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1.
PLoS Genet ; 18(6): e1009995, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35666772

RESUMO

Global regulation of spindle-associated proteins is crucial in oocytes due to the absence of centrosomes and their very large cytoplasmic volume, but little is known about how this is achieved beyond involvement of the Ran-importin pathway. We previously uncovered a novel regulatory mechanism in Drosophila oocytes, in which the phospho-docking protein 14-3-3 suppresses microtubule binding of Kinesin-14/Ncd away from chromosomes. Here we report systematic identification of microtubule-associated proteins regulated by 14-3-3 from Drosophila oocytes. Proteins from ovary extract were co-sedimented with microtubules in the presence or absence of a 14-3-3 inhibitor. Through quantitative mass-spectrometry, we identified proteins or complexes whose ability to bind microtubules is suppressed by 14-3-3, including the chromosomal passenger complex (CPC), the centralspindlin complex and Kinesin-14/Ncd. We showed that 14-3-3 binds to the disordered region of Borealin, and this binding is regulated differentially by two phosphorylations on Borealin. Mutations at these two phospho-sites compromised normal Borealin localisation and centromere bi-orientation in oocytes, showing that phospho-regulation of 14-3-3 binding is important for Borealin localisation and function.


Assuntos
Cinesinas , Proteínas Associadas aos Microtúbulos , Proteínas 14-3-3/genética , Proteínas 14-3-3/metabolismo , Animais , Proteínas de Ciclo Celular/genética , Centrômero/metabolismo , Drosophila/genética , Feminino , Cinesinas/genética , Proteínas Associadas aos Microtúbulos/genética , Microtúbulos/genética , Microtúbulos/metabolismo , Oócitos/metabolismo , Fuso Acromático/genética , Fuso Acromático/metabolismo
2.
Healthc Manage Forum ; 32(3): 153-157, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30971145

RESUMO

Health organizations charged with addressing public problems sometimes employ persons with relevant lived experience in meaningful organizational roles. Because of their prior experience, these individuals have intimate knowledge of the subject matter that professional training and education cannot replicate. Mental health treatment facilities in particular have demonstrated a growing trend toward incorporating staff members with lived experience. This study conducted semi-structured interviews with senior-level managers of organizations in this field to gain insight into the public values associated with this practice. Findings reveal that several public values, including dialogue, social cohesion, sustainability, productivity, and altruism, are cultivated when treatment facilities incorporate staff members with lived experience into service delivery. This study concludes with lessons for mental health leaders seeking to address mental illness.


Assuntos
Pessoal de Saúde/psicologia , Transtornos Mentais/psicologia , Serviços de Saúde Mental/organização & administração , Valores Sociais , Feminino , Humanos , Entrevistas como Assunto , Masculino , Gestão de Recursos Humanos
3.
Br J Anaesth ; 121(4): 758-767, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30236238

RESUMO

BACKGROUND: We investigated potential for hypersensitivity reactions after repeated sugammadex administration and explored the mechanism of hypersensitivity. METHODS: In this double-blind, placebo-controlled study (NCT00988065), 448 healthy volunteers were randomised to one of three arms to receive three repeat i.v. administrations of either sugammadex 4 mg kg-1, 16 mg kg-1, or placebo. Primary endpoint was percentage of subjects with hypersensitivity (assessed by an independent adjudication committee). Secondary endpoint of anaphylaxis was classified per Sampson and Brighton criteria. Exploratory endpoints included skin testing, serum tryptase, anti-sugammadex antibodies [immunoglobulin (Ig) E/IgG], and other immunologic parameters. RESULTS: Hypersensitivity was adjudicated for 1/148 (0.7%), 7/150 (4.7%), and 0/150 (0.0%) subjects after sugammadex 4 mg kg-1, 16 mg kg-1, and placebo, respectively. After sugammadex 16 mg kg-1, one subject met Sampson criterion 1 and Brighton level 1 (highest certainty) anaphylaxis criteria; two met Brighton level 2 criteria. After database lock it was determined that certain protocol deviations could have introduced bias in the reporting of hypersensitivity signs/symptoms in a subject subset. Objective laboratory investigations indicated that potential underlying hypersensitivity mechanisms were unlikely to have been activated; the results suggest that most of the observed hypersensitivity reactions were unlikely IgE/IgG-mediated. CONCLUSION: Dose-dependent hypersensitivity or anaphylaxis reactions to sugammadex were observed when administered without prior neuromuscular blocking agent. Laboratory investigations do not suggest prevalent allergen-specific IgE/IgG-mediated immunologic hypersensitivity. Because it could not be fully excluded that estimates of hypersensitivity/anaphylaxis incidence were unbiased, an additional study was conducted to characterise the potential for hypersensitivity reactions and is described in a companion report. CLINICAL TRIAL REGISTRATION: http://www.clinicaltrials.gov NCT00988065; Protocol number P06042.


