scholarly journals Stem cell intrinsic, Seven-up-triggered temporal factor gradients diversify intermediate neural progenitors

2017 ◽  
Author(s):  
Qingzhong Ren ◽  
Ching-Po Yang ◽  
Zhiyong Liu ◽  
Ken Sugino ◽  
Kent Mok ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Neural Progenitors ◽  
Small Range ◽  
Type Ii ◽  
Genetic Manipulations ◽  
Temporal Windows ◽  
Number Of Cells ◽  
Temporal Factor

SummaryDrosophila type II neuroblasts produce numerous neurons and glia due to transiently amplifying, intermediate neural progenitors (INP). Consecutively born INPs produce morphologically distinct progeny, presumably due to temporal patterning in type II neuroblasts. We therefore profiled type II neuroblasts’ transcriptome across time. Our results reveal opposing temporal gradients of Imp and Syp RNA-binding proteins (descending and ascending, respectively). Maintaining Imp expression throughout brain development expands the number of neurons/glia with early temporal fate at the expense of cells with late fate. Conversely, precocious upregulation of Syp reduces the number of cells with early fate. Further, we reveal that the transcription factor, Seven-up initiates progression of the Imp/Syp gradients. Interestingly, genetic manipulations that fix Imp or Syp levels still yield progeny with a small range of early fates. We propose that the Seven-up-initiated Imp/Syp gradients create coarse temporal windows within type II neuroblasts to pattern INPs, which subsequently undergo fine-tuned subtemporal patterning.

scholarly journals Structure and functional implications of WYL-domain-containing transcription factor PafBC involved in the mycobacterial DNA damage response

2019 ◽  
Author(s):  
Andreas U. Müller ◽  
Marc Leibundgut ◽  
Nenad Ban ◽  
Eilika Weber-Ban
Keyword(s):  
Dna Damage ◽  
Transcription Factor ◽  
Transcription Factors ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Structural Information ◽  
Rna Molecules ◽  
Bacterial Transcription ◽  
Arthrobacter Aurescens

AbstractIn mycobacteria, transcriptional activator PafBC is responsible for upregulating the majority of genes induced by DNA damage. Understanding the mechanism of PafBC activation is impeded by a lack of structural information on this transcription factor that contains a widespread, but poorly understood WYL domain frequently encountered in bacterial transcription factors. Here, we determined the crystal structure ofArthrobacter aurescensPafBC. The protein consists of two modules, each harboring an N-terminal helix-turn-helix DNA binding domain followed by a central WYL and a C-terminal extension (WCX) domain. The WYL domains exhibit Sm-folds, while the WCX domains adopt ferredoxin-like folds, both characteristic for RNA binding proteins. Our results suggest a mechanism of regulation in which WYL domain-containing transcription factors may be activated by binding RNA molecules. Using anin vivomutational screen inMycobacterium smegmatis, we identify potential co-activator binding sites on PafBC.

scholarly journals Transcription factor-like 5 is a potential DNA/RNA-binding protein essential for maintaining male fertility in mice. Running title: Tcfl5 is haploinsufficient in vivo

2021 ◽  
Author(s):  
Weiya Xu ◽  
Yiyun Zhang ◽  
Dongdong Qin ◽  
Yiqian Gui ◽  
Shu Wang ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Fragile X ◽  
Specific Protein ◽  
Dual Function ◽  
Specific Cell ◽  
Chip Sequencing ◽  
Dna And Rna

Tissue-specific transcription factors often play key roles in the development of specific cell lineages. Transcription factor-like 5 (TCFL5) is a testis-specific protein that contains the basic helix-loop-helix domain, although the in vivo functions of TCFL5 remain unknown. Herein, we generated CRISPR/Cas9-mediated knockout mice to dissect the function of TCFL5 in mouse testes. Surprisingly, we found that it was difficult to generate homozygous mice with the Tcfl5 deletion since the heterozygous males (Tcfl5+/-) were infertile. We did, however, observe markedly abnormal phenotypes of spermatids and spermatozoa in the testes and epididymides of Tcfl5+/- mice. Mechanistically, we demonstrated that TCFL5 transcriptionally regulated a set of genes participating in male germ cell development, which we uncovered via RNA-sequencing and TCFL5 ChIP-sequencing. We also found that TCFL5 interacted with RNA-binding proteins (RBPs) that regulated RNA processing, and further identified the fragile X mental retardation gene 1, autosomal homolog (FXR1, a known RBP) as an interacting partner of TCFL5 that may coordinate the transition and localization of TCFL5 in the nucleus. Collectively, we herein report for the first time that Tcfl5 is haploinsufficient in vivo and hypothesize that TCFL5 may be a dual-function protein that mediates DNA and RNA to regulate spermatogenesis.

scholarly journals The splicing regulator PTBP1 controls the activity of the transcription factor Pbx1 during neuronal differentiation

