Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 17 de 17
Filtrar
Mais filtros








Base de dados
Intervalo de ano de publicação
1.
J Appl Microbiol ; 134(12)2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-38012110

RESUMO

AIMS: Approximately 10% of children are born prematurely, and bacterial vaginosis during pregnancy is associated with preterm delivery. Highly accurate species-level vaginal microflora analysis helps control bacteria-induced preterm birth. Therefore, we aimed to conduct a bioinformatic analysis of gene sequences using 16S databases and compare their efficacy in comprehensively identifying potentially pathogenic vaginal microbiota in Japanese women. METHODS AND RESULTS: The 16 s rRNA databases, Silva, Greengenes, and the basic local alignment search tool (BLAST) were compared to determine whether the classification quality could be improved using the V3-V4 region next-generation sequencing (NGS) sequences. It was found that NGS data were aligned using the BLAST database with the QIIME 2 platform, whose classification quality was higher than that of Silva, and the combined Silva and Greengenes databases based on the mutual complementarity of the two databases. CONCLUSIONS: The reference database selected during the bioinformatic processing influenced the recognized sequence percentage, taxonomic rankings, and accuracy. This study showed that the BLAST database was the best choice for NGS data analysis of Japanese women's vaginal microbiota.


Assuntos
Microbiota , Nascimento Prematuro , Recém-Nascido , Criança , Feminino , Humanos , Japão , Filogenia , RNA Ribossômico 16S/genética , Microbiota/genética , Software , Sequenciamento de Nucleotídeos em Larga Escala/métodos
2.
Gynecol Oncol Rep ; 40: 100943, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35265741

RESUMO

Cervical cancer is the fourth most common cancer in women globally. Based on several epidemiologic studies, human papillomavirus is strongly associated with cervical neoplasia. Aside from HPV, other bacterial infections in the genital tract were associated with cervical neoplasia. This study aimed to determine the prevalence of HPV infection; and co-infection with Ureaplasma spp., Mycoplasma spp., Chlamydia trachomatis, and Neisseria gonorrheae in Filipino cervical cancer patients. Forty-four patients (28 patients with cervical carcinoma and 16 patients with non-malignant cervix) who consulted in the Philippine General Hospital from 2016 to 2017 were included in this study. HPV genotyping and genetic detection of Ureaplasma spp., Mycoplasma spp., C. trachomatis, and N. gonorrheae were done using different PCR assays. The prevalence of HPV 16/18/33/52 was 75% in cervical cancer patients and 25% in control patients. Infection with HPV 16/18/33/52 was significantly associated with having cervical cancer (OR: 9.00; 95% CI: 2.18-37.18; p = 0.0024). HPV-16 was the most prevalent HPV genotype among Filipino cervical cancer patients. HPV-18 and HPV-52 were only detected from cervical cancer patients. Among HPV-positive patients, we noted a 22.73% co-infection with Ureaplasma spp. and 9.09% co-infection with Mycoplasma spp. To our knowledge, this is the first study on the co-infection of HPV and sexually transmitted infections among cervical cancer patients in the Philippines.

3.
Cell Microbiol ; 23(12): e13392, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34490709

RESUMO

Previously, we found that Ureaplasma parvum internalised into HeLa cells and cytosolic accumulation of galectin-3. U. parvum induced the host cellular membrane damage and survived there. Here, we conducted vesicular trafficking inhibitory screening in yeast to identify U. parvum vacuolating factor (UpVF). U. parvum triggered endoplasmic reticulum (ER) stress and upregulated the unfolded protein response-related factors, including BiP, P-eIF2 and IRE1 in the host cells, but it blocked the induction of the downstream apoptotic factors. MicroRNA library screening of U. parvum-infected cells and UpVF-transfected cells identified miR-211 and miR-214 as the negative regulators of the apoptotic cascade under ER stress. Transient expression of UpVF induced HeLa cell death with intracellular vacuolization; however, some stable UpVF transformant survived. U. parvum-infected cervical cell lines showed resistance to actinomycin D, and UpVF stable transformant cell lines exhibited resistance to X-ray irradiation, as well as cisplatin and paclitaxel. UpVF expressing cervical cancer xenografts in nude mice also acquired resistance to cisplatin and paclitaxel. A mycoplasma expression vector based on Mycoplasma mycoides, Syn-MBA (multiple banded antigen)-UpVF, reduced HeLa cell survival compared with that of Syn-MBA after 72 hr of infection. These findings together suggest novel mechanisms for Ureaplasma infection and the possible implications for cervical cancer malignancy. TAKE AWAYS: • Ureaplasmal novel virulence factor, UpVF, was identified. • UpVF triggered ER stress but suppressed apoptotic cascade via miR-211 and -214. • UpVF conferred resistance to anticancer treatments both in vivo and in vitro. • Dual expression of MBA and UpVF in JCVI-syn3B showed host cell damage.