Assuntos
Hipersensibilidade a Drogas/imunologia , Sugammadex/efeitos adversos , Administração Intravenosa , Adolescente , Adulto , Anafilaxia/imunologia , Anticorpos/imunologia , Método Duplo-Cego , Feminino , Voluntários Saudáveis , Humanos , Imunoglobulina E/imunologia , Imunoglobulina G/imunologia , Masculino , Pessoa de Meia-Idade , Segurança , Testes Cutâneos , Sugammadex/administração & dosagem , Triptases/sangue , Adulto Jovem
4.
J Cell Sci ; 125(Pt 19): 4457-62, 2012 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-22854045

RESUMO

In Drosophila oocytes, after the completion of recombination, meiotic chromosomes form a compact cluster called the karyosome within the nucleus, and later assemble spindle microtubules without centrosomes. Although these oocyte-specific phenomena are also observed in humans, their molecular basis is not well understood. Here, we report essential roles for the conserved kinase SRPK in both karyosome formation and spindle microtubule assembly in oocytes. We have identified a female-sterile srpk mutant through a cytological screen for karyosome defects. Unlike most karyosome mutants, the karyosome defect is independent of the meiotic recombination checkpoint. Heterochromatin clustering found within the wild-type karyosome is disrupted in the mutant. Strikingly, a loss of SRPK severely prevents microtubule assembly for acentrosomal spindles in mature oocytes. Subsequently, bi-orientation and segregation of meiotic chromosomes are also defective. Therefore, this study demonstrates new roles of this conserved kinase in two independent meiotic steps specific to oocytes.


Assuntos
Cromossomos de Insetos/metabolismo , Sequência Conservada , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/citologia , Drosophila melanogaster/enzimologia , Oócitos/enzimologia , Proteínas Serina-Treonina Quinases/metabolismo , Fuso Acromático/enzimologia , Animais , Pontos de Checagem do Ciclo Celular , Centrômero/metabolismo , Proteínas de Drosophila/química , Proteínas de Drosophila/genética , Feminino , Meiose , Mutação/genética , Oócitos/citologia , Proteínas Serina-Treonina Quinases/química , Proteínas Serina-Treonina Quinases/genética
5.
PLoS Genet ; 6(10): e1001179, 2010 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-21060809

RESUMO

The meiotic recombination checkpoint is a signalling pathway that blocks meiotic progression when the repair of DNA breaks formed during recombination is delayed. In comparison to the signalling pathway itself, however, the molecular targets of the checkpoint that control meiotic progression are not well understood in metazoans. In Drosophila, activation of the meiotic checkpoint is known to prevent formation of the karyosome, a meiosis-specific organisation of chromosomes, but the molecular pathway by which this occurs remains to be identified. Here we show that the conserved kinase NHK-1 (Drosophila Vrk-1) is a crucial meiotic regulator controlled by the meiotic checkpoint. An nhk-1 mutation, whilst resulting in karyosome defects, does so independent of meiotic checkpoint activation. Rather, we find unrepaired DNA breaks formed during recombination suppress NHK-1 activity (inferred from the phosphorylation level of one of its substrates) through the meiotic checkpoint. Additionally DNA breaks induced by X-rays in cultured cells also suppress NHK-1 kinase activity. Unrepaired DNA breaks in oocytes also delay other NHK-1 dependent nuclear events, such as synaptonemal complex disassembly and condensin loading onto chromosomes. Therefore we propose that NHK-1 is a crucial regulator of meiosis and that the meiotic checkpoint suppresses NHK-1 activity to prevent oocyte nuclear reorganisation until DNA breaks are repaired.


