RESUMO
The Lifshitz transition, a change in Fermi surface topology, is likely to greatly influence exotic correlated phenomena in solids, such as high-temperature superconductivity and complex magnetism. However, since the observation of Fermi surfaces is generally difficult in the strongly correlated systems, a direct link between the Lifshitz transition and quantum phenomena has been elusive so far. Here, we report a marked impact of the pressure-induced Lifshitz transition on thermoelectric performance for SnSe, a promising thermoelectric material without a strong electron correlation. By applying pressure up to 1.6 GPa, we have observed a large enhancement of the thermoelectric power factor by more than 100% over a wide temperature range (10-300 K). Furthermore, the high carrier mobility enables the detection of quantum oscillations of resistivity, revealing the emergence of new Fermi pockets at â¼0.86 GPa. The observed thermoelectric properties linked to the multivalley band structure are quantitatively reproduced by first-principles calculations, providing novel insight into designing the SnSe-related materials for potential valleytronic as well as thermoelectric applications.
RESUMO
Various types of piperidinium ionic liquids (ILs) equipped with an oxygen atom-containing alkyl side chain on the positively charged nitrogen atom were systematically synthesized and their physical properties investigated. The thermal stability, viscosity, electrochemical window, and ion conductivity were influenced significantly by changing the position of the oxygen atom in the alkyl chain. Although the lowest viscosity was recorded for 1-((2-methoxyethoxy)methyl)-1-methylpiperidin-1-ium bis(trifluoromethylsulfonyl)amide ([PP1MEM][Tf2N]), 1-methyl-1-(2-propoxyethyl)piperidin-1-ium bis(trifluoromethylsulfonyl)amide ([PP1PE][Tf2N]) can be recommended as the best IL as an electrolyte due to its low viscosity and high thermal and electrochemical stability among the seven ILs tested.
RESUMO
A neutron scattering study of heavily hole-overdoped superconducting KFe2As2 revealed a well-defined low-energy incommensurate spin fluctuation at [π(1 ± 2 δ),0] with δ = 0.16. The incommensurate structure differs from the previously observed commensurate peaks in electron-doped AFe2As2 (A = Ba, Ca, or Sr) at low energies. The direction of the peak splitting is perpendicular to that observed in Fe(Te,Se) or in Ba(Fe,Co)2As2 at high energies. A band structure calculation suggests interband scattering between bands around the Γ and X points as an origin of this incommensurate peak. The perpendicular direction of the peak splitting can be understood within the framework of multiorbital band structure. The results suggest that spin fluctuation is more robust in hole-doped than in electron-doped samples, which can be responsible for the appearance of superconductivity in the heavily hole-doped samples.
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Advanced ovarian cancer may extend into the spleen, and even the pancreatic tail, in which a splenectomy associated with distal pancreatectomy is crucial for optimal cytoreduction. A new linear stapler preloaded with tissue reinforcement is currently introduced. We herein report the first three cases of successful application of this device for distal pancreatectomy performed during cytoreductive surgery for ovarian cancer.
