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1.
Mol Cell ; 84(2): 293-308.e14, 2024 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-38113892

RESUMO

Ubiquitylation is catalyzed by coordinated actions of E3 and E2 enzymes. Molecular principles governing many important E3-E2 partnerships remain unknown, including those for RING-family GID/CTLH E3 ubiquitin ligases and their dedicated E2, Ubc8/UBE2H (yeast/human nomenclature). GID/CTLH-Ubc8/UBE2H-mediated ubiquitylation regulates biological processes ranging from yeast metabolic signaling to human development. Here, cryoelectron microscopy (cryo-EM), biochemistry, and cell biology reveal this exquisitely specific E3-E2 pairing through an unconventional catalytic assembly and auxiliary interactions 70-100 Å away, mediated by E2 multisite phosphorylation. Rather than dynamic polyelectrostatic interactions reported for other ubiquitylation complexes, multiple Ubc8/UBE2H phosphorylation sites within acidic CK2-targeted sequences specifically anchor the E2 C termini to E3 basic patches. Positions of phospho-dependent interactions relative to the catalytic domains correlate across evolution. Overall, our data show that phosphorylation-dependent multivalency establishes a specific E3-E2 partnership, is antagonistic with dephosphorylation, rigidifies the catalytic centers within a flexing GID E3-substrate assembly, and facilitates substrate collision with ubiquitylation active sites.


Assuntos
Saccharomyces cerevisiae , Enzimas de Conjugação de Ubiquitina , Humanos , Enzimas de Conjugação de Ubiquitina/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Fosforilação , Microscopia Crioeletrônica , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitinação
2.
Proc Natl Acad Sci U S A ; 121(11): e2316284121, 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38442176

RESUMO

Entire chromosomes are typically only transmitted vertically from one generation to the next. The horizontal transfer of such chromosomes has long been considered improbable, yet gained recent support in several pathogenic fungi where it may affect the fitness or host specificity. To date, it is unknown how these transfers occur, how common they are, and whether they can occur between different species. In this study, we show multiple independent instances of horizontal transfers of the same accessory chromosome between two distinct strains of the asexual entomopathogenic fungus Metarhizium robertsii during experimental co-infection of its insect host, the Argentine ant. Notably, only the one chromosome-but no other-was transferred from the donor to the recipient strain. The recipient strain, now harboring the accessory chromosome, exhibited a competitive advantage under certain host conditions. By phylogenetic analysis, we further demonstrate that the same accessory chromosome was horizontally transferred in a natural environment between M. robertsii and another congeneric insect pathogen, Metarhizium guizhouense. Hence, horizontal chromosome transfer is not limited to the observed frequent events within species during experimental infections but also occurs naturally across species. The accessory chromosome that was transferred contains genes that may be involved in its preferential horizontal transfer or support its establishment. These genes encode putative histones and histone-modifying enzymes, as well as putative virulence factors. Our study reveals that both intra- and interspecies horizontal transfer of entire chromosomes is more frequent than previously assumed, likely representing a not uncommon mechanism for gene exchange.


Assuntos
Formigas , Animais , Filogenia , Histonas , Insetos , Cromossomos
3.
Haematologica ; 108(2): 543-554, 2023 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-35522148

RESUMO

Histone methylation-modifiers, such as EZH2 and KMT2D, are recurrently altered in B-cell lymphomas. To comprehensively describe the landscape of alterations affecting genes encoding histone methylation-modifiers in lymphomagenesis we investigated whole genome and transcriptome data of 186 mature B-cell lymphomas sequenced in the ICGC MMML-Seq project. Besides confirming common alterations of KMT2D (47% of cases), EZH2 (17%), SETD1B (5%), PRDM9 (4%), KMT2C (4%), and SETD2 (4%), also identified by prior exome or RNA-sequencing studies, we here found recurrent alterations to KDM4C in chromosome 9p24, encoding a histone demethylase. Focal structural variation was the main mechanism of KDM4C alterations, and was independent from 9p24 amplification. We also identified KDM4C alterations in lymphoma cell lines including a focal homozygous deletion in a classical Hodgkin lymphoma cell line. By integrating RNA-sequencing and genome sequencing data we predict that KDM4C structural variants result in loss-offunction. By functional reconstitution studies in cell lines, we provide evidence that KDM4C can act as a tumor suppressor. Thus, we show that identification of structural variants in whole genome sequencing data adds to the comprehensive description of the mutational landscape of lymphomas and, moreover, establish KDM4C as a putative tumor suppressive gene recurrently altered in subsets of B-cell derived lymphomas.


