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1.
Front Microbiol ; 10: 2127, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31572333

RESUMO

Microlunatus phosphovorus NM-1 is a polyphosphate (poly-P)-accumulating bacterium that accumulates poly-P under aerobic conditions and degrades poly-P under anaerobic conditions. In this study, the two-component system (TCS) PolS-PolR was identified in NM-1, and the response regulator PolR was found to directly bind to the promoters of genes related to phosphate transport (MLP_RS00235, MLP_RS23035, and MLP_RS24590); poly-P catabolism (MLP_RS12905) and poly-P synthesis (MLP_RS23025). RT-qPCR assays showed that ppgk (MLP_RS12905), ppk (MLP_RS23025), pstS (MLP_RS23035), and pit (MLP_RS24590) were down-regulated during the aerobic-anaerobic shift. The sequence GTTCACnnnnnGTTCaC was identified as a recognition sequence for PolR by MEME analysis and DNase I footprinting. EMSAs and ChIP-qPCR assays indicated that PolR binds to the promoters of pit (MLP_RS00235), ppgk (MLP_RS12905), ppk (MLP_RS23025), pstS (MLP_RS23035) and pit (MLP_RS24590), and ChIP-qPCR further suggested that the binding affinity of PolR was lower under anaerobic conditions than under aerobic conditions in vivo. These findings indicate that the PolS-PolR TCS in M. phosphovorus may be involved in the regulation of poly-P metabolism in response to levels of dissolved oxygen in the environment, and our results provide insights into new approaches for understanding the mechanisms of phosphorus accumulation and release.

2.
AMB Express ; 9(1): 118, 2019 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-31352530

RESUMO

During industrial fermentation, Streptomyces clavuligerus F613-1 simultaneously produces primary product clavulanic acid (CA) and cephamycin C. The cephamycin C biosynthetic gene cluster and pathway have been basically elucidated and the CcaR positive regulator was found to control the cephamycin genes expression. However, additional mechanisms of regulation cannot be excluded. The BB341_RS13780/13785 gene pair in S. clavuligerus F613-1 (annotated as SCLAV_2960/2959 in S. clavuligerus ATCC27064) encodes a bacterial two-component system (TCS) and were designated as CepRS (for cephamycin regulator/sensor). CepRS significantly affects cephamycin C production but only slightly affects CA production. To further understand the regulation of cephamycin C biosynthesis, the cepRS genes were deleted from S. clavuligerus F613-1. The deletion mutant resulted in decreased cephamycin C production but had no phenotypic effects. Real-time quantitative polymerase chain reaction analysis revealed that CepRS regulates the expression of most genes involved in cephamycin C biosynthesis, with electrophoretic mobility shift assays showing that CepR interacts with the cefD-cmcI intergenic region. These results demonstrate that the CepR response regulator serves as a transcriptional activator of cephamycin C biosynthesis, which may provide an approach for metabolic engineering methods for CA production by S. clavuligerus F613-1 in future.

3.
Microb Drug Resist ; 25(3): 317-325, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30864883

RESUMO

Development of antibiotic resistance can be achieved either by mutation or by acquiring a resistance gene from foreign sources, with some resistance genes likely originating in microbial populations to counteract antibiotics present in natural ecosystems. In this study, we describe the first report of a strain of nonclinical multidrug-resistant Stenotrophomonas sp. strain G4 with high-level resistance to colistin and meropenem, phylogenetically distinct from well-studied multiple drug-resistant species of Stenotrophomonas maltophilia. As the high-level colistin resistance of this strain was of great concern, the genome of this strain was completely sequenced. Only one chromosome was identified, and no plasmids were found. Chromosomal gene variants and other potential genetic determinants conferring resistance to colistin and meropenem were comparatively analyzed, and results showed that strain G4 harbored two putative colistin resistance determinants (named mcr-5.3 and mcr-8.2) and four extended-spectrum ß-lactamase genes. In addition, 12 genes potentially encoding seven different types of efflux pumps were identified, which may have a major role in acquisition/transfer of colistin resistance. Our discovery of multiple antibiotic resistance determinants in this environmental strain extensively expands our understanding of the extent of dissemination of colistin and meropenem resistance.


