Sp1/3 and NF-1 mediate basal transcription of the human P2X1 gene in megakaryoblastic MEG-01 cells.

摘要: P2X1 receptors play an important role in platelet function as they can induce shape change, granule centralization and are also involved thrombus formation. As platelets have no nuclei, the level of expression depends on transcriptional regulation megakaryocytes, precursor cell. Since nothing is known about molecular mechanisms regulating megakaryocytic expression, this study aimed to identify functionally characterize core promoter utilized human megakaryoblastic cell line MEG-01. In order cis-acting elements ability 4.7 kb upstream sequence drive luciferase reporter gene was tested. Low activity detected proliferating MEG-01 cells. This increased 20-fold after phorbol-12-myristate-13-acetate (PMA) induced differentiation. A transcription start site 365 bp codon by primer extension. Deletion analysis constructs indicated a located within region -68 +149 that contained two Sp1 sites (named Sp1a Sp1b) NF-1 site. Individual mutations Sp1b or binding severely reduced whereas triple mutation Sp1a, completely abolished both untreated PMA treated Sp1/3 proteins were shown bind their respective EMSA interaction Sp1/3, TFIIB with endogenous cells demonstrated chromatin immunoprecipitation. Alignment genes from human, chimp, rat, mouse dog revealed consensus equivalent positions thereby demonstrating evolutionary conservation these sites. has identified characterized direct vicinity essential for basal transcription. Targeting factors megakaryocytes may therefore provide basis future therapeutic manipulation function.