Assuntos
MicroRNAs , Ureaplasma , Animais , Morte Celular , Estresse do Retículo Endoplasmático , Células HeLa , Humanos , Camundongos , Camundongos Nus , MicroRNAs/genética , Ureaplasma/genética
4.
PLoS One ; 16(6): e0252789, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34086827

RESUMO

The general methods to detect the RNA of severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) in clinical diagnostic testing involve reverse transcriptases and thermostable DNA polymerases. In this study, we compared the detection of SARS-CoV-2 by a one-step real-time RT-PCR method using a heat-resistant reverse transcriptase variant MM4 from Moloney murine leukemia virus, two thermostable DNA polymerase variants with reverse transcriptase activity from Thermotoga petrophila K4 and Thermococcus kodakarensis KOD1, or a wild-type DNA polymerase from Thermus thermophilus M1. The highest performance was achieved by combining MM4 with the thermostable DNA polymerase from T. thermophilus M1. These enzymes efficiently amplified specific RNA using uracil-DNA glycosylase (UNG) to remove contamination and human RNase P RNA amplification as an internal control. The standard curve was obtained from 5 to 105 copies of synthetic RNA. The one-step real-time RT-PCR method's sensitivity and specificity were 99.44% and 100%, respectively (n = 213), compared to those of a commercially available diagnostic kit. Therefore, our method will be useful for the accurate detection and quantification of SARS-CoV-2.


Assuntos
COVID-19 , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , SARS-CoV-2/genética , COVID-19/diagnóstico , COVID-19/genética , Humanos
5.
F S Sci ; 2(1): 13-23, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-35559760

RESUMO

OBJECTIVE: To examine the effect of Ureaplasma parvum (U. parvum) infection on mouse sperm motility, structure, and fertilizing ability and on embryo development. DESIGN: In vitro model of the effects of U. parvum serovar 3 infection on mouse sperm. SETTING: Basic research laboratory. INTERVENTION(S): None. ANIMALS: Mice. MAIN OUTCOME MEASURE(S): Mouse sperm motility was examined using the swim-up method, and their motility parameters were analyzed using the sperm motility analysis system. Localization and invasion of U. parvum were observed with fluorescence, confocal, and scanning electron microscopy. After in vitro fertilization with U. parvum-infected sperm, the quality of the fertilized egg and embryo development were assessed. RESULT(S): U. parvum was attached and internalized into mouse sperms and localized mainly at the sperm head and midpiece. U. parvum-infected mouse sperms exhibited decreased motility in a dose- and duration-dependent manner. Electron micrographs revealed that U. parvum infection induced the aggregation and morphological destruction of mouse sperm. Infected mouse sperm transported U. parvum into the fertilized egg with reduced fertilization rates, and infected embryo development was impaired. CONCLUSION(S): U. parvum infection caused deterioration of the mouse sperm quality and its functions, which affected the fertilization rate and embryo development.


