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1.
Psychol Med ; 48(7): 1148-1156, 2018 05.
Artículo en Inglés | MEDLINE | ID: mdl-28893330

RESUMEN

BACKGROUND: Cognitive-behavioral therapy (CBT) is thought to be useful for chronic pain, with the pathology of the latter being closely associated with cognitive-emotional components. However, there are few resting-state functional magnetic resonance imaging (R-fMRI) studies. We used the independent component analysis method to examine neural changes after CBT and to assess whether brain regions predict treatment response. METHODS: We performed R-fMRI on a group of 29 chronic pain (somatoform pain disorder) patients and 30 age-matched healthy controls (T1). Patients were enrolled in a weekly 12-session group CBT (T2). We assessed selected regions of interest that exhibited differences in intrinsic connectivity network (ICN) connectivity strength between the patients and controls at T1, and compared T1 and T2. We also examined the correlations between treatment effects and rs-fMRI data. RESULTS: Abnormal ICN connectivity of the orbitofrontal cortex (OFC) and inferior parietal lobule within the dorsal attention network (DAN) and of the paracentral lobule within the sensorimotor network in patients with chronic pain normalized after CBT. Higher ICN connectivity strength in the OFC indicated greater improvements in pain intensity. Furthermore, ICN connectivity strength in the dorsal posterior cingulate cortex (PCC) within the DAN at T1 was negatively correlated with CBT-related clinical improvements. CONCLUSIONS: We conclude that the OFC is crucial for CBT-related improvement of pain intensity, and that the dorsal PCC activation at pretreatment also plays an important role in improvement of clinical symptoms via CBT.


Asunto(s)
Dolor Crónico/terapia , Terapia Cognitivo-Conductual , Giro del Cíngulo/fisiopatología , Imagen por Resonancia Magnética , Corteza Prefrontal/fisiopatología , Adulto , Mapeo Encefálico , Estudios de Casos y Controles , Dolor Crónico/fisiopatología , Femenino , Humanos , Japón , Masculino , Persona de Mediana Edad , Vías Nerviosas/fisiopatología , Psicoterapia de Grupo , Descanso , Regresión Espacial
2.
BMC Psychiatry ; 15: 302, 2015 Nov 25.
Artículo en Inglés | MEDLINE | ID: mdl-26602093

RESUMEN

BACKGROUND: Cognitive behavioral therapy (CBT) usually involves homework, the completion of which is a known predictor of a positive outcome. The aim of the present study was to examine the session-by-session relationships between enthusiasm to complete the homework and the improvement of psychological distress in depressed people through the course of therapy. METHODS: Working people with subthreshold depression were recruited to participate in the telephone CBT (tCBT) program with demonstrated effectiveness. Their enthusiasm for homework was enhanced with motivational interviewing techniques and was measured by asking two questions: "How strongly do you feel you want to do this homework?" and "How confident do you feel you can actually accomplish this homework?" at the end of each session. The outcome was the K6 score, which was administered at the start of each session. The K6 is an index of psychological distress including depression and anxiety. We used structural equation modeling (SEM) to elucidate the relationships between enthusiasm and the K6 scores from session to session. RESULTS: The best fitting model suggested that, throughout the course of behavior therapy (BT), enthusiasm to complete the homework was negatively correlated with the K6 scores for the subsequent session, while the K6 score measured at the beginning of the session did not influence the enthusiasm to complete the homeworks assigned for that session. CONCLUSIONS: Empirical data now support the practitioners of BT when they try to enhance their patient's enthusiasm for homework regardless of the participant's distress, which then would lead to a reduction in distress in the subsequent week. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov NCT00885014 . April 20, 2009.


