Transcriptional Regulation Of PTPRO Gene By E2F1 During PC12 Differentiation After NGF Stimulation

PTPRO is a member of the receptor-type protein tyrosine phosphatases(RPTPs) family, which is involved in podocyte function,axon pathfinding and tumor suppression.The expression of PTPRO varies under different conditions.For example,in kidney,PTPRO is expressed on the apical surface of the podocyte early in development and is present on the apical surface of podocyte foot processes in the mature phenotype;in brain,maximal expression of PTPRO iscoincident with mid to late gestation and axonogenesis.It is reported that Receptor-type protein tyrosine phosphatases(RPTPs) are required for appropriate growth of axons during nervous system development in Drosophila.In the vertebrate,typeâ…¡a RPTPs [protein tyrosine phosphatase(PTP) and LAR(leukocyte common-antigenrelated)]and the typeâ…¢RPTP have been implicated in the regulation of axon growth,However,people know little about the regulation mechanisms for PTPRO expression and its function in neuronal differentiation.To clarify the regulation of PTPRO gene transcription during PC12 neuronal differentiation after stimulated by NGF,PCR(Real-time PCR) and Westem bloting was used to examine the up-regulation of PTPRO gene in the differentiation of PC12 cell line.By applying a series of transient transfection and relative luciferase activity assays,we found that transcription factor E2F1 promoted the activities of the PTPRO promoter evidently.The results of real-time PCR and Western bloting confirmed the effects of E2F1 in promoting the PTPRO gene expression.Additionally,by using ChIP,we showed that E2F1 bound to PTPRO promoter in vivo.Our data demonstrated that the transcription factor E2F1 was involved in the transcriptional regulation of PTPRO gene.PTPRO was identified as a new target of E2F1. This work provides further insight into the regulation mechanisms of PTPRO gene and its function in neuronal diffenentiation.