Assuntos
Neoplasias Ovarianas/cirurgia , Pancreatectomia/instrumentação , Grampeadores Cirúrgicos , Adulto , Desenho de Equipamento , Feminino , Humanos , Pessoa de Meia-Idade , Invasividade Neoplásica , EsplenectomiaRESUMO
BACKGROUND: Complete hydatidiform mole (CHM) is a high-risk pregnancy for gestational trophoblastic neoplasia (GTN). Patients with CHM have a 10-30% chance of trophoblastic sequelae. CHM includes androgenic homozygous (monospermic) and androgenic heterozygous (dispermic) moles. It is controversial whether the risk of GTN is higher with heterozygous than with homozygous CHM. A prospective cohort study was conducted to assess risk of GTN in homozygous and heterozygous CHM using short tandem repeat (STR) polymorphisms, and a meta-analysis of previous reports. METHODS: Twenty-eight consecutive molar pregnancies were evacuated and followed by regular hCG measurements to detect GTN. Persistent GTN was diagnosed according to the International Federation of Gynecology and Obstetrics 2000 system. Cytogenesis of the mole was determined by STR polymorphisms of molar tissue and parental blood. A meta-analysis of the GTN rate from previous reports was conducted using Mantel-Haenszel methods. RESULTS: Of 28 molar pregnancies, 24 were homozygous and three were heterozygous CHM. The remaining mole was diandric triploidy (a partial hydatidiform mole). Of the 24 homozygous CHMs, six (25%) cases developed GTN and received chemotherapy. Meanwhile, all three cases (100%) of heterozygous mole developed GTN and needed chemotherapy. The GTN risk was higher in heterozygous (P = 0.029, Fisher's exact test) than homozygous moles. A systematic review revealed only five previous reports (with more than 15 cytogenetically diagnosed cases), and the pooled relative risk of persistent GTN for heterozygous mole was not significant (odds ratio, 2.0; 95% confidence interval, 0.98-4.07). CONCLUSIONS: Heterozygous CHM had a higher risk for GTN than homozygous CHM.
Assuntos
Mola Hidatiforme/genética , Neoplasias Uterinas/genética , Adulto , Gonadotropina Coriônica/sangue , Estudos de Coortes , Feminino , Heterozigoto , Homozigoto , Humanos , Mola Hidatiforme/sangue , Mola Hidatiforme/classificação , Masculino , Repetições de Microssatélites , Pessoa de Meia-Idade , Gravidez , Estudos Prospectivos , Fatores de Risco , Neoplasias Uterinas/sangue , Adulto JovemRESUMO
BACKGROUND: The current study examined the clinical usefulness of YKL-40 in detection and prognosis of uterine cervical cancer. PATIENTS AND METHODS: Serum levels of YKL-40, cancer antigen 125 (CA 125), carbohydrate antigen 19-9 (CA19-9), and squamous cell carcinoma (SCC) antigen were determined by enzyme-linked immunosorbent assay in women with benign gynecologic disease (n=24), cervical malignancy (SCC, n=104; adenocarcinoma, n=37), and age-matched healthy controls (n=45). Immunohistochemical analysis for local YKL-40 expression was carried out on 28 adenocarcinomas. RESULTS: Receiver operating characteristic curve analysis showed that YKL-40 [area under the curve (AUC)=0.882] was significantly better at discriminating adenocarcinoma from healthy control than SCC antigen, CA 125, and CA19-9. For SCC, YKL-40 (AUC=0.898) carried out similarly to SCC antigen and was better than CA 125 and CA19-9. Using a cut-off YKL-40 value of 92.2 ng/ml, sensitivity of YKL-40 in stage I adenocarcinoma (68%) was higher than that of the other three markers (11%-21%). Tumor-associated macrophages showed immunoreactivity for YKL-40 in 2 of 28 adenocarcinoma tissue samples, but adenocarcinoma cells themselves were nonimmunoreactive in all samples. Multivariate Cox regression analysis revealed that elevated pretreatment YKL-40 levels predicted unfavorable prognosis, independent of International Federation of Gynecology and Obstetrics stage and age at diagnosis. CONCLUSIONS: Pretreatment serum YKL-40 level is a possible prognosticator of cervical adenocarcinoma.
