homolog. The ENR of A. salmonicida (FabVas) exhibited significant homology with previously known FabV, including the catalytic domain YX₍₈₎K. fabVas introduction into E. coli dramatically increased its resistance to triclosan. Heterologous expression of FabVas might functionally replace the triclosan-sensitive FabI in vivo to confer E. coli with triclosan resistance. A genome-wide search for fabVas homologs revealed the presence of an additional fabV gene (fabVas2) paralog in A. salmonicida strains and the fabVas orthologs from other gram-negative fish pathogens. Both of the potential FabV ENRs expressed similarly with or without triclosan supplement. This is the first report about the presence of two potential FabV ENRs in a single pathogenic bacterium. Our result suggests that triclosan-resistant ENRs are widely distributed in various bacteria in nature, and the wide use of this biocide can spread these triclosan-tolerant ENRs among fish pathogens and other pathogenic bacteria.

• 한국수산과학회지
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• 제44권2호
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• pp.126-140
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• 2011

Genetic determinants of two metallothionein isoforms (MT-A and MT-B) were isolated and characterized from the perciform species, rockbream (Oplegnathus fasciatus). Rockbream MT-A and MT-B shared a high degree of homology at amino acid levels with representative orthologs from other perciform species, especially with respect to the conserved cysteine residues. At the genomic level, both MT-A and MT-B genes represent a tripartite structure typical of vertebrate MT genes. However, rockbream MT-B showed unusually large introns (1.2 kb and 0.8 kb for intron I and II, respectively), a phenomenon that has rarely been seen in other vertebrate MT genes. MT-A and MT-B transcripts were ubiquitously detected in a wide array of tissues, wherein brain and eye showed the highest basal expression levels, and the fin exhibited the lowest expression of both isoforms. The basal expression of MT-A in most tissues was significantly higher (ranging from 4- to 10-fold) than that of MT-B. Upon heavy metal exposures to Cd, Cu or Zn at 25 ppb for 48 h, MT-A and MT-B transcripts in the liver were significantly activated by Cd and moderately by Zn. On the other hand, exposure to Cu did not result in alterations of MT-A, nor in the significant suppression of MT-B. Following bacterial challenges with Escherichia coli, Edwardsiella tarda or Streptococcus iniae, MT isoforms in the liver, kidney and spleen were highly modulated and exhibited a pattern that was dependent on the bacterial species, tissues and isoforms. These results suggest that the two MT isoforms could be taken into account as potential indicators of metal toxicity and immune perturbations of this aquaculture-relevant species.

• The Plant Pathology Journal
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• 제38권6호
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• pp.603-615
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• 2022

Soybean (Glycine max (L) Merr.) provides plant-derived proteins, soy vegetable oils, and various beneficial metabolites to humans and livestock. The importance of soybean is highly underlined, especially when carbon-negative sustainable agriculture is noticeable. However, many diseases by pests and pathogens threaten sustainable soybean production. Therefore, understanding molecular interaction between diverse cultivated varieties and pathogens is essential to developing disease-resistant soybean plants. Here, we established a pathosystem of the Korean domestic cultivar Kwangan against Pseudomonas syringae pv. syringae B728a. This bacterial strain caused apparent disease symptoms and grew well in trifoliate leaves of soybean plants. To examine the disease susceptibility of the cultivar, we analyzed transcriptional changes in soybean leaves on day 5 after P. syringae pv. syringae B728a infection. About 8,900 and 7,780 differentially expressed genes (DEGs) were identified in this study, and significant proportions of DEGs were engaged in various primary and secondary metabolisms. On the other hand, soybean orthologs to well-known plant immune-related genes, especially in plant hormone signal transduction, mitogen-activated protein kinase signaling, and plant-pathogen interaction, were mainly reduced in transcript levels at 5 days post inoculation. These findings present the feature of the compatible interaction between cultivar Kwangan and P. syringae pv. syringae B728a, as a hemibiotroph, at the late infection phase. Collectively, we propose that P. syringae pv. syringae B728a successfully inhibits plant immune response in susceptible plants and deregulates host metabolic processes for their colonization and proliferation, whereas host plants employ diverse metabolites to protect themselves against infection with the hemibiotrophic pathogen at the late infection phase.