Asunto(s)
Terapia Cognitivo-Conductual/métodos , Trastorno Depresivo/terapia , Cooperación del Paciente/psicología , Estrés Psicológico/terapia , Logro , Adulto , Trastornos de Ansiedad/psicología , Trastorno Depresivo/psicología , Emociones , Femenino , Humanos , Masculino , Persona de Mediana Edad , Motivación , Entrevista Motivacional/métodos , Teléfono , Trabajo/psicología , Adulto Joven
3.
Diabetologia ; 55(12): 3318-30, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22983607

RESUMEN

AIMS/HYPOTHESIS: Insufficient insulin secretion and reduced pancreatic beta cell mass are hallmarks of type 2 diabetes. Here, we focused on a family of serine-threonine kinases known as homeodomain-interacting protein kinases (HIPKs). HIPKs are implicated in the modulation of Wnt signalling, which plays a crucial role in transcriptional activity, and in pancreas development and maintenance. The aim of the present study was to characterise the role of HIPKs in glucose metabolism. METHODS: We used RNA interference to characterise the role of HIPKs in regulating insulin secretion and transcription activity. We conducted RT-PCR and western blot analyses to analyse the expression and abundance of HIPK genes and proteins in the islets of high-fat diet-fed mice. Glucose-induced insulin secretion and beta cell proliferation were measured in islets from Hipk3 ( -/- ) mice, which have impaired glucose tolerance owing to an insulin secretion deficiency. The abundance of pancreatic duodenal homeobox (PDX)-1 and glycogen synthase kinase (GSK)-3ß phosphorylation in Hipk3 ( -/- ) islets was determined by immunohistology and western blot analyses. RESULTS: We found that HIPKs regulate insulin secretion and transcription activity. Hipk3 expression was most significantly increased in the islets of high-fat diet-fed mice. Furthermore, glucose-induced insulin secretion and beta cell proliferation were decreased in the islets of Hipk3 ( -/- ) mice. Levels of PDX1 and GSK-3ß phosphorylation were significantly decreased in Hipk3 ( -/- ) islets. CONCLUSIONS/INTERPRETATION: Depletion of HIPK3 impairs insulin secretion and glucose tolerance. Decreased levels of HIPK3 may play a substantial role in the pathogenesis of type 2 diabetes.


Asunto(s)
Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Proteínas de Homeodominio/metabolismo , Células Secretoras de Insulina/metabolismo , Insulina/metabolismo , Animales , Células Cultivadas , Diabetes Mellitus Experimental/patología , Diabetes Mellitus Tipo 2/patología , Dieta Alta en Grasa , Femenino , Prueba de Tolerancia a la Glucosa , Secreción de Insulina , Células Secretoras de Insulina/patología , Masculino , Ratones , Ratones Noqueados , Páncreas/metabolismo , Interferencia de ARN
5.
Clin Exp Immunol ; 164(2): 236-47, 2011 May.
Artículo en Inglés | MEDLINE | ID: mdl-21391989

RESUMEN

Alpha-carba-GalCer (RCAI-56), a novel synthetic analogue of α-galactosylceramide (α-GalCer), stimulates invariant natural killer T (NK T) cells to produce interferon (IFN)-γ. IFN-γ exhibits immunoregulatory properties in autoimmune diseases by suppressing T helper (Th)-17 cell differentiation and inducing regulatory T cells and apoptosis of autoreactive T cells. Here, we investigated the protective effects of α-carba-GalCer on collagen-induced arthritis (CIA) in mice. First, we confirmed that α-carba-GalCer selectively induced IFN-γ in CIA-susceptible DBA/1 mice in vivo. Then, DBA/1 mice were immunized with bovine type II collagen (CII) and α-carba-GalCer. The incidence and clinical score of CIA were significantly lower in α-carba-GalCer-treated mice. Anti-IFN-γ antibodies abolished the beneficial effects of α-carba-GalCer, suggesting that α-carba-GalCer ameliorated CIA in an IFN-γ-dependent manner. Treatment with α-carba-GalCer reduced anti-CII antibody production [immunoglobulin (Ig)G and IgG2a] and CII-reactive interleukin (IL)-17 production by draining lymph node (DLN) cells, did not induce apoptosis or regulatory T cells, and significantly increased the ratio of the percentage of IFN-γ-producing T cells to IL-17-producing T cells (Th1/Th17 ratio). Moreover, the gene expression levels of IL-6 and IL-23p19, Th17-related cytokines, were reduced significantly in mice treated with α-carba-GalCer. In addition, we observed higher IFN-γ production by NK T cells in α-carba-GalCer-treated mice in the initial phase of CIA. These findings indicate that α-carba-GalCer polarizes the T cell response toward Th1 and suppresses Th17 differentiation or activation, suggesting that α-carba-GalCer, a novel NK T cell ligand, can potentially provide protection against Th17-mediated autoimmune arthritis by enhancing the Th1 response.


