Transcription factor that binds to the octamer motif (5'-ATTTGCAT-3'). Forms a trimeric complex with SOX2 on DNA and controls the expression of a number of genes involved in embryonic development such as YES1, FGF4, UTF1 and ZFP206. Critical for early embryogenesis and for embryonic stem cell pluripotency.
Successful reprogramming of differentiated human somatic cells into a pluripotent state would allow creation of patient- and disease-specific stem cells. We previously reported generation of induced pluripotent stem (iPS) cells, capable of germline transmission, from mouse somatic cells by transduction of four defined transcription factors. Here, we demonstrate the generation of iPS cells from adult human dermal fibroblasts with the same four factors: Oct3/4, Sox2, Klf4, and c-Myc. Human iPS cells were similar to human embryonic stem (ES) cells in morphology, proliferation, surface antigens, gene expression, epigenetic status of pluripotent cell-specific genes, and telomerase activity. Furthermore, these cells could differentiate into cell types of the three germ layers in vitro and in teratomas. These findings demonstrate that iPS cells can be generated from adult human fibroblasts.
The transcription factors OCT4, SOX2, and NANOG have essential roles in early development and are required for the propagation of undifferentiated embryonic stem (ES) cells in culture. To gain insights into transcriptional regulation of human ES cells, we have identified OCT4, SOX2, and NANOG target genes using genome-scale location analysis. We found, surprisingly, that OCT4, SOX2, and NANOG co-occupy a substantial portion of their target genes. These target genes frequently encode transcription factors, many of which are developmentally important homeodomain proteins. Our data also indicate that OCT4, SOX2, and NANOG collaborate to form regulatory circuitry consisting of autoregulatory and feedforward loops. These results provide new insights into the transcriptional regulation of stem cells and reveal how OCT4, SOX2, and NANOG contribute to pluripotency and self-renewal.
Interacting selectively and non-covalently with a microRNA, a 21-23 nucleotide RNA that is processed from a stem-loop RNA precursor (pre-miRNA) that is encoded within plant and animal genomes.
MicroRNAs (miRNAs) are posttranscriptional modulators of gene expression and play an important role in many developmental processes. We report here that expression of microRNA-145 (miR-145) is low in self-renewing human embryonic stem cells (hESCs) but highly upregulated during differentiation. We identify the pluripotency factors OCT4, SOX2, and KLF4 as direct targets of miR-145 and show that endogenous miR-145 represses the 3' untranslated regions of OCT4, SOX2, and KLF4. Increased miR-145 expression inhibits hESC self-renewal, represses expression of pluripotency genes, and induces lineage-restricted differentiation. Loss of miR-145 impairs differentiation and elevates OCT4, SOX2, and KLF4. Furthermore, we find that the miR-145 promoter is bound and repressed by OCT4 in hESCs. This work reveals a direct link between the core reprogramming factors and miR-145 and uncovers a double-negative feedback loop involving OCT4, SOX2, KLF4, and miR-145.
Oct4 and Sox2 are transcription factors required for pluripotency during early embryogenesis and for the maintenance of embryonic stem cell (ESC) identity. Functional mechanisms contributing to pluripotency are expected to be associated with genes transcriptionally activated by these factors. Here, we show that Oct4 and Sox2 bind to a conserved promoter region of miR-302, a cluster of eight microRNAs expressed specifically in ESCs and pluripotent cells. The expression of miR-302a is dependent on Oct4/Sox2 in human ESCs (hESCs), and miR-302a is expressed at the same developmental stages and in the same tissues as Oct4 during embryogenesis. miR-302a is predicted to target many cell cycle regulators, and the expression of miR-302a in primary and transformed cell lines promotes an increase in S-phase and a decrease in G(1)-phase cells, reminiscent of an ESC-like cell cycle profile. Correspondingly, the inhibition of miR-302 causes hESCs to accumulate in G(1) phase. Moreover, we show that miR-302a represses the productive translation of an important G(1) regulator, cyclin D1, in hESCs. The transcriptional activation of miR-302 and the translational repression of its targets, such as cyclin D1, may provide a link between Oct4/Sox2 and cell cycle regulation in pluripotent cells.
Interacting selectively and non-covalently with any protein or protein complex (a complex of two or more proteins that may include other nonprotein molecules).
Evidence
1:
Inferred from Physical InteractionUniProtKB
The Oct-4 gene encodes a transcription factor that plays an important role in maintaining the pluripotent state of embryonic stem cells and may prevent expression of genes activated during differentiation. Although its role in maintaining embryonic stem cell pluripotency is well established, there is still little known about the binding partners that regulate its function. To identify proteins that control Oct-4 function, we used affinity chromatography on immobilized Oct-4 (POU) together with MALDI-TOF (matrix-assisted laser-desorption ionization-time-of-flight) MS (mass spectrometry) and isolated a novel Oct-4-interacting protein, pyruvate kinase type M2 (PKM2 or M2-PK). PKM2 is an isozyme of pyruvate kinase that is specifically expressed in proliferating cells, such as embryonic stem cells, embryonic carcinoma cells, as well as cancer cells. Oct-4 and PKM2 were co-affinity precipitated from cell extracts, and glutathione S-transferase pull-down assays revealed that the POU DNA binding domain of Oct-4 was required for interaction with PKM2. In addition, the C-terminal domain of PKM2 (amino acids 307-531) was involved in binding to Oct-4. Moreover, ectopic expression of the PKM2 enhanced Oct-4-mediated transcription. These observations indicate that the transactivation potential of the Oct-4 transcription factor is positively modulated by PKM2.
Evidence
2:
Inferred from Physical InteractionIntAct
The POU homeodomain protein Oct-4 and the Forkhead Box protein FoxD3 (previously Genesis) are transcriptional regulators expressed in embryonic stem cells. Down-regulation of Oct-4 during gastrulation is essential for proper endoderm development. After gastrulation, FoxD3 is generally down-regulated during early endoderm formation, although it specifically remains expressed in the embryonic neural crest. In these studies, we have found that Oct-4 and FoxD3 can bind to identical regulatory DNA sequences. In addition, Oct-4 physically interacted with the FoxD3 DNA-binding domain. Cotransfection of Oct-4 and FoxD3 expression vectors activated the osteopontin enhancer, which is expressed in totipotent embryonic stem cells. FoxA1 and FoxA2 (previously HNF-3alpha and HNF-3beta) are Forkhead Box transcription factors that participate in liver and lung formation from foregut endoderm. Although FoxD3 activated the FoxA1 and FoxA2 promoters, Oct-4 inhibited FoxD3 activation of the FoxA1 and FoxA2 endodermal promoters. These data indicate that Oct-4 functions as a corepressor of FoxD3 to provide embryonic lineage-specific transcriptional regulatory activity to maintain appropriate developmental timing.
Evidence
3:
Inferred from Physical InteractionBHF-UCL
Urinary excretion of cationic xenobiotics is believed to be mediated by organic cation transporter (OCT and OCTN) families expressed on both basolateral and brush-border membranes of renal tubules, although the molecular mechanisms for targeting of these transporters to each membrane are poorly understood. Here, to examine the regulatory mechanisms for cell-surface expression and function of these transporters, we evaluated the interaction of these transporters with several PDZ proteins. A pull-down study using recombinant C-terminal proteins of OCTs and OCTNs identified a specific interaction of apical transporters OCTN1 and OCTN2, but not basolateral transporters OCT1 and OCT2, with PDZK1, intestinal and kidney-enriched PDZ protein, and Na+/H+ exchanger regulatory factor 2 (also called E3KARP, SIP-1, or TKA-1). Both yeast two-hybrid and pull-down studies suggested a requirement of the last four amino acids in OCTN1 and OCTN2 for the interaction. The interaction of PDZK1 with the C terminus of OCTN2 was also confirmed in a pull-down study using kidney brush-border membrane vesicles. Immunohistochemical analysis revealed that both PDZK1 and OCTN2 are colocalized in brush-border membranes of the kidney. Finally, double transfection of OCTN2 with PDZK1 stimulated the uptake by OCTN2 of its endogenous substrate carnitine, and this increase could be accounted for by the 6-fold increase in transport capacity. Such an increase was not observed for OCTN2 with deletion of the last four amino acids. Biotinylation study of surface proteins revealed minimal effect of PDZK1 on cell-surface expression of OCTN2. The present findings are the first to identify PDZK1 as a functional regulator of OCTN2 through direct interaction with the C terminus.
Interacting selectively and non-covalently with DNA of a specific nucleotide composition, e.g. GC-rich DNA binding, or with a specific sequence motif or type of DNA e.g. promotor binding or rDNA binding.
Cardiomyocyte proliferation is high in early development and decreases progressively with gestation, resulting in the lack of a robust cardiomyocyte proliferative response in the adult heart after injury. Little is understood about how both cell-autonomous and nonautonomous signals are integrated to regulate the balance of cardiomyocyte proliferation during development. In this study, we show that a single transcription factor, Foxp1, can control the balance of cardiomyocyte proliferation during development by targeting different pathways in the endocardium and myocardium. Endocardial loss of Foxp1 results in decreased Fgf3/Fgf16/Fgf17/Fgf20 expression in the heart, leading to reduced cardiomyocyte proliferation. This loss of myocardial proliferation can be rescued by exogenous Fgf20, and is mediated, in part, by Foxp1 repression of Sox17. In contrast, myocardial-specific loss of Foxp1 results in increased cardiomyocyte proliferation and decreased differentiation, leading to increased myocardial mass and neonatal demise. We show that Nkx2.5 is a direct target of Foxp1 repression, and Nkx2.5 expression is increased in Foxp1-deficient myocardium. Moreover, transgenic overexpression of Nkx2.5 leads to increased cardiomyocyte proliferation and increased ventricular mass, similar to the myocardial-specific loss of Foxp1. These data show that Foxp1 coordinates the balance of cardiomyocyte proliferation and differentiation through cell lineage-specific regulation of Fgf ligand and Nkx2.5 expression.
Isoform
B
Sequence-specific DNA binding RNA polymerase II transcription factor activitydefinition[GO:0000981]
Interacting selectively and non-covalently with a specific DNA sequence in order to modulate transcription by RNA polymerase II. The transcription factor may or may not also interact selectively with a protein or macromolecular complex.
Interacting selectively and non-covalently with a specific DNA sequence in order to modulate transcription. The transcription factor may or may not also interact selectively with a protein or macromolecular complex.
The transcription factors OCT4, SOX2, and NANOG have essential roles in early development and are required for the propagation of undifferentiated embryonic stem (ES) cells in culture. To gain insights into transcriptional regulation of human ES cells, we have identified OCT4, SOX2, and NANOG target genes using genome-scale location analysis. We found, surprisingly, that OCT4, SOX2, and NANOG co-occupy a substantial portion of their target genes. These target genes frequently encode transcription factors, many of which are developmentally important homeodomain proteins. Our data also indicate that OCT4, SOX2, and NANOG collaborate to form regulatory circuitry consisting of autoregulatory and feedforward loops. These results provide new insights into the transcriptional regulation of stem cells and reveal how OCT4, SOX2, and NANOG contribute to pluripotency and self-renewal.
Oct4 exerts a dose-dependent dual action, as both a gatekeeper for stem cell pluripotency and in driving cells toward specific lineages. Here, we identify the molecular mechanism underlying this dual function. BMP2- or transgene-induced Oct4 up-regulation drives human embryonic and induced pluripotent stem cells to become cardiac progenitors. When embryonic stem cell pluripotency is achieved, Oct4 switches from the Sox2 to the Sox17 promoter. This switch allows the cells to turn off the pluripotency Oct4-Sox2 loop and to turn on the Sox17 promoter. This powerful process generates a subset of endoderm-expressing Sox17 and Hex, both regulators of paracrine signals for cardiogenesis (i.e., Wnt, BMP2) released into the medium surrounding colonies of embryonic stem cells. Our data thus reveal a novel molecular Oct4- and Sox17-mediated mechanism that disrupts the stem cell microenvironment favoring pluripotency to provide a novel paracrine endodermal environment in which cell lineage is determined and commits the cells to a cardiogenic fate.
Interacting selectively and non-covalently with a DNA region that regulates the transcription of a region of DNA, which may be a gene, cistron, or operon. Binding may occur as a sequence specific interaction or as an interaction observed only once a factor has been recruited to the DNA by other factors.
Oct4 exerts a dose-dependent dual action, as both a gatekeeper for stem cell pluripotency and in driving cells toward specific lineages. Here, we identify the molecular mechanism underlying this dual function. BMP2- or transgene-induced Oct4 up-regulation drives human embryonic and induced pluripotent stem cells to become cardiac progenitors. When embryonic stem cell pluripotency is achieved, Oct4 switches from the Sox2 to the Sox17 promoter. This switch allows the cells to turn off the pluripotency Oct4-Sox2 loop and to turn on the Sox17 promoter. This powerful process generates a subset of endoderm-expressing Sox17 and Hex, both regulators of paracrine signals for cardiogenesis (i.e., Wnt, BMP2) released into the medium surrounding colonies of embryonic stem cells. Our data thus reveal a novel molecular Oct4- and Sox17-mediated mechanism that disrupts the stem cell microenvironment favoring pluripotency to provide a novel paracrine endodermal environment in which cell lineage is determined and commits the cells to a cardiogenic fate.
POU transcription factor OCT4 not only plays an essential role in maintaining the pluripotent and self-renewing state of embryonic stem (ES) cells but also acts as a cell fate determinant through a gene dosage effect. However, the molecular mechanisms that control the intracellular OCT4 protein level remain elusive. Here, we report that human WWP2, an E3 ubiquitin (Ub)-protein ligase, interacts with OCT4 specifically through its WW domain and enhances Ub modification of OCT4 both in vitro and in vivo. We first demonstrated that endogenous OCT4 in human ES cells can be post-translationally modified by Ub. Furthermore, we found that WWP2 promoted degradation of OCT4 through the 26S proteasome in a dosage-dependent manner, and the active site cysteine residue of WWP2 was required for both its enzymatic activity and proteolytic effect on OCT4. Remarkably, our data show that the endogenous OCT4 protein level was significantly elevated when WWP2 expression was downregulated by specific RNA interference (RNAi), suggesting that WWP2 is an important regulator for maintaining a proper OCT4 protein level in human ES cells. Moreover, northern blot analysis showed that the WWP2 transcript was widely present in diverse human tissues/organs and highly expressed in undifferentiated human ES cells. However, its expression level was quickly decreased after human ES cells differentiated, indicating that WWP2 expression might be developmentally regulated. Our findings demonstrate that WWP2 is an important regulator of the OCT4 protein level in human ES cells.
Oct4 is a mammalian POU transcription factor expressed by early embryo cells and germ cells. We report that the activity of Oct4 is essential for the identity of the pluripotential founder cell population in the mammalian embryo. Oct4-deficient embryos develop to the blastocyst stage, but the inner cell mass cells are not pluripotent. Instead, they are restricted to differentiation along the extraembryonic trophoblast lineage. Furthermore, in the absence of a true inner cell mass, trophoblast proliferation is not maintained in Oct4-/- embryos. Expansion of trophoblast precursors is restored, however, by an Oct4 target gene product, fibroblast growth factor-4. Therefore, Oct4 also determines paracrine growth factor signaling from stem cells to the trophectoderm.
The process whose specific outcome is the progression of the blastocyst over time, from its formation to the mature structure. The mammalian blastocyst is a hollow ball of cells containing two cell types, the inner cell mass and the trophectoderm.
A series of molecular signals initiated by the binding of a member of the BMP (bone morphogenetic protein) family to a receptor on the surface of a target cell, which contributes to heart induction.
Oct4 exerts a dose-dependent dual action, as both a gatekeeper for stem cell pluripotency and in driving cells toward specific lineages. Here, we identify the molecular mechanism underlying this dual function. BMP2- or transgene-induced Oct4 up-regulation drives human embryonic and induced pluripotent stem cells to become cardiac progenitors. When embryonic stem cell pluripotency is achieved, Oct4 switches from the Sox2 to the Sox17 promoter. This switch allows the cells to turn off the pluripotency Oct4-Sox2 loop and to turn on the Sox17 promoter. This powerful process generates a subset of endoderm-expressing Sox17 and Hex, both regulators of paracrine signals for cardiogenesis (i.e., Wnt, BMP2) released into the medium surrounding colonies of embryonic stem cells. Our data thus reveal a novel molecular Oct4- and Sox17-mediated mechanism that disrupts the stem cell microenvironment favoring pluripotency to provide a novel paracrine endodermal environment in which cell lineage is determined and commits the cells to a cardiogenic fate.
The process involved in cardiac cell fate commitment. Once determination has taken place, a cell becomes committed to differentiate down a particular pathway regardless of its environment.
Oct4 exerts a dose-dependent dual action, as both a gatekeeper for stem cell pluripotency and in driving cells toward specific lineages. Here, we identify the molecular mechanism underlying this dual function. BMP2- or transgene-induced Oct4 up-regulation drives human embryonic and induced pluripotent stem cells to become cardiac progenitors. When embryonic stem cell pluripotency is achieved, Oct4 switches from the Sox2 to the Sox17 promoter. This switch allows the cells to turn off the pluripotency Oct4-Sox2 loop and to turn on the Sox17 promoter. This powerful process generates a subset of endoderm-expressing Sox17 and Hex, both regulators of paracrine signals for cardiogenesis (i.e., Wnt, BMP2) released into the medium surrounding colonies of embryonic stem cells. Our data thus reveal a novel molecular Oct4- and Sox17-mediated mechanism that disrupts the stem cell microenvironment favoring pluripotency to provide a novel paracrine endodermal environment in which cell lineage is determined and commits the cells to a cardiogenic fate.
Oct4 exerts a dose-dependent dual action, as both a gatekeeper for stem cell pluripotency and in driving cells toward specific lineages. Here, we identify the molecular mechanism underlying this dual function. BMP2- or transgene-induced Oct4 up-regulation drives human embryonic and induced pluripotent stem cells to become cardiac progenitors. When embryonic stem cell pluripotency is achieved, Oct4 switches from the Sox2 to the Sox17 promoter. This switch allows the cells to turn off the pluripotency Oct4-Sox2 loop and to turn on the Sox17 promoter. This powerful process generates a subset of endoderm-expressing Sox17 and Hex, both regulators of paracrine signals for cardiogenesis (i.e., Wnt, BMP2) released into the medium surrounding colonies of embryonic stem cells. Our data thus reveal a novel molecular Oct4- and Sox17-mediated mechanism that disrupts the stem cell microenvironment favoring pluripotency to provide a novel paracrine endodermal environment in which cell lineage is determined and commits the cells to a cardiogenic fate.
The cell fate determination process that results in a cell becoming capable of differentiating autonomously into an endoderm cell in an environment that is neutral with respect to the developmental pathway; upon specification, the cell fate can be reversed.
Cardiomyocyte proliferation is high in early development and decreases progressively with gestation, resulting in the lack of a robust cardiomyocyte proliferative response in the adult heart after injury. Little is understood about how both cell-autonomous and nonautonomous signals are integrated to regulate the balance of cardiomyocyte proliferation during development. In this study, we show that a single transcription factor, Foxp1, can control the balance of cardiomyocyte proliferation during development by targeting different pathways in the endocardium and myocardium. Endocardial loss of Foxp1 results in decreased Fgf3/Fgf16/Fgf17/Fgf20 expression in the heart, leading to reduced cardiomyocyte proliferation. This loss of myocardial proliferation can be rescued by exogenous Fgf20, and is mediated, in part, by Foxp1 repression of Sox17. In contrast, myocardial-specific loss of Foxp1 results in increased cardiomyocyte proliferation and decreased differentiation, leading to increased myocardial mass and neonatal demise. We show that Nkx2.5 is a direct target of Foxp1 repression, and Nkx2.5 expression is increased in Foxp1-deficient myocardium. Moreover, transgenic overexpression of Nkx2.5 leads to increased cardiomyocyte proliferation and increased ventricular mass, similar to the myocardial-specific loss of Foxp1. These data show that Foxp1 coordinates the balance of cardiomyocyte proliferation and differentiation through cell lineage-specific regulation of Fgf ligand and Nkx2.5 expression.
Any process that decreases the rate, frequency, or extent of the downregulation of gene expression through the action of microRNAs (miRNAs), endogenous 21-24 nucleotide small RNAs processed from stem-loop RNA precursors (pre-miRNAs). Once incorporated into a RNA-induced silencing complex (RISC), miRNAs can downregulate gene expression by either of two posttranscriptional mechanisms: mRNA cleavage or translational repression.
Evidence
1:
Inferred from Mutant PhenotypeUniProtKB
MicroRNAs (miRNAs) are posttranscriptional modulators of gene expression and play an important role in many developmental processes. We report here that expression of microRNA-145 (miR-145) is low in self-renewing human embryonic stem cells (hESCs) but highly upregulated during differentiation. We identify the pluripotency factors OCT4, SOX2, and KLF4 as direct targets of miR-145 and show that endogenous miR-145 represses the 3' untranslated regions of OCT4, SOX2, and KLF4. Increased miR-145 expression inhibits hESC self-renewal, represses expression of pluripotency genes, and induces lineage-restricted differentiation. Loss of miR-145 impairs differentiation and elevates OCT4, SOX2, and KLF4. Furthermore, we find that the miR-145 promoter is bound and repressed by OCT4 in hESCs. This work reveals a direct link between the core reprogramming factors and miR-145 and uncovers a double-negative feedback loop involving OCT4, SOX2, KLF4, and miR-145.
Oct4 exerts a dose-dependent dual action, as both a gatekeeper for stem cell pluripotency and in driving cells toward specific lineages. Here, we identify the molecular mechanism underlying this dual function. BMP2- or transgene-induced Oct4 up-regulation drives human embryonic and induced pluripotent stem cells to become cardiac progenitors. When embryonic stem cell pluripotency is achieved, Oct4 switches from the Sox2 to the Sox17 promoter. This switch allows the cells to turn off the pluripotency Oct4-Sox2 loop and to turn on the Sox17 promoter. This powerful process generates a subset of endoderm-expressing Sox17 and Hex, both regulators of paracrine signals for cardiogenesis (i.e., Wnt, BMP2) released into the medium surrounding colonies of embryonic stem cells. Our data thus reveal a novel molecular Oct4- and Sox17-mediated mechanism that disrupts the stem cell microenvironment favoring pluripotency to provide a novel paracrine endodermal environment in which cell lineage is determined and commits the cells to a cardiogenic fate.
Any process that increases the rate, frequency or extent of SMAD protein import into the nucleus, i.e. the directed movement of a SMAD proteins from the cytoplasm into the nucleus. Pathway-restricted SMAD proteins and common-partner SMAD proteins are involved in the transforming growth factor beta receptor signaling pathways.
Oct4 exerts a dose-dependent dual action, as both a gatekeeper for stem cell pluripotency and in driving cells toward specific lineages. Here, we identify the molecular mechanism underlying this dual function. BMP2- or transgene-induced Oct4 up-regulation drives human embryonic and induced pluripotent stem cells to become cardiac progenitors. When embryonic stem cell pluripotency is achieved, Oct4 switches from the Sox2 to the Sox17 promoter. This switch allows the cells to turn off the pluripotency Oct4-Sox2 loop and to turn on the Sox17 promoter. This powerful process generates a subset of endoderm-expressing Sox17 and Hex, both regulators of paracrine signals for cardiogenesis (i.e., Wnt, BMP2) released into the medium surrounding colonies of embryonic stem cells. Our data thus reveal a novel molecular Oct4- and Sox17-mediated mechanism that disrupts the stem cell microenvironment favoring pluripotency to provide a novel paracrine endodermal environment in which cell lineage is determined and commits the cells to a cardiogenic fate.
Cardiomyocyte proliferation is high in early development and decreases progressively with gestation, resulting in the lack of a robust cardiomyocyte proliferative response in the adult heart after injury. Little is understood about how both cell-autonomous and nonautonomous signals are integrated to regulate the balance of cardiomyocyte proliferation during development. In this study, we show that a single transcription factor, Foxp1, can control the balance of cardiomyocyte proliferation during development by targeting different pathways in the endocardium and myocardium. Endocardial loss of Foxp1 results in decreased Fgf3/Fgf16/Fgf17/Fgf20 expression in the heart, leading to reduced cardiomyocyte proliferation. This loss of myocardial proliferation can be rescued by exogenous Fgf20, and is mediated, in part, by Foxp1 repression of Sox17. In contrast, myocardial-specific loss of Foxp1 results in increased cardiomyocyte proliferation and decreased differentiation, leading to increased myocardial mass and neonatal demise. We show that Nkx2.5 is a direct target of Foxp1 repression, and Nkx2.5 expression is increased in Foxp1-deficient myocardium. Moreover, transgenic overexpression of Nkx2.5 leads to increased cardiomyocyte proliferation and increased ventricular mass, similar to the myocardial-specific loss of Foxp1. These data show that Foxp1 coordinates the balance of cardiomyocyte proliferation and differentiation through cell lineage-specific regulation of Fgf ligand and Nkx2.5 expression.
Oct4 exerts a dose-dependent dual action, as both a gatekeeper for stem cell pluripotency and in driving cells toward specific lineages. Here, we identify the molecular mechanism underlying this dual function. BMP2- or transgene-induced Oct4 up-regulation drives human embryonic and induced pluripotent stem cells to become cardiac progenitors. When embryonic stem cell pluripotency is achieved, Oct4 switches from the Sox2 to the Sox17 promoter. This switch allows the cells to turn off the pluripotency Oct4-Sox2 loop and to turn on the Sox17 promoter. This powerful process generates a subset of endoderm-expressing Sox17 and Hex, both regulators of paracrine signals for cardiogenesis (i.e., Wnt, BMP2) released into the medium surrounding colonies of embryonic stem cells. Our data thus reveal a novel molecular Oct4- and Sox17-mediated mechanism that disrupts the stem cell microenvironment favoring pluripotency to provide a novel paracrine endodermal environment in which cell lineage is determined and commits the cells to a cardiogenic fate.
Any process that modulates the frequency, rate or extent of gene expression. Gene expression is the process in which a gene's coding sequence is converted into a mature gene product or products (proteins or RNA). This includes the production of an RNA transcript as well as any processing to produce a mature RNA product or an mRNA (for protein-coding genes) and the translation of that mRNA into protein. Some protein processing events may be included when they are required to form an active form of a product from an inactive precursor form.
Evidence
1:
Inferred from Mutant PhenotypeUniProtKB
Human embryonic stem (hES) cells, derived from blastocysts, are capable of unlimited self-renewal and differentiation into all cell lineages of the body. Because of their pluripotent nature, hES cells are valuable tools for understanding human development and advancing the field of regenerative medicine. However, one key to harnessing the therapeutic power of hES cells for biomedical applications begins with determining how these cells maintain their pluripotent and undifferentiated state. Studies in mice have implicated three factors in regulating pluripotency in embryonic stem cells, Oct4, Nanog, and Sox2. However, significant differences in growth regulation between mouse embryonic stem and hES cells have been identified, suggesting a need to determine when and how factors work in hES cells. To date, the transcription factors Oct4 and Nanog have been identified as critical regulators of stem cell fate by functional studies in hES cells. To determine the role of Sox2 in maintaining hES cell pluripotency and self-renewal, we used RNA interference to specifically knock down Sox2 gene expression. Reduction of Sox2 expression in hES cells results in loss of the undifferentiated stem cell state, as indicated by a change in cell morphology, altered stem cell marker expression, and increased expression of trophectoderm markers. In addition, knockdown of Sox2 results in reduced expression of several key stem cell factors, including Oct4 and Nanog, linking these three factors together in a pluripotent regulatory network. Disclosure of potential conflicts of interest is found at the end of this article.
Isoform
A
Regulation of heart induction by regulation of canonical Wnt receptor signaling pathwaydefinition[GO:0090081]
Any process that modulates the rate, frequency or extent of canonical Wnt receptor signaling pathway that regulates heart induction. Canonical Wnt receptor signaling pathway involved in heart induction is the series of molecular signals initiated by binding of Wnt protein to a frizzled family receptor on the surface of the target cell, followed by relaying of the signal via beta-catenin, and ending with a change in transcription of target genes.
Oct4 exerts a dose-dependent dual action, as both a gatekeeper for stem cell pluripotency and in driving cells toward specific lineages. Here, we identify the molecular mechanism underlying this dual function. BMP2- or transgene-induced Oct4 up-regulation drives human embryonic and induced pluripotent stem cells to become cardiac progenitors. When embryonic stem cell pluripotency is achieved, Oct4 switches from the Sox2 to the Sox17 promoter. This switch allows the cells to turn off the pluripotency Oct4-Sox2 loop and to turn on the Sox17 promoter. This powerful process generates a subset of endoderm-expressing Sox17 and Hex, both regulators of paracrine signals for cardiogenesis (i.e., Wnt, BMP2) released into the medium surrounding colonies of embryonic stem cells. Our data thus reveal a novel molecular Oct4- and Sox17-mediated mechanism that disrupts the stem cell microenvironment favoring pluripotency to provide a novel paracrine endodermal environment in which cell lineage is determined and commits the cells to a cardiogenic fate.
Any process that modulates the rate, frequency, or extent of the repression of transcription by methylation of DNA, leading to the formation of heterochromatin.
Oct4 exerts a dose-dependent dual action, as both a gatekeeper for stem cell pluripotency and in driving cells toward specific lineages. Here, we identify the molecular mechanism underlying this dual function. BMP2- or transgene-induced Oct4 up-regulation drives human embryonic and induced pluripotent stem cells to become cardiac progenitors. When embryonic stem cell pluripotency is achieved, Oct4 switches from the Sox2 to the Sox17 promoter. This switch allows the cells to turn off the pluripotency Oct4-Sox2 loop and to turn on the Sox17 promoter. This powerful process generates a subset of endoderm-expressing Sox17 and Hex, both regulators of paracrine signals for cardiogenesis (i.e., Wnt, BMP2) released into the medium surrounding colonies of embryonic stem cells. Our data thus reveal a novel molecular Oct4- and Sox17-mediated mechanism that disrupts the stem cell microenvironment favoring pluripotency to provide a novel paracrine endodermal environment in which cell lineage is determined and commits the cells to a cardiogenic fate.
The transcription factors OCT4, SOX2, and NANOG have essential roles in early development and are required for the propagation of undifferentiated embryonic stem (ES) cells in culture. To gain insights into transcriptional regulation of human ES cells, we have identified OCT4, SOX2, and NANOG target genes using genome-scale location analysis. We found, surprisingly, that OCT4, SOX2, and NANOG co-occupy a substantial portion of their target genes. These target genes frequently encode transcription factors, many of which are developmentally important homeodomain proteins. Our data also indicate that OCT4, SOX2, and NANOG collaborate to form regulatory circuitry consisting of autoregulatory and feedforward loops. These results provide new insights into the transcriptional regulation of stem cells and reveal how OCT4, SOX2, and NANOG contribute to pluripotency and self-renewal.
Any process that results in a change in state or activity of a cell or an organism (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of a stimulus indicating damage to the organism.
Evidence
1:
Inferred from Expression PatternUniProtKB
PURPOSE: The corneal endothelium is a monolayer of cells in the posterior cornea that is responsible for maintaining a clear cornea. Corneal endothelial cells may be induced to divide, but it has been held that they do not divide in the normal cornea of an adult human. Some studies have suggested that a stem cell population for the corneal endothelium exists. This population could give rise to mature corneal endothelial cells and may reside either in the peripheral corneal endothelium or in the adjacent posterior limbus. This study was initiated to demonstrate the presence of such stem cells in the region of the posterior limbus and to show the response of these cells to corneal wounding. METHODS: Unwounded and wounded corneas with their attached limbal sections were analyzed by immunofluorescence for the presence of nestin, telomerase, Oct-3/4, Pax-6, Wnt-1, and Sox-2. Alkaline phosphatase activity was observed with an enzyme-based reaction that produced a fluorescent product. RESULTS: In the unwounded cornea, stem cell markers nestin, alkaline phosphatase, and telomerase were found in the trabecular meshwork (TM) and in the transition zone between the TM and the corneal endothelial periphery (including Schwalbe's line). Telomerase was also present in the peripheral corneal endothelium. When wounded corneas and their attached limbii were tested, the same markers were found. However, after wounding, additional stem cell markers, Oct-3/4 (in the TM) and Wnt-1 (in both the TM and the transition zone), appeared. Moreover, the differentiation markers Pax-6 and Sox-2 were seen. Pax-6 and Sox-2 were also manifest in the peripheral endothelium post-wounding. CONCLUSIONS: Well documented specific stem cell markers were found in the TM and the transition zone of the human posterior limbus. Wounding of the corneas activated the production of two additional stem cell markers (Oct-3/4, Wnt-1) as well as two differentiation markers (Pax-6, Sox-2), the latter of which also appeared in the corneal endothelial periphery. It is suggested that stem cells reside in the posterior limbus and respond to corneal wounding to initiate an endothelial repair process. The stem cells may also contribute to a normal, slow replacement of corneal endothelial cells.
The process in which an organism retains a population of somatic stem cells, undifferentiated cells in the embryo or adult which can undergo unlimited division and give rise to cell types of the body other than those of the germ-line.
Evidence
1:
Inferred from Mutant PhenotypeUniProtKB
Human embryonic stem (hES) cells, derived from blastocysts, are capable of unlimited self-renewal and differentiation into all cell lineages of the body. Because of their pluripotent nature, hES cells are valuable tools for understanding human development and advancing the field of regenerative medicine. However, one key to harnessing the therapeutic power of hES cells for biomedical applications begins with determining how these cells maintain their pluripotent and undifferentiated state. Studies in mice have implicated three factors in regulating pluripotency in embryonic stem cells, Oct4, Nanog, and Sox2. However, significant differences in growth regulation between mouse embryonic stem and hES cells have been identified, suggesting a need to determine when and how factors work in hES cells. To date, the transcription factors Oct4 and Nanog have been identified as critical regulators of stem cell fate by functional studies in hES cells. To determine the role of Sox2 in maintaining hES cell pluripotency and self-renewal, we used RNA interference to specifically knock down Sox2 gene expression. Reduction of Sox2 expression in hES cells results in loss of the undifferentiated stem cell state, as indicated by a change in cell morphology, altered stem cell marker expression, and increased expression of trophectoderm markers. In addition, knockdown of Sox2 results in reduced expression of several key stem cell factors, including Oct4 and Nanog, linking these three factors together in a pluripotent regulatory network. Disclosure of potential conflicts of interest is found at the end of this article.
Oct4 exerts a dose-dependent dual action, as both a gatekeeper for stem cell pluripotency and in driving cells toward specific lineages. Here, we identify the molecular mechanism underlying this dual function. BMP2- or transgene-induced Oct4 up-regulation drives human embryonic and induced pluripotent stem cells to become cardiac progenitors. When embryonic stem cell pluripotency is achieved, Oct4 switches from the Sox2 to the Sox17 promoter. This switch allows the cells to turn off the pluripotency Oct4-Sox2 loop and to turn on the Sox17 promoter. This powerful process generates a subset of endoderm-expressing Sox17 and Hex, both regulators of paracrine signals for cardiogenesis (i.e., Wnt, BMP2) released into the medium surrounding colonies of embryonic stem cells. Our data thus reveal a novel molecular Oct4- and Sox17-mediated mechanism that disrupts the stem cell microenvironment favoring pluripotency to provide a novel paracrine endodermal environment in which cell lineage is determined and commits the cells to a cardiogenic fate.
MicroRNAs (miRNAs) are posttranscriptional modulators of gene expression and play an important role in many developmental processes. We report here that expression of microRNA-145 (miR-145) is low in self-renewing human embryonic stem cells (hESCs) but highly upregulated during differentiation. We identify the pluripotency factors OCT4, SOX2, and KLF4 as direct targets of miR-145 and show that endogenous miR-145 represses the 3' untranslated regions of OCT4, SOX2, and KLF4. Increased miR-145 expression inhibits hESC self-renewal, represses expression of pluripotency genes, and induces lineage-restricted differentiation. Loss of miR-145 impairs differentiation and elevates OCT4, SOX2, and KLF4. Furthermore, we find that the miR-145 promoter is bound and repressed by OCT4 in hESCs. This work reveals a direct link between the core reprogramming factors and miR-145 and uncovers a double-negative feedback loop involving OCT4, SOX2, KLF4, and miR-145.
The synthesis of RNA from a DNA template by RNA polymerase II, originating at an RNA polymerase II promoter. Includes transcription of messenger RNA (mRNA) and certain small nuclear RNAs (snRNAs).
ISSOrtholog Curator
Note
Several pseudogenes of POU5F1 have been described on chromosomes 1, 3, 8, 10 and 12. 2 of them, localized in chromosomes 8 and 10, are transcribed in cancer tissues but not in normal ones and may be involved in the regulation of POU5F1 gene activity in carcinogenesis.
Protein involved in the transfer of genetic information from DNA to messenger RNA (mRNA) by DNA-directed RNA polymerase. In the case of some RNA viruses, protein involved in the transfer of genetic information from RNA to messenger RNA (mRNA) by RNA-directed RNA polymerase.
Protein involved in development, the process whereby a multicellular organism develops from its early immature forms, e.g., zygote, larva, embryo, into an adult.
A reference proteome is a set of protein sequences derived from a complete proteome which constitutes a defined standard for a particular user community. Reference proteomes are manually defined according to a number of criteria. They cover the proteomes of well- studied model organisms and other proteomes of interest for biomedical and biotechnological research. Reference proteomes have been selected to provide broad coverage of the tree of life, and constitute a representative cross-section of the taxonomic diversity to be found within UniProtKB.
My favorites 
My labels 
Login
