scholarly journals SUMO conjugation susceptibility of Akt/protein kinase B affects the expression of the pluripotency transcription factor Nanog in embryonic stem cells

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0254447
Author(s):  
Marcos Francia ◽  
Martin Stortz ◽  
Camila Vazquez Echegaray ◽  
Camila Oses ◽  
Paula Verneri ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Es Cells ◽  
Embryonic Stem ◽  
Dependent Manner ◽  
Cellular Functions ◽  
Cellular Processes ◽  
Sumo Conjugation ◽  
Heterologous System ◽  
Canonical Pathways ◽  
The Impact

Akt/PKB is a kinase involved in the regulation of a wide variety of cell processes. Its activity is modulated by diverse post-translational modifications (PTMs). Particularly, conjugation of the small ubiquitin-related modifier (SUMO) to this kinase impacts on multiple cellular functions, such as proliferation and splicing. In embryonic stem (ES) cells, this kinase is key for pluripotency maintenance. Among other functions, Akt is known to promote the expression of Nanog, a central pluripotency transcription factor (TF). However, the relevance of this specific PTM of Akt has not been previously analyzed in this context. In this work, we study the effect of Akt1 variants with differential SUMOylation susceptibility on the expression of Nanog. Our results demonstrate that both, the Akt1 capability of being modified by SUMO conjugation and a functional SUMO conjugase activity are required to induce Nanog gene expression. Likewise, we found that the common oncogenic E17K Akt1 mutant affected Nanog expression in ES cells also in a SUMOylatability dependent manner. Interestingly, this outcome takes places in ES cells but not in a non-pluripotent heterologous system, suggesting the presence of a crucial factor for this induction in ES cells. Remarkably, the two major candidate factors to mediate this induction, GSK3-β and Tbx3, are non-essential players of this effect, suggesting a complex mechanism probably involving non-canonical pathways. Furthermore, we found that Akt1 subcellular distribution does not depend on its SUMOylatability, indicating that Akt localization has no influence on the effect on Nanog, and that besides the membrane localization of E17K Akt mutant, SUMOylation is also required for its hyperactivity. Our results highlight the impact of SUMO conjugation in the function of a kinase relevant for a plethora of cellular processes, including the control of a key pluripotency TF.

Redirecting differentiation of hematopoietic progenitors by a transcription factor, GATA-2

Blood ◽  
2006 ◽  
Vol 107 (5) ◽  
pp. 1857-1863 ◽  
Author(s):  
Kenji Kitajima ◽  
Makoto Tanaka ◽  
Jie Zheng ◽  
Hilo Yen ◽  
Ayuko Sato ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Es Cells ◽  
Critical Role ◽  
Embryonic Stem ◽  
Erythroid Differentiation ◽  
Dependent Manner ◽  
Hematopoietic Differentiation ◽  
Macrophage Differentiation ◽  
Conditional Gene Expression

GATA-2 is a zinc finger transcription factor essential for differentiation of immature hematopoietic cells. We analyzed the function of GATA-2 by a combined method of tetracycline-dependent conditional gene expression and in vitro hematopoietic differentiation from mouse embryonic stem (ES) cells using OP9 stroma cells (OP9 system). In the presence of macrophage colony-stimulating factor (M-CSF), the OP9 system induced macrophage differentiation. GATA-2 expression in this system inhibited macrophage differentiation and redirected the fate of hematopoietic differentiation to other hematopoietic lineages. GATA-2 expression commencing at day 5 or day 6 induced megakaryocytic or erythroid differentiation, respectively. Expression levels of PU.1, a hematopoietic transcription factor that interferes with GATA-2, appeared to play a critical role in differentiation to megakaryocytic or erythroid lineages. Transcription of PU.1 was affected by histone acetylation induced by binding of GATA-2 to the PU.1 promoter region. This study demonstrates that the function of GATA-2 is modified in a context-dependent manner by expression of PU.1, which in turn is regulated by GATA-2.

scholarly journals Arginine Decarboxylase Is Essential for Pneumococcal Stress Responses

Pathogens ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 286
Author(s):  
Mary Frances Nakamya ◽  
Moses B. Ayoola ◽  
Leslie A. Shack ◽  
Mirghani Mohamed ◽  
Edwin Swiatlo ◽  
...  
Keyword(s):  
Stress Responses ◽  
Critical Role ◽  
Acid Stress ◽  
Arginine Decarboxylase ◽  
Arginine Deiminase ◽  
Dependent Manner ◽  
Cellular Processes ◽  
Opportunistic Human Pathogen ◽  
Thiol Peroxidase ◽  
The Impact

