cAMP response element binding protein (CREB) is a transcription factor in nucleus. The activating CREB can specifically bind to the cAMP response element (CRE). The present result showed that erythropoietin (EPO) coul...cAMP response element binding protein (CREB) is a transcription factor in nucleus. The activating CREB can specifically bind to the cAMP response element (CRE). The present result showed that erythropoietin (EPO) could induce the phosphorylation of CREB on Serine133 (Pser133), as detected by western blot analysis. in addition, the EPO-dependent activation of CREB binding to CRE element was demonstrated by electrophoretic mobility shift assay. However, the binding of CREB to CRE element could be inhibited by anti-CREB-Pser133 antibody. The data obtained suggested that the EPO-mediated CREB phosphorylation might be critical to both the binding of CREB to the CRE element and the activation of the CREB transcription factor.展开更多
High mobility group (HMG) proteins are abundant non-histone proteins in the nuclei of eukaryocytes. It has been shown that HMG proteins may play important roles in the structure and function of chromatin. In the prese...High mobility group (HMG) proteins are abundant non-histone proteins in the nuclei of eukaryocytes. It has been shown that HMG proteins may play important roles in the structure and function of chromatin. In the present study, the binding of HMG proteins (HMG1/2 and HMG14/17) to the human e-globin gene promoter (e-promo-ter, -177-+1 bp) has been examined by using both the in vitro nucleosome reconstitution and the electrophoresis mobility shift assay (EMSA). We found that HMG1/2 proteins could bind to the naked e-promoter DNA, however, HMG14/17 could not. Using the in vitro nucleosome reconstitution, we revealed that HMG14/17 could bind to the mononucleosome reconstituted in vitro with E-promoter, while HMG1/2 could not. Those results indicate that the binding of HMG proteins to e-promoter is dynamic as the nucleosome assembling and disassembling. We speculated that this selective binding of HMG proteins to e-promoter might play a critical role in the regulation of e-globin gene expression.展开更多
文摘cAMP response element binding protein (CREB) is a transcription factor in nucleus. The activating CREB can specifically bind to the cAMP response element (CRE). The present result showed that erythropoietin (EPO) could induce the phosphorylation of CREB on Serine133 (Pser133), as detected by western blot analysis. in addition, the EPO-dependent activation of CREB binding to CRE element was demonstrated by electrophoretic mobility shift assay. However, the binding of CREB to CRE element could be inhibited by anti-CREB-Pser133 antibody. The data obtained suggested that the EPO-mediated CREB phosphorylation might be critical to both the binding of CREB to the CRE element and the activation of the CREB transcription factor.
基金This work was supported by the National Natural Science Foundation of China (Grant No. 39893320)the Foundation of Chinese Academy of Sciences (Grant No. KJ 951 -A 1 -603 (2)).
文摘High mobility group (HMG) proteins are abundant non-histone proteins in the nuclei of eukaryocytes. It has been shown that HMG proteins may play important roles in the structure and function of chromatin. In the present study, the binding of HMG proteins (HMG1/2 and HMG14/17) to the human e-globin gene promoter (e-promo-ter, -177-+1 bp) has been examined by using both the in vitro nucleosome reconstitution and the electrophoresis mobility shift assay (EMSA). We found that HMG1/2 proteins could bind to the naked e-promoter DNA, however, HMG14/17 could not. Using the in vitro nucleosome reconstitution, we revealed that HMG14/17 could bind to the mononucleosome reconstituted in vitro with E-promoter, while HMG1/2 could not. Those results indicate that the binding of HMG proteins to e-promoter is dynamic as the nucleosome assembling and disassembling. We speculated that this selective binding of HMG proteins to e-promoter might play a critical role in the regulation of e-globin gene expression.