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Anthony J Linares ◽  
Chia-Ho Lin ◽  
Andrey Damianov ◽  
Katrina L Adams ◽  
Bennett G Novitch ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Neuronal Development ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Embryonic Stem ◽  
Regulatory Elements ◽  
Cytoskeletal Proteins ◽  
Control Programs ◽  
Neuronal Progenitor ◽  
Neuronal Genes

The RNA-binding proteins PTBP1 and PTBP2 control programs of alternative splicing during neuronal development. PTBP2 was found to maintain embryonic splicing patterns of many synaptic and cytoskeletal proteins during differentiation of neuronal progenitor cells (NPCs) into early neurons. However, the role of the earlier PTBP1 program in embryonic stem cells (ESCs) and NPCs was not clear. We show that PTBP1 controls a program of neuronal gene expression that includes the transcription factor Pbx1. We identify exons specifically regulated by PTBP1 and not PTBP2 as mouse ESCs differentiate into NPCs. We find that PTBP1 represses Pbx1 exon 7 and the expression of the neuronal Pbx1a isoform in ESCs. Using CRISPR-Cas9 to delete regulatory elements for exon 7, we induce Pbx1a expression in ESCs, finding that this activates transcription of neuronal genes. Thus, PTBP1 controls the activity of Pbx1 to suppress its neuronal transcriptional program prior to induction of NPC development.

scholarly journals Homeodomain protein Six4 prevents the generation of supernumerary Drosophila type II neuroblasts and premature differentiation of intermediate neural progenitors

PLoS Genetics ◽  
2021 ◽  
Vol 17 (2) ◽  
pp. e1009371
Author(s):  
Rui Chen ◽  
Yanjun Hou ◽  
Marisa Connell ◽  
Sijun Zhu
Keyword(s):  
Stem Cells ◽  
Transcription Factor ◽  
Neural Stem Cells ◽  
Neurological Diseases ◽  
Neural Progenitors ◽  
Homeodomain Protein ◽  
Type Ii ◽  
Trimeric Complex ◽  
Expression And Activity

In order to boost the number and diversity of neurons generated from neural stem cells, intermediate neural progenitors (INPs) need to maintain their homeostasis by avoiding both dedifferentiation and premature differentiation. Elucidating how INPs maintain homeostasis is critical for understanding the generation of brain complexity and various neurological diseases resulting from defects in INP development. Here we report that Six4 expressed in Drosophila type II neuroblast (NB) lineages prevents the generation of supernumerary type II NBs and premature differentiation of INPs. We show that loss of Six4 leads to supernumerary type II NBs likely due to dedifferentiation of immature INPs (imINPs). We provide data to further demonstrate that Six4 inhibits the expression and activity of PntP1 in imINPs in part by forming a trimeric complex with Earmuff and PntP1. Furthermore, knockdown of Six4 exacerbates the loss of INPs resulting from the loss of PntP1 by enhancing ectopic Prospero expression in imINPs, suggesting that Six4 is also required for preventing premature differentiation of INPs. Taken together, our work identified a novel transcription factor that likely plays important roles in maintaining INP homeostasis.

scholarly journals Snf1-Dependent Transcription Confers Glucose-Induced Decay upon the mRNA Product

2015 ◽  
Vol 36 (4) ◽  
pp. 628-644 ◽  
Author(s):  
Katherine A. Braun ◽  
Kenneth M. Dombek ◽  
Elton T. Young
Keyword(s):  
Transcription Factor ◽  
Protein Kinase ◽  
Mrna Decay ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Binding Motif ◽  
Content Type ◽  
Amp Activated Protein Kinase ◽  
Yeast Metabolic Cycle ◽  
Metabolic Cycle

In the yeastSaccharomyces cerevisiae, the switch from respiratory metabolism to fermentation causes rapid decay of transcripts encoding proteins uniquely required for aerobic metabolism. Snf1, the yeast ortholog of AMP-activated protein kinase, has been implicated in this process because inhibiting Snf1 mimics the addition of glucose. In this study, we show that theSNF1-dependentADH2promoter, or just the major transcription factor binding site, is sufficient to confer glucose-induced mRNA decay upon heterologous transcripts.SNF1-independent expression from theADH2promoter prevented glucose-induced mRNA decay without altering the start site of transcription.SNF1-dependent transcripts are enriched for the binding motif of the RNA binding protein Vts1, an important mediator of mRNA decay and mRNA repression whose expression is correlated with decreased abundance ofSNF1-dependent transcripts during the yeast metabolic cycle. However, deletion ofVTS1did not slow the rate of glucose-induced mRNA decay.ADH2mRNA rapidly dissociated from polysomes after glucose repletion, and sequences bound by RNA binding proteins were enriched in the transcripts from repressed cells. Inhibiting the protein kinase A pathway did not affect glucose-induced decay ofADH2mRNA. Our results suggest that Snf1 may influence mRNA stability by altering the recruitment activity of the transcription factor Adr1.

