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1.
Cancer Cell Int ; 23(1): 11, 2023 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-36698173

RESUMO

Ovarian cancer (OC) is one of the most common gynecological malignancies with high morbidity and mortality. The peritoneum is one of the most common metastatic sites in ovarian cancer, involving large amounts of ascites. However, its mechanism is unclear. The peritoneal microenvironment composed of peritoneal effusion and peritoneum creates favorable conditions for ovarian cancer progression and metastasis. Here, we reviewed the peritoneal metastasis patterns and molecular mechanisms of ovarian cancer, as well as major components of the peritoneal microenvironment, peritoneal effusion, and immune microenvironment, and investigated the relationship between the peritoneal microenvironment and ovarian cancer metastasis.

2.
Plant Dis ; 2023 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-37669172

RESUMO

Vigna unguiculata belongs to the Legume family, and is an annual twining, herbaceous vine plant, which is native to Africa. V. unguiculata is the most economically beneficial type of off-season vegetables in Hainan, China because of its rich in nutrients such as protein, minerals, dietary fiber, and vitamins (Jayathilake et al. 2018). In April 2022, typical powdery mildew infection was observed on V. unguiculata leaves in Haikou, Hainan Province, China (20°3'40.428"N, 110°19'45.217"E). More than 70% leaves of 13 V. unguiculata plants displayed severe powdery mildew disease. The diseased leaves at first exhibited white rounded irregular patches, which gradually enlarged, fused and covered all the leaf as well as stems. Edges of the infected leaves crinkled upwards, and the leaves often fell off the plants at the late infection stage. On the infected leaves, many conidiophores and dense mycelium were observed by microscopic analysis. Hyphae were septate, branched, epigenous, and flexuous to straight. Hyphal appressoria were indistinct or slightly nipple-shaped, and the haustoria developed were in the shape of oval-sphere and 9 to 11µm long. Foot cells of conidiophores were straight, cylindrical, and measured 43 to 70 × 10 to 12 µm. The conidiophores arising straightly from a hyphal cell, were measured 168 to 252 (mean = 204) µm in length and produced 6 to 9 immature conidia in each chain. Conidia were ovate, pyriform or barrel-shaped, with fibrosin bodies, and measured 26 to 32 (mean = 29.4) × 16 to 20 (mean = 18.6) µm. The chasmothecia was not found in all samples. These morphological characteristics were typical of the conidial stage of the powdery mildew Podosphaera xanthii of genus Podosphaera (Braun and Cook 2012). To further confirm the identity of this causal fungus, the internal transcribed spacer (ITS) region, and the partial sequence of large subunit ribosomal RNA gene (28S rRNA), were amplified with primer pairs ITS1/ ITS4 (White et al. 1990) and NL1/NLP2 (Mori et al. 2000) from extracted genomic DNA. The obtained 563-bp ITS region and 715-bp 28S rRNA gene sequences were deposited in GenBank (ITS, OQ415534; 28S rRNA, OQ415545.1), and were compared with BLAST analysis in the GenBank nr database. The results revealed that the ITS region sequence was 99.82% identity with P. xanthii isolate HUVU-08 (MH143485.1), and the 28S rRNA gene partial sequence was 100% identity with P. xanthii isolate XHL1 (MK357442.1). On the basis of the morphological characteristics and sequence analysis, this fungus was identified as P. xanthii. Pathogenicity tests were performed by gently brushing conidia onto the leaves of six healthy potted V. unguiculata plants. Six non-inoculated plants were used as control. All plants were maintained in a greenhouse at 26 ± 2°C. After 2 weeks inoculation, similar symptoms were observed in the inoculated plants, whereas no symptoms occurred on the control plants. By microscopic observation, the fungus present on the inoculated plants was morphologically identical to those on originally diseased plants. Furthermore, ITS and 28S rRNA sequences of the re-isolated fungus individually displayed 100% identity with OQ415534 and OQ415545.1. So far, although powdery mildew disease caused by P. xanthii on different plants including Sigesbeckia orientalis (Mukhtar et al. 2022), Vigna radiata (Sheu et al. 2021), Cosmos bipinnatus (Kong et al. 2023), Verbena brasiliensis (Luecke et al. 2020), Cucurbita ficifolia (Choi et al. 2022), Glandularia tenera (Pei et al. 2023) and Verbena bonariensis (Choi et al. 2023) have been reported, to our knowledge, this is the first report of powdery mildew caused by P. xanthii on V. unguiculata in Hainan, China, which seriously threatens the utilization of V. unguiculata on off-season vegetables industry.