Assuntos
Infecções por Ureaplasma , Ureaplasma , Animais , Desenvolvimento Embrionário , Fertilização , Masculino , Camundongos , Motilidade dos Espermatozoides , Espermatozoides
6.
PLoS One ; 15(2): e0228052, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32053625

RESUMO

The rod shape of bacilli is maintained by bacterial cytoskeletal protein MreB, an actin homolog that acts in concert with the inner membrane protein RodZ. We previously reported RodZ binds RNA to control the posttranscriptional regulation of invE (virB), which controls the type III secretion system essential for the virulence of Shigella. Here, we show that purified RodZ forms "superstructures" of high molecular mass that dissociate into a midsized "basal complex" in the presence of nonionic detergent, or to a monomer in the presence of dithiothreitol. We used mass spectrometry to show that the basal complex was a hexamer. Electrophoresis mobility shift assays combined with gel filtration detected the RNA-binding activity in fractions containing molecules larger than the basal hexamer. The superstructure was consistently detected with MreB in crude cell lysates of S. sonnei that were fractionated using gel filtration. Immunofluorescence microscopy using two different super-resolution settings showed that wild-type RodZ was distributed in cells as separate dots. Consistent with the superstructure comprising homohexamers, majority of the dots distributed among areas of discrete values. In addition, simultaneous immunodetection of MreB provided the first evidence of colocalization with RodZ as larger patch like signals. These findings indicate that native RodZ forms clusters of various sizes, which may correspond to a superstructure comprising multiple hexamers required for the RNA-binding activity.


Assuntos
Bacillus/química , Proteínas de Bactérias/química , Multimerização Proteica , Shigella sonnei/química , Substituição de Aminoácidos , Proteínas de Bactérias/ultraestrutura , Cisteína/genética , Análise Mutacional de DNA , Imageamento Tridimensional , Peso Molecular , Mutação/genética , Domínios Proteicos , Mapeamento de Interação de Proteínas , Shigella sonnei/citologia
7.
Microbiologyopen ; 6(3)2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28088841

RESUMO

Genital mycoplasmas, including Ureaplasma spp., are among the smallest human pathogenic bacteria and are associated with preterm birth. Electron microscopic observation of U. parvum showed that these prokaryotes have a regular, spherical shape with a mean diameter of 146 nm. U. parvum was internalized into HeLa cells by clathrin-mediated endocytosis and survived for at least 14 days around the perinuclear region. Intracellular U. parvum reached endosomes in HeLa cells labeled with EEA1, Rab7, and LAMP-1 within 1 to 3 hr. After 3 hr of infection, U. parvum induced the cytosolic accumulation of galectin-3 and was subsequently entrapped by the autophagy marker LC3. However, when using atg7-/- MEF cells, autophagy was inadequate for the complete elimination of U. parvum in HeLa cells. U. parvum also colocalized with the recycling endosome marker Rab11. Furthermore, the exosomes purified from infected HeLa cell culture medium included U. parvum. In these purified exosomes ureaplasma lipoprotein multiple banded antigen, host cellular annexin A2, CD9, and CD63 were detected. This research has successfully shown that Ureaplasma spp. utilize the host cellular membrane compartments possibly to evade the host immune system.


Assuntos
Autofagossomos/imunologia , Autofagia , Células Epiteliais/imunologia , Interações Hospedeiro-Patógeno , Ureaplasma/imunologia , Autofagossomos/microbiologia , Autofagossomos/ultraestrutura , Células Epiteliais/microbiologia , Células Epiteliais/ultraestrutura , Células HeLa , Humanos , Evasão da Resposta Imune , Microscopia Eletrônica , Ureaplasma/ultraestrutura
8.
Pediatr Res ; 80(3): 433-9, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27100048

RESUMO

BACKGROUND: Maternal intrauterine infection/inflammation represents the major etiology of preterm delivery and the leading cause of neonatal mortality and morbidity. The aim of this study was to investigate the anti-inflammatory properties of thioredoxin-1 in vivo and its potential ability to attenuate the rate of inflammation-induced preterm delivery. METHODS: Two intraperitoneal injections of lipopolysaccharide from Escherichia coli were administered in pregnant mice on gestational day 15, with a 3-h interval between the injections. From either 1 h before or 1 h after the first lipopolysaccharide injection, mice received three intravenous injections of either recombinant human thioredoxin-1, ovalbumin, or vehicle, with a 3-h interval between injections. RESULTS: Intraperitoneal injection of lipopolysaccharide induced a rise of tumor necrosis factor-α, interferon-γ, monocyte chemotactic protein 1, and interleukin-6 in maternal serum levels and provoked preterm delivery. Recombinant human thoredoxin-1 prevented the rise in these proinflammatory cytokine levels. After the inflammatory challenge, placentas exhibited severe maternal vascular dilatation and congestion and a marked decidual neutrophil activation. These placental pathological findings were ameliorated by recombinant human thioredoxin-1, and the rate of inflammation-induced preterm delivery was attenuated. CONCLUSION: Thioredoxin-1 may thus represent a novel effective treatment to delay inflammation-induced preterm delivery.


