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A PKS gene, pks-1, is involved in chaetoglobosin biosynthesis, pigmentation and sporulation in Chaetomium globosum

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Science China(Life Sciences) 2012年第12期55卷 1100-1108页

作者： HU Yang HAO XiaoRan LOU Jing ZHANG Ping PAN Jiao ZHU XuDong State Key program of microbiology and Department of microbiology College of Life Sciences Nankai University Tianjin 300071 China

Chaetomium globosum is one of the most common fungi in nature. It is best known for producing chaetoglobosins; however, the molecular basis of chaetoglobosin biosynthesis is poorly understood in this fungus. In this study, we utilized RNA inter- ference （RNAi） to characterize a polyketide synthase gene, pks-1, in C. globosum that is involved in the production of chaeto- globosin A. When pks-1 was knocked down by RNAi, the production of chaetoglobosin A dramatically decreased. Knock-down mutants also displayed a pigment-deficient phenotype. These results suggest that the two polyketides, melanin and chaetoglobosin, are likely to share common biosynthetic steps. Most importantly, we found that pks-I also plays a critical role in sporulation. The silenced mutants ofpks-1 lost the ability to produce spores. We propose that polyketides may modulate cellular development via an unidentified action. We also suggest that C. globosum pks-1 is unique because of its triple role in melanin formation, chaetoglobosin biosynthesis and sporulation. This work may shed light on chaetoglobosin biosynthesis and indicates a relationship between secondary metabolism and fungal morphogenesis.

关键词： polyketide synthase (PKS) melanin chaetoglobosin A Chaetomium globosum

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Notch signaling regulates expression of Mcl-1 andapoptosis in PPD-treated macrophages

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Cellular & Molecular Immunology 2013年第5期10卷 444-452页

作者： Tanapat P alaga Siriluk Ratanabunyong Thitiporn Pattarakankul Naunpun Sangphech Wipawee Wongchana Yukihiro Hadae Patipark Kueanjinda Department of microbiology Faculty of Science Chulalongkorn University Bangkok 10330 Thailand Interdisciplinary program in Medical microbiology Graduate School Chulalongkorn University Bangkok 10330 Thailand Graduate program in Industrial microbiology Faculty of Science Chulalongkorn University Bangkok 10330 Thailand Graduate program in Biotechnology Faculty of Science Chulalongkorn University Bangkok 10330 Thailand International Center for Biotechnology Osaka University Osaka 565-0871 Japan

Macrophages are cellular targets for infection by bacteria and viruses. The fate of infected macrophages plays a key role in determining the outcome of the host immune response. Apoptotic cell death of macrophages is considered to be a protective host defense that eliminates pathogens and infected cells. In this study, we investigated the involvement of Notch signaling in regulating apoptosis in macrophages treated with tuberculin purified protein derivative （PPD）. Murine bone marrow-derived macrophages （BMMs） treated with PPD or infected with Mycobacterium bovis Bacillus Calmette-Guerin （BCG） induced upregulation of Notch1. This upregulation correlated well with the upregulation of the anti-apoptotic gene mcl-1 both at the transcriptional and translational levels. Decreased levels of Notch I and Mcl- 1 were observed in BMM treated with PPD when a gamma secretase inhibitor （GSI）, which inhibits the processing of Notch receptors, was used. Moreover, silencing Notch1 in the macrophage-like cell line RAW264.7 decreased Mcl-1 protein expression, suggesting that Notch1 is critical for Mcl-1 expression in macrophages. A significant increase in apoptotic cells was observed upon treatment of BMM with PPD in the presence of GSI compared to the vehicle-control treated cells. Finally, analysis of the mcl-1 promoter in humans and mice revealed a conserved potential CSURBP-Jκ binding site. The association of Notch I with the mcl-1 promoter was confirmed by chromatin immunoprecipitation. Taken together, these results indicate that Notch I inhibits apoptosis of macrophages stimulated with PPD by directly controlling the mcl-1 promoter.

