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- 저자 : Ho Am Jang (검색결과 40 건)
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Ho Am Jang,Chan-Hee Kim,Ho Jeong Eo,Jun Beom Lee,Jin Hee Byeon,Dae Woo Son,You Sun Lee,Jiyeun Kate Kim,Bok Luel Lee 한국응용곤충학회 2014 한국응용곤충학회 학술대회논문집 Vol.2014 No.04
The Riptortus-Burkholderia symbiosis is a newly emerging insect-bacterium symbiotic system. This symbiosis system has a good merit as an experimental model system to produce the non-symbiotic (apo) and symbiotic (sym) host insect. In recent reported papers, the symbionts play important biological roles for the host insects. Meanwhile, juvenile hormone (JH) is one of major hormone synthesized corpora allata(CA) to control many physiology of insect. However, the study for cross-talk mechanism between symbionts and host hormones to control important physiological phenomenon of insects is almost none. In this study, we found that Riptortus speed up adult emerging and increase egg laying on presence of symbiont Burkholderia. Also we found that hexamerin proteins, which were controlled the expression by JH, were accumulated in sym-Riptortus hemolymph compare with apo-Riptortus. According as combined results, we hypothesized that the gut symbiont Burkholderia can control JH titer to conclude out beneficial effects such as development and reproduction of R. pedestris. To verify this hypothesis, we examined measurement of JH titer, expression of hexamerins as JH response genes and RNAi for hexamerin protein during whole Riptortus life on presence or absence of symbiont Burkholderia. All results demonstrated that gut symbiont controlled JH titer of Riptortus. Controlled JH amount by symbiont Burkholderia in host midgut regulated hexamerin protein expression for speeding up adult emerging and increasing egg production.
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Selection Mechanism for the Burkholderia Gut Symbiont via Host Salivary Gland
Ho Am Jang,Jiyeun Kate Kim,Bok Luel Lee 한국응용곤충학회 2014 한국응용곤충학회 학술대회논문집 Vol.2014 No.10
The Riptortus pedestris-Burkholderia symbiotic system is a promising model for understanding molecular mechanism of symbiosis. In previous studies, the Burkholderia symbiont has been shown to play important biological roles in the growth and fitness of host R. pedestris. The Burkholderia symbiont, one of bacteria found in the soil, is the only bacterium that can colonize the symbiotic midgut region of R. pedestris. However, the molecular mechanism of host selectivity for the Burkholderia symbiont remains unknown. To determine where the selection occurs, we firstly compared initial infectivity of different mid-gut regions after oral infection of Escherichia coli and Burkholderia. Interestingly, E. coli were not detected in any regions of mid-gut, while Burkholderia could reach to the posterior region of mid-gut. Therefore, we hypothesized that host selectivity for the Burkholderia symbiont is occurred in the salivary gland. To address this hypothesis, we treated E. coli and Burkholderia with lysate of salivary gland and examined their survival by estimation of colony forming unit (CFU) on the plate. We found that E. coli, but not Burkholderia, was susceptible to the lysate of salivary gland. To determine molecular basis of the selective mechanism in the salivary gland, we analyzed antimicrobial proteins (AMPs) from lysate of salivary gland. we identified three AMPs, namely rip-trialysin1, rip-trialysin2 and lysozyme and further purified rip-trialysin1 and rip-trialysin2. When E. coli and Burkholderia were treated with rip-trialysin1 and rip-trialysin2, rip-trialysin1 exhibited little antimicrobial activity, but rip-trialysin2 exhibited antimicrobial activity. Furthermore, we found that E. coli was susceptible, but Burkholderia is resistant to commerciallypurchased egg white lysozyme. Our results suggest that R. pedestris salivary gland provides a chance of selection for the Burkholderia symbiont and lysozyme in salivary gland seems to play an important role for the selection of gut symbiont.
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Ho Am Jang,Eun Sil Seo,Jun Beom Lee,Bok Luel Lee 한국응용곤충학회 2017 한국응용곤충학회 학술대회논문집 Vol.2017 No.04
In order to establish symbiotic host-bacterial relationships, symbionts in insects evolved a mechanism to overcome host immune responses. Here we provide the resistance of symbiotic bacteria on the insect immune system. As a result, through the transposon mutagenesis, we found a salivary gland (SG) susceptible mutant. The disrupted gene was identified as nlpB involved in lipoprotein synthesis. The nlpB, bla double deletion mutant was sensitive to SG like nlpB-Tn5 inserted mutant. This mutant increases outer membrane permeability. It provides an explanation for SG susceptibility, because the antimicrobial peptide in SG would be able to translocate across the outer membrane more easily than in the wild type. These results indicate that nlpB and bla are likely to be important factors in terms of determining resistance against SG of Riptortus that is connected with the successful colonization of the Riptortus midgut.
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Jang Ho Am,Park Ki Beom,Kim Bo Bae,Ali Mohammadie Kojour Maryam,Bae Young Min,Baliarsingh Snigdha,Lee Yong Seok,Han Yeon Soo,Jo Yong Hun 한국곤충학회 2020 Entomological Research Vol.50 No.9
Antimicrobial peptides (AMPs) are effector candidates that elicit humoral immunity in invertebrates. AMPs facilitate bacterial clearance by either physically disrupting the microbial membranes or the intracellular targets. In the Coleopteran pest, Tenebrio molitor, transcriptional regulation of AMPs has been studied in the context of innate immune signaling cascades and antimicrobial immunity. Here, we report the transcriptional response of three AMP genes, Coleoptericin A, B, and C (TmCole A, B and C) in T. molitor in response to bacterial (Escherichia coli, Staphylococcus aureus), and fungal (Candida albicans) challenges. These genes were expressed essentially in the gut and hemocytes followed by the integument tissue of the T. molitor larva. Further, these genes were highly expressed in the late-larval, pupal, and early adult stages. Furthermore, while all of these transcripts were highly upregulated in the fat body and Malpighian tubules after bacterial challenge, TmCole B and TmCole C were induced in the gut after E. coli challenge. Fungal stimulation was not required for the upregulation of the transcription of Coleoptericin genes in T. molitor.
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Jang Ho Am,Park Ki Beom,Kim Bo Bae,Ali Mohammadie Kojour Maryam,Bae Young Min,Baliarsingh Snigdha,Lee Yong Seok,Han Yeon Soo,Jo Yong Hun 한국곤충학회 2020 Entomological Research Vol.50 No.12
Defensins are a major family of antimicrobial peptides that serve as the innate immune defense of both vertebrates and invertebrates. Due to their antimicrobial, chemotactic, and regulatory activities, Defensins have been exploited for their therapeutic potential. Insect Defensins are cysteine‐rich and contain an N‐terminal loop, α‐helix, and antiparallel β‐sheet, forming a “cysteine‐stabilized alpha beta (CSαβ)” or “loop–helix‐sheet” structure. In this study, we identified the full‐length open reading frame (ORF) sequences of Defensin (TmDef) and Defensin‐like (TmDef‐like) genes from the mealworm beetle Tenebrio molitor using in silico methods. TmDef and TmDef‐like genes encode the peptides of 72 and 71 amino acid residues, respectively. TmDefensin is comprised of a Defensin domain and the TmDefensin‐like is comprised of a signal peptide of 21 amino acid residues. Phylogenetic analysis revealed close similarities of TmDefensin with the Defensin of Acalolepta luxuriosa of the longhorn beetle family. The expression of TmDef mRNA was found to be greater than that of TmDef‐like mRNA and was mostly expressed in the pupal and adult stages. Tissue distribution showed high expression of TmDef‐like mRNA in larval hemocytes, gut, integument, and fat body, while in adults, the expression was high in gut and hemocytes. Following bacterial and fungal stimulation in vivo, TmDef was upregulated at 24 h post‐infection in whole body, fat body, and hemocytes of the larvae. Even TmDef‐like mRNA was upregulated in the gut and hemocytes at 12 and 9 h post‐infection respectively. These results suggest that TmDef and TmDef‐like genes play important roles in protecting T. molitor from microbial contact.