Assuntos
Núcleo Celular/metabolismo , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Meiose/genética , Protamina Quinase/genética , Animais , Linhagem Celular , Polaridade Celular , Quebras de DNA de Cadeia Dupla/efeitos da radiação , Dano ao DNA , Reparo do DNA/genética , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/citologia , Drosophila melanogaster/metabolismo , Feminino , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Histonas/metabolismo , Immunoblotting , Masculino , Modelos Biológicos , Mutação , Oócitos/metabolismo , Fosforilação , Protamina Quinase/metabolismo
6.
Gene Ther ; 19(7): 742-51, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21900961

RESUMO

The safety and toxicokinetics of SCH 721015, an adenovirus encoding the human interferon alpha-2b gene, and Syn3 (SCH 209702), a novel excipient, were assessed in cynomolgus monkeys administered intravesical doses of 2.5 × 10E11 or 1.25 × 10E13 particles SCH 721015 in 25 mg Syn3 or 25 mg Syn3 alone on study days 1 and 91. There was no systemic toxicity. Monkeys dosed with SCH 721015 in Syn3 were positive for SCH 721015-specific DNA in the urine for 2 to 3 days following each dose and had interferon alpha-2b protein in the urine for 1-3 days after a single dose and in fewer animals after a second dose. Intracystic administration was associated with inflammation and focal/multifocal ulceration in the urinary bladder and irritation in the ureters and urethra at necropsy. The physical trauma from catheterization and filling/emptying of the bladder was likely a contributing factor and Syn3 exacerbated the trauma. There was nearly complete resolution of these findings 2 months after the last dose. The trauma to the bladder likely contributed to low, transient systemic exposure to Syn3, SCH 721015 and human interferon protein. The results of this study support the clinical investigation of SCH 721015 in Syn3.


Assuntos
Adenoviridae/genética , Ácidos Cólicos/efeitos adversos , Dissacarídeos/efeitos adversos , Técnicas de Transferência de Genes/efeitos adversos , Interferon-alfa/genética , Adenoviridae/imunologia , Administração Intravesical , Animais , Feminino , Humanos , Interferon alfa-2 , Interferon-alfa/sangue , Interferon-alfa/imunologia , Interferon-alfa/urina , Macaca fascicularis , Masculino , Proteínas Recombinantes/sangue , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/urina , Bexiga Urinária/efeitos dos fármacos
7.
J Phys Chem A ; 116(3): 943-51, 2012 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-22257138

RESUMO

Reactions of Au(+)((1)S) and Au(+)((3)D) with CH(3)F and CH(3)Cl have been carried out in a drift cell in He at a pressure of 3.5 Torr at both room temperature and reduced temperatures in order to explore the influence of the electronic state of the metal on reaction outcomes. State-specific product channels and overall two-body rate constants were identified using electronic state chromatography. These results indicate that Au(+)((1)S) reacts to yield an association product in addition to AuCH(2)(+) in parallel steps with both neutrals. Product distributions for association vs HX elimination were determined to be 79% association/21% HX elimination for X = F and 50% association/50% HX elimination when X = Cl. Reaction of Au(+)((3)D) with CH(3)F also results in HF elimination, which in this case is thought to produce (3)AuCH(2)(+). With CH(3)Cl, Au(+)((3)D) reacts to form AuCH(3)(+) and CH(3)Cl(+) in parallel steps. An additional product channel initiated by Au(+)((3)D) is also observed with both methyl halides, which yields CH(2)X(+) as a higher-order product. Kinetic measurements indicate that the reaction efficiency for both Au(+) states is significantly greater with CH(3)Cl than with CH(3)F. The observed two-body rate constant for depletion of Au(+)((1)S) by CH(3)F represents less than 5% of the limiting rate constant predicted by the average dipole orientation model (ADO) at room temperature and 226 K, whereas CH(3)Cl reacts with Au(+)((1)S) at the ADO limit at both room temperature and 218 K. Rate constants for depletion of Au(+)((3)D) by CH(3)F and CH(3)Cl were measured at 226 and 218 K respectively, and indicate that Au(+)((3)D) is consumed at approximately 2% of the ADO limit by CH(3)F and 69% of the ADO limit by CH(3)Cl. Product formation and overall efficiency for all four reactions are consistent with previous experimental results and available theoretical models.


Assuntos
Ouro/química , Hidrocarbonetos Fluorados/química , Cloreto de Metila/química , Temperatura
8.
J Phys Chem A ; 116(16): 3979-88, 2012 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-22509816