关键词： apoptosis BCG macrophage Mcl-1 Notch signaling PPD

Chloride channel-dependent copper acquisition of laccase in the basidiomycetous fungus Cryptococcus neoformans

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Science China(Life Sciences) 2010年第1期53卷 125-130页

作者： ZHU ChangWei1,JIANG Nan1,XIAO DongGuang2,PAN Jiao1 & ZHU XuDong1 1 State Key program of microbiology and Department of microbiology,College of Life Sciences,Nankai University,Tianjin 300071,China 2 Tianjin Industrial microbiology Key Lab,College of Bioengineering,Tianjin University of Science & Technology,Tianjin 300457,China State Key program of microbiology and Department of microbiology College of Life Sciences Nankai University Tianjin China Tianjin Industrial microbiology Key Lab College of Bioengineering Tianjin University of Science & Technology Tianjin China

The CLC chloride channel gene CLC-A of the pathogen yeast Cryptococcus neoformans was previously reported to be critical for multicopper laccase activity and growth at an elevated *** study reports that copper homeostasis was impaired in the clc-a *** was demonstrated by the substantial decrease of the intracellular quantity of copper under copper-limited growth as determined by flame atomic absorption ***-A is a critical factor in copper homeostasis which is required for copper acquisition of laccase in ***.

关键词： chloride channel laccase copper homeostasis Cryptococcus neoformans

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Direct regulation of interleukin-6 expression by Notch signaling in macrophages

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Cellular & Molecular Immunology 2012年第2期9卷 155-162页

作者： Wipawee Wongchana Tanapat Palaga Graduate program in Biotechnology Faculty of Science Chulalongkorn University Bangkok Thailand Department of microbiology Faculty of Science Chulalongkorn University Bangkok Thailand

Interleukin-6 （IL-6） is a pleiotropic, pro-inflammatory cytokine produced by various types of cells, including macrophages. Within the IL-6 gene promoter region, the signature binding motif of CBFI/Su（H）/Lag-1 （CSL）, a key DNA-binding protein in the Notch signaling pathway, was identified and found to overlap with a consensus nuclear factor （NF）-κB-binding site. Notch signaling is highly conserved and is involved in the regulation of biological functions in immune cells. In this study, we investigated the role of Notch signaling in the regulation of the IL-6transcript in murine macrophages. The upregulation of Notch1 protein levels and the appearance of cleaved Notch1 （Va11744） correlated well with the increased IL-6 mRNA expression levels in murine primary bone marrow-derived macrophages （BMMφ） after activation by lipopolysaccharide （LPS） together with interferon-gamma （IFN-γ）. Treatment of BMMφ with the γ-secretase inhibitor IL-CHO to suppress the transduction of Notch signaling resulted in a partial decrease in the level of IL-6mRNA and the amount of I L-6 protein produced. In contrast, the overexpression of a constitutively activated intracellular Notch I protein （N^IC） in the RAW264.7 macrophage-like cell line resulted in significantly higher IL-6transcript expression levels than in cells transfected with the empty vector control. The NF-κB inhibitor completely abrogated IL-6 mRNA expression induced by the overexpression of N^IC. Chromatin immunoprecipitation （CHIP） using an anti-Notch1 antibody demonstrated that Notch 1 is associated with the IL-6promoter in RAW264.7 cells activated by LPS/IFN-γ but not in unstimulated cells. Taken together, these results strongly suggest that Notch 1 positively regulates IL-6 expression via NF-κB in activated macrophages.

关键词： CSL interleukin-6 macrophages NF-κB Notch signaling

Calreticulin surface presentation: a signal for natural killer cells to attack

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Signal Transduction and Targeted Therapy 2023年第9期8卷 3883-3884页

作者： Jasmine P.Castellanos Joseph C.Genereux microbiology Graduate program University of CaliforniaRiversideCA 92521USA Department of Chemistry University of CaliforniaRiversideCA 92521USA

In a recent article published in Nature,Sen Santara et *** a general mechanism that allows endoplasmic reticulum(ER)stress,a common response to many cellular dysfunctions,to signal to natural killer(NK)cells to destroy the stressed cell(Fig.1).1 This mechanism suggests that targeting this signaling pathway might serve as a common therapeutic approach to treat disparate diseases,including cancers and *** innate immune system recognizes molecular signa-tures that indicate threats to the organism,and transduces these signatures into an immune response to counter these *** part of the innate immune system,NK cells constitute a lymphoid immune cell type that kills infected or cancerous cells on the basis of their presentation of specific ligands or markers on the surface of abnormal cells.

