RESUMEN
NOV (nephroblastoma overexpressed gene) is a member of the CCN (connective tissue growth factor [CTGF], Cyr61/Cef10, NOV) family of proteins. These proteins are cysteine-rich and are noted for having growth-regulatory functions. We have isolated the rat NOV gene, and the DNA sequence shares 90% identity with the mouse and 80% identity with the human sequences. The rat NOV gene was expressed in all rat tissues examined, including brain, lung, heart, kidney, liver, spleen, thymus and skeletal muscle. Higher levels of rat NOV mRNA were seen in the brain, lung and skeletal muscle compared to the other tissues. Examination of NOV expression in various human cell lines revealed that NOV was expressed in U87, 293, T98G, SK-N-MC and Hs683 but not in HepG2, HL60, THP1 and Jurkat. The human NOV gene was transfected into 293 cells and the expressed protein purified. When 3T3 fibroblasts were treated with this recombinant NOV protein, a dose-dependent increase in proliferation was observed. Analysis of tyrosine-phosphorylated proteins revealed that when 3T3 cells were treated with NOV, a 221 kDa protein was phosphorylated. These data suggest that NOV can act as a growth factor for some cells and binds to a specific receptor that leads to the phosphorylation of a 221 kDa protein.
Asunto(s)
Proteínas Inmediatas-Precoces , Péptidos y Proteínas de Señalización Intercelular , Neoplasias Renales/genética , Proteínas Oncogénicas Virales/genética , Proteínas Proto-Oncogénicas/genética , Tirosina/metabolismo , Tumor de Wilms/genética , Células 3T3 , Secuencia de Aminoácidos , Animales , División Celular , Clonación Molecular , Factor de Crecimiento del Tejido Conjuntivo , ADN Complementario , Dexametasona/farmacología , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Ratones , Datos de Secuencia Molecular , Proteína Hiperexpresada del Nefroblastoma , Proteínas Oncogénicas Virales/metabolismo , Fosforilación , Proteínas Proto-Oncogénicas/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Ratas , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Homología de Secuencia de Aminoácido , Células Tumorales CultivadasRESUMEN
In humans the regulation of cellular copper homeostasis is essential for proper organ development and function. A novel cytosolic protein, named Atox 1, was recently identified in yeast that functions in shuttling intracellular mononuclear copper [Cu(I)] to copper-requiring proteins. Atox 1 and its human homolog, hAtox1, are members of an emerging family of proteins termed copper chaperones that are involved in the maintenance of copper homeostasis. Northern blot analysis demonstrates that Atox 1 is widely expressed at varying levels in a variety of rat tissues including brain. Using in situ hybridization histochemistry, we characterized the expression profile for the rat homolog of Atox1 (rAtox1) in the normal adult rat brain. There is widespread expression within the brain that appears to be primarily neuronal. The highest levels of Atox1 message consists of distinct neuronal subtypes that are also characterized by their high levels of metals like copper, iron, and zinc, which include the pyramidal neurons of the cerebral cortex and hippocampus in addition to the neurons of the locus coeruleus. The high levels of a metal chaperone like Atox1 in subsets of neurons that also sequester metals suggests that Atox1 may be important in maintaining the functionality of metal requiring enzymes. A detailed analysis of the restricted expression profile for a novel copper chaperone, rAtox1, is described in the adult rat CNS. Further analysis shows that Atoxl expression is associated with neuronal populations that sequester copper.
Asunto(s)
Encéfalo/metabolismo , Proteínas Portadoras/genética , Proteínas de Transporte de Catión , Cobre/metabolismo , Regulación de la Expresión Génica , Chaperonas Moleculares , Proteínas de Saccharomyces cerevisiae , Animales , Proteínas Portadoras/biosíntesis , Proteínas Transportadoras de Cobre , ADN Complementario/genética , Proteínas Fúngicas/genética , Hipocampo/metabolismo , Homeostasis , Humanos , Hibridación in Situ , Hierro/metabolismo , Metalochaperonas , Ratones , Especificidad de Órganos , Estrés Oxidativo , Ratas , Especificidad de la Especie , Tegmento Mesencefálico/metabolismo , Zinc/metabolismoRESUMEN
In this study, the cytokine-producing profile of progenitor T cells (pro-T cells) was determined. During screening of a complementary DNA library generated from activated mouse pro-T cells, a cytokine designated lymphotactin was discovered. Lymphotactin is similar to members of both the Cys-Cys and Cys-X-Cys chemokine families but lacks two of the four cysteine residues that are characteristic of the chemokines. Lymphotactin is also expressed in activated CD8+ T cells and CD4-CD8- T cell receptor alpha beta + thymocytes. It has chemotactic activity for lymphocytes but not for monocytes or neutrophils. The gene encoding lymphotactin maps to chromosome one. Taken together, these observations suggest that lymphotactin represents a novel addition to the chemokine superfamily.