3.
J Cell Physiol ; 234(4): 5264-5275, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30341904

RESUMO

OBJECTIVES: SMAD3 is pivotal in the biology functions of various tumors. This study is aiming to study the relationship among SMAD3, long noncoding RNAs (lncRNAs) OPA-interacting protein 5 antisense transcript 1 (OIP5-AS1), and miR-143-3p, and their effects on cervical cancer. METHODS: In our research, real-time polymerase chain reaction and western blot assay were conducted to detect the expression level of messenger RNA and protein in tumor tissues and cells. Transfection of lncRNA OIP5-AS1, miR-143-3p, or SMAD3 was performed to investigate their potential effects on the function of cell as well as the relationship among them in cervical cell lines via 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide) together with transwell assays or dual-luciferase reporter assay respectively. RESULTS: SMAD3, lncRNA OIP5-AS1 expression is significantly enhanced in cervical cancer tissues and cell lines, but miR-143-3p was inhibited. LncRNA OIP5-AS1 is demonstrated to mediate the physiological process of cervical cancer cells. Moreover, silencing SMAD3 via siRNA suppressed cell number, viability, migration and invasion, whereas overexpression of OIP5-AS1 promoted these abilities. Furthermore, lncRNA OIP5-AS1 exert its function via sponging miR-143-3p to regulate SMAD3 expression. CONCLUSIONS: LncRNA OIP5-AS1 promoted SMAD3 expression via mediating miR-143-3p to promote migration and invasion of cervical cancer cells.


Assuntos
Movimento Celular , MicroRNAs/metabolismo , RNA Longo não Codificante/metabolismo , Proteína Smad3/metabolismo , Neoplasias do Colo do Útero/metabolismo , Linhagem Celular Tumoral , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , MicroRNAs/genética , Invasividade Neoplásica , Metástase Neoplásica , RNA Longo não Codificante/genética , Transdução de Sinais , Proteína Smad3/genética , Regulação para Cima , Neoplasias do Colo do Útero/genética , Neoplasias do Colo do Útero/patologia
4.
Cancer Cell Int ; 19: 45, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30858762

RESUMO

BACKGROUND: The study purpose was to make investigation into the influence of XIST on cervical cancer progression and what's more its potential mechanism. METHODS: The cervical cancer data sets (lncRNA, miRNA, and mRNA) obtained from TCGA were analyzed with the "mixOmics" R package. Then, the expression of XIST, miR-140-5p, and ORC1 were detected using qRT-PCR and western blot in both tissues and cervical cancer cell lines (Hela and C33A) to verify the bioinformatics analyses results. CCK-8 assay, 5-ethynyl-2'-deoxyuridine (EdU) assays, cell cycle assay and cell apoptosis assay were practiced. Besides, immunohistochemistry staining was operated for the detection of the Ki-67, E-cadherin and vimentin expression in cervical cancer tissues and the apoptosis-related proteins expression (c-caspase3, Bcl-2, total PARP and cleaved PARP) was verified through western blot. And in vivo experiments were implemented. RESULTS: MiR-140-5p was down-regulated but XIST and ORC1 were up-regulated in cervical cancer tissues and cell lines. Knocking down of the XIST or ORC1 memorably suppressed cell proliferation, blocked cell cycle, decreased the expression of Bcl-2 while increased the apoptosis rate and the expression of c-caspase3 and cleaved PARP in HeLa and C33A cells. Besides, the results of immunohistochemistry staining showed knocking down the expression of XIST improved the expression levels of E-cadherin and decreased Ki-67 and vimentin expression. And overexpression of miR-140-5p also could inhibit the progression and reverse the influence of XIST and ORC1 in HeLa and C33A cells. CONCLUSION: Our study indicated the effects of XIST/miR-140-5p/ORC1 axis on the progression of cervical cancer which will shed new light on epigenetic diagnostics and therapeutics in cervical cancer.