RESUMO

The reactions of gas-phase Cu(+)((1)S) and Cu(+)((3)D) with CF(3)X and CH(3)X (X = Cl, Br, and I) have been examined experimentally using the drift cell technique at 3.5 Torr in He at room temperature. State-specific product channels and overall bimolecular rate constants for depletion of the two Cu(+) states were determined using electronic state chromatography. The results showed that Cu(+)((1)S) participates exclusively in association with all of these neutrals, whereas, depending on the neutral, Cu(+)((3)D) initiates up to three bimolecular processes, resulting in the formation of CuX(+), CuC(H/F)(3)(+), and C(H/F)(3)X(+). Possible structures for the singlet association products were explored using density functional methods. These calculations indicated that Cu(+) preferentially associates with the labile halogen (Cl, Br, I) with all neutrals except CF(3)Cl, for which a "backside" geometry occurs in which Cu(+)((1)S) is weakly bound to the -CF(3) end of the molecule. All products observed on the triplet reaction surface can be understood in terms of either known or calculated thermochemical requirements. Product distributions and overall reaction efficiencies for C-X bond activation (X = Br, I) through Cu(+)((3)D) suggest that the orientation of the neutral dipole has little or no effect in controlling access to specific product channels. Likewise, second-order rate constants for reactions with X = Br and I indicate efficient depletion of Cu(+)((3)D) and do not exhibit the dramatic variations in reaction efficiency previously observed with CH(3)Cl and CF(3)Cl. These results suggest that C-X bond activation proceeds through a bond-insertion mechanism as opposed to direct abstraction.

9.
Nat Cell Biol ; 3(7): 637-42, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11433295

RESUMO

The female meiotic spindle is commonly formed in a centrosome-independent manner. Here we report the identification of proteins at acentrosomal poles in the female meiotic spindle of Drosophila. The acentrosomal poles contain at least two proteins, Mini-spindles (Msps) and D-TACC, which are also associated with mitotic centrosomes. These proteins interact with one another and are both required for maintaining the bipolarity of acentrosomal spindles. The polar localization of Msps is dependent on D-TACC and Ncd, a kinesin-like microtubule motor. We propose that the polar localization of Msps mediated by D-TACC and Ncd may be crucial for the stabilization of meiotic spindle bipolarity.


Assuntos
Proteínas de Drosophila , Drosophila/fisiologia , Proteínas Associadas aos Microtúbulos/farmacologia , Fuso Acromático/ultraestrutura , Animais , Feminino , Imuno-Histoquímica , Cinesinas/farmacologia , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Mutagênese Sítio-Dirigida , Oócitos , Fuso Acromático/efeitos dos fármacos , Fuso Acromático/metabolismo
10.
J Cell Biol ; 171(4): 593-602, 2005 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-16301329

RESUMO

Conventional centrosomes are absent from the spindle in female meiosis in many species, but it is not clear how multiple chromosomes form one shared bipolar spindle without centrosomes. We identified a female sterile mutant in which each bivalent chromosome often forms a separate bipolar metaphase I spindle. Unlike wild type, prophase I chromosomes fail to form a single compact structure within the oocyte nucleus, although the integrity of metaphase I chromosomes appears to be normal. Molecular analysis indicates that the mutant is defective in the conserved kinase nucleosomal histone kinase-1 (NHK-1). Isolation of further alleles and RNA interference in S2 cells demonstrated that NHK-1 is also required for mitotic progression. NHK-1 itself is phosphorylated in mitosis and female meiosis, suggesting that this kinase is part of the regulatory system coordinating progression of mitosis and meiosis.


Assuntos
Centrossomo/ultraestrutura , Drosophila melanogaster/fisiologia , Mitose , Protamina Quinase/fisiologia , Alelos , Animais , Ciclo Celular , Linhagem Celular , Núcleo Celular/metabolismo , Cromossomos/ultraestrutura , Proteínas de Drosophila/química , Feminino , Meiose , Modelos Biológicos , Modelos Genéticos , Mutação , Oócitos/metabolismo , Fenótipo , Fosforilação , Protamina Quinase/genética , Fuso Acromático
11.
Public Adm Rev ; 80(5): 820-826, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32836453

RESUMO

Emerging statistics demonstrate that COVID-19 disproportionately affects African Americans. The effects of COVID-19 for this population are inextricably linked to areas of systemic oppression and disenfranchisement, which are exacerbated by COVID-19: (1) health care inequality; (2) segregation, overall health, and food insecurity; (3) underrepresentation in government and the medical profession; and (4) inequalities in participatory democracy and public engagement. Following a discussion of these issues, this essay shares early and preliminary lessons and strategies on how public administration scholars and practitioners can lead in crafting equitable responses to this global pandemic to uplift the African American community.