Assuntos
Colistina/farmacologia , Farmacorresistência Bacteriana/genética , Meropeném/farmacologia , Esgotos/microbiologia , Stenotrophomonas maltophilia/efeitos dos fármacos , Stenotrophomonas maltophilia/isolamento & purificação , Antibacterianos/farmacologia , Stenotrophomonas maltophilia/genética , Água , Microbiologia da Água , beta-Lactamases/genética
4.
Front Microbiol ; 10: 244, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30837970

RESUMO

Streptomyces clavuligerus F613-1 produces a clinically important ß-lactamase inhibitor, clavulanic acid (CA). Although the biosynthesis pathway of CA has essentially been elucidated, the global regulatory mechanisms of CA biosynthesis remain unclear. The paired genes cagS and cagR, which are annotated, respectively, as orf22 and orf23 in S. clavuligerus ATCC 27064, encode a bacterial two-component regulatory system (TCS) and were found next to the CA biosynthetic gene cluster of S. clavuligerus F613-1. To further elucidate the regulatory mechanism of CA biosynthesis, the CagRS TCS was deleted from S. clavuligerus F613-1. Deletion of cagRS resulted in decreased production of CA, but the strain phenotype was not otherwise affected. Both transcriptome and ChIP-seq data revealed that, in addition to CA biosynthesis, the CagRS TCS mainly regulates genes involved in primary metabolism, such as glyceraldehyde 3-phosphate (G3P) metabolism and arginine biosynthesis. Notably, both G3P and arginine are precursors of CA. Electrophoretic mobility shift assays demonstrated that the response regulator CagR could bind to the intergenic regions of argG, argC, oat1, oat2, ceaS1, and claR in vitro, suggesting that CagR can directly regulate genes involved in arginine and CA biosynthesis. This study indicated that CagRS is a pleiotropic regulator that can directly affect the biosynthesis of CA and indirectly affect CA production by regulating the metabolism of arginine and G3P. Our findings provide new insights into the regulation of CA biosynthetic pathways and provide an innovative approach for future metabolic engineering efforts for CA production in S. clavuligerus.

5.
Curr Microbiol ; 76(8): 954-958, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29858620

RESUMO

Ansamitocins are extraordinarily potent antitumor agents. Ansamitocin P-3 (AP-3), which is produced by Actinosynnema pretiosum, has been developed as a cytotoxic drug for breast cancer. Despite its importance, AP-3 is of limited applicability because of the low production yield. A. pretiosum strain X47 was developed from A. pretiosum ATCC 31565 by mutation breeding and shows a relatively high AP-3 yield. Here, we analyzed the A. pretiosum X47 genome, which is ~8.13 Mb in length with 6693 coding sequences, 58 tRNA genes, and 15 rRNA genes. The DNA sequence of the ansamitocin biosynthetic gene cluster is highly similar to that of the corresponding cluster in A. pretiosum ATCC 31565, with 99.9% identity. However, RT-qPCR analysis showed that the expression levels of ansamitocin biosynthetic genes were significantly increased in X47 compared with the levels in the wild-type strain, consistent with the higher yield of AP-3 in X47. The annotated complete genome sequence of this strain will facilitate understanding the molecular mechanisms of ansamitocin biosynthesis and regulation in A. pretiosum and help further genetic engineering studies to enhance the production of AP-3.


Assuntos
Actinobacteria/genética , Actinobacteria/metabolismo , Antibióticos Antineoplásicos/metabolismo , Genoma Bacteriano , Maitansina/análogos & derivados , Análise de Sequência de DNA , Vias Biossintéticas/genética , Perfilação da Expressão Gênica , Maitansina/metabolismo , Anotação de Sequência Molecular
6.
3 Biotech ; 8(11): 472, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30456006