Asunto(s)
Artritis Experimental/tratamiento farmacológico , Enfermedades Autoinmunes/tratamiento farmacológico , Galactosilceramidas/uso terapéutico , Factores Inmunológicos/uso terapéutico , Interferón gamma/metabolismo , Células T Asesinas Naturales/efectos de los fármacos , Animales , Formación de Anticuerpos/efectos de los fármacos , Artritis Experimental/inducido químicamente , Artritis Experimental/inmunología , Enfermedades Autoinmunes/inducido químicamente , Enfermedades Autoinmunes/inmunología , Bovinos , Colágeno Tipo II/toxicidad , Evaluación Preclínica de Medicamentos , Galactosilceramidas/farmacología , Interferón gamma/biosíntesis , Interferón gamma/genética , Interleucina-23/biosíntesis , Interleucina-23/genética , Interleucina-6/biosíntesis , Interleucina-6/genética , Ligandos , Ganglios Linfáticos/inmunología , Ganglios Linfáticos/patología , Activación de Linfocitos/efectos de los fármacos , Masculino , Ratones , Ratones Endogámicos DBA , Células T Asesinas Naturales/inmunología , Células T Asesinas Naturales/metabolismo , Organismos Libres de Patógenos Específicos , Linfocitos T Reguladores/efectos de los fármacos , Linfocitos T Reguladores/inmunología , Células TH1/efectos de los fármacos , Células TH1/inmunología , Células TH1/metabolismo , Células Th17/efectos de los fármacos
6.
Diabetologia ; 52(8): 1554-60, 2009 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-19455301

RESUMEN

AIMS/HYPOTHESIS: Additional susceptibility loci for type 2 diabetes have been identified by a meta-analysis of genome-wide association studies (GWASs) in European populations. To examine further the roles of these new loci, we performed a replication study for the association of these single-nucleotide polymorphism (SNP) loci with the disease in three independent Japanese populations. METHODS: We genotyped seven of the 11 SNPs that emerged in stage 2 of the meta-analysis for European GWASs (rs864745 in JAZF1, rs12779790 near CDC123/CAMK1D, rs7961581 near TSPAN8/LGR5, rs4607103 near ADAMTS9, rs10923931 in NOTCH2, rs1153188 near DCD and rs9472138 near VEGFA) for three independent Japanese populations (first set, 1,630 type 2 diabetes patients vs 1,064 controls; second set, 1,272 type 2 diabetes patients vs 856 controls; third set, 486 type 2 diabetes patients vs 936 controls) using a TaqMan assay. The association of the SNP loci in each population was analysed using a logistic regression analysis, adjusting for age, sex and BMI, and the data were evaluated by a meta-analysis. RESULTS: A meta-analysis for the three case-control studies identified a nominal association of rs864745 in JAZF1 with type 2 diabetes (OR 1.148, 95% CI 1.034-1.275, p = 0.0098, corrected p = 0.069). The association of other loci did not reach statistically significant levels (nominal p > 0.05). CONCLUSIONS/INTERPRETATION: From these results the contribution of these seven loci in conferring susceptibility to type 2 diabetes is considered minor in the Japanese population, if they are present.


Asunto(s)
Diabetes Mellitus Tipo 2/epidemiología , Diabetes Mellitus Tipo 2/genética , Estudio de Asociación del Genoma Completo , Polimorfismo de Nucleótido Simple , Anciano , Proteínas Co-Represoras , Proteínas de Unión al ADN , Susceptibilidad a Enfermedades , Femenino , Predisposición Genética a la Enfermedad , Humanos , Japón , Masculino , Metaanálisis como Asunto , Persona de Mediana Edad , Proteínas de Neoplasias/genética , Medición de Riesgo , Dedos de Zinc/genética
7.
Science ; 251(5000): 1476-9, 1991 Mar 22.
Artículo en Inglés | MEDLINE | ID: mdl-2006421

