scholarly journals Sperm fate is promoted by the mir-44 microRNA family in the Caenorhabditis elegans hermaphrodite germline

Genetics ◽  
2020 ◽  
Vol 217 (1) ◽  
Author(s):  
Katherine A Maniates ◽  
Benjamin S Olson ◽  
Allison L Abbott

Abstract Posttranscriptional regulation of gene expression, typically effected by RNA-binding proteins, microRNAs (miRNAs), and translation initiation factors, is essential for normal germ cell function. Numerous miRNAs have been detected in the germline; however, the functions of specific miRNAs remain largely unknown. Functions of miRNAs have been difficult to determine as miRNAs often modestly repress target mRNAs and are suggested to sculpt or fine tune gene expression to allow for the robust expression of cell fates. In Caenorhabditis elegans hermaphrodites, cell fate decisions are made for germline sex determination during larval development when sperm are generated in a short window before the switch to oocyte production. Here, analysis of newly generated mir-44 family mutants has identified a family of miRNAs that modulate the germline sex determination pathway in C. elegans. Mutants with the loss of mir-44 and mir-45 produce fewer sperm, showing both a delay in the specification and formation of sperm as well as an early termination of sperm specification accompanied by a premature switch to oocyte production. mir-44 and mir-45 are necessary for the normal period of fog-1 expression in larval development. Through genetic analysis, we find that mir-44 and mir-45 may act upstream of fbf-1 and fem-3 to promote sperm specification. Our research indicates that the mir-44 family promotes sperm cell fate specification during larval development and identifies an additional posttranscriptional regulator of the germline sex determination pathway.

2019 ◽  
Vol 11 (10) ◽  
pp. 930-939 ◽  
Author(s):  
Michaela Müller-McNicoll ◽  
Oliver Rossbach ◽  
Jingyi Hui ◽  
Jan Medenbach

Abstract RNA-binding proteins (RBPs) are key regulators in post-transcriptional control of gene expression. Mutations that alter their activity or abundance have been implicated in numerous diseases such as neurodegenerative disorders and various types of cancer. This highlights the importance of RBP proteostasis and the necessity to tightly control the expression levels and activities of RBPs. In many cases, RBPs engage in an auto-regulatory feedback by directly binding to and influencing the fate of their own mRNAs, exerting control over their own expression. For this feedback control, RBPs employ a variety of mechanisms operating at all levels of post-transcriptional regulation of gene expression. Here we review RBP-mediated autogenous feedback regulation that either serves to maintain protein abundance within a physiological range (by negative feedback) or generates binary, genetic on/off switches important for e.g. cell fate decisions (by positive feedback).


2018 ◽  
Vol 217 (7) ◽  
pp. 2247-2259 ◽  
Author(s):  
Juan Manuel Schvartzman ◽  
Craig B. Thompson ◽  
Lydia W.S. Finley

Dynamic regulation of gene expression in response to changing local conditions is critical for the survival of all organisms. In metazoans, coherent regulation of gene expression programs underlies the development of functionally distinct cell lineages. The cooperation between transcription factors and the chromatin landscape enables precise control of gene expression in response to cell-intrinsic and cell-extrinsic signals. Many of the chemical modifications that decorate DNA and histones are adducts derived from intermediates of cellular metabolic pathways. In addition, several of the enzymes that can remove these marks use metabolites as part of their enzymatic reaction. These observations have led to the hypothesis that fluctuations in metabolite levels influence the deposition and removal of chromatin modifications. In this review, we consider the emerging evidence that cellular metabolic activity contributes to gene expression and cell fate decisions through metabolite-dependent effects on chromatin organization.


Development ◽  
1999 ◽  
Vol 126 (15) ◽  
pp. 3275-3283 ◽  
Author(s):  
G. Seydoux ◽  
S. Strome

One hundred years after Weismann's seminal observations, the mechanisms that distinguish the germline from the soma still remain poorly understood. This review describes recent studies in Caenorhabditis elegans, which suggest that germ cells utilize unique mechanisms to regulate gene expression. In particular, mechanisms that repress the production of mRNAs appear to be essential to maintain germ cell fate and viability.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Lionel Condé ◽  
Yulemi Gonzalez Quesada ◽  
Florence Bonnet-Magnaval ◽  
Rémy Beaujois ◽  
Luc DesGroseillers