RESUMO

Mobile genetic elements involved in mediating horizontal transfer events contribute to bacterial evolution, and bacterial genomic plasticity and instability result in variation in functional genetic information in Streptomyces secondary metabolism. In a previous study, we reported the complete genome sequence of the industrial Streptomyces strain F613-1, which produces high yields of clavulanic acid. In this study, we used comparative genomics and bioinformatics to investigate the unique genomic features of this strain. Taken together, comparative genomics were used to systematically investigate secondary metabolism capabilities and indicated that frequent exchange of genetic materials between Streptomyces replicons may shape the remarkable diversities in their secondary metabolite repertoires. Moreover, a 136.9-kb giant region of plasticity (RGP) was found in the F613-1 chromosome, and the chromosome and plasmid pSCL4 are densely packed with an exceptionally large variety of potential secondary metabolic gene clusters, involving several determinants putatively accounting for antibiotic production. In addition, the differences in the architecture and size of plasmid pSCL4 between F613-1 and ATCC 27064 suggest that the pSCL4 plasmid could evolve from pSCL4-like and pSCL2-like extrachromosomal replicons. Furthermore, the genomic analyses revealed that strain F613-1 has developed specific genomic architectures and genetic patterns that are well suited to meet the requirements of industrial innovation processes.

7.
Tuberculosis (Edinb) ; 112: 62-68, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30205970

RESUMO

MprAB and PhoPR are important two-component systems (TCSs) in Mycobacterium tuberculosis, and both regulate EspR, a key regulator of the ESX-1 secretion system. Although previous studies suggest that the response regulator PhoP does not directly regulate mprA, the interplay between MprAB and PhoPR remains unclear. In this study, we found that the response regulator MprA can bind to the phoP promoter. Four repeat motifs, D1-D4, constituting two predicted binding sites, were located in the region protected by MprA in DNA footprinting. D1-D4 lack the reported conserved MprA binding sequences, indicating that MprA can recognize a greater range of target sites. Interestingly, D1-D2 overlap a previously reported PhoP binding site, and mutation of D1-D2 inhibited PhoP binding, whereas the D3-D4 site, but not the D1-D2 site, was required for MprA binding. EMSA assays also suggest that MprA and PhoP compete to bind to the phoP promoter. The results of the transcriptional and western blot assays are consistent with a model in which MprA positively controls the phoP expression, which in turn upregulates the expression of espR. These findings reveal complex regulation of a major mycobacterial TCS by dual TCSs.


Assuntos
Proteínas de Bactérias/metabolismo , Mycobacterium tuberculosis/metabolismo , Proteínas de Bactérias/genética , Sítios de Ligação , Regulação Bacteriana da Expressão Gênica , Mutação , Mycobacterium tuberculosis/genética , Motivos de Nucleotídeos , Regiões Promotoras Genéticas , Ligação Proteica
8.
FEMS Microbiol Lett ; 365(6)2018 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-29481594

RESUMO

The ability of Microlunatus phosphovorus to accumulate large amounts of polyphosphate (Poly-P) plays an important role in removing soluble phosphorus from wastewater. Strain JN459, isolated from a sewage system, was previously demonstrated to be Microlunatus phosphovorus. In this study, we analyzed the phosphorus-accumulating and phosphorus-releasing characteristics of strain JN459. Our analyses indicate that strain JN459 accumulates Poly-P under aerobic conditions but releases phosphorus under anaerobic conditions. To determine the mechanisms underlying Poly-P metabolism in strain JN459, we compared transcriptional profiles under aerobic and anaerobic conditions. Significant differences were detected in the expression levels of genes associated with Poly-P metabolism between aerobic and anaerobic conditions, including ppk (MLP_47700, MLP_50300 and MLP_05750), ppgk (MLP_05430 and MLP_26610), ppx (MLP_44770), pap (MLP_23310) and ppnk (MLP_17420). The high expression of polyphosphate glucokinase (MLP_05430) and polyphosphate/ATP-dependent NAD kinase (MLP_17420) indicated that both of them might be responsible for utilizing Poly-P as the energy resource for growth under anaerobic conditions. These findings enhance our understanding of phosphate metabolism in a major bacterial species involved in wastewater phosphorus reduction.


Assuntos
Regulação Bacteriana da Expressão Gênica , Redes e Vias Metabólicas/genética , Fósforo/metabolismo , Polifosfatos/metabolismo , Propionibacteriaceae/genética , Propionibacteriaceae/metabolismo , Aerobiose , Anaerobiose , Microbiologia Ambiental , Perfilação da Expressão Gênica , Fosfotransferases/genética , Fosfotransferases/metabolismo
9.
Genome Announc ; 6(1)2018 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-29301883

RESUMO

Streptomyces gilvosporeus strain F607 is a producer of high levels of natamycin used in the fermentation industry. In this study, the complete genome sequence of strain F607 was determined. This genome sequence provides a basis for understanding natamycin biosynthesis and regulation in a high-natamycin-producing strain and will aid in the development of useful strategies for improving industrial strains.