scholarly journals The myopathic transcription factor DUX4 induces the production of truncated RNA-binding proteins in human muscle cells

2021 ◽  
Author(s):  
Amy E Campbell ◽  
Michael C Dyle ◽  
Lorenzo Calviello ◽  
Tyler Matheny ◽  
Michael A Cortázar ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Rna Binding ◽  
Temporal Dynamics ◽  
Rna Binding Proteins ◽  
Muscle Cells ◽  
Facioscapulohumeral Muscular Dystrophy ◽  
Potent Effect ◽  
High Concordance ◽  
Muscle Homeostasis ◽  
Human Muscle Cells

DUX4 is an embryonic transcription factor whose misexpression in skeletal muscle causes facioscapulohumeral muscular dystrophy (FSHD). DUX4 dysregulates multiple pathways that could contribute to FSHD pathophysiology. However, lack of temporal data and the knowledge of which RNAs are actively translated following DUX4 expression has hindered our understanding of the cascade of events that lead to muscle cell death. Here, we interrogate the DUX4 transcriptome and translatome over time and find dysregulation of most key pathways as early as 4 hours after DUX4 induction, demonstrating the potent effect of DUX4 in disrupting muscle homeostasis. We also observe extensive transcript downregulation as well as induction, and a high concordance between mRNA abundance and translation status. Significantly, DUX4 triggers widespread production of truncated protein products derived from aberrant RNAs that are degraded in normal muscle cells. One such protein, truncated serine/arginine-rich splicing factor 3 (SRSF3-TR), is present in FSHD muscle cells and disrupts splicing autoregulation when ectopically expressed in myoblasts. Taken together, the temporal dynamics of DUX4 induction show how the pathologic presence of an embryonic transcription factor in muscle cells alters gene expression at all levels of the central dogma.

scholarly journals Nanos promotes epigenetic reprograming of the germline by down-regulation of the THAP transcription factor LIN-15B

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Chih-Yung Sean Lee ◽  
Tu Lu ◽  
Geraldine Seydoux
Keyword(s):  
Transcription Factor ◽  
Cell Fate ◽  
Transcriptional Activation ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Primordial Germ Cells ◽  
Germline Development ◽  
C Elegans ◽  
Maternal Transcripts ◽  
Underlying Mechanisms

Nanos RNA-binding proteins are required for germline development in metazoans, but the underlying mechanisms remain poorly understood. We have profiled the transcriptome of primordial germ cells (PGCs) lacking the nanos homologs nos-1 and nos-2 in C. elegans. nos-1nos-2 PGCs fail to silence hundreds of transcripts normally expressed in oocytes. We find that this misregulation is due to both delayed turnover of maternal transcripts and inappropriate transcriptional activation. The latter appears to be an indirect consequence of delayed turnover of the maternally-inherited transcription factor LIN-15B, a synMuvB class transcription factor known to antagonize PRC2 activity. PRC2 is required for chromatin reprogramming in the germline, and the transcriptome of PGCs lacking PRC2 resembles that of nos-1nos-2 PGCs. Loss of maternal LIN-15B restores fertility to nos-1nos-2 mutants. These findings suggest that Nanos promotes germ cell fate by downregulating maternal RNAs and proteins that would otherwise interfere with PRC2-dependent reprogramming of PGC chromatin.

scholarly journals The master transcription factor SOX2, mutated in anophthalmia/microphthalmia, is post-transcriptionally regulated by the conserved RNA-binding protein RBM24 in vertebrate eye development

2019 ◽  
Vol 29 (4) ◽  
pp. 591-604 ◽  
Author(s):  
Soma Dash ◽  
Lindy K Brastrom ◽  
Shaili D Patel ◽  
C Anthony Scott ◽  
Diane C Slusarski ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Transcriptional Control ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Eye Development ◽  
Ocular Tissue ◽  
Binding Motif ◽  
Mobility Shift ◽  
Developmental Defects ◽  
Protein Levels