12.
J Cell Biol ; 146(5): 1005-18, 1999 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-10477755

RESUMO

We describe a new Drosophila gene, mini spindles (msps) identified in a cytological screen for mitotic mutant. Mutation in msps disrupts the structural integrity of the mitotic spindle, resulting in the formation of one or more small additional spindles in diploid cells. Nucleation of microtubules from centrosomes, metaphase alignment of chromosomes, or the focusing of spindle poles appears much less affected. The msps gene encodes a 227-kD protein with high similarity to the vertebrate microtubule-associated proteins (MAPs), human TOGp and Xenopus XMAP215, and with limited similarity to the Dis1 and STU2 proteins from fission yeast and budding yeast. Consistent with their sequence similarity, Msps protein also associates with microtubules in vitro. In the embryonic division cycles, Msps protein localizes to centrosomal regions at all mitotic stages, and spreads over the spindles during metaphase and anaphase. The absence of centrosomal staining in interphase of the cellularized embryos suggests that the interactions between Msps protein and microtubules or centrosomes may be regulated during the cell cycle.


Assuntos
Drosophila melanogaster/genética , Proteínas de Insetos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Proteínas de Schizosaccharomyces pombe , Fuso Acromático/metabolismo , Proteínas de Xenopus , Sequência de Aminoácidos , Animais , Ciclo Celular , Centrossomo/efeitos dos fármacos , Centrossomo/metabolismo , Segregação de Cromossomos/efeitos dos fármacos , Clonagem Molecular , Colchicina/farmacologia , Citoesqueleto/efeitos dos fármacos , Citoesqueleto/metabolismo , Drosophila melanogaster/citologia , Drosophila melanogaster/embriologia , Drosophila melanogaster/crescimento & desenvolvimento , Feminino , Humanos , Proteínas de Insetos/química , Proteínas de Insetos/metabolismo , Proteínas Associadas aos Microtúbulos/química , Proteínas Associadas aos Microtúbulos/genética , Microtúbulos/efeitos dos fármacos , Microtúbulos/metabolismo , Mitose/efeitos dos fármacos , Mitose/genética , Dados de Sequência Molecular , Mutação/genética , Paclitaxel/farmacologia , Homologia de Sequência de Aminoácidos , Fuso Acromático/efeitos dos fármacos , Fuso Acromático/genética
13.
J Cell Biol ; 156(1): 23-8, 2002 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-11777938

RESUMO

The fission yeast plo1(+) gene encodes a polo-like kinase, a member of a conserved family of kinases which play multiple roles during the cell cycle. We show that Plo1 kinase physically interacts with the anaphase-promoting complex (APC)/cyclosome through the noncatalytic domain of Plo1 and the tetratricopeptide repeat domain of the subunit, Cut23. A new cut23 mutation, which specifically disrupts the interaction with Plo1, results in a metaphase arrest. This arrest can be rescued by high expression of Plo1 kinase. We suggest that this physical interaction is crucial for mitotic progression by targeting polo kinase activity toward the APC.


Assuntos
Proteínas de Drosophila , Ligases/metabolismo , Mitose , Mutação/genética , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas de Schizosaccharomyces pombe/metabolismo , Schizosaccharomyces/citologia , Schizosaccharomyces/metabolismo , Complexos Ubiquitina-Proteína Ligase , Alelos , Sequência de Aminoácidos , Ciclossomo-Complexo Promotor de Anáfase , Subunidade Apc8 do Ciclossomo-Complexo Promotor de Anáfase , Sequência Conservada , Metáfase , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Ligação Proteica , Proteínas Serina-Treonina Quinases/química , Proteínas Serina-Treonina Quinases/genética , Estrutura Terciária de Proteína , Subunidades Proteicas , Schizosaccharomyces/genética , Proteínas de Schizosaccharomyces pombe/química , Proteínas de Schizosaccharomyces pombe/genética , Técnicas do Sistema de Duplo-Híbrido , Ubiquitina-Proteína Ligases
14.
Behav Brain Res ; 362: 249-257, 2019 04 19.
Artigo em Inglês | MEDLINE | ID: mdl-30633938