10.
Can J Microbiol ; 64(1): 87-90, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29073359

RESUMO

Enterobacter cloacae strain R11 is a multidrug-resistant bacterium isolated from sewage water near a swine feedlot in China. Strain R11 can survive in medium containing up to 192 µg/mL polymyxin E, indicating a tolerance for this antibiotic that is significantly higher than that reported for other gram-negative bacteria. In this study, conjugation experiments showed that partial polymyxin E resistance could be transferred from strain R11 to Escherichia coli strain 25922, revealing that some genes related to polymyxin E resistance are plasmid-based. The complete genome sequence of this strain was determined, yielding a total of 4 993 008 bp (G+C content, 53.15%) and 4908 genes for the circular chromosome and 4 circular plasmids. Genome analysis revealed a total of 73 putative antibiotic resistance genes, including several polymyxin E resistance genes and genes potentially involved in multidrug resistance. These data provide insights into the genetic basis of the polymyxin E resistance and multidrug resistance of E. cloacae.


Assuntos
Farmacorresistência Bacteriana/genética , Enterobacter cloacae/genética , Genoma Bacteriano/genética , China , Resistência a Múltiplos Medicamentos/genética , Plasmídeos/genética
11.
Curr Microbiol ; 75(4): 401-409, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29134265

RESUMO

Rv1057 is the only ß-propeller protein in Mycobacterium tuberculosis, but its biological function is still unclear. In this study, we generated a deletion mutant of Rv1057 (D1057) in the virulent M. tuberculosis strain H37Rv and examined the characteristics of the mutant in vitro and in macrophages. We found that deletion of Rv1057 reduces secretion of the major virulence factor ESAT-6 and ESAT-6 stops in the cell envelope fraction during secretion, although ESAT-6 levels were similar in lysates of the mutant and control strains. In infected macrophages, Rv1057 deletion significantly reduced the secretion levels of cytokines IL-1ß, IL-10, TNF-α, and INF-γ, but did not affect IL-4 and IL-8. D1057-infected macrophages also release less LDH and produce more nitric oxide (NO) than H37Rv- and D1057com (Rv1057 complemented strain of D1057com)-infected macrophages, indicating that D1057 has the decreased cytotoxicity compared to H37Rv or D1057com. In addition, the capacity of the Rv1057 deletion mutant to grow in macrophages was significantly lower than that of H37Rv and D1057com. Our findings support a role for Rv1057 in ESAT-6 secretion and in modulating the interactions between M. tuberculosis and macrophages.


Assuntos
Antígenos de Bactérias/genética , Proteínas de Bactérias/genética , Mycobacterium tuberculosis/crescimento & desenvolvimento , Mycobacterium tuberculosis/genética , Tuberculose/microbiologia , Antígenos de Bactérias/metabolismo , Proteínas de Bactérias/metabolismo , Células Cultivadas , Deleção de Genes , Humanos , Interleucina-10/genética , Interleucina-10/metabolismo , Interleucina-4/genética , Interleucina-4/metabolismo , Macrófagos/metabolismo , Macrófagos/microbiologia , Mycobacterium tuberculosis/metabolismo , Óxido Nítrico/metabolismo , Tuberculose/genética , Tuberculose/metabolismo , Fatores de Virulência/genética , Fatores de Virulência/metabolismo
12.
FEMS Microbiol Lett ; 364(22)2017 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-29069461

RESUMO

The xdhR gene encodes a TetR-family regulator in Streptomyces coelicolor. However, little is known about the function of XdhR in regulating actinorhodin production. Here, we report that XdhR negatively regulates actinorhodin biosynthesis in S. coelicolor. Deletion of xdhR resulted in overproduction of actinorhodin by approximately 2.5-fold compared to the wild-type strain. Complementation of the xdhR deletion strain restored actinorhodin production to normal levels. In addition, the relative expression levels of actinorhodin cluster genes were all significantly increased in the xdhR deletion strain compared to the wild-type strain. XdhR can specifically bind the promoters of actII-4 and actII-1, two pathway-specific regulators of actinorhodin biosynthesis. These results suggest that xdhR negatively controls actinorhodin biosynthesis by directly regulating actII-4 and actII-1 in S. coelicolor.


Assuntos
Proteínas de Bactérias/genética , Streptomyces coelicolor/genética , Xantina Desidrogenase/genética , Antraquinonas/análise , Antraquinonas/metabolismo , Proteínas de Bactérias/metabolismo , Escherichia coli/genética , Deleção de Genes , Regulação Bacteriana da Expressão Gênica/genética , Genoma Bacteriano , Regiões Promotoras Genéticas , Ligação Proteica , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Streptomyces coelicolor/metabolismo , Xantina Desidrogenase/metabolismo
13.
Electron. j. biotechnol ; 28: 41-46, July. 2017. tab, ilus, graf
Artigo em Inglês | LILACS | ID: biblio-1015839

RESUMO

Background: Streptomyces clavuligerus was the producer of clavulanic acid, claR, a pathway-specific transcriptional regulator in S. clavuligerus, positively regulates clavulanic acid biosynthesis. In this study, the promoter-less kanamycin resistance gene neo was fused with claR to obtain strain NEO from S. clavuligerus F613-1. The claR-neo fusion strain NEO was mutated using physical and chemical mutagens and then screened under high concentrations of kanamycin for high-yield producers of clavulanic acid. Results: The reporter gene neo was fused downstream of claR and used as an indicator for expression levels of claR in strain NEO. After three rounds of continuous treatment and screening, the high-yield clavulanic acid-producing strain M3-19 was obtained. In the shaking flask model, the clavulanic acid titer of M3-19 reached 4.33 g/L, which is an increase of 33% over the titer of 3.26 g/L for the starting strains S. clavuligerus F613-1 and NEO. Conclusions: Our results indicate that neo can be effectively used as a reporter for the expression of late-stage biosynthetic genes when screening for high-yield strains and that this approach has strong potential for improving Streptomyces strains of industrial value.


Assuntos
Streptomyces/genética , Streptomyces/metabolismo , Canamicina , Ácido Clavulânico/biossíntese , Fatores de Transcrição/genética , Transcrição Genética , Bioensaio , Proteínas Recombinantes , Cromatografia Líquida de Alta Pressão , Mutagênese , Regiões Promotoras Genéticas , Genes Reporter , Fusão Gênica , Fermentação , Reação em Cadeia da Polimerase em Tempo Real
14.
Genom Data ; 12: 116-117, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28491497

RESUMO

The complete genome sequence of Streptomyces violaceus strain S21, a valuable natural compounds producer isolated from the forest soil, is firstly presented here. The genome comprised 7.91M bp, with a G + C content of 72.65%. A range of genes involved in pathways of secondary product biosynthesis were predicted. The genome sequence is available at DDBJ/EMBL/Genbank under the accession number CP020570. This genome is annotated with 6856 predicted genes identifying the natural product biosynthetic gene clusters in S. violaceus.

15.
Genome Announc ; 5(20)2017 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-28522727

RESUMO

Streptomyces tsukubaensis strain F601 was found to be a producer of the immunosuppressive drug tacrolimus. The draft genome sequence of this strain was approximately 8.52 Mbp. Genes involved in the biosynthesis of tacrolimus were identified in the genome. This draft genome sequence will provide insights into the genetic basis of tacrolimus biosynthesis and regulation.

16.
Curr Genet ; 63(2): 229-239, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-27387517

RESUMO

The yeast Saccharomyces cerevisiae is capable of responding to various environmental stresses, such as salt stress. Such responses require a complex network and adjustment of the gene expression network. The goal of this study is to further understand the molecular mechanism of salt stress response in yeast, especially the molecular mechanism related to genes BDF1 and HAL2. The Bromodomain Factor 1 (Bdf1p) is a transcriptional regulator, which is part of the basal transcription factor TFIID. Cells lacking Bdf1p are salt sensitive with an abnormal mitochondrial function. We previously reported that the overexpression of HAL2 or deletion of HDA1 lowers the salt sensitivity of bdf1Δ. To better understand the mechanism behind the HAL2-related response to salt stress, we compared three global transcriptional profiles (bdf1Δ vs WT, bdf1Δ + HAL2 vs bdf1Δ, and bdf1Δhda1Δ vs bdf1Δ) in response to salt stress using DNA microarrays. Our results reveal that genes for iron acquisition and cellular and mitochondrial remodeling are induced by HAL2. Overexpression of HAL2 decreases the concentration of nitric oxide. Mitochondrial iron-sulfur cluster (ISC) assembly also decreases in bdf1Δ + HAL2. These changes are similar to the changes of transcriptional profiles induced by iron starvation. Taken together, our data suggest that mitochondrial functions and iron homeostasis play an important role in bdf1Δ-induced salt sensitivity and salt stress response in yeast.


Assuntos
Regulação Fúngica da Expressão Gênica/genética , Ferro/metabolismo , Nucleotidases/genética , Proteínas de Saccharomyces cerevisiae/genética , Tolerância ao Sal/genética , Fatores de Transcrição/genética , Perfilação da Expressão Gênica/métodos , Regulação Fúngica da Expressão Gênica/efeitos dos fármacos , Ontologia Genética , Immunoblotting , Mutação , Nucleotidases/metabolismo , Análise de Sequência com Séries de Oligonucleotídeos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Transdução de Sinais/genética , Cloreto de Sódio/farmacologia , Estresse Fisiológico , Fatores de Transcrição/metabolismo
17.
Genome Announc ; 4(5)2016 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-27660792

RESUMO

Streptomyces clavuligerus strain F613-1 is an industrial strain with high-yield clavulanic acid production. In this study, the complete genome sequence of S. clavuligerus strain F613-1 was determined, including one linear chromosome and one linear plasmid, carrying numerous sets of genes involving in the biosynthesis of clavulanic acid.

18.
Curr Microbiol ; 70(5): 671-8, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25572496

RESUMO

Bromodomain-containing transcription factor, a kind of important regulating protein, can recognize and bind to acetylated histone. The homologous genes, BDF1 and BDF2, in Saccharomyces cerevisiae, respectively, encode a bromodomain-containing transcription factor. Previously study has demonstrated that both BDF1 and BDF2 participate in yeast salt stress response. Bdf1p deletion cells are sensitive to salt stress and this phenotype is suppressed by its homologue BDF2 in a dosage-dependent manner. In this study, we show that the histone deacetylase SIR2 over-expression enhanced dosage-dependent compensation of BDF2. SIR2 over-expression induced a global transcription change, and 1959 gene was down-regulated. We deleted some of the most significant down-regulated genes and did the spot assay. The results revealed that LSP1, an upstream component of endocytosis pathway, and CIN5, a transcription factor that mediates cellular resistance to stresses, can enhance salt resistance of bdf1∆. Further analysis demonstrated that under salt stress the endocytosis is over-activated in bdf1∆ but was recovered in bdf1∆ lsp1∆. To our best knowledge, this is the first report that the transcription factor Bdf1p regulates endocytosis under salt stress via LSP1, a major component of eisosomes that regulate the sites of endocytosis.


Assuntos
Endocitose , Fosfoproteínas/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharomyces cerevisiae/fisiologia , Sais/toxicidade , Estresse Fisiológico , Fatores de Transcrição/metabolismo , Deleção de Genes , Perfilação da Expressão Gênica , Regulação Fúngica da Expressão Gênica , Teste de Complementação Genética , Fosfoproteínas/genética , Proteínas de Saccharomyces cerevisiae/genética , Proteínas Reguladoras de Informação Silenciosa de Saccharomyces cerevisiae/genética , Proteínas Reguladoras de Informação Silenciosa de Saccharomyces cerevisiae/metabolismo , Sirtuína 2/genética , Sirtuína 2/metabolismo , Fatores de Transcrição/genética
19.
PLoS One ; 9(11): e113754, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25412184

RESUMO

BACKGROUND: PTPRD, encoding protein tyrosine phosphatases receptor type D, is located at chromosome 9p23-24.1, a loci frequently lost in many types of tumors. Recently, PTPRD has been proposed to function as a tumor suppressor gene. The current study aimed to investigate PTPRD expression and its prognostic significance in primary gastric adenocarcinoma. METHODS AND RESULTS: Quantitative real time reverse transcription PCR (qRT-PCR) and western blotting were used to examine PTPRD expression in paired gastric tumourous and paracancerous tissues. Compared with the matched normal gastric mucosa tissues, both the mRNA (P = 0.0138) and protein (P = 0.0093) expression of PTPRD in fresh surgical specimens were significantly reduced. Clinicopathological and prognostic roles of PTPRD in gastric adenocarcinoma were investigated using immunohistochemistry with 513 paraffin-embedded gastric adenocarcinoma tissue blocks. Statistical analysis revealed that reduced PTPRD expression was significantly associated with T stage (P = 0.004), TNM stage (P<0.001) and tumor size (P = 0.003). Furthermore, Kaplan-Meier survival analysis revealed that low expression of PTPRD significantly correlated with poor survival of gastric cancer patients (P<0.001). Cox regression analysis confirmed PTPRD expression as independent predictor of the overall survival of gastric cancer patients. The MTT assay determined the effects of PTPRD on cell proliferation of MGC803 and GES1 cell lines. Restoring PTPRD expression in MGC803 cells significantly inhibited their growth rate. Silencing PTPRD expression by siRNA treatment in GES1 significantly enhanced cell proliferation compared with mock siRNA treatment. Methylation analysis of PTPRD promoter CpG island in 3 primary GC samples showed one case with partial methylation. CONCLUSIONS: These results indicated that PTPRD is a candidate tumour suppressor in gastric cancer. Thus, PTPRD may play an important role in gastric tumorigenesis and serve as a valuable prognostic marker of gastric adenocarcinoma.


Assuntos
Adenocarcinoma/diagnóstico , Proteínas Tirosina Fosfatases Classe 2 Semelhantes a Receptores/genética , Neoplasias Gástricas/diagnóstico , Adenocarcinoma/mortalidade , Adenocarcinoma/patologia , Idoso , Linhagem Celular Tumoral , Proliferação de Células , Cromossomos Humanos Par 9 , Ilhas de CpG , Metilação de DNA , Feminino , Seguimentos , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Prognóstico , Regiões Promotoras Genéticas , Interferência de RNA , Proteínas Tirosina Fosfatases Classe 2 Semelhantes a Receptores/antagonistas & inibidores , Proteínas Tirosina Fosfatases Classe 2 Semelhantes a Receptores/metabolismo , Neoplasias Gástricas/mortalidade , Neoplasias Gástricas/patologia
20.
FEMS Yeast Res ; 14(4): 575-85, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25035869

RESUMO

Bromodomain factor 1 (Bdf1p) is a transcriptional regulator. The absence of Bdf1p causes salt sensitivity with abnormal nucleus and mitochondrial dysfunction. In this study, we reported that the salt sensitivity, mitochondrial dysfunction, and nuclear instability of bdf1Δ mutant were suppressed by HDA1 deletion or MEF1 overexpression. Hda1p overexpression inhibited the relieving effects of low-copy overexpression of MEF1. Further analysis showed that Bdf1p regulated HDA1 transcription positively by binding to its promoter at −201 to +6 bp, whereas Hda1p modulated MEF1 expression negatively by binding to its promoter at −201 to +6 bp. These results suggested that Bdf1p likely regulated MEF1 expression negatively by regulating HDA1 positively. Mitochondrial proteomics analysis showed that the expression levels of six mitochondrial proteins were significantly changed by MEF1 overexpression. Among the six genes, over-expression of PDB1, ILV5, or ATP2 partially recovered the salt stress sensitivity of bdf1Δ. However, none of these mitochondrial proteins could recover mitochondrial respiration indicating that the individual functional proteins could not replace Mef1p activity. It indicated that positive regulation of MEF1 was important in recovering the salt sensitivity of bdf1Δ mutant.


Assuntos
Tolerância a Medicamentos , Proteínas de Ligação ao GTP/biossíntese , Regulação Fúngica da Expressão Gênica , Histona Desacetilases/metabolismo , Proteínas de Saccharomyces cerevisiae/biossíntese , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharomyces cerevisiae/genética , Sais/toxicidade , Fatores de Transcrição/deficiência , Instabilidade Genômica , Mitocôndrias/metabolismo
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