Assuntos
Anti-Inflamatórios/farmacologia , Trabalho de Parto Prematuro/tratamento farmacológico , Tiorredoxinas/farmacologia , Animais , Animais Recém-Nascidos , Quimiocina CCL2/sangue , Citocinas/sangue , Feminino , Humanos , Inflamação , Interferon gama/sangue , Interleucina-6/sangue , Lipopolissacarídeos , Macrófagos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C3H , Trabalho de Parto Prematuro/induzido quimicamente , Placenta/metabolismo , Gravidez , Espécies Reativas de Oxigênio/metabolismo , Proteínas Recombinantes/farmacologia , Tiorredoxinas/fisiologia , Fator de Necrose Tumoral alfa/sangue
9.
Pediatr Surg Int ; 32(1): 59-63, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26510735

RESUMO

PURPOSE: Necrotizing enterocolitis (NEC) is a devastating inflammatory disease of preterm infants that may depend on overexpression of toll-like receptor-4 (TLR4) in the immature intestine. Surfactant protein (SP)-D is a member of the collectin family and plays an important role in innate immunity, particularly in the airways. Although SP-D also exists in the intestines, little is known about its function. This study investigated whether SP-D can attenuate the inflammatory response of TLR4-overexpressing embryonal intestinal cells. METHODS: All experimental procedures were performed using the human intestinal cell line INT407 originally derived from human embryonal intestines. Platelet-activating factor (PAF), reported to be elevated in NEC patients, was used to induce TLR4 overexpression in the human embryonal intestinal cell line INT407. TLR4 expression was measured using quantitative real-time PCR. Inflammatory responses to PAF (5 µM), the TLR4 agonist lipopolysaccharide (LPS, 100 ng/ml), PAF + LPS, and PAF + LPS following SP-D pretreatment (20 µg/ml) were assessed by enzyme-linked immunosorbent assay (ELISA) of interleukin-8 (IL-8) release (in pg/ml). RESULTS: Expression of TLR4 mRNA (mean ± SD) was upregulated by PAF (369 % ± 28 %, p < 0.001). Stimulation with PAF + LPS resulted in higher IL-8 release (1959.3 ± 52.3) than control (141.2 ± 12.4), LPS (167.3 ± 65.8), or PAF (1527.2 ± 129.4) treatment (p < 0.05). Release in response to PAF + LPS (1590.1 ± 319.3) was attenuated by SP-D pretreatment (1161.6 ± 131.6; p < 0.05). CONCLUSION: SP-D attenuates LPS-induced IL-8 production in TLR4-overexpressing intestinal cells, suggesting that SP-D may have a protective effect in the development of NEC in preterm infants.


Assuntos
Inflamação/metabolismo , Mucosa Intestinal/metabolismo , Lipopolissacarídeos , Proteína D Associada a Surfactante Pulmonar/farmacologia , Receptor 4 Toll-Like/metabolismo , Técnicas de Cultura de Células , Ensaio de Imunoadsorção Enzimática , Humanos , Intestinos/efeitos dos fármacos , Reação em Cadeia da Polimerase em Tempo Real , Receptor 4 Toll-Like/efeitos dos fármacos
10.
Toxicol Rep ; 2: 574-579, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-28962392

RESUMO

Silver nanoparticles (AgNPs) induce the production of reactive oxygen species (ROS) and apoptosis. These effects are enhanced by smaller particles. Using live-cell imaging, we show that AgNPs induced ROS production rapidly in a size-dependent manner after exposure of cells to 70-nm and 1-nm AgNPs (AgNPs-70, AgNPs-1), but not AgNO3. Exposure of cells to 5 µg/mL each of AgNPs-70, AgNPs-1 or AgNO3 for 1 h decreased the cell viability by approximately 40%, 100% and 20%, respectively. ROS were rapidly induced after 5 and 60 min by AgNPs-1 and AgNPs-70, respectively, whereas AgNO3 had no detectable effect. ROS production detected using the reporter dichlorodihydrofluorescein was observed in whole cells and mitochondria 5 and 60 min after exposure to AgNPs-1. The present study is the first, to our knowledge, to report the temporal expression and intracellular localisation of ROS induced by AgNPs.