Polyamines such as putrescine, cadaverine, and spermidine are small cationic molecules that play significant roles in cellular processes, including bacterial stress responses and host–pathogen interactions. Streptococcus pneumoniae is an opportunistic human pathogen, which causes several diseases that account for significant morbidity and mortality worldwide. As it transits through different host niches, S. pneumoniae is exposed to and must adapt to different types of stress in the host microenvironment. We earlier reported that S. pneumoniae TIGR4, which harbors an isogenic deletion of an arginine decarboxylase (ΔspeA), an enzyme that catalyzes the synthesis of agmatine in the polyamine synthesis pathway, has a reduced capsule. Here, we report the impact of arginine decarboxylase deletion on pneumococcal stress responses. Our results show that ΔspeA is more susceptible to oxidative, nitrosative, and acid stress compared to the wild-type strain. Gene expression analysis by qRT-PCR indicates that thiol peroxidase, a scavenger of reactive oxygen species and aguA from the arginine deiminase system, could be important for peroxide stress responses in a polyamine-dependent manner. Our results also show that speA is essential for endogenous hydrogen peroxide and glutathione production in S. pneumoniae. Taken together, our findings demonstrate the critical role of arginine decarboxylase in pneumococcal stress responses that could impact adaptation and survival in the host.

scholarly journals Erythroid-cell-specific properties of transcription factor GATA-1 revealed by phenotypic rescue of a gene-targeted cell line.

1997 ◽  
Vol 17 (3) ◽  
pp. 1642-1651 ◽  
Author(s):  
M J Weiss ◽  
C Yu ◽  
S H Orkin
Keyword(s):  
Transcription Factor ◽  
Cell Line ◽  
Zinc Finger ◽  
Es Cells ◽  
Embryonic Stem ◽  
Erythroid Cell ◽  
Transactivation Domain ◽  
Stage Of Development ◽  
Erythroid Maturation

The zinc finger transcription factor GATA-1 is essential for erythropoiesis. In its absence, committed erythroid precursors arrest at the proerythroblast stage of development and undergo apoptosis. To study the function of GATA-1 in an erythroid cell environment, we generated an erythroid cell line from in vitro-differentiated GATA-1- murine embryonic stem (ES) cells. These cells, termed G1E for GATA-1- erythroid, proliferate as immature erythroblasts yet complete differentiation upon restoration of GATA-1 function. We used rescue of terminal erythroid maturation in G1E cells as a stringent cellular assay system in which to evaluate the functional relevance of domains of GATA-1 previously characterized in nonhematopoietic cells. At least two major differences were established between domains required in G1E cells and those required in nonhematopoietic cells. First, an obligatory transactivation domain defined in conventional nonhematopoietic cell transfection assays is dispensable for terminal erythroid maturation. Second, the amino (N) zinc finger, which is nonessential for binding to the vast majority of GATA DNA motifs, is strictly required for GATA-1-mediated erythroid differentiation. Our data lead us to propose a model in which a nuclear cofactor(s) interacting with the N-finger facilitates transcriptional action by GATA-1 in erythroid cells. More generally, our experimental approach highlights critical differences in the action of cell-specific transcription proteins in different cellular environments and the power of cell lines derived from genetically modified ES cells to elucidate gene function.

Strain-specific transgene methylation occurs early in mouse development and can be recapitulated in embryonic stem cells

Development ◽  
1995 ◽  
Vol 121 (9) ◽  
pp. 2853-2859 ◽  
Author(s):  
A. Weng ◽  
T. Magnuson ◽  
U. Storb
Keyword(s):  
De Novo ◽  
Es Cells ◽  
Embryonic Stem ◽  
Dependent Manner ◽  
Mouse Development ◽  
Partial Methylation ◽  
Distal Chromosome ◽  
Before And After ◽  
Endogenous Genes ◽  
De Novo Methylation

A murine transgene, HRD, is methylated only when carried in certain inbred strain backgrounds. A locus on distal chromosome 4, Ssm1 (strain-specific modifier), controls this phenomenon. In order to characterize the activity of Ssm1, we have investigated developmental acquisition of methylation over the transgene. Analysis of postimplantation embryos revealed that strain-specific methylation is initiated prior to embryonic day (E) 6.5. Strain-specific transgene methylation is all-or-none in pattern and occurs exclusively in the primitive ectoderm lineage. A strain-independent pattern of partial methylation occurs in the primitive endoderm and trophectoderm lineages. To examine earlier stages, embryonic stem (ES) cells were derived from E3.5 blastocysts and examined for transgene methylation before and after differentiation. Though the transgene had already acquired some methylation in undifferentiated ES cells, differentiation induced further, de novo methylation in a strain-dependent manner. Analysis of methylation in ES cultures suggests that the transgene and endogenous genes (such as immunoglobulin genes) are synchronously methylated during early development. These results are interpreted in the context of a model in which Ssm1-like modifier genes produce alterations in chromatin structure during and/or shortly after implantation, thereby marking target loci for de novo methylation with the rest of the genome during gastrulation.