RESUMO

Maternal alcohol consumption throughout pregnancy can result in long term behavioural deficits in offspring. However, less is known about the impact of alcohol during the periconceptional period (PC). The aim of this study was to examine the effect of PC ethanol (PC:EtOH) exposure on long term cognitive function; including memory and anxiety. Rats were exposed to a liquid diet containing ethanol (EtOH) (12.5% vol;vol) or a control diet from 4 days prior to mating until day 4 of pregnancy. Separate cohorts of animals were tested at 6 months (adult) or 15-18 months of age (aged). Offspring underwent a series of behavioural tests to assess anxiety, spatial and recognition memory. The hippocampus was collected, and mRNA expression of epigenetic modifiers and genes implicated in learning and memory were examined. PC:EtOH exposure resulted in a subtle anxiety like behaviour in adult female offspring with a significant reduction in directed exploring/head dipping behaviour during holeboard testing. In aged male offspring, PC:EtOH exposure resulted in a tendency for increased directed exploring/head dipping behaviour during holeboard testing. No differences between treatments were observed in the elevated plus maze. Aged female offspring exposed to PC:EtOH demonstrated short term spatial memory impairment (P < 0.05). PC:EtOH resulted in an upregulation of hippocampal mRNA expression of bdnf, grin2a and grin2b at 18 months of age along with increased expression of epigenetic modifiers (dnmt1, dnmt3a and hdac2). In conclusion, PC:EtOH can lead to sex specific anxiety-like behaviour and impairments in spatial memory and altered hippocampal gene expression.


Assuntos
Consumo de Bebidas Alcoólicas/efeitos adversos , Etanol/farmacologia , Expressão Gênica/efeitos dos fármacos , Memória/efeitos dos fármacos , Efeitos Tardios da Exposição Pré-Natal/fisiopatologia , Animais , Ansiedade/etiologia , Comportamento Animal/efeitos dos fármacos , Comportamento Exploratório/efeitos dos fármacos , Feminino , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Gravidez , Ratos Sprague-Dawley
15.
Mol Biol Cell ; 16(2): 891-901, 2005 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15591130

RESUMO

EB1 is a conserved microtubule plus end tracking protein considered to play crucial roles in microtubule organization and the interaction of microtubules with the cell cortex. Despite intense studies carried out in yeast and cultured cells, the role of EB1 in multicellular systems remains to be elucidated. Here, we describe the first genetic study of EB1 in developing animals. We show that one of the multiple Drosophila EB1 homologues, DmEB1, is ubiquitously expressed and has essential functions during development. Hypomorphic DmEB1 mutants show neuromuscular defects, including flightlessness and uncoordinated movement, without any general cell division defects. These defects can be partly explained by the malfunction of the chordotonal mechanosensory organs. In fact, electrophysiological measurements indicated that the auditory chordotonal organs show a reduced response to sound stimuli. The internal organization of the chordotonal organs also is affected in the mutant. Consistently, DmEB1 is enriched in those regions important for the structure and function of the organs. Therefore, DmEB1 plays a crucial role in the functional and structural integrity of the chordotonal mechanosensory organs in Drosophila.


Assuntos
Drosophila/crescimento & desenvolvimento , Mecanorreceptores/fisiologia , Proteínas Associadas aos Microtúbulos/fisiologia , Células Receptoras Sensoriais/fisiologia , Sequência de Aminoácidos , Animais , Sequência Conservada , Eletrofisiologia , Mecanorreceptores/ultraestrutura , Proteínas Associadas aos Microtúbulos/química , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Dados de Sequência Molecular , Mutação Puntual , Células Receptoras Sensoriais/ultraestrutura , Homologia de Sequência de Aminoácidos
16.
J Dev Orig Health Dis ; 9(2): 223-231, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29039297

RESUMO

Alcohol consumption around the time of conception is highly prevalent in Western countries. Exposure to ethanol levels during gestation has been associated with altered development of the mesolimbic reward pathway in rats and increased propensity to addiction, however the effect of exposure only around the time of conception is unknown. The current study investigated the effects of periconceptional alcohol exposure (PC:EtOH) on alcohol and palatable food preferences and gene expression in the ventral tegmental area (VTA) and the nucleus accumbens of the adult offspring. Rats were exposed to a liquid diet containing ethanol (EtOH) (12.5% vol/vol) or a control diet from 4 days before mating until 4 days after mating. PC:EtOH had no effect on alcohol preference in either sex. At 15 months of age, however, male PC:EtOH offspring consumed more high-fat food when compared with male control offspring, but this preference was not observed in females. Expression of the dopamine receptor type 1 (Drd1a) was lower in the VTA of male PC:EtOH offspring compared with their control counterparts. There was no effect of PC:EtOH on mRNA expression of the µ-opioid receptor, tyrosine hydroxylase (Th), dopamine receptor type 2 (Drd2) or dopamine active transporter (Slc6a3). These data support the hypothesis that periconceptional alcohol exposure can alter expression of key components of the mesolimbic reward pathway and heighten the preference of offspring for palatable foods and may therefore increase their propensity towards diet-induced obesity. These results highlight the importance of alcohol avoidance when planning a pregnancy.