RESUMEN

A cellular DNA binding protein, LBP-1, sequentially interacts in a concentration-dependent manner with two sites that surround the transcriptional initiation site of the human immunodeficiency virus type 1 (HIV-1) promoter. Although sequences in the downstream site (site I) were found to enhance transcription, purified LBP-1 specifically repressed transcription in vitro by binding to the upstream site (site II), which overlaps the TATA element. The binding of human TATA binding factor (TFIID) to the promoter before LBP-1 blocked repression, suggesting that repression resulted from an inhibition of TFIID binding to the TATA element. Furthermore, mutations that eliminated binding to site II both prevented repression in vitro and increased HIV-1 transcription in stably transformed cells. These findings suggest that a cellular factor regulates HIV-1 transcription in a manner that is characteristic of bacterial repressors and that this factor could be important in HIV-1 latency.


Asunto(s)
Regulación Viral de la Expresión Génica , VIH-1/genética , Proteínas Represoras/genética , Secuencia de Bases , Proteínas de Unión al ADN/genética , Datos de Secuencia Molecular , Regiones Promotoras Genéticas , Factor de Transcripción TFIID , Factores de Transcripción/metabolismo , Transcripción Genética
8.
Science ; 261(5120): 463-6, 1993 Jul 23.
Artículo en Inglés | MEDLINE | ID: mdl-8332911

RESUMEN

Transcription initiation factor TFIIB recruits RNA polymerase II to the promoter subsequent to interaction with a preformed TFIID-promoter complex. The domains of TFIIB required for binding to the TFIID-promoter complex and for transcription initiation have been determined. The carboxyl-terminal two-thirds of TFIIB, which contains two direct repeats and two basic residue repeats, is sufficient for interaction with the TFIID-promoter complex. An extra 84-residue amino-terminal region, with no obvious known structural motifs, is required for basal transcription activity. Basic residues within the second basic repeat of TFIIB are necessary for stable interaction with the TFIID-promoter complex, whereas the basic character of the first basic repeat is not. Functional roles of other potential structural motifs are discussed in light of the present study.


Asunto(s)
Proteínas de Unión al ADN/metabolismo , Regiones Promotoras Genéticas , Factores de Transcripción/química , Factores de Transcripción/metabolismo , Secuencia de Aminoácidos , Animales , Sitios de Unión , Drosophila , Datos de Secuencia Molecular , Mutación , Unión Proteica , Factor de Transcripción TFIIB , Factor de Transcripción TFIID
9.
Mol Cell Biol ; 8(10): 4028-40, 1988 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-3185540

RESUMEN

Selective and accurate transcription of purified genes by RNA polymerase II requires multiple factors. The factor designated TFIID was purified extensively from HeLa cell nuclear extracts by using a simple and novel complementation assay. Thus, TFIID was preferentially inactivated by mild heat treatment of a nuclear extract, and supplementation of the heat-treated extract with TFIID-containing fractions restored adenovirus major late (ML) promoter-dependent transcription. By using this assay, TFIID was purified approximately 300-fold by conventional chromatographic methods. The most purified TFIID fraction was demonstrated to be required for transcription of a number of other cellular and viral class II genes. This factor showed specific interactions with both the adenovirus ML promoter and a human heat shock 70 (hsp-70) promoter. On the ML promoter, the DNase I-protected region extended from around position -40 to position +35, although some discontinuities (and associated hypersensitive sites) were apparent near the initiation site and near position +27; the upstream and downstream boundaries of the TFIID-binding site were also confirmed by exonuclease III digestion experiments. In contrast to these results, the DNase I-protected regions on the human hsp-70 promoter were confined to a smaller area that extended from positions -35 to -19. DNase I hypersensitive sites were observed in both the adenovirus ML and hsp-70 promoters, most notably in the region at position -47. These results indicate either that there are different forms of TFIID or that a single TFIID can interact differently with distinct promoters.