11.
Genome Announc ; 2(3)2014 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-24855292

RESUMO

Here, we present the complete genome sequence of Ureaplasma parvum serovar 3, clinical strain SV3F4, isolated from a Japanese patient with a history of an infectious abortion.

12.
Biol Cell ; 105(4): 162-74, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23294349

RESUMO

BACKGROUND INFORMATION: S1-1, also called RBM10, is an RNA-binding protein of 852 residues. An alteration of its activity causes TARP syndrome, a severe X-linked disorder with pre- or post-natal lethality in affected males. Its molecular function, although still largely unknown, has been suggested to be transcription and alternative splicing. In fact, S1-1 localises in the nucleus in tissue cells and cultured cells. RESULTS: By deletion and substitution mutagenesis, a classical 17-amino-acid (aa) nuclear localisation sequence (NLS1) was identified at aa 743-759 in the C-terminal region of S1-1. NLS1 was bipartite, with its N-terminal basic cluster weakly contributing to the NLS activity. S1-1 contained two additional NLSs. One was in the aa 60-136 RNA recognition motif region (NLS2), and the other was a novel NLS motif sequence in the aa 481-540 octamer-repeat (OCRE) region (NLS3). The OCRE is a domain known to be critical in splicing regulation, as shown with RBM5, a close homologue of RBM10 [Bonnal et al. (2008) Mol. Cell 32, 81-95]. The NLS activities were verified by expressing each DNA sequence linked to EGFP or a FLAG tag. These multiple NLSs acted cooperatively, and S1-1 became completely cytoplasmic after the concomitant removal of all NLS domains. In some cell types, however, S1-1 was partly cytoplasmic, suggesting that cellular localisation of S1-1 is subjected to regulation. CONCLUSIONS: The present results indicate that S1-1 contains multiple NLSs that act cooperatively. Among them, the OCRE is a hitherto unreported NLS. The nuclear localisation of S1-1 appears to be regulated under certain circumstances. We discuss these NLSs in relation to the biochemical processes they are involved in.


Assuntos
Núcleo Celular/metabolismo , Sinais de Localização Nuclear , Proteínas de Ligação a RNA/química , Proteínas de Ligação a RNA/metabolismo , Sequência de Aminoácidos , Núcleo Celular/genética , Humanos , Dados de Sequência Molecular , Estrutura Terciária de Proteína , Transporte Proteico , Proteínas de Ligação a RNA/genética
13.
Int J Dev Biol ; 54(8-9): 1347-53, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20712004

RESUMO

We have reported elsewhere that offspring from the No. 65 female of Xenopus laevis cleaved normally, but their development was arrested at the onset of gastrulation, like the Ambystoma ova-deficient (o) mutant, irrespective of mating with different wild-type males, and that an acidic, 38 kDa protein present in wild-type eggs was lacking in eggs of the female. In the current study, we first determined the partial amino acid sequence (VANLE) of one of the well-separated tryptic peptides from the protein, which was found in elongation factor 1 delta (Ef1delta) in Xenopus, and finally identified the protein as one of the Ef1delta isoforms, Ef1delta2, by peptide mass spectrometry. RT-PCR analyses for Ef1delta2 and its close homolog Ef1delta1 in wild-type oocytes and embryos demonstrated that both transcripts are maternal and Ef1delta1 is present more abundantly than Ef1delta2 throughout the stages examined. Importantly, the amount of the Ef1delta2 transcript per embryo decreased gradually after gastrulation, in accordance with the gradual decrease of the 38 kDa protein per embryo reported in our earlier study. Because pharmacological inhibition of translation induces gastrulation arrest in wild-type embryos, it is reasonable to conclude that the mutant embryos arrest in development due to the lack of Ef1delta2 that is indispensable for translation. Thus, the present study provides the first molecular information on the cause of the gastrulation-defective mutation in Amphibia.