Assuntos
Adenocarcinoma/diagnóstico , Biomarcadores Tumorais/sangue , Glicoproteínas/sangue , Neoplasias do Colo do Útero/diagnóstico , Adenocarcinoma/sangue , Adenocarcinoma/metabolismo , Adipocinas , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/metabolismo , Carcinoma de Células Escamosas/sangue , Carcinoma de Células Escamosas/diagnóstico , Carcinoma de Células Escamosas/metabolismo , Estudos de Casos e Controles , Proteína 1 Semelhante à Quitinase-3 , Feminino , Glicoproteínas/metabolismo , Glicoproteínas/normas , Humanos , Lectinas , Pessoa de Meia-Idade , Prognóstico , Valores de Referência , Sensibilidade e Especificidade , Neoplasias do Colo do Útero/sangue , Neoplasias do Colo do Útero/metabolismoRESUMO
The aim of this study was to assess acute toxicities of concurrent low-dose daily cisplatin and extended-field radiation therapy (EFRT) for carcinoma of the uterine cervix. Fifteen women with cervical cancer who were treated with concurrent daily low-dose cisplatin and EFRT were analyzed. Daily cisplatin dose was fixed to 8 mg/m(2), which was determined in the preceding phase I study using pelvic radiotherapy. Twelve patients underwent either combined external beam radiation therapy and intracavitary brachytherapy or external beam radiation therapy alone. Three other patients were treated with adjuvant chemoradiotherapy after surgery. A total dose of EFRT ranged from 40 to 45 Gy, with an additional boost to the gross tumor volume up to 50.4-55 Gy. A median total dose of cisplatin during entire radiation therapy course was 224 mg/m(2) (range, 200-240 mg/m(2)). In 14 of 15 patients (93%), daily cisplatin could be delivered continuously as planned without any modification. Administration of cisplatin had to be interrupted in only one patient for only 3 days. Fourteen patients developed grade 2 or worse leukopenia including five after treatment, grade 2 in four, grade 3 in eight, and grade 4 in two. Grade 3 thrombocytopenia was observed in three patients. Grade 2 or worse anemia was observed in 12. Three patients had grade 3 nonhematologic toxicities, diarrhea in two, and nausea/vomiting in one. Although moderate to severe hematologic toxicities are common, this study suggests that concurrent low-dose daily cisplatin and EFRT are feasible. A cumulative cisplatin dose of greater than 200 mg/m(2) during radiation therapy could be achieved by using daily cisplatin dose of 8 mg/m(2).
Assuntos
Antineoplásicos/uso terapêutico , Braquiterapia , Cisplatino/uso terapêutico , Neoplasias do Colo do Útero/terapia , Adenocarcinoma/terapia , Adulto , Carcinoma de Células Escamosas/terapia , Quimioterapia Adjuvante , Terapia Combinada , Intervalo Livre de Doença , Estudos de Viabilidade , Feminino , Seguimentos , Humanos , Histerectomia , Pessoa de Meia-Idade , Prognóstico , Estudos Prospectivos , Radioterapia Adjuvante , Medição de Risco , Taxa de Sobrevida , Resultado do Tratamento , Neoplasias do Colo do Útero/tratamento farmacológico , Neoplasias do Colo do Útero/radioterapia , Neoplasias do Colo do Útero/cirurgiaRESUMO
As-Based Zintl compounds Ba1-xKxCd2As2 crystallized in the CaAl2Si2-type structure (space group P3[combining macron]m1) were prepared using solid-state reactions followed by hot-pressing. We have successfully substituted K for Ba up to x = 0.08, producing hole-carrier doping with concentrations up to 1.60 × 1020 cm-3. We have determined the band-gap value of non-doped BaCd2As2 to be 0.40 eV from the temperature dependence of the electrical resistivity. Both the electrical resistivity and the Seebeck coefficient decrease with hole doping, leading to a power factor value of 1.28 mW m-1 K-2 at 762 K for x = 0.04. A first-principles band calculation shows that the relatively large power factor mainly originates from the two-fold degeneracy of the bands comprising As px,y orbitals and from the anisotropic band structure at the valence-band maximum. The lattice thermal conductivity is suppressed by the K doping to 0.46 W m-1 K-1 at 773 K for x = 0.08, presumably due to randomness. The effect of randomness is compensated by an increase in the electronic thermal conductivity, which keeps the total thermal conductivity approximately constant. In consequence, the dimensionless figure-of-merit ZT reaches a maximum value of 0.81 at 762 K for x = 0.04.
