The putative nuclear receptor mediator TIF1alpha is tightly associated with euchromatin

1999 ◽  
Vol 112 (11) ◽  
pp. 1671-1683 ◽  
Author(s):  
E. Remboutsika ◽  
Y. Lutz ◽  
A. Gansmuller ◽  
J.L. Vonesch ◽  
R. Losson ◽  
...  

Ligand-dependent transcriptional regulation by nuclear receptors is believed to be mediated by intermediary factors (TIFs) acting on remodelling of the chromatin structure and/or the activity of the transcriptional machinery. The putative transcriptional mediator TIF1alpha is a nuclear protein kinase that has been identified via its interaction with liganded nuclear receptors, including retinoic acid (RAR), retinoid X (RXR) and estrogen (ER) receptors. Here, we demonstrate that TIF1alpha is a non-histone chromosomal protein tightly associated with highly accessible euchromatic regions of the genome. Immunofluorescence confocal microscopy reveals that TIF1alpha exhibits a finely granular distribution in euchromatin of interphase nuclei, while it is mostly excluded from condensed chromatin and metaphase chromosomes. Immunoelectron microscopy shows that, in contrast to the heterochromatin protein HP1alpha, most of TIF1alpha is associated with euchromatin, where it is preferentially localised on regions known to be sites for RNA polymerase II (perichromatin fibrils and borders between euchromatin and heterochromatin). Early mouse embryos as well as embryonal carcinoma (EC) and embryonic stem (ES) cells express high levels of TIF1alpha. These levels dramatically decrease during organogenesis and upon differentiation of P19 EC cells, indicating that TIF1alpha is preferentially expressed in undifferentiated pluripotent cells in the course of development. Therefore, TIF1alpha could belong to a novel class of chromatin-associated TIFs that facilitate the access of transregulators (e.g. liganded nuclear receptors) to their cognate sites in target genes, thereby participitating in the epigenetic control of transcription during embryonic development and cell differentiation.

Endocrinology ◽  
2005 ◽  
Vol 146 (2) ◽  
pp. 776-783 ◽  
Author(s):  
Yan-Yun Liu ◽  
Gregory A. Brent

Abstract T3 is required for normal early development, but relatively few T3-responsive target genes have been identified. In general, in vitro stem cell differentiation techniques stimulate a wide range of developmental programs, including thyroid hormone receptor (TR) pathways. We developed several in vitro stem cell models to more specifically identify TR-mediated gene expression in early development. We found that embryonic carcinoma (EC) cells have reduced T3 nuclear binding capacity and only modestly express the known T3 target genes, neurogranin (RC3) and Ca2+/calmodulin-dependent protein kinase IV (CaMKIV), in response to T3. Full T3 induction in transient transfection of EC cells was restored with cotransfection of a TR expression vector. We, therefore, performed gene expression profiles in wild-type embryonic stem (ES) cells compared with expression in cells with deficient (EC) or mutant TR (TRα P398H mutant ES cells), to identify T3 target genes. T3 stimulation of wild-type ES cells altered mRNA expression of 610 known genes (26% of those studied), although only approximately 60 genes (1%) met criteria for direct T3 stimulation based on the magnitude of induction and requirement for the presence of TR. We selected five candidate T3 target genes, neurexophilin 2, spermatid perinuclear RNA-binding protein (SPNR), kallikrein-binding protein (KBP), prostate-specific membrane antigen (PSMA), and synaptotagmin II, for more detailed study. T3 responsiveness of these genes was evaluated in both in vitro endogenous gene expression and in vivo mouse model systems. These genes identified in a novel stem cell system, including those induced and repressed in response to T3, may mediate thyroid hormone actions in early development.


2021 ◽  
Vol 7 (4) ◽  
pp. eabb9149
Author(s):  
Zhijun Huang ◽  
Jiyoung Yu ◽  
Wei Cui ◽  
Benjamin K. Johnson ◽  
Kyunggon Kim ◽  
...  

5-Methylcytosine (5mC) oxidases, the ten-eleven translocation (TET) proteins, initiate DNA demethylation, but it is unclear how 5mC oxidation is regulated. We show that the protein SMCHD1 (structural maintenance of chromosomes flexible hinge domain containing 1) is found in complexes with TET proteins and negatively regulates TET activities. Removal of SMCHD1 from mouse embryonic stem (ES) cells induces DNA hypomethylation, preferentially at SMCHD1 target sites and accumulation of 5-hydroxymethylcytosine (5hmC), along with promoter demethylation and activation of the Dux double-homeobox gene. In the absence of SMCHD1, ES cells acquire a two-cell (2c) embryo–like state characterized by activation of an early embryonic transcriptome that is substantially imposed by Dux. Using Smchd1/Tet1/Tet2/Tet3 quadruple-knockout cells, we show that DNA demethylation, activation of Dux, and other genes upon SMCHD1 loss depend on TET proteins. These data identify SMCHD1 as an antagonist of the 2c-like state of ES cells and of TET-mediated DNA demethylation.