Assuntos
Gástrula/metabolismo , Mutação , Proteínas de Xenopus/genética , Xenopus laevis/genética , Sequência de Aminoácidos , Animais , Embrião não Mamífero/embriologia , Embrião não Mamífero/metabolismo , Feminino , Gástrula/embriologia , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Immunoblotting , Masculino , Espectrometria de Massas , Peso Molecular , Oócitos/citologia , Oócitos/metabolismo , Fator 1 de Elongação de Peptídeos/química , Fator 1 de Elongação de Peptídeos/genética , Fator 1 de Elongação de Peptídeos/metabolismo , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sequência de Proteína , Fatores de Tempo , Proteínas de Xenopus/química , Proteínas de Xenopus/metabolismo , Xenopus laevis/embriologia
14.
Cell Struct Funct ; 34(1): 47-59, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19305101

RESUMO

An important consideration in the design of multigene delivery technology is the availability of suitable vectors to introduce multiple genes stably and stoichiometrically into living cells and co-express these genes efficiently. As a promising system for this purpose, we developed multi-cDNA expression constructs harboring two to three tandemly situated cDNAs in a single plasmid. The utility of this vector system is amplified by combining it with the psiC31 recombinase system which mediates site-specific integration of the genes into naturally occurring chromosomal sequences. By analyzing 55 psiC31-mediated integration events with five different constructs, each carrying one, two or three tandem cDNA expression cassettes, we identified 39 pseudo attP sites in the HeLaS3 chromosomes. All these sites share a common motif containing an inverted repeat and showing a similarity to the native psiC31 attP. The 36 integration events represented 27 different pseudo attP sites, suggesting the possibility of duplicate integration of the multigene expression plasmids into different genomic loci in a single cell. We demonstrated successive introduction of two different multi-cDNA expression plasmids into definite chromosomal pseudo attP sites, attaining integration of four cDNAs of known genomic constitution at precise genomic loci of a single HeLaS3 cell. The expression levels of these several transgenes were enhanced and made equally stable and robust by inserting the cHS4 insulator between genes.


Assuntos
Bacteriófagos/enzimologia , DNA Complementar , Vetores Genéticos , Integrases/metabolismo , Transfecção , Sítios de Ligação Microbiológicos , Bacteriófagos/genética , Sequência de Bases , Linhagem Celular , Cromossomos , Células HeLa , Humanos , Integrases/genética , Dados de Sequência Molecular , Plasmídeos/genética , Recombinação Genética , Transgenes/genética
15.
J Cell Biol ; 180(3): 493-506, 2008 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-18268099

RESUMO

Nucleocytoplasmic transport factors mediate various cellular processes, including nuclear transport, spindle assembly, and nuclear envelope/pore formation. In this paper, we identify the chromokinesin human kinesin-like DNA binding protein (hKid) as an import cargo of the importin-alpha/beta transport pathway and determine its nuclear localization signals (NLSs). Upon the loss of its functional NLSs, hKid exhibited reduced interactions with the mitotic chromosomes of living cells. In digitonin-permeabilized mitotic cells, hKid was bound only to the spindle and not to the chromosomes themselves. Surprisingly, hKid bound to importin-alpha/beta was efficiently targeted to mitotic chromosomes. The addition of Ran-guanosine diphosphate and an energy source, which generates Ran-guanosine triphosphate (GTP) locally at mitotic chromosomes, enhanced the importin-beta-mediated chromosome loading of hKid. Our results indicate that the association of importin-beta and -alpha with hKid triggers the initial targeting of hKid to mitotic chromosomes and that local Ran-GTP-mediated cargo release promotes the accumulation of hKid on chromosomes. Thus, this study demonstrates a novel nucleocytoplasmic transport factor-mediated mechanism for targeting proteins to mitotic chromosomes.