Abstract Mutations in the key transcription factor, SOX2, alone account for 20% of anophthalmia (no eye) and microphthalmia (small eye) birth defects in humans—yet its regulation is not well understood, especially on the post-transcription level. We report the unprecedented finding that the conserved RNA-binding motif protein, RBM24, positively controls Sox2 mRNA stability and is necessary for optimal SOX2 mRNA and protein levels in development, perturbation of which causes ocular defects, including microphthalmia and anophthalmia. RNA immunoprecipitation assay indicates that RBM24 protein interacts with Sox2 mRNA in mouse embryonic eye tissue. and electrophoretic mobility shift assay shows that RBM24 directly binds to the Sox2 mRNA 3’UTR, which is dependent on AU-rich elements (ARE) present in the Sox2 mRNA 3’UTR. Further, we demonstrate that Sox2 3’UTR AREs are necessary for RBM24-based elevation of Sox2 mRNA half-life. We find that this novel RBM24–Sox2 regulatory module is essential for early eye development in vertebrates. We show that Rbm24-targeted deletion using a constitutive CMV-driven Cre in mouse, and rbm24a-CRISPR/Cas9-targeted mutation or morpholino knockdown in zebrafish, results in Sox2 downregulation and causes the developmental defects anophthalmia or microphthalmia, similar to human SOX2-deficiency defects. We further show that Rbm24 deficiency leads to apoptotic defects in mouse ocular tissue and downregulation of eye development markers Lhx2, Pax6, Jag1, E-cadherin and gamma-crystallins. These data highlight the exquisite specificity that conserved RNA-binding proteins like RBM24 mediate in the post-transcriptional control of key transcription factors, namely, SOX2, associated with organogenesis and human developmental defects.

scholarly journals A CRISPR RNA-binding protein screen reveals regulators of RUNX1 isoform generation

2021 ◽  
Vol 5 (5) ◽  
pp. 1310-1323
Author(s):  
Amanda G. Davis ◽  
Jaclyn M. Einstein ◽  
Dinghai Zheng ◽  
Nathan D. Jayne ◽  
Xiang-Dong Fu ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Rna Processing ◽  
Posttranscriptional Regulation ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Hematologic Malignancy ◽  
Alternative Polyadenylation ◽  
Protein Isoforms ◽  
Self Renewal ◽  
Hematopoietic Stem

Abstract The proper balance of hematopoietic stem cell (HSC) self-renewal and differentiation is critical for normal hematopoiesis and is disrupted in hematologic malignancy. Among regulators of HSC fate, transcription factors have a well-defined central role, and mutations promote malignant transformation. More recently, studies have illuminated the importance of posttranscriptional regulation by RNA-binding proteins (RBPs) in hematopoiesis and leukemia development. However, the RBPs involved and the breadth of regulation are only beginning to be elucidated. Furthermore, the intersection between posttranscriptional regulation and hematopoietic transcription factor function is poorly understood. Here, we studied the posttranscriptional regulation of RUNX1, a key hematopoietic transcription factor. Alternative polyadenylation (APA) of RUNX1 produces functionally antagonistic protein isoforms (RUNX1a vs RUNX1b/c) that mediate HSC self-renewal vs differentiation, an RNA-processing event that is dysregulated in malignancy. Consequently, RBPs that regulate this event directly contribute to healthy and aberrant hematopoiesis. We modeled RUNX1 APA using a split GFP minigene reporter and confirmed the sensitivity of our model to detect changes in RNA processing. We used this reporter in a clustered regularly interspaced short palindromic repeats (CRISPR) screen consisting of single guide RNAs exclusively targeting RBPs and uncovered HNRNPA1 and KHDRBS1 as antagonistic regulators of RUNX1a isoform generation. Overall, our study provides mechanistic insight into the posttranscriptional regulation of a key hematopoietic transcription factor and identifies RBPs that may have widespread and important functions in hematopoiesis.

scholarly journals Cooption of antagonistic RNA-binding proteins establishes cell hierarchy in Drosophila neuro-developmental tumors

2018 ◽  
Author(s):  
Sara Genovese ◽  
Raphaël Clément ◽  
Cassandra Gaultier ◽  
Florence Besse ◽  
Karine Narbonne-Reveau ◽  
...  
Keyword(s):  
Tumor Heterogeneity ◽  
Binding Proteins ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Stochastic Modelling ◽  
Clonal Analysis ◽  
Neural Progenitors ◽  
Hierarchical Organization ◽  
Self Renewal ◽  
Intermediate Progenitors

AbstractThe mechanisms that govern the hierarchical organization of tumors are still poorly understood, especially in highly heterogeneous neural cancers. Previously, we had shown that aggressive neural tumors can be induced upon dedifferentiation of susceptible intermediate progenitors produced during early development (Narbonne-Reveau et al., 2016). Using clonal analysis, stochastic modelling and single-cell transcriptomics, we now find that such tumors rapidly become heterogeneous, containing progenitors with different proliferative potentials. We demonstrate that tumor heterogeneity emerges from the deregulated transition between two antagonistic RNA-binding proteins, Imp and Syncrip, that switch neural progenitors from a default self-renewing to a differentiation-prone state during development. Consequently, aberrant maintenance of Imp confers a cancer stem cell-like identity as Imp+ progenitors sustain tumor growth while being able to continuously generate Syncrip+ progenitors. The latter exhibit limited self-renewal likely due to Syncrip-mediated metabolic exhaustion. This study provides an example of how a subverted developmental transition establishes a hierarchical tumor.

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