5.
Mol Plant Pathol ; 25(1): e13415, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38279853

RESUMO

Oidium heveae HN1106, a powdery mildew (PM) that infects rubber trees, has been found to trigger disease resistance in Arabidopsis thaliana through ENHANCED DISEASE SUSCEPTIBILITY 1 (EDS1)-, PHYTOALEXIN DEFICIENT 4 (PAD4)- and salicylic acid (SA)-mediated signalling pathways. In this study, a typical TOLL-INTERLEUKIN 1 RECEPTOR, NUCLEOTIDE-BINDING, LEUCINE-RICH REPEAT (TIR-NB-LRR)-encoding gene, WHITE RUST RESISTANCE 4 (WRR4B), was identified to be required for the resistance against O. heveae in Arabidopsis. The expression of WRR4B was upregulated by O. heveae inoculation, and WRR4B positively regulated the expression of genes involved in SA biosynthesis, such as EDS1, PAD4, ICS1 (ISOCHORISMATE SYNTHASE 1), SARD1 (SYSTEMIC-ACQUIRED RESISTANCE DEFICIENT 1) and CBP60g (CALMODULIN-BINDING PROTEIN 60 G). Furthermore, WRR4B triggered self-amplification, suggesting that WRR4B mediated plant resistance through taking part in the SA-based positive feedback loop. In addition, WRR4B induced an EDS1-dependent hypersensitive response in Nicotiana benthamiana and contributed to disease resistance against three other PM species: Podosphaera xanthii, Erysiphe quercicola and Erysiphe neolycopersici, indicating that WRR4B is a broad-spectrum disease resistance gene against PMs.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/genética , Arabidopsis/metabolismo , Resistência à Doença/genética , Erysiphe/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Transdução de Sinais , Doenças das Plantas/genética , Ácido Salicílico/metabolismo
6.
Dis Markers ; 2022: 9328972, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36393971

RESUMO

Background: Epithelial ovarian cancer (EOC) has the lowest survival rate among female reproductive cancers present with symptoms of aggressive malignancies, poor prognosis, drug resistance and postoperative recurrence. The majority of patients with EOC are diagnosed at an advanced stage due to the therapeutic challenges including lack of early diagnosis and effective therapeutic targets for EOC. Methods: Pan-cancer analyses were performed to explore the features of forkhead-box (FOX) A1 (FOXA1) using data from TCGA and GTEx databases. R package "clusterprofiler" was used to perform the enrichment analysis of FOXA1 in EOC. Data downloaded from Drug Sensitivity in Cancer (GDSC) database were used to evaluate the association between FOXA1 and antitumor drug sensitivity. In experimental verification, FOXA1 expression was detected using qRT-PCR and western blot assays. Western blot, immunofluorescence staining, and Transwell assays were used to assess the influence of FOXA1 silencing on epithelial-mesenchymal transition (EMT) of EOC cells. Results: We found that FOXA1 was highly expressed in EOC and predicted poorer survival of EOC patients. We observed that FOXA1 expression was positively correlated EMT-related pathways. Through experimental verification, we found the underlying function of FOXA1 to promote EMT in ovarian cancers. The results from western blot, immunofluorescence staining, and Transwell assays showed that FOXA1 silencing impeded the progression of EMT and invasiveness of the cancer cells. Furthermore, CCK-8 and invasion assays suggested that siRNA-FOXA1 attenuated the ability of cancer cells to metastasize and proliferate. Dual-luciferase reporter assays confirmed the binding activity of FOXA1 to the promoter of connective tissue growth factor (CTGF). In addition, we found that FOXA1 was closely correlated immunosuppressive microenvironment of EOC. High FOXA1 expression may contribute to the resistance of many anticancer drugs. Conclusions: Our results predict and validate the function of FOXA1 in promoting EMT and the progression of disease in EOC. Targeting FOXA1 may improve the sensitivity of EOC treatment.


