NANOG is a direct target of TGFbeta/activin-mediated SMAD signaling in human ESCs.
Self-renewal of human embryonic stem cells (ESCs) is promoted by FGF and TGFbeta/Activin signaling, and differentiation is promoted by BMP signaling, but how these signals regulate genes critical to the maintenance of pluripotency has been unclear. Using a defined medium, we show here that both TGFbeta and FGF signals synergize to inhibit BMP signaling; sustain expression of pluripotency-associated genes such as NANOG, OCT4, and SOX2; and promote long-term undifferentiated proliferation of human ESCs. We also show that both TGFbeta- and BMP-responsive SMADs can bind with the NANOG proximal promoter. NANOG promoter activity is enhanced by TGFbeta/Activin and FGF signaling and is decreased by BMP signaling. Mutation of putative SMAD binding elements reduces NANOG promoter activity to basal levels and makes NANOG unresponsive to BMP and TGFbeta signaling. These results suggest that direct binding of TGFbeta/Activin-responsive SMADs to the NANOG promoter plays an essential role in sustaining human ESC self-renewal.
Xu
Ren-He
RH
Department of Genetics and Developmental Biology, University of Connecticut Health Center, University of Connecticut Stem Cell Institute, Farmington, CT 06030, USA. renhexu@uchc.edu
Sampsell-Barron
Tori L
TL
Gu
Feng
F
Root
Sierra
S
Peck
Ruthann M
RM
Pan
Guangjin
G
Yu
Junying
J
Antosiewicz-Bourget
Jessica
J
Tian
Shulan
S
Stewart
Ron
R
Thomson
James A
JA
D001549:Benzamides / Q000494:pharmacology; D019485:Bone Morphogenetic Proteins / Q000037:antagonists & inhibitors / Q000235:genetics; D002454:Cell Differentiation / Q000187:drug effects / Q000235:genetics; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D004149:Dioxoles / Q000494:pharmacology; D053595:Embryonic Stem Cells / Q000166:cytology / Q000378:metabolism*; D005346:Fibroblast Growth Factors / Q000235:genetics / Q000494:pharmacology; D018398:Homeodomain Proteins / Q000235:genetics*; D006801:Humans; D008233:Lymphotoxin-alpha / Q000235:genetics* / Q000494:pharmacology; D000071317:Nanog Homeobox Protein; D011401:Promoter Regions, Genetic; D011485:Protein Binding / Q000187:drug effects; D011994:Recombinant Proteins / Q000235:genetics / Q000494:pharmacology; D015398:Signal Transduction / Q000187:drug effects / Q000235:genetics; D051899:Smad2 Protein / Q000037:antagonists & inhibitors / Q000235:genetics*; D051900:Smad3 Protein / Q000037:antagonists & inhibitors / Q000235:genetics*; D015533:Transcriptional Activation / Q000187:drug effects / Q000235:genetics
C459179:4-(5-benzo(1,3)dioxol-5-yl-4-pyridin-2-yl-1H-imidazol-2-yl)benzamide; D001549:Benzamides; D019485:Bone Morphogenetic Proteins; D004149:Dioxoles; D018398:Homeodomain Proteins; D008233:Lymphotoxin-alpha; C486780:NANOG protein, human; D000071317:Nanog Homeobox Protein; D011994:Recombinant Proteins; D051899:Smad2 Protein; D051900:Smad3 Protein; D005346:Fibroblast Growth Factors