scholarly journals Transcription Factor Lbx1 Expression in Mouse Embryonic Stem Cell-Derived Phenotypes

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Stefanie Schmitteckert ◽  
Cornelia Ziegler ◽  
Liane Kartes ◽  
Alexandra Rolletschek
Keyword(s):  
Transcription Factor ◽  
Developmental Stages ◽  
Troponin T ◽  
Es Cells ◽  
Expression Patterns ◽  
Embryonic Stem ◽  
Mouse Embryonic Stem Cell ◽  
Cardiac Cells ◽  
Cell Stage

Transcription factor Lbx1 is known to play a role in the migration of muscle progenitor cells in limb buds and also in neuronal determination processes. In addition, involvement of Lbx1 in cardiac neural crest-related cardiogenesis was postulated. Here, we used mouse embryonic stem (ES) cells which have the capacity to develop into cells of all three primary germ layers. Duringin vitrodifferentiation, ES cells recapitulate cellular developmental processes and gene expression patterns of early embryogenesis. Transcript analysis revealed a significant upregulation ofLbx1at the progenitor cell stage. Immunofluorescence staining confirmed the expression of Lbx1 in skeletal muscle cell progenitors and GABAergic neurons. To verify the presence of Lbx1 in cardiac cells, triple immunocytochemistry of ES cell-derived cardiomyocytes and a quantification assay were performed at different developmental stages. Colabeling of Lbx1 and cardiac specific markers troponin T, α-actinin, GATA4, and Nkx2.5 suggested a potential role in early myocardial development.

Vascular endothelial growth factor synergistically enhances bone morphogenetic protein-4-dependent lymphohematopoietic cell generation from embryonic stem cells in vitro

Blood ◽  
2000 ◽  
Vol 95 (7) ◽  
pp. 2275-2283 ◽  
Author(s):  
Naoki Nakayama ◽  
Jae Lee ◽  
Laura Chiu
Keyword(s):  
Vascular Endothelial Growth Factor ◽  
Growth Factor ◽  
Bone Morphogenetic Protein ◽  
Es Cells ◽  
Embryonic Stem ◽  
Dependent Manner ◽  
Vascular Endothelial ◽  
Morphogenetic Protein ◽  
Endothelial Growth Factor

Abstract The totipotent mouse embryonic stem (ES) cell is known to differentiate into cells expressing the β-globin gene when stimulated with bone morphogenetic protein (BMP)-4. Here, we demonstrate that BMP-4 is essential for generating both erythro-myeloid colony-forming cells (CFCs) and lymphoid (B and NK) progenitor cells from ES cells and that vascular endothelial growth factor (VEGF) synergizes with BMP-4. The CD45+ myelomonocytic progenitors and Ter119+ erythroid cells began to be detected with 0.5 ng/mL BMP-4, and their levels plateaued at approximately 2 ng/mL. VEGF alone weakly elevated the CD34+ cell population though no lymphohematopoietic progenitors were induced. However, when combined with BMP-4, 2 to 20 ng/mL VEGF synergistically augmented the BMP-4-dependent generation of erythro-myeloid CFCs and lymphoid progenitors from ES cells, which were enriched in CD34+ CD31lo and CD34+CD45− cell populations, respectively, in a dose-dependent manner. Furthermore, during the 7 days of in vitro differentiation, BMP-4 was required within the first 4 days, whereas VEGF was functional after the action of BMP-4 (in the last 3 days). Thus, VEGF is a synergistic enhancer for the BMP-4-dependent differentiation processes, and it seems to be achieved by the ordered action of the 2 factors.

scholarly journals Fgf and Esrrb integrate epigenetic and transcriptional networks that regulate self-renewal of trophoblast stem cells

2015 ◽  
Vol 6 (1) ◽  
Author(s):  
Paulina A. Latos ◽  
Angela Goncalves ◽  
David Oxley ◽  
Hisham Mohammed ◽  
Ernest Turro ◽  
...  
Keyword(s):  
Stem Cells ◽  
Transcription Factor ◽  
Transcription Factors ◽  
Rna Polymerase Ii ◽  
Es Cells ◽  
Embryonic Stem ◽  
Transcriptional Networks ◽  
Self Renewal ◽  
Downstream Target ◽  
Trophoblast Stem

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.

scholarly journals Regulation of circular dorsal ruffles, macropinocytosis, and cell migration by RhoG and its exchange factor, Trio

