TY - JOUR
T1 - Retinoic acid-mediated down-regulation of Oct3/4 coincides with the loss of promoter occupancy in vivo
AU - Minucci, Saverio
AU - Botquin, Valérie
AU - Yeom, Young Il
AU - Dey, Anup
AU - Sylvester, Ian
AU - Zand, Dina J.
AU - Ohbo, Kazuyuki
AU - Ozato, Keiko
AU - Schöler, Hans R.
PY - 1996
Y1 - 1996
N2 - Oct3/4, a hallmark of the earliest stages of embryogenesis, is expressed in undifferentiated embryonal carcinoma (EC) and embryonic stem (ES) cells. Oct3/4 gene expression is dependent on the promoter region, the proximal enhancer and the newly identified distal enhancer. We have analysed in vivo occupancy of these elements. In undifferentiated EC and ES cells, strong footprints were detected at specific sites of ail three regulatory elements. These were promptly lost upon RA treatment in ES cells and in P19 EC cells, in parallel with sharply reduced Oct3/4 mRNA levels. Thus, the occupancy of regulatory elements is coupled with Oct3/4 expression, and RA treatment causes coordinated factor displacement, leading to extinction of gene activity. In F9 EC cells, footprint was first abolished at the proximal enhancer. However, this loss of binding site occupancy did not result in a decrease in Oct3/4 mRNA levels. The partial factor displacement seen in F9 EC cells, combined with the observation that EC and ES cells utilize the proximal and distal enhancers in a differential manner, indicate the complex pattern of Oct3/4 gene regulation, which could reflect a cell type- and lineage-specific expression of the gene in vivo.
AB - Oct3/4, a hallmark of the earliest stages of embryogenesis, is expressed in undifferentiated embryonal carcinoma (EC) and embryonic stem (ES) cells. Oct3/4 gene expression is dependent on the promoter region, the proximal enhancer and the newly identified distal enhancer. We have analysed in vivo occupancy of these elements. In undifferentiated EC and ES cells, strong footprints were detected at specific sites of ail three regulatory elements. These were promptly lost upon RA treatment in ES cells and in P19 EC cells, in parallel with sharply reduced Oct3/4 mRNA levels. Thus, the occupancy of regulatory elements is coupled with Oct3/4 expression, and RA treatment causes coordinated factor displacement, leading to extinction of gene activity. In F9 EC cells, footprint was first abolished at the proximal enhancer. However, this loss of binding site occupancy did not result in a decrease in Oct3/4 mRNA levels. The partial factor displacement seen in F9 EC cells, combined with the observation that EC and ES cells utilize the proximal and distal enhancers in a differential manner, indicate the complex pattern of Oct3/4 gene regulation, which could reflect a cell type- and lineage-specific expression of the gene in vivo.
KW - Embryonal carcinoma cells
KW - Embryonic stem cells
KW - Gene regulation
KW - In vivo footprinting
KW - POU
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M3 - Article
C2 - 8631309
AN - SCOPUS:0030059509
VL - 15
SP - 888
EP - 899
JO - EMBO Journal
JF - EMBO Journal
SN - 0261-4189
IS - 4
ER -