Asunto(s)
Regiones Promotoras Genéticas , ARN Polimerasa II/metabolismo , Factores de Transcripción/aislamiento & purificación , Factores de Transcripción/fisiología , Transcripción Genética , Adenoviridae/genética , Secuencia de Bases , Células HeLa , Proteínas de Choque Térmico/genética , Datos de Secuencia Molecular , Secuencias Reguladoras de Ácidos Nucleicos , Factor de Transcripción TFIID
10.
Mol Cell Biol ; 9(4): 1733-45, 1989 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-2786141

RESUMEN

Within the human T-cell leukemia virus type I promoter, there are three copies of a 21-base-pair repeat (hereafter called the tax-responsive element [TRE]) that both contributes to basal promoter activity and mediates induction by the viral activator TAX. We have identified and separated three nuclear proteins that interact with the TRE. The TRE-binding protein designated TREB-3 bound more avidly to a multimerized TRE than to a single-copy TRE, while the other two TRE-binding proteins, TREB-1 and TREB-2, bound equally well to either TRE. TREB-1 has been purified to near homogeneity, and binding activity was localized to a protein of 35 to 43 kilodaltons. The affinity-purified TREB-1 activated transcription from the human T-cell leukemia virus type I promoter in vitro. The purified TREB-1 fraction contained activating transcription factor binding activity and showed a cooperative interaction with the TATA-binding factor (TFIID) on the adenovirus E4 promoter.


Asunto(s)
Proteínas de Unión al ADN/metabolismo , Antígenos HTLV-I/metabolismo , Virus Linfotrópico T Tipo 1 Humano/genética , Factores de Transcripción/metabolismo , Secuencia de Bases , Sitios de Unión , Línea Celular Transformada , ADN Viral/genética , ADN Viral/metabolismo , Proteínas de Unión al ADN/aislamiento & purificación , Antígenos HTLV-I/aislamiento & purificación , Virus Linfotrópico T Tipo 1 Humano/metabolismo , Humanos , Datos de Secuencia Molecular , Regiones Promotoras Genéticas , Secuencias Repetitivas de Ácidos Nucleicos , Transactivadores , Factores de Transcripción/aislamiento & purificación
11.
Mol Cell Biol ; 15(9): 4856-66, 1995 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-7651404

RESUMEN

The general transcription factor TFIIE recruits TFIIH at a late stage of transcription initiation complex formation and markedly stimulates TFIIH-dependent phosphorylation of the carboxy-terminal domain (CTD) of RNA polymerase II. To study this function of TFIIE in more detail, systematic deletion mutations were introduced into the large subunit of TFIIE (TFIIE-alpha) and were analyzed with regard to their effects on TFIIH-dependent CTD phosphorylation, TFIIE-dependent basal and enhancer-dependent transcription, and interactions of TFIIE-alpha with both TFIIE-beta and TFIIH. The amino (N)-terminal half of TFIIE-alpha, which possesses several putative structural motifs, was sufficient for the phosphorylation and transcription activities and for TFIIE-beta interactions, whereas a site effecting both strong interactions with TFIIH and large stimulatory effects on transcription and CTD phosphorylation was localized to an acidic region near the carboxy (C) terminus. The fact that these activities appear to be tightly linked supports the idea that TFIIE interacts physically and functionally with TFIIH and that CTD phosphorylation is essential for transcription under normal conditions. The present results suggest that TFIIE, via its effect on TFIIH, may act as a checkpoint for formation of a preinitiation complex.


Asunto(s)
Factores de Transcripción TFII , Factores de Transcripción/metabolismo , Transcripción Genética , Secuencia de Bases , Análisis Mutacional de ADN , Regulación de la Expresión Génica , Vectores Genéticos , Datos de Secuencia Molecular , Fosforilación , Pruebas de Precipitina , Unión Proteica , Conformación Proteica , Proteínas Recombinantes/metabolismo , Eliminación de Secuencia , Relación Estructura-Actividad , Factor de Transcripción TFIIH , Factores de Transcripción/genética , Dedos de Zinc
12.
Mol Cell Biol ; 12(11): 5189-96, 1992 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-1406690