Assuntos
Consumo de Bebidas Alcoólicas/efeitos adversos , Gorduras na Dieta/administração & dosagem , Preferências Alimentares/efeitos dos fármacos , Núcleo Accumbens/efeitos dos fármacos , Efeitos Tardios da Exposição Pré-Natal/induzido quimicamente , Área Tegmentar Ventral/efeitos dos fármacos , Fatores Etários , Consumo de Bebidas Alcoólicas/metabolismo , Consumo de Bebidas Alcoólicas/tendências , Animais , Gorduras na Dieta/efeitos adversos , Gorduras na Dieta/metabolismo , Etanol/administração & dosagem , Etanol/efeitos adversos , Feminino , Preferências Alimentares/fisiologia , Expressão Gênica , Masculino , Núcleo Accumbens/metabolismo , Gravidez , Efeitos Tardios da Exposição Pré-Natal/metabolismo , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Recompensa , Área Tegmentar Ventral/metabolismo
17.
Mol Cell Biol ; 8(1): 330-9, 1988 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-3275873

RESUMO

The carboxyl-terminal domain (CTD) of the mouse RNA polymerase II largest subunit consists of 52 repeats of a seven-amino-acid block with the consensus sequence Tyr-Ser-Pro-Thr-Ser-Pro-Ser. A genetic approach was used to determine whether the CTD plays an essential role in RNA polymerase function. Deletion, insertion, and substitution mutations were created in the repetitive region of an alpha-amanitin-resistant largest-subunit gene. The effects of these mutations on RNA polymerase II activity were assayed by measuring the ability of mutant genes to confer alpha-amanitin resistance after transfection of susceptible rodent cells. Mutations that resulted in CTDs containing between 36 and 78 repeats had no effect on the transfer of alpha-amanitin resistance, whereas mutations with 25 or fewer repeats were inactive in this assay. Mutations that contained 29, 31, or 32 repeats had an intermediate effect; the number of alpha-amanitin-resistant colonies was lower and the colonies obtained were smaller, indicating that the mutant RNA polymerase II was defective. In addition, not all of the heptameric repeats were functionally equivalent in that repeats that diverged in up to three amino acids from the consensus sequence could not substitute for the conserved heptamer repeats. We concluded that the CTD is essential for RNA polymerase II activity, since substantial mutations in this region result in loss of function.


Assuntos
Camundongos/genética , RNA Polimerase II/genética , Amanitinas/farmacologia , Animais , Sequência de Bases , Clonagem Molecular , Análise Mutacional de DNA , Genes , RNA Polimerase II/antagonistas & inibidores , Proteínas Recombinantes , Saccharomyces cerevisiae/genética , Relação Estrutura-Atividade , Transfecção
18.
Behav Brain Res ; 328: 39-47, 2017 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-28389335

RESUMO

It is well established that maternal undernutrition and micronutrient deficiencies can lead to altered development and behaviour in offspring. However, few studies have explored the implications of maternal Mg deficiency and programmed behavioural and neurological outcomes in offspring. We used a model of Mg deficiency (prior to and during pregnancy and lactation) in CD1 mice to investigate if maternal Mg deficiency programmed changes in behaviour and NMDAR subunit expression in offspring. Hippocampal tissue was collected at postnatal day 2 (PN2), PN8, PN21 and 6 months, and protein expression of NMDAR subunits GluN1, GluN2A and GluN2B was determined. At 6 months of age, offspring were subject to behavioural tasks testing aspects of anxiety-like behaviour, memory, and neophobia. Maternal hypomagnesemia was associated with increased GluN1, GluN2A and GluN2B subunit expression in female offspring at 6 months, but decreased GluN1 and GluN2A expression in males. The GluN2B:GluN2A expression ratio was increased in both sexes. Male (but not female) offspring from Mg-deficient dams showed anxiety-like behaviour, with reduced head dips (Suok test), and reduced exploration of open arms (elevated plus maze). Both male and female offspring from Mg-deficient dams also showed impaired recognition memory (novel object test). These findings suggest that maternal Mg deficiency can result in behavioural deficits in adult life, and that these changes may be related to alterations in hippocampal NMDA receptor expression.


