Retinoic acid-mediated down-regulation of Oct3/4 coincides with the loss of promoter occupancy in vivo.

摘要: Oct3/4, a hallmark of the earliest stages embryogenesis, is expressed in undifferentiated embryonal carcinoma (EC) and embryonic stem (ES) cells. Oct3/4 gene expression dependent on promoter region, proximal enhancer newly identified distal enhancer. We have analysed vivo occupancy these elements. In EC ES cells, strong footprints were detected at specific sites all three regulatory These promptly lost upon RA treatment cells P19 parallel with sharply reduced mRNA levels. Thus, elements coupled expression, causes coordinated factor displacement, leading to extinction activity. F9 footprint was first abolished However, this loss binding site did not result decrease The partial displacement seen combined observation that utilize enhancers differential manner, indicate complex pattern regulation, which could reflect cell type- lineage-specific vivo.