RESUMO
Axin forms a complex with adenomatous polyposis coli gene product (APC), glycogen synthase kinase-3beta (GSK-3beta), and beta-catenin through different binding sites and downregulates beta-catenin. GSK-3beta-dependent phosphorylation of APC-(1211-2075) which has the Axin-binding site was facilitated by Axin, but that of APC-(959-1338) which lacks the Axin-binding site was not. Axin-(298-506) or Axin-(298-832), which has the GSK-3beta- and beta-catenin- but not APC-binding sites, did not enhance GSK-3beta-dependent phosphorylation of either APC-(1211-2075) or APC-(959-1338). Furthermore, beta-catenin stimulated the phosphorylation of APC-(959-1338) and APC-(1211-2075) by GSK-3beta in the presence of Axin. Consistent with these in vitro observations, expression of beta-catenin or Axin in COS cells promoted an SDS gel band shift of APC. These results indicate that APC complexed with Axin is effectively phosphorylated by GSK-3beta and that beta-catenin may modulate this phosphorylation. In addition, the heterodimeric form of protein phosphatase 2A (PP2A) directly bound to Axin, and PP2A complexed with Axin dephosphorylated APC phosphorylated by GSK-3beta. Taken together, these results suggest that GSK-3beta-dependent phosphorylation of APC can be modulated by beta-catenin and PP2A complexed with Axin.
Assuntos
Proteínas Quinases Dependentes de Cálcio-Calmodulina/metabolismo , Proteínas do Citoesqueleto/metabolismo , Genes APC , Fosfoproteínas Fosfatases/metabolismo , Processamento de Proteína Pós-Traducional , Proteínas/metabolismo , Proteínas Repressoras , Transativadores , Proteína da Polipose Adenomatosa do Colo , Animais , Proteína Axina , Sítios de Ligação , Células COS , Chlorocebus aethiops , Proteínas do Citoesqueleto/genética , Regulação da Expressão Gênica , Quinase 3 da Glicogênio Sintase , Quinases da Glicogênio Sintase , Células L , Substâncias Macromoleculares , Camundongos , Fragmentos de Peptídeos/metabolismo , Fosforilação , Proteína Fosfatase 2 , Proteínas Recombinantes de Fusão/biossíntese , beta CateninaRESUMO
Polyamine hydrochlorides, NaCl and magnesium acetate stimulated the enzymatic dephosphorylation of phosphorylated H2B histone by two forms (large form, mol. wt. 250 000; small form, mol. wt. 30 000) of a pig heart phosphoprotein phosphatase (phosphoprotein phosphohydrolase, EC 3.1.3.16). These ionic compounds stimulated the large form of the enzyme 5--9-fold but stimulated the small form of theenzyme only 2-fold. With phosphorylated H2B histone as substrate, these effectors caused an increase in both Km and V values of the two forms of the enzyme. On the other hand, when a tryptic phosphodecapeptide derived from phosphorylated H2B histone was used as substrate, these effectors were always inhibitory apparently non-competitively with respect to the substrate. Using phosphorylated H1 histone as substrate, these effectors stimulated the large form of the enzyme 2-fold but inhibited the small form. With phosphorylase a as substrate, the reactions were also inhibited by these effectors irrespective of the enzyme employed. With respect to phosphorylase a, this inhibition was apparently of a competitive type for the large form and a non-competitive type for the small form of the enzyme.
