RESUMO
Tissues from human fetuses of 12-18 weeks gestational age were examined for expression of c-oncogenes. Dot blot hybridization showed that N-ras and C-H-ras were expressed to varying degrees in all tissues. Some of the tissues were further examined by Northern blot hybridization, and transcripts of approximately 2.2 Kb and 5.2 Kb were detected using N-ras cDNA probe. A further transcript of approximately 1.4 Kb was observed when the same blot was hybridized to C-H-ras cDNA probe. No hybridization was detected between the fetal tissues and c-K-ras, c-myc, v-erb, c-fos, c-sis and c-src.
Assuntos
Feto/fisiologia , Proteínas Proto-Oncogênicas/genética , Proto-Oncogenes , Regulação da Expressão Gênica , Idade Gestacional , Humanos , Hibridização de Ácido Nucleico , RNA Mensageiro/genética , Distribuição TecidualRESUMO
Calmodulin was extracted and purified from pig anterior pituitary gland. The protein was characterized by its migration on sodium dodecyl sulphate/polyacrylamide-gel electrophoresis in the presence of Ca2+ or EGTA, its U.V. spectrum between 240 and 290 nm and the activation of calmodulin-deficient cyclic AMP phosphodiesterase. The yield was 370 mg/kg wet wt. mRNA was also extracted from the same tissue and translated in a wheat-germ cell-free translation system. Translated calmodulin was identified by its heat-stability, its co-migration with authentic anterior-pituitary calmodulin on sodium dodecyl sulphate/polyacrylamide-gel electrophoresis, its acidic isoelectric point (4.15) on flat-bed isoelectric focusing, its Ca2+-dependent binding to fluphenazine-Sepharose 6B, and its co-elution from this gel with authentic unlabelled calmodulin with EGTA buffer. Calmodulin was not translated as a precursor form. In this tissue it was calculated that calmodulin accounted for 0.5-1% of the total translated protein.
Assuntos
Calmodulina/isolamento & purificação , Adeno-Hipófise/análise , Animais , Calmodulina/biossíntese , Sistema Livre de Células , Cromatografia em Gel , Eletroforese em Gel de Poliacrilamida , Técnicas In Vitro , Biossíntese de Proteínas , RNA Mensageiro/metabolismo , SuínosRESUMO
mRNA from pig duodenal mucosa directs synthesis, in a wheat-germ cell-free system, of two products precipitated by antiserum to pure calcium-binding protein. One of these products has a higher molecular weight than authentic calcium-binding protein, but, like the authentic protein, is heat-stable. The other protein co-migrates with pure calcium-binding protein on sodium dodecyl sulphate/polyacrylamide-gel electrophoresis, is stable on heating to 70 degrees C for 15 min and alters its elution position on ion-exchange chromatography depending on whether Ca2+ is present in or absent from the elution buffer. The synthesized protein has these properties in common with authentic calcium-binding protein.
Assuntos
Proteínas de Ligação ao Cálcio/biossíntese , Mucosa Intestinal/metabolismo , RNA Mensageiro/metabolismo , Animais , Sistema Livre de Células , Cromatografia em Gel , Cromatografia por Troca Iônica , Eletroforese em Gel de Poliacrilamida , Temperatura Alta , Biossíntese de Proteínas , SuínosAssuntos
Proteínas de Transporte/biossíntese , Biossíntese de Proteínas , RNA Mensageiro/metabolismo , Proteína G de Ligação ao Cálcio S100/biossíntese , Animais , Sistema Livre de Células , Duodeno/análise , Técnicas In Vitro , Mucosa Intestinal/análise , RNA Mensageiro/isolamento & purificação , SuínosRESUMO
We report the isolation of high affinity calcium-binding peptides from homogenates of gills, gut and kidneys of the freshwater eel Anguilla anguilla. These peptides show identical gel-filtration profiles on Biogel P-6, from which a molecular weight of 3500 was estimated. The average binding constant (Kf) for calcium is 7 . 10(7)M-1, and MgCl2 up to 5 mM does not displace calcium.