Assuntos
Pareamento Cromossômico/genética , Cromossomos/metabolismo , Proteínas de Ligação a DNA/metabolismo , Cinesinas/metabolismo , Mitose/genética , beta Carioferinas/fisiologia , Proteína ran de Ligação ao GTP/genética , Transporte Ativo do Núcleo Celular/genética , Núcleo Celular/genética , Núcleo Celular/metabolismo , Cromossomos/genética , Citoplasma/genética , Citoplasma/metabolismo , Proteínas de Ligação a DNA/genética , Guanosina Trifosfato/metabolismo , Células HeLa , Humanos , Cinesinas/genética , Membrana Nuclear/genética , Membrana Nuclear/metabolismo , Sinais de Localização Nuclear/genética , Fosforilação , Transporte Proteico/genética , Fuso Acromático/genética , alfa Carioferinas/genética , beta Carioferinas/genética
16.
Dev Biol ; 297(2): 483-92, 2006 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-16806152

RESUMO

In order to know the role of the Xdsg gene in presumptive PGCs (pPGCs) of Xenopus, we attempted to inhibit the translation of Xdsg mRNA in pPGCs by injecting antisense morpholino oligo (asMO), together with Fluorescein Dextran-Lysine (FDL), into single germ plasm-bearing cells of 32-cell embryos. Among three types of asMOs complementary to different parts of the 5'-untranslated region of Xdsg mRNA tested, only one asMO, designated as Xdsg-3, inhibited the translation of the mRNA in FDL-labeled pPGCs, resulting in the absence of labeled PGCs in experimental tadpoles. On the other hand, two other asMOs, Xdsg-1 and -2, did not inhibit the translation, so that a similar number of labeled PGCs found in FDL-injected but asMO-uninjected control tadpoles were observed in experimental tadpoles derived from asMO-injected embryos. Surprisingly, use of Xdsg-3 asMO resulted in the disappearance of the protein of Xenopus vasa homolog (Xenopus vasa-like gene 1, XVLG1) from FDL-labeled pPGCs by inhibiting the translation of XVLG1 mRNA. However, the effect of Xdsg-3 asMO on the translation of Xdsg and XVLG1 mRNAs and PGC formation could be canceled by the coinjection with Xdsg mRNA. Consequently, the Xdsg protein in pPGCs may play an important role in the formation of PGCs by regulating the production of XVLG1 protein.


Assuntos
Regulação da Expressão Gênica no Desenvolvimento , Células Germinativas/citologia , Proteínas de Xenopus/fisiologia , Sequência de Aminoácidos , Animais , Sequência de Bases , Diferenciação Celular , Linhagem da Célula , Feminino , Hibridização In Situ , Masculino , Dados de Sequência Molecular , Proteínas Nucleares/metabolismo , Oligonucleotídeos Antissenso/química , Xenopus , Proteínas de Xenopus/química
17.
Dev Growth Differ ; 47(1): 37-48, 2005 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-15740585

RESUMO

We investigated the mode of migration of presumptive primordial germ cells (pPGC) in the endoderm cell mass of Xenopus embryos at stages 7-40. The molecules underlying the migration were also studied cytochemically and immunocytologically. By examining the relative positions of pPGC and somatic cells derived from the single, fluorescein-dextran lysine (FDL)-injected, germ plasm-bearing cells of stage 6 embryos, pPGC in embryos at stages 7-23 and those at stages later than 24 were assumed to passively and actively migrate in the endoderm cell mass, respectively. This assumption was supported by the observation that F-actin, essential for active cell migration, was recognized on pPGC of the latter stages, but never on those of the former ones. In addition, the molecule like CXC chemokine receptor 4 (CXCR4) found on directionally migrating PGC in mouse and zebrafish, probably Xenopus CXCR4 (xCXCR4), was detected on pPGC only at latter stages. Accordingly, F-actin and xCXCR4, and probably beta1-integrin and collagen type IV, which are indispensable for the formation of F-actin, are thought to be involved in the active migration of pPGC in the endoderm cell mass.


Assuntos
Movimento Celular/fisiologia , Endoderma/fisiologia , Células Germinativas/fisiologia , Xenopus/embriologia , Actinas/metabolismo , Animais , Cromatografia de Afinidade , Primers do DNA , Embrião não Mamífero/metabolismo , Embrião não Mamífero/fisiologia , Células Germinativas/metabolismo , Imuno-Histoquímica , Receptores CXCR4/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA