Publications (3)4.46 Total impact
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ABSTRACT: ObjectiveTo explore the influence of EBP50 (ezrin-radixin-moesin-binding phospho-protein-50) on microfilament cytoskeleton content and distribution in cultured Hela cells, and to investigate the relationship between the changes in microfilament cytoskeleton localization and EBP50 after PDGF (platelet-derived growth factor) stimulation, and to further clarify the molecular mechanism by which EBP50 suppresses tumor cell proliferation and migration. MethodspBK-CMV-HAEBP50 wild type recombinant plasmid and pBK-CMV-HA empty vector were transfected into Hela cells. G418 at 350 mg/L was used to screen for cell clones stably expressing EBP50. Western blot was carried out to detect EBP50 expression. Similarities and differences in microfilament cytoskeleton content and distribution in Hela cells transfected with pBK-CMV-HA-EBP50 wild type recombinant plasmid and pBK-CMV-HA empty vector were also treated with PDGF (10 ng/mL and 20 ng/mL, 37 °C, 15 min) and stained by rhodamine-labeled phalloidin to observe the distribution of microfilament cytoskeleton in the two groups. EBP50 protein distribution in PDGF-stimulated Hela cells was detected by immunofluorescence. ResultsWestern blot results confirmed that the EBP50 cDNA fragment could express EBP50 in cultured Hela cell lines and that cell lines stably expressing EBP50 were successfully obtained. Western blot and fluorescence results showed that in the cell line transfected with empty vector, the microfilament cytoskeleton was thick, loose, multidirectional and displayed crossing arrangements. The content of microfilament cytoskeleton in the cell line transfected with pBK-CMV-HA-EBP50 was different from that found in the cell line transfected with empty vector. EBP50 expression enhanced microfilament cytoskeleton polymerization into compact thin filaments. Under the stimulation of PDGF, EBP50 migrated to the cell membrane from the cytosol together with microfilament cytoskeleton and co-localized there. ConclusionEBP50 can change the distribution of microfilament cytoskeleton in cultured Hela cells and can also bind the microfilament cytoskeleton to the cell membrane under the stimulation of PDGF. EBP50 may play a role in the proliferation and migration of tumor cells by influencing the distribution and localization of microfilament cytoskeleton.The Chinese-German Journal of Clinical Oncology 04/2012; 8(5):282-285.
Article: Na(+)/H(+) exchanger regulatory factor 1 (NHERF1) is required for the estradiol-dependent increase of phosphatase and tensin homolog (PTEN) protein expression.[show abstract] [hide abstract]
ABSTRACT: Expression of phosphatase and tensin homologue deleted on chromosome 10 (PTEN) can be induced by estrogens at the posttranscriptional level. However, the molecular mechanism of the process is unclear. In this study, we found that the C terminus (CT) of PTEN is indispensable for 17-β-estradiol (E2)-increased PTEN expression. Therefore, we screened for PTEN-CT-associated proteins using a glutathione-S-transferase pull-down approach in combination with mass spectrometry-based proteomic analyses. Our experiments led to the identification of Na(+)/H(+) exchanger regulatory factor 1 (NHERF1) as a major PTEN-CT binding partner. The first postsynaptic density protein-95/Discslarge/zonula occludens-1 homology domain of NHERF1 and the last four amino acids of PTEN were found to be key determinants of this interaction. By associating with PTEN, NHERF1 could enhance PTEN protein expression by retention of PTEN turnover, as demonstrated by NHERF1 overexpression and small interfering RNA-mediated knockdown experiments, respectively. Furthermore, NHERF1 inhibited ubiquitination of the PTEN protein upon competition with binding of PTEN to neural precursor cell expressed, developmentally down-regulated 4, an ubiquitin E3 ligase. E2 strongly induced the expression of NHERF1 and PTEN only in estrogen receptor (ER)-positive cells but not in ER-negative cells. ICI182780, an ER-specific inhibitor, decreased the expression of both NHERF1 and PTEN, and ICI182780 pretreatment also retarded E2-increased PTEN expression in ER-MDA-MB-231 cells. In both ER-MDA-MB-231 and MCF-7 cells, E2 failed to increase PTEN expression when NHERF1 was knocked down. Taken together, these are the first results that present a possible mechanism for E2-increased PTEN expression. In this process, E2 first induces NHERF1 expression by activating the ER. Upon competition with neural precursor cell expressed, developmentally down-regulated 4, NHERF1 then interacts with PTEN to inhibit PTEN degradation, through an ubiquitination-dependent pathway. This in turn leads to the increase of PTEN expression at the protein level.Endocrinology 12/2011; 152(12):4537-49. · 4.46 Impact Factor
Conference Proceeding: The Design and Building of Metadata Model in XBRL Taxonomy Engineering.4th International Symposium on Computational Intelligence and Design, ISCID 2011, Hangzhou, China, October 28-30, 2011, 2 Volumes; 01/2011