RESUMEN
The plastid gene psbC encodes the CP43 subunit of PSII. Most psbC mRNAs of many organisms possess two possible initiation codons, AUG and GUG, and their coding regions are generally annotated from the upstream AUG. Using a chloroplast in vitro translation system, we show here that translation of the tobacco plastid psbC mRNA initiates from the GUG. This mRNA possesses a long Shine-Dalgarno (SD)-like sequence, GAGGAGGU, nine nucleotides upstream of the GUG. Point mutations in this sequence abolished translation, suggesting that a strong interaction between this extended SD-like sequence and the 3' end of 16S rRNA facilitates translation initiation from the GUG.
Asunto(s)
Cloroplastos/genética , Nicotiana/genética , Complejo de Proteína del Fotosistema II/genética , Biosíntesis de Proteínas , ARN del Cloroplasto/genética , ARN Mensajero/genética , Secuencia de Bases , Cloroplastos/metabolismo , Codón Iniciador , Datos de Secuencia Molecular , Complejo de Proteína del Fotosistema II/biosíntesis , Proteínas de Plantas/biosíntesis , Proteínas de Plantas/genética , ARN del Cloroplasto/metabolismo , ARN Mensajero/metabolismo , Nicotiana/metabolismoRESUMEN
A ligand-receptor pair, bone morphogenetic protein-7 (BMP7) and activin receptor IIB (actRIIB), was identified from a pool of DNA fragments recovered from MCF7 cells treated with 17beta-estradiol (E2) by chromatin immunoprecipitation with antiestrogen receptor-alphaantibody. The E2 responsiveness of both genes was confirmed in MCF cells and in the mouse uterus. Repeated treatment with E2 resulted in decreased expression of both actRIIB and BMP7 mRNA in the uteri of ovariectomized mice. A single oral administration of bisphenol A (BPA), an environmental estrogen, inhibited actRIIB and BMP7 expression and apoptosis in the luminal epithelium of the mouse uterus at diestrus (or early proestrus). This decrease, due to BPA administration, was restored by an estrogen receptor (ER) antagonist suggesting that it is mediated through ERs. These results suggest that E2 and BPA suppress estrogen-dependent apoptosis of epithelial cells of the endometrium through down-regulation of actRIIB and BMP7. Thus, we propose that BMP7 and actRIIB, a ligand-receptor pair, are involved in regulation of the apoptotic signaling pathway and might therefore be new biomarkers of the effects of environmental estrogens on the female reproductive tract.
Asunto(s)
Receptores de Activinas Tipo II/genética , Contaminantes Ocupacionales del Aire/toxicidad , Apoptosis/efectos de los fármacos , Estrógenos/farmacología , Proteínas/genética , Animales , Apoptosis/genética , Apoptosis/inmunología , Biomarcadores , Proteína Morfogenética Ósea 7 , Proteínas Morfogenéticas Óseas , Línea Celular Tumoral , Cromatina/inmunología , Regulación hacia Abajo/efectos de los fármacos , Regulación hacia Abajo/genética , Células Epiteliales/citología , Células Epiteliales/inmunología , Estradiol/farmacología , Estrógenos/toxicidad , Femenino , Perfilación de la Expresión Génica , Regulación de la Expresión Génica/efectos de los fármacos , Sustancias Peligrosas/toxicidad , Humanos , Ratones , Ovariectomía , Regiones Promotoras Genéticas , ARN Mensajero , Receptores de Estrógenos/inmunología , Transducción de Señal/efectos de los fármacos , Transducción de Señal/genética , Útero/citología , Útero/inmunologíaRESUMEN
We collected and completely sequenced 28,469 full-length complementary DNA clones from Oryza sativa L. ssp. japonica cv. Nipponbare. Through homology searches of publicly available sequence data, we assigned tentative protein functions to 21,596 clones (75.86%). Mapping of the cDNA clones to genomic DNA revealed that there are 19,000 to 20,500 transcription units in the rice genome. Protein informatics analysis against the InterPro database revealed the existence of proteins presented in rice but not in Arabidopsis. Sixty-four percent of our cDNAs are homologous to Arabidopsis proteins.