RESUMEN

DNA-binding studies with Saccharomyces cerevisiae TFIID point mutants indicated that TFIIA interacts with the basic repeat region of TFIID and induces structural changes. The latter was shown by the ability of TFIIA to compensate for TFIID point mutants defective for DNA binding. Interaction with TFIIA also rendered TFIID binding temperature independent, thus mimicking the effect of removing the nonconserved N terminus of TFIID. In addition, N-terminal truncation of the TFIID point mutants defective for DNA binding mimicked the ability of TFIIA to restore DNA binding of those mutants. Taken together, these results suggest that TFIIA enhances TFIID binding to DNA by eliminating an otherwise inhibitory effect of the nonconserved N terminus of TFIID. Furthermore, analyses of TFIID contact points on DNA and binding studies with TATA-containing oligonucleotide probes showed that TFIIA decreases the effect of sequences flanking the adenovirus major late TATA element on TFIID binding to DNA, suggesting a possible role of TFIIA in allowing TFIID to recognize a wider variety of promoters.


Asunto(s)
Factores de Transcripción/química , Factores de Transcripción/metabolismo , Secuencia de Bases , ADN/metabolismo , Humanos , Datos de Secuencia Molecular , Mutación , Regiones Promotoras Genéticas , Unión Proteica , Conformación Proteica , Secuencias Repetitivas de Ácidos Nucleicos , TATA Box , Temperatura , Factor de Transcripción TFIIA , Factor de Transcripción TFIID , Transcripción Genética
13.
Mol Cell Biol ; 11(10): 4809-21, 1991 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-1922021

RESUMEN

We have examined the structure-function relationships of TFIID through in vivo complementation tests. A yeast strain was constructed which lacked the chromosomal copy of SPT15, the gene encoding TFIID, and was therefore dependent on a functional plasmid-borne wild-type copy of this gene for viability. By using the plasmid shuffle technique, the plasmid-borne wild-type TFIID gene was replaced with a family of plasmids containing a series of systematically mutated TFIID genes. These various forms of TFIID were expressed from three different promoter contexts of different strengths, and the ability of each mutant form of TFIID to complement our chromosomal TFIID null allele was assessed. We found that the first 61 amino acid residues of TFIID are totally dispensable for vegetative cell growth, since yeast strains containing this deleted form of TFIID grow at wild-type rates. Amino-terminally deleted TFIID was further shown to be able to function normally in vivo by virtue of its ability both to promote accurate transcription initiation from a large number of different genes and to interact efficiently with the Gal4 protein to activate transcription of GAL1 with essentially wild-type kinetics. Any deletion removing sequences from within the conserved carboxy-terminal region of S. cerevisiae TFIID was lethal. Further, the exact sequence of the conserved carboxy-terminal portion of the molecule is critical for function, since of several heterologous TFIID homologs tested, only the highly related Schizosaccharomyces pombe gene could complement our S. cerevisiae TFIID null mutant. Taken together, these data indicate that all important functional domains of TFIID appear to lie in its carboxy-terminal 179 amino acid residues. The significance of these findings regarding TFIID function are discussed.


Asunto(s)
Saccharomyces cerevisiae/genética , Factores de Transcripción/fisiología , Secuencia de Aminoácidos , Secuencia de Bases , Análisis Mutacional de ADN , Prueba de Complementación Genética , Immunoblotting , Cinética , Datos de Secuencia Molecular , Plásmidos/genética , Regiones Promotoras Genéticas/genética , Saccharomyces cerevisiae/crecimiento & desarrollo , Relación Estructura-Actividad , Factor de Transcripción TFIID , Factores de Transcripción/genética
14.
Mol Cell Biol ; 13(12): 7859-63, 1993 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-8247000

RESUMEN

Transcription initiation factor TFIID is a multimeric protein complex that plays a central role in mediating promoter responses to various activators and repressors. To further understand the role of the 85-kDa TFIID subunit (p85), we have cloned the corresponding cDNA with a probe based on an amino acid sequence of the purified protein. The recombinant p85 interacts directly with both the TATA box-binding subunit (TFIID tau or TBP) and the 110-kDa subunit (p110) of TFIID, suggesting that p85 may play a role in helping to anchor p110 within the TFIID complex and, with other studies, that TFIID assembly and function may involve a concerted series of subunit interactions. Interestingly, the carboxy terminus of p85 contains eight of the WD-40 repeats found originally in the beta subunit of G proteins and more recently in other transcriptional regulatory factors. However, truncated p85 lacking all the WD-40 repeats maintained interactions with both TFIID tau and p110. These observations leave open the possibility of a distinct function for the WD-40 repeats, possibly in transducing signals by interactions with transcriptional regulators and/or other components of the basic transcriptional machinery.


Asunto(s)
Drosophila/genética , Factores de Transcripción/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Clonación Molecular , ADN Complementario/genética , Expresión Génica , Genes de Insecto , Datos de Secuencia Molecular , Conformación Proteica , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Secuencias Repetitivas de Ácidos Nucleicos , Factor de Transcripción TFIID , Factores de Transcripción/química
15.
Cancer Res ; 46(4 Pt 1): 1648-53, 1986 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-3004701

RESUMEN

The role of epidermal growth factor (EGF) and its receptors in human cancers was studied using 24 human cell cultures including 15 of squamous cell carcinoma (SCC) of the skin, oral cavity, and esophagus. EGF was found to inhibit the growth and colony formation of all the SCC cells at doses that are mitogenic in many other cells, including epidermal keratinocytes and dermal fibroblasts. This inhibitory effect of EGF on SCCs was specific, because EGF did not inhibit and in some cases slightly stimulated the growth of other tumor cells, such as adenocarcinomas of the stomach, cervix, and breast and sarcomas. The amounts of EGF receptors on these SCC cells were measured by immunoprecipitation of labeled proteins with anti-EGF receptor polyclonal antibody and binding assay of membrane preparations using 125I-EGF. Of 13 SCC cell cultures tested, all except 3 of esophageal SCC showed higher levels of EGF receptor than normal epidermal keratinocytes, which contain 1.5 X 10(5) binding sites/cell. In general, SCCs of the skin and oral cavity had large amounts of EGF receptor on the order of 10(6)/cell, whereas the receptor of esophageal SCCs was on the order of 10(5)/cell. Some SCC cells had about twice as many EGF receptors as A431 cells. The values for the equilibrium dissociation constant (Kd) of these cells were on the order of nM. The sensitivity to the inhibitory effect of EGF correlated well with the elevated level of EGF receptors in 12 SCC cell lines, and higher significance was obtained when data on esophageal SCCs were excluded. The present observations suggest that EGF and EGF receptors play a role in the development of SCCs.


Asunto(s)
Carcinoma de Células Escamosas/análisis , Factor de Crecimiento Epidérmico/farmacología , Receptores de Superficie Celular/análisis , Carcinoma de Células Escamosas/patología , Células Cultivadas , Receptores ErbB , Neoplasias Esofágicas/análisis , Amplificación de Genes , Humanos , Neoplasias de la Boca/análisis , Proto-Oncogenes , Neoplasias Cutáneas/análisis
16.
Cancer Res ; 43(9): 4338-42, 1983 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-6871867

RESUMEN

The effect of platinum(II) complexes on RNA polymerase II was studied. (D-Glucuronato)(1R,2R-cyclohexanediamine)platinum(II) nitrate (II-GHP) preferentially inhibited RNA synthesis in the presence of S-II, an essential component of eukaryotic transcription. When DNA was pretreated with I-GHP, its template activity decreased significantly, especially when assayed in the presence of S-II. The target of platinum(II) complexes is probably DNA. When DNA is modified, regulatory proteins of transcription, such as S-II, seem to lose their function preferentially on such a template, resulting in the inhibition of RNA synthesis.


Asunto(s)
Proteínas de Neoplasias/antagonistas & inhibidores , Compuestos Organoplatinos/farmacología , Factores Generales de Transcripción , Factores de Transcripción/antagonistas & inhibidores , Transcripción Genética/efectos de los fármacos , Factores de Elongación Transcripcional , Células HeLa/efectos de los fármacos , Células HeLa/metabolismo , Humanos , Cinética , ARN Polimerasa II/metabolismo , ARN Neoplásico/genética , Moldes Genéticos
17.
Biochim Biophys Acta ; 868(4): 243-8, 1986 Dec 18.
Artículo en Inglés | MEDLINE | ID: mdl-3790568

RESUMEN

A fraction containing a transcription factor(s) of RNA polymerase II was prepared from a nuclear lysate of Ehrlich ascites tumor cells and its binding to a promoter region of the adenovirus 2 major late gene was examined. Results showed that this fraction contained a factor(s) binding to two distinct regions: a region including the 'TATA' box and another region further upstream. The upstream protected region was different from that reported to be protected by a HeLa cell factor, suggesting species specificity of transcription factor(s) in DNA binding.


Asunto(s)
Adenovirus Humanos/genética , Carcinoma de Ehrlich/metabolismo , Genes Virales , Genes , Factores de Transcripción/metabolismo , Proteínas Virales/genética , Animales , Secuencia de Bases , Núcleo Celular/metabolismo , Ratones , Regiones Promotoras Genéticas , ARN Polimerasa II/metabolismo , Factores de Transcripción/aislamiento & purificación , Transcripción Genética
18.
Gene ; 173(2): 281-5, 1996 Sep 16.
Artículo en Inglés | MEDLINE | ID: mdl-8964515

RESUMEN

The H1 class of histones is implicated in organizing a higher order of chromatin structure and in involvement with transcriptional repression. They compromise multiple subtypes that presumably have a specific function. We report here the isolation and characterization of a human cDNA encoding a novel subtype of histone H1. It is the most distantly related subtype of mammalian H1 reported to date. However, it still shares the characteristic features of H1: the tripartite structure, conservation in the globular domain, the profile of hydropathy and the basic isoelectric point. The expression of this H1 subtype was ubiquitously observed in all tissues examined. Our findings suggest that novel subtypes of H1 may remain unidentified in mammals.


Asunto(s)
Histonas/genética , Secuencia de Aminoácidos , Secuencia de Bases , Clonación Molecular , ADN Complementario , Humanos , Datos de Secuencia Molecular , ARN Mensajero/metabolismo , Homología de Secuencia de Aminoácido , Distribución Tisular
19.
Gene ; 164(2): 369-70, 1995 Oct 27.
Artículo en Inglés | MEDLINE | ID: mdl-7590360

RESUMEN

A cDNA clone encoding a Xenopus laevis (Xl) homologue of human transcription factor IID (TFIID) subunit p80 was isolated and sequenced. The deduced 618-amino-acid (aa) sequence was compared to the homologous from human, mouse, rat and Drosophila melanogaster (Dm). A highly conserved region exists in the central region among these species. In contrast, the C-terminal region has significant homology among vertebrates, whereas the corresponding region of the Dm homologue shows poor homology.


Asunto(s)
Factores de Transcripción/genética , Vertebrados/genética , Xenopus laevis/genética , Secuencia de Aminoácidos , Animales , Secuencia Conservada , Drosophila melanogaster , Humanos , Sustancias Macromoleculares , Ratones , Datos de Secuencia Molecular , Ratas , Homología de Secuencia de Aminoácido , Factor de Transcripción TFIID , Factores de Transcripción/química
20.
Gene ; 161(2): 301-2, 1995 Aug 19.
Artículo en Inglés | MEDLINE | ID: mdl-7665100

RESUMEN

A cDNA encoding a mouse transcription factor IID (TFIID) subunit, containing histone H4 homology, was cloned and sequenced. The predicted 678-amino-acid (aa) sequence of this molecule showed 97 and 41% identity to the human and Drosophila melanogaster homologues, respectively. Four putative direct repeats were found in the most highly conserved region in the central part of this protein.


Asunto(s)
ADN Complementario/genética , Histonas/genética , Factores de Transcripción/genética , Secuencia de Aminoácidos , Animales , Clonación Molecular , Secuencia Conservada , ADN Complementario/aislamiento & purificación , Drosophila melanogaster , Humanos , Ratones , Datos de Secuencia Molecular , Conformación Proteica , Secuencias Repetitivas de Ácidos Nucleicos , Homología de Secuencia de Aminoácido , Especificidad de la Especie , Factor de Transcripción TFIID , Factores de Transcripción/química
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