Assuntos
Linfoma de Células B , Linfoma , Humanos , Histonas/metabolismo , Histona Desmetilases/genética , Homozigoto , Deleção de Sequência , Linfoma/genética , Linfoma de Células B/genética , Sequenciamento Completo do Genoma , RNA , Histona Desmetilases com o Domínio Jumonji/genética , Histona Desmetilases com o Domínio Jumonji/química , Histona Desmetilases com o Domínio Jumonji/metabolismo , Histona-Lisina N-Metiltransferase/genética
4.
Appl Microbiol Biotechnol ; 107(10): 3329-3339, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37060465

RESUMO

Pandemics like SARS-Cov-2 very frequently have their origin in different animals and in particular herds of camels could be a source of zoonotic diseases. This study took advantage on a highly sensitive and adaptable method for the fast and reliable detection of viral antibodies in camels using low-cost equipment. Magnetic nanoparticles (MNP) have high variability in their functionalization with different peptides and proteins. We confirm that 3-aminopropyl triethoxysilane (APTES)-coated MNP could be functionalized with viral proteins. The protein loading could be confirmed by simple loading controls using FACS-analysis (p < 0.05). Complementary combination of antigen and antibody yields in a significant signal increase could be proven by both FACS and COMPASS. However, COMPASS needs only a few seconds for the measurement. In COMPASS, the phase φn on selected critical point of the fifth higher harmonic (n = 5th). Here, positive sera display highly significant signal increase over the control or negative sera. Furthermore, a clear distinction could be made in antibody detection as an immune response to closely related viruses (SARS-CoV2 and MERS). Using modified MNPs along with COMPASS offers a fast and reliable method that is less cost intensive than current technologies and offers the possibility to be quickly adapted in case of new occurring viral infections. KEY POINTS: • COMPASS (critical offset magnetic particle spectroscopy) allows the fast detection of antibodies. • Magnetic nanoparticles can be adapted by exchange of the linked bait molecule. • Antibodies could be detected in camel sera without washing steps within seconds.


Assuntos
COVID-19 , Coronavírus da Síndrome Respiratória do Oriente Médio , Animais , Anticorpos Antivirais , Camelus , RNA Viral , Coronavírus da Síndrome Respiratória do Oriente Médio/genética , SARS-CoV-2 , Análise Espectral , Fenômenos Magnéticos
5.
Development ; 145(6)2018 03 21.
Artigo em Inglês | MEDLINE | ID: mdl-29490983

RESUMO

In addition to its function as an inhibitor of histone acetyltransferases, Nir (Noc2l) binds to p53 and TAp63 to regulate their activity. Here, we show that epidermis-specific ablation of Nir impairs epidermal stratification and barrier function, resulting in perinatal lethality. Nir-deficient epidermis lacks appendages and remains single layered during embryogenesis. Cell proliferation is inhibited, whereas apoptosis and p53 acetylation are increased, indicating that Nir is controlling cell proliferation by limiting p53 acetylation. Transcriptome analysis revealed that Nir regulates the expression of essential factors in epidermis development, such as keratins, integrins and laminins. Furthermore, Nir binds to and controls the expression of p63 and limits H3K18ac at the p63 promoter. Corroborating the stratification defects, asymmetric cell divisions were virtually absent in Nir-deficient mice, suggesting that Nir is required for correct mitotic spindle orientation. In summary, our data define Nir as a key regulator of skin development.


Assuntos
Epiderme/metabolismo , Histona Acetiltransferases/metabolismo , Proteínas Repressoras/metabolismo , Animais , Apoptose/genética , Divisão Celular Assimétrica/genética , Técnicas de Cultura de Células , Divisão Celular , Proliferação de Células/genética , Imunoprecipitação da Cromatina , Epiderme/crescimento & desenvolvimento , Imunofluorescência , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Camundongos , Fosfoproteínas/metabolismo , Transativadores/metabolismo , Proteína Supressora de Tumor p53/metabolismo
6.
Psychosom Med ; 81(2): 155-164, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30702549