Endocrinology ◽  
2011 ◽  
Vol 152 (7) ◽  
pp. 2870-2882 ◽  
Author(s):  
Unmesh Jadhav ◽  
J. Larry Jameson

Steroidogenic factor 1 (SF-1) is essential for the development and function of steroidogenic tissues. Stable incorporation of SF-1 into embryonic stem cells (SF-1-ES cells) has been shown to prime the cells for steroidogenesis. When provided with exogenous cholesterol substrate, and after treatment with retinoic acid and cAMP, SF-1-ES cells produce progesterone but do not produce other steroids such as cortisol, estradiol, or testosterone. In this study, we explored culture conditions that optimize SF-1-mediated differentiation of ES cells into defined steroidogenic lineages. When embryoid body formation was used to facilitate cell lineage differentiation, SF-1-ES cells were found to be restricted in their differentiation, with fewer cells entering neuronal pathways and a larger fraction entering the steroidogenic lineage. Among the differentiation protocols tested, leukemia inhibitory factor (LIF) removal, followed by prolonged cAMP treatment was most efficacious for inducing steroidogenesis in SF-1-ES cells. In this protocol, a subset of SF-1-ES cells survives after LIF withdrawal, undergoes morphologic differentiation, and recovers proliferative capacity. These cells are characterized by induction of steroidogenic enzyme genes, use of de novo cholesterol, and production of multiple steroids including estradiol and testosterone. Microarray studies identified additional pathways associated with SF-1 mediated differentiation. Using biotinylated SF-1 in chromatin immunoprecipitation assays, SF-1 was shown to bind directly to multiple target genes, with induction of binding to some targets after steroidogenic treatment. These studies indicate that SF-1 expression, followed by LIF removal and treatment with cAMP drives ES cells into a steroidogenic pathway characteristic of gonadal steroid-producing cells.


2005 ◽  
Vol 280 (16) ◽  
pp. 16484-16498 ◽  
Author(s):  
Eduardo Martinez-Ceballos ◽  
Pierre Chambon ◽  
Lorraine J. Gudas

Homeobox (Hox) genes encode a family of transcription factors that regulate embryonic patterning and organogenesis. In embryos, alterations of the normal pattern of Hox gene expression result in homeotic transformations and malformations. Disruption of theHoxa1gene, the most 3′ member of the Hoxa cluster and a retinoic acid (RA) direct target gene, results in abnormal ossification of the skull, hindbrain, and inner ear deficiencies, and neonatal death. We have generated Hoxa1-/-embryonic stem (ES) cells (named Hoxa1-15) from Hoxa1-/-mutant blastocysts to study the Hoxa1 signaling pathway. We have characterized in detail these Hoxa1-/-ES cells by performing microarray analyses, and by this technique we have identified a number of putative Hoxa-1 target genes, including genes involved in bone development (e.g. Col1a1,Postn/Osf2, and the bone sialoprotein gene orBSP), genes that are expressed in the developing brain (e.g. Nnat,Wnt3a,BDNF,RhoB, andGbx2), and genes involved in various cellular processes (e.g. M-RAS,Sox17,Cdkn2b,LamA1,Col4a1,Foxa2,Foxq1,Klf5, andIgf2). Cell proliferation assays and Northern blot analyses of a number of ES cell markers (e.g. Rex1,Oct3/4,Fgf4, andBmp4) suggest that the Hoxa1 protein plays a role in the inhibition of cell proliferation by RA in ES cells. Additionally, Hoxa1-/-ES cells express high levels of various endodermal markers, includingGata4andDab2, and express much lessFgf5after leukemia inhibitory factor (LIF) withdrawal. Finally, we propose a model in which the Hoxa1 protein mediates repression of endodermal differentiation while promoting expression of ectodermal and mesodermal characteristics.


2015 ◽  
Vol 6 (1) ◽  
Author(s):  
Paulina A. Latos ◽  
Angela Goncalves ◽  
David Oxley ◽  
Hisham Mohammed ◽  
Ernest Turro ◽  
...  

Abstract Esrrb (oestrogen-related receptor beta) is a transcription factor implicated in embryonic stem (ES) cell self-renewal, yet its knockout causes intrauterine lethality due to defects in trophoblast development. Here we show that in trophoblast stem (TS) cells, Esrrb is a downstream target of fibroblast growth factor (Fgf) signalling and is critical to drive TS cell self-renewal. In contrast to its occupancy of pluripotency-associated loci in ES cells, Esrrb sustains the stemness of TS cells by direct binding and regulation of TS cell-specific transcription factors including Elf5 and Eomes. To elucidate the mechanisms whereby Esrrb controls the expression of its targets, we characterized its TS cell-specific interactome using mass spectrometry. Unlike in ES cells, Esrrb interacts in TS cells with the histone demethylase Lsd1 and with the RNA Polymerase II-associated Integrator complex. Our findings provide new insights into both the general and context-dependent wiring of transcription factor networks in stem cells by master transcription factors.