Assuntos
Regulação Neoplásica da Expressão Gênica , Neoplasias Ovarianas , Humanos , Feminino , Carcinoma Epitelial do Ovário/genética , Carcinoma Epitelial do Ovário/patologia , Prognóstico , Neoplasias Ovarianas/patologia , Biomarcadores , Microambiente Tumoral , Fator 3-alfa Nuclear de Hepatócito/genética , Fator 3-alfa Nuclear de Hepatócito/metabolismo
7.
Aging (Albany NY) ; 13(5): 7416-7429, 2021 03 03.
Artigo em Inglês | MEDLINE | ID: mdl-33686968

RESUMO

Fc fragment of IgG-binding protein (FCGBP) is differentially expressed in various tumors. However, the correlation between FCGBP and immune cell infiltration in ovarian cancer remains unclear. FCGBP expression was analyzed using The Cancer Genome Atlas (TCGA) pan-cancer data, and the ovarian cancer expression profile was analyzed using the Gene Expression Omnibus database. The clinical prognostic value of FCGBP was evaluated using clinical survival data from TCGA. Enrichment analysis of FCGBP was performed using the R package clusterProfiler. Based on known immune cell infiltration scores for samples found in TCGA, we analyzed the association between immune cell infiltration level and FCGBP expression. FCGBP was highly expressed and associated with poorer overall survival (p = 0.00051) and disease-specific survival (p = 0.0012) in ovarian cancer and other tumors. Additionally, high FCGBP expression correlated significantly with immune-related gene sets, including those involved in chemokine signaling pathways and innate and adaptive immunity. Further analysis showed that M2 macrophage infiltration increased and M1 macrophage infiltration decreased in tissues with high FCGBP expression. Our study suggests that FCGBP contributes to M2 macrophage polarization by acting as an oncogene in ovarian cancer. FCGBP may represent a clinically helpful biomarker for predicting overall survival of ovarian cancer patients.


Assuntos
Moléculas de Adesão Celular/metabolismo , Neoplasias Ovarianas/metabolismo , Biologia Computacional , Feminino , Humanos , Linfócitos do Interstício Tumoral/patologia , Macrófagos/patologia , Neoplasias Ovarianas/diagnóstico , Neoplasias Ovarianas/mortalidade , Neoplasias Ovarianas/patologia , Ovário/metabolismo , Ovário/patologia , Prognóstico , Análise de Sobrevida , Transcriptoma
8.
Front Oncol ; 10: 1733, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33117670

RESUMO

Background: The literature reports conflicting results regarding the effect of human papillomavirus (HPV) genotype 16 (HPV-16)/18 (HPV-18) positivity on cervical cancer (CC) prognosis. Aim: To conduct a meta-analysis to examine the effect of HPV-16/18 positivity on the prognosis of patients with CC. Methods: PubMed, Embase, and the Cochrane Library were searched for available papers published up to March 2020. The main outcome was the hazard ratio (HR) of overall survival (OS) or disease-free survival (DFS) comparing HPV-16 or HPV-18 positivity and negativity. The random-effects model was used for synthesizing survival outcomes. Results: Nine studies and 2,028 patients were included. Four studies reported OS in HPV-16 positivity, and no association was found between HPV-16 positivity and OS to CC (HR = 0.79, 95% CI: 0.26-2.39, P = 0.675). Three studies reported DFS in HPV-16 positivity, and no association was found between HPV-16 positivity and DFS to CC (HR = 0.80, 95% CI: 0.30-2.11, P = 0.654). Two studies reported DFS in HPV-18 positivity, and no association was found between HPV-18 positivity and DFS to CC (HR = 0.99, 95% CI: 0.55-1.78, P = 0.984). One study reported progression-free survival (PFS) in HPV-18 positivity, and an association was observed between HPV-18 positivity and PFS to CC (HR = 2.66, 95% CI: 1.44-4.94, P = 0.002). The sensitivity analyses showed that one study biased the analysis of the association between HPV-16 and OS, and another study biased the association between HPV-16 and DFS. Conclusion: The presence of HPV-16 and HPV-18 positivity appears to have no significant association with prognosis in CC in either OS or PFS. The presence of HPV-16 or HPV-18 positivity has no significant association with prognosis in CC in either OS or PFS.