2017 ◽  
Vol 28 (13) ◽  
pp. 1768-1781 ◽  
Author(s):  
Alejandra Valdivia ◽  
Silvia M. Goicoechea ◽  
Sahezeel Awadia ◽  
Ashtyn Zinn ◽  
Rafael Garcia-Mata
Keyword(s):  
Cell Migration ◽  
Mammalian Cells ◽  
Dorsal Surface ◽  
Receptor Internalization ◽  
Dependent Manner ◽  
Cellular Functions ◽  
Unique Type ◽  
Exchange Factor ◽  
Cellular Processes

Circular dorsal ruffles (CDRs) are actin-rich structures that form on the dorsal surface of many mammalian cells in response to growth factor stimulation. CDRs represent a unique type of structure that forms transiently and only once upon stimulation. The formation of CDRs involves a drastic rearrangement of the cytoskeleton, which is regulated by the Rho family of GTPases. So far, only Rac1 has been consistently associated with CDR formation, whereas the role of other GTPases in this process is either lacking or inconclusive. Here we show that RhoG and its exchange factor, Trio, play a role in the regulation of CDR dynamics, particularly by modulating their size. RhoG is activated by Trio downstream of PDGF in a PI3K- and Src-dependent manner. Silencing RhoG expression decreases the number of cells that form CDRs, as well as the area of the CDRs. The regulation of CDR area by RhoG is independent of Rac1 function. In addition, our results show the RhoG plays a role in the cellular functions associated with CDR formation, including macropinocytosis, receptor internalization, and cell migration. Taken together, our results reveal a novel role for RhoG in the regulation of CDRs and the cellular processes associated with their formation.

Regulation of the dual-function transcription factor Sp3 by SUMO

2007 ◽  
Vol 35 (6) ◽  
pp. 1393-1396 ◽  
Author(s):  
A. Valin ◽  
G. Gill
Keyword(s):  
Transcription Factor ◽  
Transcription Factors ◽  
Histone Deacetylases ◽  
Current Data ◽  
Dual Function ◽  
Dependent Manner ◽  
Dual Nature ◽  
Protein Protein Interaction ◽  
Sumo Conjugation ◽  
Specificity Protein

In eukaryotes, gene expression is controlled by a relatively small number of regulators. Post-translational modifications dramatically increase the functional possibilities of those regulators. Modification of many transcription factors and cofactors by SUMO (small ubiquitin-related modifier) correlates, in most cases, with inhibition of transcription. Recent studies suggest a model whereby SUMO conjugation to transcription factors promotes the recruitment of co-repressors through direct protein–protein interaction with the SUMO protein. HDACs (histone deacetylases) are important, but not exclusive, effectors of SUMO-mediated repression. Sp3 (specificity protein 3), a zinc-finger DNA-binding domain transcription factor, has the ability to both activate and repress transcription in a context-dependent manner. SUMOylation regulates the dual nature of Sp3 function. Current data suggest that Sp3 represses transcription in a SUMO-dependent manner but independent of HDACs. Recent studies to identify additional co-repressors associated with SUMO and further investigate regulated activity of Sp3 are providing a deeper understanding of SUMO-dependent mechanisms of transcriptional regulation.

scholarly journals Nucleus-cytoskeleton communication impacts on OCT4-chromatin interactions in embryonic stem cells

BMC Biology ◽  
2022 ◽  
Vol 20 (1) ◽  
Author(s):  
Juan José Romero ◽  
María Cecilia De Rossi ◽  
Camila Oses ◽  
Camila Vázquez Echegaray ◽  
Paula Verneri ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Cell Fate ◽  
Opposite Effect ◽  
Es Cells ◽  
Three Dimensional ◽  
Embryonic Stem ◽  
Cytoskeleton Organization ◽  
Chromatin Interactions ◽  
Cellular Environment ◽  
Dimensional Distribution

Abstract Background The cytoskeleton is a key component of the system responsible for transmitting mechanical cues from the cellular environment to the nucleus, where they trigger downstream responses. This communication is particularly relevant in embryonic stem (ES) cells since forces can regulate cell fate and guide developmental processes. However, little is known regarding cytoskeleton organization in ES cells, and thus, relevant aspects of nuclear-cytoskeletal interactions remain elusive. Results We explored the three-dimensional distribution of the cytoskeleton in live ES cells and show that these filaments affect the shape of the nucleus. Next, we evaluated if cytoskeletal components indirectly modulate the binding of the pluripotency transcription factor OCT4 to chromatin targets. We show that actin depolymerization triggers OCT4 binding to chromatin sites whereas vimentin disruption produces the opposite effect. In contrast to actin, vimentin contributes to the preservation of OCT4-chromatin interactions and, consequently, may have a pro-stemness role. Conclusions Our results suggest roles of components of the cytoskeleton in shaping the nucleus of ES cells, influencing the interactions of the transcription factor OCT4 with the chromatin and potentially affecting pluripotency and cell fate.

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