RESUMO

OBJECTIVE: Impairments in facial emotion recognition are an underlying factor of deficits in emotion regulation and interpersonal difficulties in mental disorders and are evident in eating disorders (EDs). METHODS: We used a computerized psychophysical paradigm to manipulate parametrically the quantity of signal in facial expressions of emotion (QUEST threshold seeking algorithm). This was used to measure emotion recognition in 308 adult women (anorexia nervosa [n = 61], bulimia nervosa [n = 58], healthy controls [n = 130], and mixed mental disorders [mixed, n = 59]). The M (SD) age was 22.84 (3.90) years. The aims were to establish recognition thresholds defining how much information a person needs to recognize a facial emotion expression and to identify deficits in EDs compared with healthy and clinical controls. The stimuli included six basic emotion expressions (fear, anger, disgust, happiness, sadness, surprise), plus a neutral expression. RESULTS: Happiness was discriminated at the lowest, fear at the highest threshold by all groups. There were no differences regarding thresholds between groups, except for the mixed and the bulimia nervosa group with respect to the expression of disgust (F(3,302) = 5.97, p = .001, η = .056). Emotional clarity, ED pathology, and depressive symptoms did not predict performance (RChange ≤ .010, F(1,305) ≤ 5.74, p ≥ .079). The confusion matrix did not reveal specific biases in either group. CONCLUSIONS: Overall, within-subject effects were as expected, whereas between-subject effects were marginal and psychopathology did not influence emotion recognition. Facial emotion recognition abilities in women experiencing EDs compared with women experiencing mixed mental disorders and healthy controls were similar. Although basic facial emotion recognition processes seems to be intact, dysfunctional aspects such as misinterpretation might be important in emotion regulation problems. CLINICAL TRIAL REGISTRATION NUMBER: DRKS-ID: DRKS00005709.


Assuntos
Regulação Emocional , Expressão Facial , Reconhecimento Facial/fisiologia , Transtornos da Alimentação e da Ingestão de Alimentos/fisiopatologia , Percepção Social , Adolescente , Adulto , Feminino , Humanos , Adulto Jovem
7.
Vet Surg ; 48(7): 1271-1277, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31348538

RESUMO

OBJECTIVE: To describe the clinical signs, conservative treatment, and short- and long-term outcomes of lateral radioulnar subluxation in cattle. ANIMALS: Three cattle with lateral radioulnar subluxation. STUDY DESIGN: Case series. METHODS: One 3-year-old Red Holstein cow, one 2-year-old Red Holstein cow, and one 9-month-old Holstein heifer were presented with acute, grade greater than 3 of 5, mixed lameness in one forelimb. Clinical, radiographic, and ultrasonographic examination results revealed radioulnar subluxation with lateral displacement in all cases. RESULTS: The subluxations were manually reduced under general anesthesia by simultaneous maximum flexion of the elbow and carpal joints, medial rotation of the forearm, and application of strong pressure to the radial head and olecranon. The short-term clinical outcome after stall rest was excellent in all three cases. Clinical and radiographic follow-up examinations were performed at varying intervals, with a final on-farm examination in all three cattle 12, 7, and 9 months after reduction. Osteoarthritic changes were visible in all three cases, mainly at the medial humeral trochlea, but lameness had completely resolved in all three animals. CONCLUSION: Conservative management of lateral radioulnar subluxation had an excellent clinical outcome in all three cattle. Follow-up radiographs revealed osseous proliferation mainly in the region of the medial trochlea of the humerus and subtle signs of osteoarthritic changes. CLINICAL SIGNIFICANCE: Lateral radio-ulnar subluxation is a rare but possibly underdiagnosed cause of lameness in cattle. It should be part of the differential diagnosis in cattle with elbow joint pain.


Assuntos
Doenças dos Bovinos/diagnóstico , Membro Anterior/lesões , Luxações Articulares/veterinária , Animais , Bovinos , Doenças dos Bovinos/patologia , Doenças dos Bovinos/terapia , Feminino , Membro Anterior/diagnóstico por imagem , Luxações Articulares/diagnóstico por imagem , Luxações Articulares/terapia , Osteotomia/veterinária , Radiografia/veterinária , Amplitude de Movimento Articular , Resultado do Tratamento , Ultrassonografia/veterinária
8.
Eur J Haematol ; 101(6): 766-773, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30091166

RESUMO

OBJECTIVE: Azacitidine (Vidaza® ) is the standard treatment for patients with higher-risk myelodysplastic syndromes (MDS) not eligible for allogeneic stem cell transplantation. In the noninterventional study PIAZA, we evaluated the effectiveness and safety of azacitidine treatment in 149 patients with higher-risk MDS, chronic myelomonocytic leukemia (CMML) and acute myeloid leukemia (AML) in routine clinical practice. METHOD: Patients were treated according to physician's discretion. Besides evaluation of safety and effectiveness, impact of covariates on progression-free survival (PFS) was assessed. RESULTS: Median age of patients was 75 years. 61.1% of patients were diagnosed with MDS, 31.5% with AML and 7.4% with CMML. Patients were treated with azacitidine for a median of seven cycles. Median PFS was 10.9 months. Median OS was 14.1 months. Two-year survival rate was 28.9%. 45.9% of patients showed CR or PR. Stable and progressive disease were observed in 37.2% and 8% of patients, respectively. Transfusion independence was reported in 64 of 89 patients. Eastern cooperative oncology group (ECOG) performance status (PS) and red blood cell (RBC) transfusion before azacitidine therapy were identified as predictive factors for PFS. CONCLUSION: In conclusion, we estimated the duration of PFS in a real-world setting and identified ECOG PS and RBC transfusion as predictive factors for PFS. The safety of azacitidine showed a similar profile as demonstrated in the pivotal clinical trials.


