EBP50影响HeLa细胞微丝骨架的分布和定位

摘要

Objective:To explore the influence of EBP50 (ezrin-radixin-moesin-binding phospho-protein-50) on microfila-ment 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. Methods:pBK-CMV-HA-EBP50 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 ℃, 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. Results:Western 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. Conclusion:EBP50 can change the distribution of microfilament cytoskel-eton in cultured Hela cells and can also bind the microfilament cytoskeleton to the cell membrane under the stimulation of PDGE EBP50 may play a role in the proliferation and migration of tumor cells by influencing the distribution and localization of microfilament cytoskeleton.