Assuntos
Miocárdio/enzimologia , Fosfoproteínas Fosfatases/metabolismo , Poliaminas/farmacologia , Animais , Histonas/metabolismo , Cinética , Magnésio/farmacologia , Fragmentos de Peptídeos/metabolismo , Fosfoproteínas Fosfatases/isolamento & purificação , Cloreto de Sódio/farmacologia , SuínosRESUMO
Treatment of a pig heart phosphoprotein phosphatase (phosphoprotein phosphohydrolase, EC 3.1.3.16) of Mr 224 000 with 40% ethanol followed by gel-filtration on Sephadex G-150, dissociated the enzyme into an active component of Mr 31 000 and an inactive component of Mr 80 000. The inactive component reassociated with the active component, resulting in the formation of an enzyme form of Mr 123 000. A large excess of either component in the reassociation produced only this enzyme form. The ability of the inactive component to associate with the active component was lost by treatment of the inactive component with trypsin and heat (60 degrees C, 2 min) but not with DNAase and RNAase. Effects of the inactive component on the activities of the active component by the association were as followings. The inactive component: (1) stimulated slightly the 32P-H2B histone phosphatase activity in the presence of either NaCl or Mg(CH3COO)2 but inhibited strongly in the absence of the salts; (2) stimulated the 32P-H1 histone phosphatase activity in the presence of the salts; (3) inhibited the phosphorylase a phosphatase activity in the presence and absence of the salts; (4) enhanced the response to the stimulatory effects of the salts on the dephosphorylation of 32P-histone; and (5) protected the phosphorylase a phosphatase activity from inhibition by the salts.
Assuntos
Fosfoproteínas Fosfatases/isolamento & purificação , Animais , Centrifugação com Gradiente de Concentração , Cromatografia em Gel , Ativação Enzimática , Substâncias Macromoleculares , Miocárdio , Fosfoproteínas Fosfatases/antagonistas & inibidores , Fosfoproteínas Fosfatases/metabolismo , Fosforilase Fosfatase/metabolismo , Especificidade por SubstratoRESUMO
BACKGROUND: Extended thymectomy is indicated for children with myasthenia gravis (MG) when drug-resistance or dependence is seen. We have employed a technique for mediastinoscopic extended thymectomy (MET) on children with MG. METHOD: A total of 14 children underwent MET at Kanagawa Children's Medical Center between 2005 and 2013. A mediastinal operation field was made by a V-shaped hook infrasternally to extirpate the thymus with adipose tissue around the thymus. RESULTS: The operation time and the amount of blood loss were 182±44 minutes and 34±43 ml, respectively. Postoperative complications, in the form of transient paralysis of the right recurrent nerve, occurred in 2 patients. The median length of postoperative hospital stay was 4.5 days. After MET, 6 patients achieved complete remission and 7 patients achieved steroid dose reduction, but no improvement was seen in 1 patient. CONCLUSIONS: This procedure offers the advantage of good surgical access for dissection around the bilateral phrenic nerves in extended total thymectomy, while achieving good cosmetic results.
Assuntos
Mediastinoscopia/métodos , Microcirurgia/métodos , Miastenia Gravis/cirurgia , Timectomia/métodos , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Resultado do TratamentoRESUMO
A novel cDNA clone encoding a protein structurally related to the transcriptional repressor Polycomb group (PcG) proteins, which regulate homeotic genes and others, was isolated from mouse and rat brain. The coding protein contained the SPM domain and mbt repeats, both of which are characteristic of the PcG proteins, and showed significant similarity in amino acid sequence to the Drosophila Sex comb on midleg (Scm) protein. Since this novel protein contains the mbt repeats in four tandem copies, we designated this murine gene as Sfmbt for Scm-related gene containing four mbt domains. Cloning and characterization of the mouse Sfmbt gene revealed that the coding sequence comprised 20 exons, dispersed along approximately 40kb, and mapped to the proximal part of Chromosome 14. Northern blot analysis showed that the Sfmbt mRNAs were expressed most abundantly in the adult testis, and less intensively in all other tissues examined.
Assuntos
Proteínas de Ligação a DNA/genética , Genes/genética , Proteínas Repressoras/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Northern Blotting , Mapeamento Cromossômico , Clonagem Molecular , DNA/química , DNA/genética , DNA Complementar/química , DNA Complementar/genética , Éxons , Feminino , Íntrons , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Dados de Sequência Molecular , Muridae , Proteínas do Grupo Polycomb , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos , Distribuição TecidualRESUMO
In this report, we deal with the isolation of a novel vasorelaxing peptide from a chymotryptic digest of ovalbumin and its vasorelaxing activities. This peptide is composed of Arg-Ala-Asp-His-Pro-Phe (RADHPF) in its sequence, corresponding to residues 359-364 of ovalbumin. This peptide (30-300 microM) exerted a dose-dependent vasodilation in an isolated mesenteric artery from a spontaneously hypertensive rat which was pre-constricted by phenylephrine, besides the relaxation being endothelium-dependent. It is noteworthy that the nitric oxide synthase inhibitor N(G)-nitro-L-arginine methyl ester inhibited this relaxation, implying involvement of nitric oxide in its mechanism of action. Following oral administration of RADHPF at a dose of 10 mg/kg, the systolic blood pressure in a spontaneously hypertensive rat was significantly lowered.
Assuntos
Anti-Hipertensivos/farmacologia , Artérias Mesentéricas/efeitos dos fármacos , NG-Nitroarginina Metil Éster/farmacologia , Óxido Nítrico/fisiologia , Ovalbumina/farmacologia , Fragmentos de Peptídeos/farmacologia , Vasodilatação/efeitos dos fármacos , Sequência de Aminoácidos , Animais , Anti-Hipertensivos/química , Quimotripsina , Proteínas do Ovo/farmacologia , Técnicas In Vitro , Masculino , Artérias Mesentéricas/fisiologia , Artérias Mesentéricas/fisiopatologia , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/fisiologia , Ovalbumina/química , Papaverina/farmacologia , Fragmentos de Peptídeos/química , Fenilefrina/farmacologia , Ratos , Ratos Endogâmicos SHR , Ratos Endogâmicos WKY , Vasodilatadores/farmacologiaRESUMO
When membrane fractions from mouse liver, Ehrlich ascites tumor and MH134 hepatoma were incubated with [gamma-32P]ATP at 0 degree C in the presence of MnCl2, ZnCl2 and NaVO3, proteins were phosphorylated on tyrosines to a larger extent in liver membranes than in tumor membranes. Separation of labelled proteins by SDS-gel electrophoresis showed phosphorylated alkali-resistant bands of 170, 140, 130, 80, 56, 53 and 46 kDa proteins in Ehrlich ascites tumor membranes; liver membranes exhibited more strongly phosphorylated bands of 170, 56, 53 and 46 kDa proteins. Epidermal growth factor stimulated the tyrosine phosphorylation of only a 170 kDa protein, which was more significant in liver membranes. Liver membranes exhibited slightly higher levels of tyrosine protein kinase activity compared to tumor membranes.
Assuntos
Carcinoma de Ehrlich/metabolismo , Neoplasias Hepáticas Experimentais/metabolismo , Fígado/metabolismo , Proteínas de Membrana/metabolismo , Tirosina/metabolismo , Animais , Eletroforese em Gel de Poliacrilamida , Fator de Crescimento Epidérmico/farmacologia , Técnicas In Vitro , Masculino , Camundongos , Camundongos Endogâmicos C3H , Fosforilação , Proteínas Quinases/análise , Proteínas Tirosina QuinasesRESUMO
Since the nucleotide sequence of cholecystokinin (CCK) cDNA was found in the rat gene, we applied cDNA to quantitate the CCK mRNA. The size of the mRNA for a CCK precursor was 850 nucleotides in length using brain cytoplasmic RNA. There were no bands except CCK mRNA by Northern blot analysis. We also examined the developmental changes and regional distribution of CCK mRNA in rat brains by dot-blot and gel-blot hybridization using CCK cDNA as a probe. CCK mRNA was barely detectable in the fetal brain, but started to increase postnatally and attained the plateau level after 20-30 days. Further, the level of CCK mRNA was highest in the frontal cortex, followed by those of the hippocampus and striatum. The cerebellum contained only negligible CCK mRNA. These results are in agreement with those of CCK concentration in the corresponding brain areas and suggest a transcriptional control of CCK concentration.
Assuntos
Encéfalo/metabolismo , Colecistocinina/genética , RNA Mensageiro/metabolismo , Envelhecimento , Animais , Sequência de Bases , Encéfalo/crescimento & desenvolvimento , Cerebelo/metabolismo , DNA/análise , Lobo Frontal/metabolismo , Hipocampo/metabolismo , Hibridização de Ácido Nucleico , Ratos , Ratos EndogâmicosRESUMO
Two cDNAs for possible splicing variants of a 74-kDa regulatory subunit (B" or delta) of human protein phosphatase 2A, were isolated. These variants were identified from human cerebral cortex by library screening and PCR, and designated delta1 and delta3 isoforms, while the previously reported isoform [Tanabe et al. (1996) FEBS Lett. 379, 107-1111 was designated delta2. Compared with the delta2 isoform, the delta1 isoform contained a 32-residue insertion beginning at residue 84, and consisted of 602 amino acids in all. The delta3 isoform lacked a 74-residue sequence corresponding to residues 1083 of the delta2 isoform, and consisted of 496 amino acids. Using isoform-specific antipeptide antisera, the 74-kDa subunit (B" or delta) originally purified from human erythrocytes was identified as the delta1 isoform.
Assuntos
Córtex Cerebral/enzimologia , Isoenzimas/genética , Fosfoproteínas Fosfatases/genética , Processamento Alternativo , Sequência de Aminoácidos , Sequência de Bases , Western Blotting , Clonagem Molecular , DNA Complementar/química , DNA Complementar/genética , Escherichia coli/genética , Expressão Gênica , Humanos , Isoenzimas/química , Dados de Sequência Molecular , Fosfoproteínas Fosfatases/química , Reação em Cadeia da Polimerase , Proteína Fosfatase 2 , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Análise de Sequência , Deleção de SequênciaRESUMO
The primary structure of the bovine S-100 alpha mRNA on the basis of molecular cloning and sequence analysis of the cDNA are described. The sequence is composed of 532 bp which include the 282 bp of the complete coding region, 89 bp at the 5'-noncoding region, 161 bp at the 3'-noncoding region, polyadenylation signal, ATTAAA and poly(A) tail. Northern blot analysis shows that the size of S-100 alpha mRNA is about 700-800 bases long and a single mRNA occurs in bovine brain. Bovine brain contains both S100 alpha and beta subunits and their mRNAs. In contrast, the rat brain contains only S100 beta subunit and its mRNA.
Assuntos
Clonagem Molecular , RNA Mensageiro/genética , Proteínas S100/genética , Animais , Sequência de Bases , Encéfalo/metabolismo , Bovinos , Cerebelo/metabolismo , DNA , Regulação da Expressão Gênica , Hibridização de Ácido Nucleico , Ratos , Proteínas S100/biossínteseRESUMO
Human erythrocyte protein phosphatase 2A, which comprises a 34-kDa catalytic C subunit, a 63-kDa regulatory A subunit and a 74-kDa regulatory B'' (delta) subunit, was phosphorylated at serine residues of B'' in vitro by cAMP-dependent protein kinase (A-kinase). In the presence and absence of 0.5 microM okadaic acid (OA), A-kinase gave maximal incorporation of 1.7 and 1.0 mol of phosphate per mol of B'', respectively. The Km value of A-kinase for CAB'' was 0.17 +/- 0.01 microM in the presence of OA. The major in vitro phosphorylation sites of B'' were identified as Ser-60, -75 and -573 in the presence of OA, and Ser-75 and -573 in the absence of OA. Phosphorylation of B'' did not dissociate B'' from CA, and stimulated the molecular activity of CAB'' toward phosphorylated H1 and H2B histones, 3.8- and 1.4-fold, respectively, but not toward phosphorylase a.