Assuntos
Antimetabólitos Antineoplásicos/uso terapêutico , Azacitidina/uso terapêutico , Transfusão de Sangue , Leucemia Mieloide Aguda/terapia , Leucemia Mielomonocítica Crônica/terapia , Síndromes Mielodisplásicas/terapia , Idoso , Idoso de 80 Anos ou mais , Antimetabólitos Antineoplásicos/administração & dosagem , Antimetabólitos Antineoplásicos/efeitos adversos , Azacitidina/administração & dosagem , Azacitidina/efeitos adversos , Transfusão de Sangue/métodos , Feminino , Seguimentos , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento
9.
Nature ; 483(7391): 608-12, 2012 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-22460906

RESUMO

Deregulated expression of the MYC oncoprotein contributes to the genesis of many human tumours, yet strategies to exploit this for a rational tumour therapy are scarce. MYC promotes cell growth and proliferation, and alters cellular metabolism to enhance the provision of precursors for phospholipids and cellular macromolecules. Here we show in human and murine cell lines that oncogenic levels of MYC establish a dependence on AMPK-related kinase 5 (ARK5; also known as NUAK1) for maintaining metabolic homeostasis and for cell survival. ARK5 is an upstream regulator of AMPK and limits protein synthesis via inhibition of the mammalian target of rapamycin 1 (mTORC1) signalling pathway. ARK5 also maintains expression of mitochondrial respiratory chain complexes and respiratory capacity, which is required for efficient glutamine metabolism. Inhibition of ARK5 leads to a collapse of cellular ATP levels in cells expressing deregulated MYC, inducing multiple pro-apoptotic responses as a secondary consequence. Depletion of ARK5 prolongs survival in MYC-driven mouse models of hepatocellular carcinoma, demonstrating that targeting cellular energy homeostasis is a valid therapeutic strategy to eliminate tumour cells that express deregulated MYC.


Assuntos
Regulação Neoplásica da Expressão Gênica , Genes myc/genética , Proteínas Quinases/metabolismo , Proteínas Repressoras/metabolismo , Proteínas Quinases Ativadas por AMP/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Apoptose , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Respiração Celular , Sobrevivência Celular , Transformação Celular Neoplásica/genética , Modelos Animais de Doenças , Doxiciclina/farmacologia , Transporte de Elétrons , Glutamina/metabolismo , Homeostase , Humanos , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Alvo Mecanístico do Complexo 1 de Rapamicina , Camundongos , Mitocôndrias/metabolismo , Complexos Multiproteicos , Proteína Oncogênica p55(v-myc)/genética , Proteína Oncogênica p55(v-myc)/metabolismo , Biossíntese de Proteínas , Proteínas Quinases/deficiência , Proteínas Quinases/genética , Proteínas/antagonistas & inibidores , Proteínas/metabolismo , Interferência de RNA , Proteínas Repressoras/antagonistas & inibidores , Proteínas Repressoras/deficiência , Proteínas Repressoras/genética , Transdução de Sinais , Serina-Treonina Quinases TOR/metabolismo
10.
Genes Dev ; 24(12): 1281-94, 2010 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-20551174

RESUMO

The Myc protein suppresses the transcription of several cyclin-dependent kinase inhibitors (CKIs) via binding to Miz1; whether this interaction is important for Myc's ability to induce or maintain tumorigenesis is not known. Here we show that the oncogenic potential of a point mutant of Myc (MycV394D) that is selectively deficient in binding to Miz1 is greatly attenuated. Binding of Myc to Miz1 is continuously required to repress CKI expression and inhibit accumulation of trimethylated histone H3 at Lys 9 (H3K9triMe), a hallmark of cellular senescence, in T-cell lymphomas. Lymphomas that arise express high amounts of transforming growth factor beta-2 (TGFbeta-2) and TGFbeta-3. Upon Myc suppression, TGFbeta signaling is required to induce CKI expression and cellular senescence and suppress tumor recurrence. Binding of Myc to Miz1 is required to antagonize growth suppression and induction of senescence by TGFbeta. We demonstrate that, since lymphomas express high levels of TGFbeta, they are poised to elicit an autocrine program of senescence upon Myc inactivation, demonstrating that TGFbeta is a key factor that establishes oncogene addiction of T-cell lymphomas.


Assuntos
Comunicação Autócrina/fisiologia , Linfoma de Células T/fisiopatologia , Proteínas Nucleares/metabolismo , Proteínas Inibidoras de STAT Ativados/metabolismo , Proteínas Proto-Oncogênicas c-myc/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Animais , Doxiciclina/farmacologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Células HeLa , Humanos , Camundongos , Camundongos Transgênicos , Mutação/genética , Proteínas Proto-Oncogênicas c-myc/genética , Ubiquitina-Proteína Ligases
11.
Crit Care Med ; 44(11): 2060-2069, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27276343

RESUMO

OBJECTIVES: To evaluate test validity of the Pediatric Confusion Assessment Method for the ICU, the Pediatric Anesthesia Emergence Delirium scale, and the newly developed severity scale for the Pediatric Confusion Assessment Method for the ICU; to prospectively assess covariates and their influence on test validity of the scores. DESIGN: Prospective observational cohort study. SETTING: PICU of a tertiary care medical center. PATIENTS: Critically ill patients 5 years old or older ventilated or nonventilated with an ICU length of stay of at least 24 hours. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Patients were scored with the Pediatric Confusion Assessment Method for the ICU and the Pediatric Anesthesia Emergence Delirium scale once daily for a maximum of 21 days. Validity was determined by comparing scoring results with the evaluations of the delirium experts who used the criteria of the Diagnostic and Statistical Manual, 4th Edition, Text Revision, for delirium diagnosis. Sixty-four patients were enrolled and 214 assessments were conducted and included in data analysis. The first assessments within each patient revealed sensitivities of 69.2% for the Pediatric Anesthesia Emergence Delirium scale, 76.9% for the Pediatric Confusion Assessment Method for the ICU, and 84.9% for the severity scale for the Pediatric Confusion Assessment Method for the ICU. Specificities were 98% for all scores. Considering repeated measurements, sensitivities decreased to 35.9% for the Pediatric Anesthesia Emergence Delirium scale and to 52.3% for the Pediatric Confusion Assessment Method for the ICU. The sensitivity of the severity scale for the Pediatric Confusion Assessment Method for the ICU dropped to 71.8%, which was significantly higher compared to the Pediatric Anesthesia Emergence Delirium scale (p = 0.0008). Receiver operator characteristic regression unveiled that sedation and mechanical ventilation had a significant negative effect on the validity of the Pediatric Anesthesia Emergence Delirium scale and the severity scale for the Pediatric Confusion Assessment Method for the ICU. Age and gender had a significant impact on the receiver operator characteristic curve of the severity scale for the Pediatric Confusion Assessment Method for the ICU. CONCLUSIONS: The severity scale for the Pediatric Confusion Assessment Method for the ICU showed the best test validity when used in critically ill children of 5 years old or older. Nevertheless, validity of delirium screening itself depends on patient specific factors. These factors should be taken into consideration when choosing a delirium screening instrument.


Assuntos
Estado Terminal , Delírio/diagnóstico , Testes Neuropsicológicos , Adolescente , Criança , Estudos de Coortes , Feminino , Humanos , Unidades de Terapia Intensiva Pediátrica , Masculino , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
13.
Nature ; 464(7289): 792-6, 2010 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-20228790

RESUMO

Demethylation at distinct lysine residues in histone H3 by lysine-specific demethylase 1 (LSD1) causes either gene repression or activation. As a component of co-repressor complexes, LSD1 contributes to target gene repression by removing mono- and dimethyl marks from lysine 4 of histone H3 (H3K4). In contrast, during androgen receptor (AR)-activated gene expression, LSD1 removes mono- and dimethyl marks from lysine 9 of histone H3 (H3K9). Yet, the mechanisms that control this dual specificity of demethylation are unknown. Here we show that phosphorylation of histone H3 at threonine 6 (H3T6) by protein kinase C beta I (PKCbeta(I), also known as PRKCbeta) is the key event that prevents LSD1 from demethylating H3K4 during AR-dependent gene activation. In vitro, histone H3 peptides methylated at lysine 4 and phosphorylated at threonine 6 are no longer LSD1 substrates. In vivo, PKCbeta(I) co-localizes with AR and LSD1 on target gene promoters and phosphorylates H3T6 after androgen-induced gene expression. RNA interference (RNAi)-mediated knockdown of PKCbeta(I) abrogates H3T6 phosphorylation, enhances demethylation at H3K4, and inhibits AR-dependent transcription. Activation of PKCbeta(I) requires androgen-dependent recruitment of the gatekeeper kinase protein kinase C (PKC)-related kinase 1 (PRK1). Notably, increased levels of PKCbeta(I) and phosphorylated H3T6 (H3T6ph) positively correlate with high Gleason scores of prostate carcinomas, and inhibition of PKCbeta(I) blocks AR-induced tumour cell proliferation in vitro and cancer progression of tumour xenografts in vivo. Together, our data establish that androgen-dependent kinase signalling leads to the writing of the new chromatin mark H3T6ph, which in consequence prevents removal of active methyl marks from H3K4 during AR-stimulated gene expression.


Assuntos
Histona Desmetilases/metabolismo , Histonas/química , Histonas/metabolismo , Proteína Quinase C/metabolismo , Androgênios/metabolismo , Androgênios/farmacologia , Animais , Divisão Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Cromatina/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Técnicas de Silenciamento de Genes , Histona Desmetilases/antagonistas & inibidores , Humanos , Lisina/química , Lisina/metabolismo , Masculino , Metilação/efeitos dos fármacos , Camundongos , Camundongos Nus , Camundongos SCID , Fosforilação/efeitos dos fármacos , Fosfotreonina/metabolismo , Regiões Promotoras Genéticas/genética , Neoplasias da Próstata/enzimologia , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Proteína Quinase C/antagonistas & inibidores , Proteína Quinase C/deficiência , Proteína Quinase C/genética , Proteína Quinase C beta , Transdução de Sinais/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto
14.
Pharmacol Res ; 91: 78-87, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25481222

RESUMO

The ability of an antineoplastic drug to exert its cytostatic effect depends largely on the balance between its uptake into and extrusion from the cancer cells. ATP driven efflux transporter proteins drive the export of antineoplastic drugs and play a pivotal role in the development of chemoresistance. As regards uptake transporters, comparably less is known on their impact in drug action. In the current study, we characterized the interactions of two uptake transporter proteins, expressed mainly in the liver; the organic anion transporter 2 (OAT2, encoded by the SLC22A7 gene) and the sodium taurocholate cotransporting polypeptide (NTCP, encoded by the SLC10A1 gene), stably transfected in human embryonic kidney cells, with some antineoplastic agents that are routinely being used in cancer chemotherapy. Whereas NTCP did not show any strong interactions with the cytostatics tested, we observed a very strong inhibition of OAT2 mediated [(3)H] cGMP uptake in the presence of bendamustine, irinotecan and paclitaxel. The Ki values of OAT2 for bendamustine, irinotecan and paclitaxel were determined to be 43.3±4.33µM, 26.4±2.34µM and 10.4±0.45µM, respectively. Incubation of bendamustine with OAT2 expressing cells increased the caspase-3 activity, and this increase was inhibited by simultaneous incubation with bendamustine and probenecid, a well-known inhibitor of OATs, suggesting that bendamustine is a substrate of OAT2. A higher accumulation of irinotecan was observed in OAT2 expressing cells compared to control pcDNA cells by HPLC analysis of cell lysates. The accumulation was diminished in the presence of cGMP, the substrate we used to functionally characterize OAT2, suggesting specificity of this uptake and the fact that OAT2 mediates uptake of irinotecan.


Assuntos
Antineoplásicos/farmacologia , Transportadores de Ânions Orgânicos Dependentes de Sódio/metabolismo , Transportadores de Ânions Orgânicos Sódio-Independentes/metabolismo , Simportadores/metabolismo , Apoptose/efeitos dos fármacos , Cloridrato de Bendamustina , Transporte Biológico , Camptotecina/análogos & derivados , Camptotecina/farmacologia , GMP Cíclico/metabolismo , Estrona/análogos & derivados , Estrona/metabolismo , Células HEK293 , Humanos , Irinotecano , Compostos de Mostarda Nitrogenada/farmacologia , Paclitaxel/farmacologia
15.
J Cell Sci ; 125(Pt 17): 4103-13, 2012 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-22623719

RESUMO

An understanding of cytokinesis at the molecular level requires a detailed description of the protein complexes that perform central activities during this process. The proteins Hof1p, Cyk3p, Inn1p and Myo1p each represent one of the four genetically defined and partially complementary pathways of cytokinesis in the yeast Saccharomyces cerevisiae. Here we show that the osmosensor Sho1p is required for correct cell-cell separation. Shortly before cytokinesis Sho1p sequentially assembles with Hof1p, Inn1p and Cyk3p, into a complex (the HICS complex) that might help to connect the membrane with the actin-myosin ring. The HICS complex is formed exclusively through interactions between three SH3 domains located in Cyk3p, Hof1p and Sho1p, and five acceptor sites found in Cyk3p, Hof1p and Inn1p. Owing to the overlapping binding specificities of its members the HICS complex is best described as ensembles of isomeric interaction states that precisely coordinate the different functions of the interactors during cytokinesis.


Assuntos
Membrana Celular/metabolismo , Citocinese , Proteínas de Membrana/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/citologia , Saccharomyces cerevisiae/metabolismo , Sítios de Ligação , Membrana Celular/ultraestrutura , Ligantes , Ligação Proteica , Transporte Proteico , Saccharomyces cerevisiae/ultraestrutura , Transdução de Sinais
16.
Nat Cell Biol ; 9(3): 347-53, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17277772

RESUMO

Posttranslational modifications of histones, such as methylation, regulate chromatin structure and gene expression. Recently, lysine-specific demethylase 1 (LSD1), the first histone demethylase, was identified. LSD1 interacts with the androgen receptor and promotes androgen-dependent transcription of target genes by ligand-induced demethylation of mono- and dimethylated histone H3 at Lys 9 (H3K9) only. Here, we identify the Jumonji C (JMJC) domain-containing protein JMJD2C as the first histone tridemethylase regulating androgen receptor function. JMJD2C interacts with androgen receptor in vitro and in vivo. Assembly of ligand-bound androgen receptor and JMJD2C on androgen receptor-target genes results in demethylation of trimethyl H3K9 and in stimulation of androgen receptor-dependent transcription. Conversely, knockdown of JMJD2C inhibits androgen-induced removal of trimethyl H3K9, transcriptional activation and tumour cell proliferation. Importantly, JMJD2C colocalizes with androgen receptor and LSD1 in normal prostate and in prostate carcinomas. JMJD2C and LSD1 interact and both demethylases cooperatively stimulate androgen receptor-dependent gene transcription. In addition, androgen receptor, JMJD2C and LSD1 assemble on chromatin to remove methyl groups from mono, di and trimethylated H3K9. Thus, our data suggest that specific gene regulation requires the assembly and coordinate action of demethylases with distinct substrate specificities.


Assuntos
Proteínas de Neoplasias/metabolismo , Oxirredutases N-Desmetilantes/metabolismo , Receptores Androgênicos/metabolismo , Fatores de Transcrição/metabolismo , Animais , Linhagem Celular , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Chlorocebus aethiops , Regulação da Expressão Gênica/efeitos dos fármacos , Células HeLa , Histona Desmetilases , Histonas/metabolismo , Humanos , Histona Desmetilases com o Domínio Jumonji , Masculino , Metribolona/farmacologia , MicroRNAs/genética , Proteínas de Neoplasias/genética , Oxirredutases N-Desmetilantes/genética , Antígeno Prostático Específico/genética , Antígeno Prostático Específico/metabolismo , Neoplasias da Próstata/genética , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Ligação Proteica/efeitos dos fármacos , RNA Interferente Pequeno/genética , Receptores Androgênicos/análise , Receptores de Glucocorticoides/genética , Receptores de Glucocorticoides/metabolismo , Receptores de Progesterona/genética , Receptores de Progesterona/metabolismo , Elementos de Resposta/genética , Calicreínas Teciduais/genética , Fatores de Transcrição/genética , Transfecção
17.
J Cell Biol ; 223(1)2024 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-37938157

RESUMO

Ubiquitylation and phosphorylation control composition and architecture of the cell separation machinery in yeast and other eukaryotes. The significance of septin sumoylation on cell separation remained an enigma. Septins form an hourglass structure at the bud neck of yeast cells that transforms into a split septin double ring during mitosis. We discovered that sumoylated septins recruit the cytokinesis checkpoint protein Fir1 to the peripheral side of the septin hourglass just before its transformation into the double-ring configuration. As this transition occurs, Fir1 is released from the septins and seamlessly relocates between the split septin rings through synchronized binding to the scaffold Spa2. Fir1 binds and carries the membrane-bound Skt5 on its route to the division plane where the Fir1-Skt5 complex serves as receptor for chitin synthase III.