关键词： killer surface

An MAP kinase interacts with LHK1 and regulates nodule organogenesis in Lotus japonicus

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Science China(Life Sciences) 2019年第9期62卷 1203-1217页

作者： Jun Yin Xiaomin Guan Heng Zhang Longxiang Wang Hao Li Qing Zhang Tao Chen Zeyuan Xu Zonglie Hong Yangrong Cao Zhongming Zhang State Key Laboratory of Agricultural microbiology College of Life Science and TechnologyHuazhong Agricultural UniversityWuhan 430070China Department of Plant Soil and Entomological Sciences and Program of MicrobiologyMolecular Biology and BiochemistryUniversity of IdahoMoscowID 83844USA

Symbiosis receptor-like kinase(SymRK) is a key protein mediating the legume-Rhizobium *** previous work has identified an MAP kinase kinase,SIP2,as a SymRK-interacting protein to positively regulate nodule organogenesis in Lotus japonicus,suggesting that an MAPK cascade might be involved in Rhizobium-legume *** this study,LjMPK6 was identified as a phosphorylation target of *** transgenic *** with RNAi silencing of LjMPK6 decreased the numbers of nodule primordia(NP) and nodule,while plants overexpressing LjMPK6 increased the numbers of nodule,infection threads(ITs),and NP,indicating that LjMPK6 plays a positive role in ***6 could interact with a cytokinin receptor,LHK1 both in vivo and in ***6 was shown to compete with LHP1 to bind to the receiver domain(RD) of LHK1 and to downregulate the expression of two LjACS(1-aminocyclopropane-1-carboxylic acid synthase) genes and ethylene levels during *** study demonstrated an important role of LjMPK6 in regulation of nodule organogenesis and ethylene production in ***.

关键词： cytokinin ethylene biosynthesis LHK1 Lotus japonicus MAPK cascade root nodule symbiosis

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Biofilm analyses and exoproduct release by clinical and environmental isolates of Burkholderia pseudomallei from Brazil

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Asian Pacific Journal of Tropical Medicine 2023年第7期16卷 321-328页

作者： Glaucia Morgana de Melo Guedes Crister JoséOcadaque Alyne Soares Freitas Rodrigo Machado Pinheiro Giovanna Barbosa Riello Silviane Praciano Bandeira Rossana de Aguiar Cordeiro Marcos Fábio Gadelha Rocha JoséJúlio Costa Sidrim Débora de Souza Collares Maia Castelo-Branco Department of Pathology and Legal Medicine Postgraduate Program in Medical MicrobiologyGroup of Applied Medical MicrobiologyFederal University of CearáFortalezaCEBrazil Department of Clinical and Toxicological Analysis School of PharmacyFederal University of CearáFortalezaCEBrazil Department of Pathology and Legal Medicine Postgraduate Program in Medical MicrobiologyLaboratory of Emerging and Reemerging PathogensFederal University of CearáFortalezaCEBrazil School of Veterinary Medicine Postgraduate Program in Veterinary SciencesState University of CearáFortalezaCEBrazil