9.
Cancer Chemother Pharmacol ; 83(4): 603-613, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30627777

RESUMO

PURPOSE: Cisplatin (DDP)-based chemotherapy is a standard strategy for cervical cancer, while chemoresistance remains a huge challenge. In the present study, we aimed to explore the effects of SPP1 on the proliferation and apoptosis rate of the HeLa cervical cancer cell line with cisplatin (DDP) resistance. METHODS: Microarray analysis was employed to select differentially expressed genes in cervical cancer tissues and adjacent tissues. Then, we established a DDP-resistant HeLa cell line (res-HeLa). Western blotting was used to detect SPP1 expression in both tissue and cells. After the transfection with si-SPP1 and pcDNA3.1-SPP1, colony formation and MTT assays were applied to detect cell proliferation changes. Flow cytometry was employed to detect the cell apoptosis rate. Western blotting was performed to verify the activation of PI3K/Akt signal pathway proteins related to DDP resistance. RESULTS: SPP1 was overexpressed in cervical cancer tissues and cell lines. Compared to normal HeLa cells, expression of SPP1 was significantly enhanced in res-HeLa cells. SPP1 knockdown resulted in repressed proliferation and enhanced apoptosis of res-HeLa cells, which could be reversed by SPP1 overexpression in HeLa cells. Additionally, downregulation of SPP1 improved the DDP sensitivity of HeLa by inhibiting the PI3K/Akt signaling pathway. CONCLUSION: SPP1 inhibition could suppress proliferation, induce apoptosis and increase the DDP chemo-sensitivity of HeLa cells.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Cisplatino/farmacologia , Osteopontina/antagonistas & inibidores , Neoplasias do Colo do Útero/tratamento farmacológico , Proliferação de Células/efeitos dos fármacos , Regulação para Baixo , Resistencia a Medicamentos Antineoplásicos , Feminino , Regulação Neoplásica da Expressão Gênica , Técnicas de Silenciamento de Genes , Células HeLa , Humanos , Análise em Microsséries , Osteopontina/genética , Neoplasias do Colo do Útero/patologia
10.
J Bacteriol ; 190(19): 6501-8, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18658263

RESUMO

Halocin C8 (HalC8) is a stable microhalocin exhibiting strong antimicrobial activity against a wide range of haloarchaea. HalI, a 207-amino-acid peptide derived from the N terminus of the HalC8 preproprotein, is the immunity protein of HalC8. In this study, the molecular mechanism of the immunity function of HalI was investigated. Both pull-down and surface plasmon resonance assays revealed that HalI directly interacted with HalC8, and a mixture of purified HalI and HalC8 readily formed a heterocomplex, which was verified by gel filtration. Interestingly, HalC8 tended to form a self-associated complex, and one immunity protein likely sequestered multiple halocins. Significantly, the helix-loop-helix (HLH) motif containing a 4-amino-acid repeat (RELA) at the N terminus of HalI played a key role in its immunity activity. Disruption of the HLH motif or mutagenesis of the key residues of the RELA repeat resulted in loss of both the immunity function and the ability of HalI to bind to HalC8. These results demonstrated that HalI sequestered the activity of HalC8 through specific and direct binding.


Assuntos
Proteínas Arqueais/imunologia , Haloarcula/imunologia , Sequências Hélice-Alça-Hélice/imunologia , Peptídeos/imunologia , Sequência de Aminoácidos , Proteínas Arqueais/genética , Proteínas Arqueais/metabolismo , Cromatografia em Gel , Haloarcula/genética , Haloarcula/metabolismo , Sequências Hélice-Alça-Hélice/genética , Dados de Sequência Molecular , Mutação , Peptídeos/genética , Peptídeos/metabolismo , Ligação Proteica , Ressonância de Plasmônio de Superfície
11.
Biochem Biophys Res Commun ; 371(3): 573-7, 2008 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-18457667

RESUMO

DnaA plays a central role in initiation of DNA replication at oriC in bacteria, and is also a transcription regulator which interacts with the DnaA box relative to a specific gene. Through screening the interaction between TtDnaA and the transcription machinery in Thermoanaerobacter tengcongensis by yeast two-hybrid assays, we found for the first time that the TtDnaA could interact with an anti-terminator, TtNusG2, in this thermophilic bacterium. The direct interaction between TtDnaA and TtNusG2 was verified by surface plasmon resonance (SPR) assay in vitro, and was further confirmed by co-immunoprecipitation assay in vivo. Moreover, we demonstrated that domain I and domain III of TtDnaA were responsible for the interaction with TtNusG2. These findings might expand our understanding of cooperation of two fundamental processes, replication and transcription, in this bacterium.


Assuntos
Proteínas de Bactérias/metabolismo , Replicação do DNA , Proteínas de Ligação a DNA/metabolismo , Fatores de Alongamento de Peptídeos/metabolismo , Thermoanaerobacter/genética , Imunoprecipitação , Ressonância de Plasmônio de Superfície , Thermoanaerobacter/metabolismo , Transcrição Gênica , Técnicas do Sistema de Duplo-Híbrido
12.
Wei Sheng Wu Xue Bao ; 46(2): 318-22, 2006 Apr.
Artigo em Zh | MEDLINE | ID: mdl-16736600

RESUMO

Halocin C8 (HalC8), produced by a halophilic archaeon strain AS7092, is a gene-coded peptide microhalocin and has a wide inhibitory spectrum against the members of haloarchaea. To investigate the mechanisms of the gene expression regulation, the peptide processing and transportation of this halocin, a 9.3kb DNA gene cluster containing the halocin C8 encoding gene (proC8) and other possible involved genes was cloned, by screening of a genomic library of AS7092 as well as anchoring PCR technique. Sequence analysis indicated that it contained at least six open reading frames, including halU, halR, proC8, halT1, halT2 and halT3. The gene halU encodes a membrane-spanning protein HalU, but its function is unknown. The gene halR encodes a putative regulator protein HalR, its function was deduced to regulate the transcription of proC8 gene, which encodes the precursor for halocin C8. The gene halT1, halT2 and halT3 likely encode the transporters HalT1, HalT2 and HalT3, the functions of which were speculated to transport the halocin C8 out of the cellular membrane. This is the first report of gene cluster cloning for any halocin.


Assuntos
Archaea/genética , Clonagem Molecular , Família Multigênica , Peptídeos/genética , Sequência de Aminoácidos , Archaea/química , Archaea/metabolismo , Proteínas Arqueais/química , Proteínas Arqueais/genética , Proteínas Arqueais/metabolismo , Dados de Sequência Molecular , Fases de Leitura Aberta , Peptídeos/metabolismo , Alinhamento de Sequência
13.
Mol Plant Pathol ; 17(9): 1331-1343, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-26724785

