Influence Of Transcription Factor E2F1 On Regulation Of FOXC1 Gene Expression

FOXC1 gene is a member of the Forkhead box(FOX) transcription factor family,and it is mapped to chromosome 6p25.Northern blot showed that the transcript of FOXC1 gene was widely expressed in many tissues and organs in humans.Like normal transcription factors, FOXC1 protein has a highly conserved DNA-binding domain,a transactivation domain and some other domains.FOXC1 is involved in the development and regulation of several organs, including eyes,where FOXC1 alteration causes iris,and corneal anomalies.In humans, mutations in the FOXC1 cause Axenfeld Rieger malformations.The most serious consequence of this disorder is a heightened propensity to develop glaucoma.Furthermore, targeted deletions of FOXC1 in mice cause serious defects in the development of heart,kidney, skeletons,and somite.At present,the studies of FOXC1 mainly focus on its functions in tissue and organ development,and in Axenfeld Rieger malformations.There have been seldom studies on the mechanisms of transcriptional regulation of FOXC1 gene.The aim of this study was to clarify the regulation of FOXC1 gene transcription.By applying a series of transient transfection and relative luciferase activity assays,we found that transcription factor E2F1 evidently promoted the activities of the FOXC1 promoter.The results of RT-PCR,realtime PCR and Western blot confirmed the effects of E2F1 in promoting the FOXC1 gene expression.We also found that there existed two functional E2F1 binding sties in FOXC1 promoter.Additionally,by using chromatin immunoprecipitation (CHIP),we showed that E2F1 bound to FOXC1 promoter in vivo.Data presented in this thesis demonstrated that the transcription factor E2F1 was involved in the transcriptional regulation of FOXC1 gene.FOXC1 was identified as a new target of E2F1.This study provides further insight into the mechanisms of transcriptional regulation of FOXC1 gene and the clues for studies of E2F1.