2000 ◽  
Vol 78 (6) ◽  
pp. 703-713 ◽  
Author(s):  
Sharon Soodeen-Karamath ◽  
Ann M Verrinder Gibbins

Stathmin, which functions as an intracellular relay in signal transduction pathways, has been suggested as a potential indicator of pluripotent cells in the early mouse embryo. In this study, chicken stathmin cDNA and genomic DNA were analyzed. In mammals stathmin consists of five exons and four introns; exons 3, 4, and 5 in the mammalian stathmin gene are equivalent to one relatively large exon in the chicken stathmin gene. Introns equivalent to introns 3 and 4 in the mammalian stathmin gene are not present in the counterpart gene in chickens and, although intron 2 was shown to be present in both mammals and birds, it is smaller in the chicken stathmin gene. Despite differences in the genomic organization of the gene and its smaller size in chickens compared with that in humans and mice, similarities in the coding sequences and in the expression of the chicken and mouse stathmin genes at certain stages of embryo development, as determined by whole-mount in situ hybridization experiments, suggest that their products are functional homologues. The argument is thus substantiated for further investigations into the use of regulatory regions of the stathmin gene in a system for the establishment of long-term cultures of germline competent chicken embryonic stem (ES) cells by the selective ablation of differentiated cells in culture using drug selection.Key words: stathmin, chicken, ES cells, oct 3/4.


2015 ◽  
Vol 47-48 ◽  
pp. 101-109 ◽  
Author(s):  
Silvia Muñoz-Descalzo ◽  
Anna-Katerina Hadjantonakis ◽  
Alfonso Martinez Arias

2018 ◽  
Author(s):  
Constantine Mylonas ◽  
Peter Tessarz

The conserved and essential histone chaperone FACT (Facilitates Chromatin Transcription) reorganizes nucleosomes during DNA transcription, replication and repair and ensures both, efficient elongation of RNA Pol II and nucleosome integrity. In mammalian cells, FACT is a heterodimer, consisting of SSRP1 and SUPT16. Here, we show that in contrast to yeast, FACT accumulates at the transcription start site of genes reminiscent of RNA Polymerase II profile. Depletion of FACT in mouse embryonic stem cells leads to up-regulation of pro-proliferative genes and key pluripotency factors concomitant with hyper-proliferation of mES cells. Using MNase-, ATAC-, and Nascent Elongating Transcript Sequencing (NET-seq) we show that up-regulation of genes coincides with loss of nucleosomes upstream of the TSS and concomitant increase in antisense transcription, indicating that FACT impacts the promoter architecture to regulate expression of these genes. Finally, we demonstrate a role for FACT in cell fate determination and show that FACT depletion primes ES cells for the neuronal lineage.


2021 ◽  
Author(s):  
Chengguo Yao ◽  
Yi Ran ◽  
Shanshan Huang ◽  
Junjie Shi ◽  
Qiumin Feng ◽  
...  

It has recently been shown that CFIm25, a canonical mRNA 3’ processing factor, could play a variety of physiological roles through its molecular function in the regulation of mRNA alternative polyadenylation (APA). Here, we used CRISPR/Cas9-mediated gene editing approach in human embryonic stem cells (hESCs) for CFIm25, and obtained three gene knockdown/mutant cell lines. CFIm25 gene editing resulted in higher proliferation rate and impaired differentiation potential for hESCs, with these effects likely to be directly regulated by the target genes, including the pluripotency factor rex1. Mechanistically, we unexpected found that perturbation in CFIm25 gene expression did not significantly affect cellular mRNA 3’ processing efficiency and APA profile. Rather, we provided evidences that CFIm25 may impact RNA polymerase II (RNAPII) occupancy at the body of transcribed genes, and promote the expression level of a group of transcripts associated with cellular proliferation and/or differentiation. Further study indicated that CFIm25 association with LEO1, an RNAPII associated factor, might contribute to the effect. Taken together, these results reveal novel mechanisms underlying CFIm25’s modulation in determination of cell fate, and provide evidence that the process of mammalian gene transcription may be regulated by an mRNA 3’ processing factor.


2018 ◽  
Vol 1 (3) ◽  
pp. e201800085 ◽  
Author(s):  
Constantine Mylonas ◽  
Peter Tessarz

The conserved and essential histone chaperone, facilitates chromatin transcription (FACT), reorganizes nucleosomes during DNA transcription, replication, and repair and ensures both efficient elongation of RNA Pol II and nucleosome integrity. In mammalian cells, FACT is a heterodimer, consisting of SSRP1 and SUPT16. Here, we show that in contrast to yeast, FACT accumulates at the transcription start site of genes reminiscent of RNA polymerase II profile. Depletion of FACT in mouse embryonic stem cells leads to deregulation of developmental and pro-proliferative genes concomitant with hyper-proliferation of mES cells. Using MNase-seq, Assay for Transposase-Accessible Chromatin sequencing, and nascent elongating transcript sequencing, we show that up-regulation of genes coincides with loss of nucleosomes upstream of the transcription start site and concomitant increase in antisense transcription, indicating that FACT impacts the promoter architecture to regulate the expression of these genes. Finally, we demonstrate a role for FACT in cell fate determination and show that FACT depletion primes embryonic stem cells for the neuronal lineage.


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