RESUMO

Oidium heveae, an obligate biotrophic pathogen of rubber trees (Hevea brasiliensis), causes significant yield losses of rubber worldwide. However, the molecular mechanisms underlying the interplay between O. heveae and rubber trees remain largely unknown. In this study, we isolated an O. heveae strain, named HN1106, from cultivated H. brasiliensis in Hainan, China. We found that O. heveae HN1106 triggers the hypersensitive response in a manner that depends on the effector-triggered immunity proteins EDS1 (Enhanced Disease Susceptibility 1) and PAD4 (Phytoalexin Deficient 4) and on salicylic acid (SA) in the model plant Arabidopsis thaliana. However, SA-independent resistance also appears to limit O. heveae infection of Arabidopsis, because the pathogen does not produce conidiospores on npr1 (nonexpressor of pr1), sid2 (SA induction deficient 2) and NahG plants, which show disruptions in SA signalling. Furthermore, we found that the callose synthase PMR4 (Powdery Mildew Resistant 4) prevents O. heveae HN1106 penetration into leaves in the early stages of infection. To elucidate the potential mechanism of resistance of Arabidopsis to O. heveae HN1106, we inoculated 47 different Arabidopsis accessions with the pathogen, and analysed the plant disease symptoms and O. heveae HN1106 hyphal growth and conidiospore formation on the leaves. We found that the accession Lag2-2 showed significant susceptibility to O. heveae HN1106. Overall, this study provides a basis for future research aimed at combatting powdery mildew caused by O. heveae in rubber trees.


Assuntos
Arabidopsis/microbiologia , Ascomicetos/fisiologia , Interações Hospedeiro-Patógeno , Proteínas de Arabidopsis/metabolismo , Morte Celular , Resistência à Doença , Ecótipo , Hifas/crescimento & desenvolvimento , Fenótipo , Doenças das Plantas/microbiologia , Folhas de Planta/microbiologia , Ácido Salicílico/metabolismo
14.
Mol Microbiol ; 57(2): 537-49, 2005 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15978083

RESUMO

Halocin C8 (HalC8) is an extremely stable and hydrophobic microhalocin with 76 amino acids, and has a wide inhibitory spectrum against the haloarchaea. It is derived from the C-terminus of a 283-amino-acid prepro-protein (ProC8), which was demonstrated by molecular cloning of the halC8 gene, and verified by the N-terminal amino acid sequencing as well as MALDI-TOF-MS analysis of the purified HalC8. The production of this halocin is controlled through both transcription regulation and protein processing: the halC8 transcripts and HalC8 activity rapidly increased to maximal levels upon transition from exponential to stationary phase. However, while halC8 transcripts remained abundant, the HalC8 processing was inhibited during stationary phase. Remarkably, agar-diffusion test revealed the unprocessed ProC8 and its 207-amino-acid N-terminal peptide (HalI), with or without the putative Tat signal sequence, were capable to block the halocin activity of HalC8 in vitro. In addition, heterologous expression of HalI in Haloarcula hispanica rendered this sensitive strain remarkable resistance to HalC8, indicating that HalI encodes the immunity property of the producer. In accordance with this immunity function, HalI and ProC8 were both found localized on the cellular membrane. Protein interaction assay revealed that HalI likely sequestrated the HalC8 activity by specific binding. To our knowledge, this is the first report on halocin immunity, and our results that a single gene encodes both peptide antibiotic and immunity protein also provide a novel immune mechanism for peptide antibiotics.


Assuntos
Proteínas Arqueais/biossíntese , Proteínas Arqueais/genética , Resistência Microbiana a Medicamentos , Genes Arqueais , Haloarcula/genética , Haloarcula/metabolismo , Sequência de Aminoácidos , Proteínas Arqueais/química , Proteínas Arqueais/farmacologia , Sequência de Bases , Membrana Celular/química , DNA Arqueal/química , DNA Arqueal/genética , Dados de Sequência Molecular , Ligação Proteica , Processamento de Proteína Pós-Traducional , Estrutura Terciária de Proteína , RNA Arqueal/análise , RNA Mensageiro/análise , Análise de Sequência de DNA , Transcrição Gênica
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