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Jang, Ho Am,Seo, Eun Sil,Seong, Min Young,Lee, Bok Luel Elsevier 2017 Developmental and comparative immunology Vol.67 No.-
<P><B>Abstract</B></P> <P> <I>Riptortus pedestris</I>, a common pest in soybean fields, harbors a symbiont <I>Burkholderia</I> in a specialized posterior midgut region of insects. Every generation of second nymphs acquires new <I>Burkholderia</I> cells from the environment. We compared <I>in vitro</I> cultured <I>Burkholderia</I> with newly <I>in vivo</I> colonized <I>Burkholderia</I> in the host midgut using biochemical approaches. The bacterial cell envelope of <I>in vitro</I> cultured and <I>in vivo Burkholderia</I> differed in structure, as <I>in vivo</I> bacteria lacked lipopolysaccharide (LPS) O-antigen. The LPS O-antigen deficient bacteria had a reduced colonization rate in the host midgut compared with that of the wild-type <I>Burkholderia</I>. To determine why LPS O-antigen-deficient bacteria are less able to colonize the host midgut, we examined <I>in vitro</I> survival rates of three LPS O-antigen-deficient <I>Burkholderia</I> mutants and lysates of five different midgut regions. The LPS O-antigen-deficient mutants were highly susceptible when cultured with the lysate of a specific first midgut region (M1), indicating that the M1 lysate contains unidentified substance(s) capable of killing LPS O-antigen-deficient mutants. We identified a 17 kDa protein from the M1 lysate, which was enriched in the active fractions. The N-terminal sequence of the protein was determined to be a soybean Kunitz-type trypsin inhibitor. These data suggest that the 17 kDa protein, which was originated from a main soybean source of the <I>R. pedestris</I> host, has antibacterial activity against the LPS O-antigen deficient (rough-type) <I>Burkholderia.</I> </P> <P><B>Highlights</B></P> <P> <UL> <LI> <I>Burkholderia</I> LPS O-antigen-deficient bacteria had a reduced colonization rate in the host midgut. </LI> <LI> <I>In vitro</I> survival rates of three LPS O-antigen-deficient mutants were examined. </LI> <LI> A specific midgut contains substance killing LPS O-antigen-deficient mutants. </LI> <LI> 17 kDa trypsin inhibitor has antibacterial activity against the LPS O-antigen-deficient mutant. </LI> </UL> </P>
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Jun Beom Lee,Ho Am Jang,Dae Woo Son,Jiyeun Kate Kim,Bok Luel Lee 한국응용곤충학회 2014 한국응용곤충학회 학술대회논문집 Vol.2014 No.10
Biological properties of antimicrobial peptides (AMPs) of hemimetabolous insect are poorly characterized in innate immunity field. To investigate the biochemical properties of hemimetabolous insect’s AMPs, we purified the pyrrhocoricin-like AMP from the hemolymph of Riptortus pedestris and then named as riptocin. We successfully determined the primary protein structure and its cDNA sequence. Interestingly, the determined cDNA revealed that riptocin precursor is composed of 12 repeating units of active riptocins, which implied that riptocin precursor might require to be processed to generate active riptocins by several unidentified processing enzymes. In order to characterize the bio-processing mechanisms of riptocin precursor, we generated the antibody against active riptocin. Using quantitative PCR and Western blot analyses, we showed that gene of riptocin was started to express from the fatbody after three hours post bacterial infection. To address our hypothesis that active riptocin is generated from riptocin precursor by several processing enzymes, we need to obtain the riptocin precursor. Currently, we are expressing the recombinant riptocin precursor using in vitro translation system. Meanwhile, we investigated whether naive hemolymph (naive HL), which may contain precursor riptocin, can generate active riptocin when riptocin precursor was co-incubation with bacteria-challenged hemolymph (active HL), which may contain all processing enzymes. Actually, when naive HL was incubated with active HL, antimicrobial activity was dramatically increased, suggesting that processing enzymes in active HL may induce processing of riptocin precursor to generate active riptocins.
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Jang, Seong Han,Jang, Ho Am,Lee, Junbeom,Kim, Jong Uk,Lee, Seung Ah,Park, Kyoung-Eun,Kim, Byung Hyun,Jo, Yong Hun,Lee, Bok Luel American Society for Microbiology 2017 Applied and environmental microbiology Vol.83 No.11
<P>IMPORTANCE Bacterial polyhydroxyalkanoate (PHA) biosynthesis is a complex process requiring several enzymes. The biological roles of PHA granule synthesis enzymes and the surface proteins of PHA granules during host-gut symbiont interactions are not fully understood. Here, we report the effects on colonization ability in the host midguts and the fitness of host insects after feeding Burkholderia mutant cells (four phaP-depleted mutants and one phaR-depleted mutant) to the host insects. Analyses of both synthesized PHA granule amounts and CFU numbers suggest that the phaR gene is closely related to synthesis of the PHA granule and the colonization of the Burkholderia gut symbiont in the host insect's midgut. Like our previous report, this study also supports the idea that the environment of the host midgut may not be favorable to symbiotic Burkholderia cells and that PHA granules may be required to adapt in the host midgut.</P>
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