Assuntos
Hipocampo/crescimento & desenvolvimento , Hipocampo/metabolismo , Deficiência de Magnésio/fisiopatologia , Complicações na Gravidez/fisiopatologia , Efeitos Tardios da Exposição Pré-Natal , Receptores de N-Metil-D-Aspartato/metabolismo , Animais , Ansiedade , Estudos de Coortes , Comportamento Exploratório/fisiologia , Feminino , Masculino , Camundongos , Atividade Motora/fisiologia , Força Muscular/fisiologia , Gravidez , Reconhecimento Psicológico/fisiologia , Caracteres Sexuais
19.
J Cell Biol ; 216(10): 3029-3039, 2017 10 02.
Artigo em Inglês | MEDLINE | ID: mdl-28860275

RESUMO

The meiotic spindle is formed without centrosomes in a large volume of oocytes. Local activation of crucial spindle proteins around chromosomes is important for formation and maintenance of a bipolar spindle in oocytes. We found that phosphodocking 14-3-3 proteins stabilize spindle bipolarity in Drosophila melanogaster oocytes. A critical 14-3-3 target is the minus end-directed motor Ncd (human HSET; kinesin-14), which has well-documented roles in stabilizing a bipolar spindle in oocytes. Phospho docking by 14-3-3 inhibits the microtubule binding activity of the nonmotor Ncd tail. Further phosphorylation by Aurora B kinase can release Ncd from this inhibitory effect of 14-3-3. As Aurora B localizes to chromosomes and spindles, 14-3-3 facilitates specific association of Ncd with spindle microtubules by preventing Ncd from binding to nonspindle microtubules in oocytes. Therefore, 14-3-3 translates a spatial cue provided by Aurora B to target Ncd selectively to the spindle within the large volume of oocytes.


Assuntos
Proteínas 14-3-3/metabolismo , Cromossomos de Insetos/metabolismo , Proteínas de Drosophila/metabolismo , Cinesinas/metabolismo , Microtúbulos/metabolismo , Oócitos/metabolismo , Fuso Acromático/metabolismo , Proteínas 14-3-3/genética , Animais , Aurora Quinase B/genética , Aurora Quinase B/metabolismo , Cromossomos de Insetos/genética , Proteínas de Drosophila/genética , Drosophila melanogaster , Feminino , Cinesinas/genética , Microtúbulos/genética , Oócitos/citologia , Transporte Proteico/fisiologia , Fuso Acromático/genética
20.
Genetics ; 155(4): 1521-34, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10924454

RESUMO

We describe a general genetic method to identify genes encoding proteins that functionally interact with and/or are good candidates for downstream targets of a particular gene product. The screen identifies mutants whose growth depends on high levels of expression of that gene. We apply this to the plo1(+) gene that encodes a fission yeast homologue of the polo-like kinases. plo1(+) regulates both spindle formation and septation. We have isolated 17 high plo1(+)-dependent (pld) mutants that show defects in mitosis or septation. Three mutants show a mitotic arrest phenotype. Among the 14 pld mutants with septation defects, 12 mapped to known loci: cdc7, cdc15, cdc11 spg1, and sid2. One of the pld mutants, cdc7-PD1, was selected for suppressor analysis. As multicopy suppressors, we isolated four known genes involved in septation in fission yeast: spg1(+), sce3(+), cdc8(+), and rho1(+), and two previously uncharacterized genes, mpd1(+) and mpd2(+). mpd1(+) exhibits high homology to phosphatidylinositol 4-phosphate 5-kinase, while mpd2(+) resembles Saccharomyces cerevisiae SMY2; both proteins are involved in the regulation of actin-mediated processes. As chromosomal suppressors of cdc7-PD1, we isolated mutations of cdc16 that resulted in multiseptation without nuclear division. cdc16(+), dma1(+), byr3(+), byr4(+) and a truncated form of the cdc7 gene were isolated by complementation of one of these cdc16 mutations. These results demonstrate that screening for high dose-dependent mutants and their suppressors is an effective approach to identify functionally interacting genes.


Assuntos
Proteínas de Drosophila , Técnicas Genéticas , Proteínas Serina-Treonina Quinases/genética , Proteínas de Saccharomyces cerevisiae , Proteínas de Schizosaccharomyces pombe , Schizosaccharomyces/genética , Supressão Genética , Sequência de Aminoácidos , Proteínas de Ciclo Celular/genética , Divisão Celular/genética , Proteínas de Ligação a DNA/genética , Teste de Complementação Genética , Genótipo , Mitose/genética , Modelos Genéticos , Dados de Sequência Molecular , Mutação , Fenótipo , Proteínas Serina-Treonina Quinases/metabolismo , Saccharomyces cerevisiae/genética , Homologia de Sequência de Aminoácidos , Temperatura , Fatores de Tempo
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