Assuntos
Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae , Septinas , Sumoilação , Fatores de Poliadenilação e Clivagem de mRNA , Citoesqueleto , Saccharomyces cerevisiae/genética , Septinas/genética , Ubiquitinação , Proteínas de Saccharomyces cerevisiae/genética , Fatores de Poliadenilação e Clivagem de mRNA/genética
18.
Eur J Pharm Biopharm ; 197: 114222, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38387850

RESUMO

Lipid nanoparticles (LNPs) employing ionizable lipids are the most advanced technology for delivery of RNA, most notably mRNA, to cells. LNPs represent well-defined core-shell particles with efficient nucleic acid encapsulation, low immunogenicity and enhanced efficacy. While much is known about the structure and activity of LNPs, less attention is given to the timing of LNP uptake, cytosolic transfer and protein expression. However, LNP kinetics is a key factor determining delivery efficiency. Hence quantitative insight into the multi-cascaded pathway of LNPs is of interest to elucidate the mechanism of delivery. Here, we review experiments as well as theoretical modeling of the timing of LNP uptake, mRNA-release and protein expression. We describe LNP delivery as a sequence of stochastic transfer processes and review a mathematical model of subsequent protein translation from mRNA. We compile probabilities and numbers obtained from time resolved microscopy. Specifically, live-cell imaging on single cell arrays (LISCA) allows for high-throughput acquisition of thousands of individual GFP reporter expression time courses. The traces yield the distribution of mRNA life-times, expression rates and expression onset. Correlation analysis reveals an inverse dependence of gene expression efficiency and transfection onset-times. Finally, we discuss why timing of mRNA release is critical in the context of codelivery of multiple nucleic acid species as in the case of mRNA co-expression or CRISPR/Cas gene editing.


Assuntos
Nanopartículas , RNA , Transfecção , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Cinética , Nanopartículas/química
19.
FEBS Lett ; 598(9): 978-994, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38575527

RESUMO

Patients with Skraban-Deardorff syndrome (SKDEAS), a neurodevelopmental syndrome associated with a spectrum of developmental and intellectual delays and disabilities, harbor diverse mutations in WDR26, encoding a subunit of the multiprotein CTLH E3 ubiquitin ligase complex. Structural studies revealed that homodimers of WDR26 bridge two core-CTLH E3 complexes to generate giant, hollow oval-shaped supramolecular CTLH E3 assemblies. Additionally, WDR26 mediates CTLH E3 complex binding to subunit YPEL5 and functions as substrate receptor for the transcriptional repressor HBP1. Here, we mapped SKDEAS-associated mutations on a WDR26 structural model and tested their functionality in complementation studies using genetically engineered human cells lacking CTLH E3 supramolecular assemblies. Despite the diversity of mutations, 15 of 16 tested mutants impaired at least one CTLH E3 complex function contributing to complex assembly and interactions, thus providing first mechanistic insights into SKDEAS pathology.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal , Deficiência Intelectual , Mutação , Ubiquitina-Proteína Ligases , Humanos , Proteínas Adaptadoras de Transdução de Sinal/genética , Células HEK293 , Deficiência Intelectual/genética , Deficiência Intelectual/metabolismo , Modelos Moleculares , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitina-Proteína Ligases/química
20.
Eur J Pediatr ; 172(8): 1043-51, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23568514

RESUMO

UNLABELLED: Functional abdominal pain and irritable bowel syndrome are two prevalent disorders in childhood which are associated with recurrent or chronic abdominal pain, disabilities in daily functioning, and reduced quality of life. This study aimed to evaluate a brief hypnotherapeutic-behavioral intervention program in a prospective randomized controlled design. Thirty-eight children, 6 to 12 years of age, and their parents were randomly assigned to a standardized hypnotherapeutic-behavioral treatment (n = 20) or to a waiting list condition (n = 18). Both groups were reassessed 3 months after beginning. Primary outcome variables were child-completed pain measures and pain-related disability. Secondary outcome variables were parent-completed measures of their children's pain and pain-related disability. Health-related quality of life from both perspectives also served as a secondary outcome. In the treatment group, 11 of 20 children (55.0%) showed clinical remission (>80% improvement), whereas only one child (5.6%) in the waiting list condition was classified as responder. Children in the treatment group reported a significantly greater reduction of pain scores and pain-related disability than children of the waiting list condition. Parental ratings also showed a greater reduction of children's abdominal pain and pain-related disability. Health-related quality of life did not increase significantly. CONCLUSIONS: Hypnotherapeutic and behavioral interventions are effective in treating children with long-standing AP. Treatment success of this brief program should be further evaluated against active interventions with a longer follow-up.


Assuntos
Dor Abdominal/terapia , Terapia Comportamental/métodos , Hipnose/métodos , Síndrome do Intestino Irritável/terapia , Psicoterapia Breve/métodos , Dor Abdominal/diagnóstico , Análise de Variância , Criança , Feminino , Humanos , Síndrome do Intestino Irritável/diagnóstico , Masculino , Medição da Dor , Pais , Estudos Prospectivos , Qualidade de Vida , Indução de Remissão , Inquéritos e Questionários
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