Objective:To characterize biofilm production by clinical(n=21)and environmental(n=11)isolates of Burkholderia pseudomallei and evaluate the production of proteases,hemolysins and ***:Initially,the 32 strains were evaluated for biofilm production in Müller-Hinton broth-1%glucose(MH-1%glucose)and BHI broth-1%glucose,using the crystal violet staining ***,growing(48 h)and mature(72 h)biofilms were evaluated by confocal ***,the production of proteases,hemolysins and siderophores by planktonic aggregates,growing biofilms and mature biofilms was ***:All isolates produced biofilms,but clinical isolates had significantly higher biomass in both MH-1%glucose(P<0.001)and BHI-glucose 1%(P=0.005).The structural analyses by confocal microscopy showed thick biofilms,composed of multiple layers of cells,homogeneously arranged,with mature biofilms of clinical isolates presenting higher biomass(P=0.019)and thickness of the entire area(P=0.029),and lower roughness coefficient(P=0.007)than those of environmental *** production by growing biofilms was significantly greater than that of planktonic(P<0.001)and mature biofilms(P<0.001).Hemolysin release by planktonic aggregates was higher than that of biofilms(P<0.001).Regarding siderophores,mature biofilms presented higher production than growing biofilms(P<0.001)and planktonic aggregates(P<0.001).Conclusions:Clinical isolates have higher production of biofilms than their environmental counterparts;protease and siderophores seem important for growth and maintenance of Burkholderia pseudomallei biofilms.

关键词： Mangosteen Burkholderia pseudomallei Biofilms Proteases Hemolysins Siderophores

Notch signaling and its emerging role in autoimmunity

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Frontiers in Biology 2013年第3期8卷 279-294页

作者： Tanapat PALAGA Lisa M. MINTER Department of microbiology Faculty of Science Medical Microbiology Interdisciplinary Program Graduate School ChulalongkornUniversity Pathumwan Bangkok 10330 Thailand program in Molecular and Cellular Biology University of Massachusetts Amherst MA 01003 USA Department of Veterinary & Animal Sciences University of Massachusetts Amherst MA 01003 USA

Studies of notch signaling in immune cells have uncovered critical roles for this pathway both during the differentiation and effector function phases of immune responses. Cells of the myeloid lineage, including macrophages and dendritic cells, function as key components of innate immune defense against infection and, by acting as antigen presenting cells, can instruct cells of the adaptive immune response, specifically CD4 and CD8 T cells. Tight regulation of this functional interaction is needed to ensure a well-balanced immune response and its dysregulation may indirectly or directly cause the tissue damage characteristic of autoimmune diseases. In this review, the focus will be placed on those recent findings which support a role for notch signaling in inflammatory responses mediated by macrophages and other myeloid lineage cells, as well as peripheral T cells, and their relevance to inflammatory and autoimmne diseases.

关键词： notch signaling inflammation autoimmunity

Clinical and environmental isolates of Burkholderia pseudomallei from Brazil: Genotyping and detection of virulence gene

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Asian Pacific Journal of Tropical Medicine 2017年第10期10卷 945-951页

作者： Tereza de Jesus Pinheiro Gomes Bandeira Debora de Souza Collares Maia Castelo-Branco Marcos Fabio Gadelha Rocha Rossana de Aguiar Cordeiro Crister Jose Ocadaque Manoel de Araújo Neto Paiva Raimunda Samia Nogueira Brilhante Jose Júlio Costa Sidrim Specialized Medical Mycology Center Postgraduate Program in Medical Microbiology Federal University of Ceará Christus School of Medicine Postgraduate program in Veterinary Sciences State University of Ceará Federal Institute of Education Science and Technology of Ceará

Objective: To evaluate the genetic diversity of clinical and environmental isolates of Burkholderia pseudomallei(***) recovered in Ceara, Brazil, and screen these isolates for the presence of type three secretion system virulence ***: Nineteen *** isolates(9 from clinical cases and 10 from soils)were *** amplified polymorphic DNA was performed with primers OPQ-2, OPQ-4 and OPQ-16 to evaluate the genetic diversity, and type three secretion system gene was detected through polymerase chain ***: Random amplified polymorphic DNA showed a genetic relatedness of approximately 50% among the tested *** isolates, which were grouped into two clades, of which the biggest ones comprised 18/19 isolates for primer OPQ-2, and 17/19 isolates for primer *** OPQ-4 grouped the isolates into three clades comprising 1/19, 3/19 and 15/19 ***, type three secretion system gene was detected in all tested ***: This is an effort to type *** strains from Ceara, which is important for better understanding this pathogen, contributing for the epidemiological surveillance of melioidosis in this endemic region.

关键词： Burkholderia pseudomallei Melioidosis RAPD TTSS gene