TY - JOUR
T1 - Differential requirements for cellular enhancers in stem and differentiated cells
AU - Vogt, Thomas F.
AU - Compton, Reid S.
AU - Scott, Richard W.
AU - Tilghman, Shirley M.
N1 - Funding Information:
We wish to thank members of our laboratory for stimulating discussions. We also thank David Mann for excellent technical assistance and Noel Mann for the preparation of the manuscript. This work was supported by grants CA28050 and CA44976 from the National Institutes of Health. T.F.V. was supported by a PHS predoctoiral training grant to the Genetics Graduate Group of the University of Pennsylvania and R.S.C. and R.W.S. by PHS postdoctoral fellowships.
PY - 1988/1/25
Y1 - 1988/1/25
N2 - Multiple cis-acting regulatory elements consisting of three cellular enhancers and a proximal promoter element have been identified in the region upstream of the mouse α-fetoprotein (AFP) gene. We examined the role of these sequences during differentiation by the introduction of modified AFP genes into cells at different stages of commitment to its expression. Modified AFP genes introduced stably into F9 embryonal carcinoma stem cells by DNA transfection were silent until activated by treatment with retinoic acid to form visceral endoderm. Their activation required the presence of both the enhancer and proximal promoter domains. The introduced genes activated simultaneously with the endogenous AFP genes, but reached maximal levels of expression more rapidly, suggesting a greater initial accessibility to transcription factors. In contrast, when aodified AFP genes were stably introduced into HepG2 cells, a human hepatoraa cell line that constitutively expresses the AFP gene, the proximal promoter sequences were sufficient to direct a low level of expression. The absolute requirement for the AFP enhancers in F9 cells but not in HepG2 cells supports a model by which there is an obligate requirement for enhancers during differentiation in addition to their role in enhancing gene expression after differentiation.
AB - Multiple cis-acting regulatory elements consisting of three cellular enhancers and a proximal promoter element have been identified in the region upstream of the mouse α-fetoprotein (AFP) gene. We examined the role of these sequences during differentiation by the introduction of modified AFP genes into cells at different stages of commitment to its expression. Modified AFP genes introduced stably into F9 embryonal carcinoma stem cells by DNA transfection were silent until activated by treatment with retinoic acid to form visceral endoderm. Their activation required the presence of both the enhancer and proximal promoter domains. The introduced genes activated simultaneously with the endogenous AFP genes, but reached maximal levels of expression more rapidly, suggesting a greater initial accessibility to transcription factors. In contrast, when aodified AFP genes were stably introduced into HepG2 cells, a human hepatoraa cell line that constitutively expresses the AFP gene, the proximal promoter sequences were sufficient to direct a low level of expression. The absolute requirement for the AFP enhancers in F9 cells but not in HepG2 cells supports a model by which there is an obligate requirement for enhancers during differentiation in addition to their role in enhancing gene expression after differentiation.
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U2 - 10.1093/nar/16.2.487
DO - 10.1093/nar/16.2.487
M3 - Article
C2 - 2448754
AN - SCOPUS:0024296159
SN - 0305-1048
VL - 16
SP - 487
EP - 500
JO - Nucleic acids research
JF - Nucleic acids research
IS - 2
ER -