AbstractBackgroundStaufen2 (STAU2) is an RNA binding protein involved in the posttranscriptional regulation of gene expression. In neurons, STAU2 is required to maintain the balance between differentiation and proliferation of neural stem cells through asymmetric cell division. However, the importance of controlling STAU2 expression for cell cycle progression is not clear in non-neuronal dividing cells. We recently showed that STAU2 transcription is inhibited in response to DNA-damage due to E2F1 displacement from theSTAU2gene promoter. We now study the regulation of STAU2 steady-state levels in unstressed cells and its consequence for cell proliferation.ResultsCRISPR/Cas9-mediated and RNAi-dependent STAU2 depletion in the non-transformed hTERT-RPE1 cells both facilitate cell proliferation suggesting that STAU2 expression influences pathway(s) linked to cell cycle controls. Such effects are not observed in the CRISPR STAU2-KO cancer HCT116 cells nor in the STAU2-RNAi-depleted HeLa cells. Interestingly, a physiological decrease in the steady-state level of STAU2 is controlled by caspases. This effect of peptidases is counterbalanced by the activity of the CHK1 pathway suggesting that STAU2 partial degradation/stabilization fines tune cell cycle progression in unstressed cells. A large-scale proteomic analysis using STAU2/biotinylase fusion protein identifies known STAU2 interactors involved in RNA translation, localization, splicing, or decay confirming the role of STAU2 in the posttranscriptional regulation of gene expression. In addition, several proteins found in the nucleolus, including proteins of the ribosome biogenesis pathway and of the DNA damage response, are found in close proximity to STAU2. Strikingly, many of these proteins are linked to the kinase CHK1 pathway, reinforcing the link between STAU2 functions and the CHK1 pathway. Indeed, inhibition of the CHK1 pathway for 4 h dissociates STAU2 from proteins involved in translation and RNA metabolism.ConclusionsThese results indicate that STAU2 is involved in pathway(s) that control(s) cell proliferation, likely via mechanisms of posttranscriptional regulation, ribonucleoprotein complex assembly, genome integrity and/or checkpoint controls. The mechanism by which STAU2 regulates cell growth likely involves caspases and the kinase CHK1 pathway.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Mika J. Välimäki ◽  
Robert S. Leigh ◽  
Sini M. Kinnunen ◽  
Alexander R. March ◽  
Ana Hernández de Sande ◽  
...  

AbstractBackgroundPharmacological modulation of cell fate decisions and developmental gene regulatory networks holds promise for the treatment of heart failure. Compounds that target tissue-specific transcription factors could overcome non-specific effects of small molecules and lead to the regeneration of heart muscle following myocardial infarction. Due to cellular heterogeneity in the heart, the activation of gene programs representing specific atrial and ventricular cardiomyocyte subtypes would be highly desirable. Chemical compounds that modulate atrial and ventricular cell fate could be used to improve subtype-specific differentiation of endogenous or exogenously delivered progenitor cells in order to promote cardiac regeneration.MethodsTranscription factor GATA4-targeted compounds that have previously shown in vivo efficacy in cardiac injury models were tested for stage-specific activation of atrial and ventricular reporter genes in differentiating pluripotent stem cells using a dual reporter assay. Chemically induced gene expression changes were characterized by qRT-PCR, global run-on sequencing (GRO-seq) and immunoblotting, and the network of cooperative proteins of GATA4 and NKX2-5 were further explored by the examination of the GATA4 and NKX2-5 interactome by BioID. Reporter gene assays were conducted to examine combinatorial effects of GATA-targeted compounds and bromodomain and extraterminal domain (BET) inhibition on chamber-specific gene expression.ResultsGATA4-targeted compounds 3i-1000 and 3i-1103 were identified as differential modulators of atrial and ventricular gene expression. More detailed structure-function analysis revealed a distinct subclass of GATA4/NKX2-5 inhibitory compounds with an acetyl lysine-like domain that contributed to ventricular cells (%Myl2-eGFP+). Additionally, BioID analysis indicated broad interaction between GATA4 and BET family of proteins, such as BRD4. This indicated the involvement of epigenetic modulators in the regulation of GATA-dependent transcription. In this line, reporter gene assays with combinatorial treatment of 3i-1000 and the BET bromodomain inhibitor (+)-JQ1 demonstrated the cooperative role of GATA4 and BRD4 in the modulation of chamber-specific cardiac gene expression.ConclusionsCollectively, these results indicate the potential for therapeutic alteration of cell fate decisions and pathological gene regulatory networks by GATA4-targeted compounds modulating chamber-specific transcriptional programs in multipotent cardiac progenitor cells and cardiomyocytes. The compound scaffolds described within this study could be used to develop regenerative strategies for myocardial regeneration.


2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Godfrey Grech ◽  
Marieke von Lindern

Organisation of RNAs into functional subgroups that are translated in response to extrinsic and intrinsic factors underlines a relatively unexplored gene expression modulation that drives cell fate in the same manner as regulation of the transcriptome by transcription factors. Recent studies on the molecular mechanisms of inflammatory responses and haematological disorders indicate clearly that the regulation of mRNA translation at the level of translation initiation, mRNA stability, and protein isoform synthesis is implicated in the tight regulation of gene expression. This paper outlines how these posttranscriptional control mechanisms, including control at the level of translation initiation factors and the role of RNA binding proteins, affect hematopoiesis. The clinical relevance of these mechanisms in haematological disorders indicates clearly the potential therapeutic implications and the need of molecular tools that allow measurement at the level of translational control. Although the importance of miRNAs in translation control is well recognised and studied extensively, this paper will exclude detailed account of this level of control.


2010 ◽  
Vol 18 (4) ◽  
pp. 675-685 ◽  
Author(s):  
Guoji Guo ◽  
Mikael Huss ◽  
Guo Qing Tong ◽  
Chaoyang Wang ◽  
Li Li Sun ◽  
...  

Development ◽  
1993 ◽  
Vol 119 (4) ◽  
pp. 1019-1027 ◽  
Author(s):  
K. Fitzgerald ◽  
H.A. Wilkinson ◽  
I. Greenwald

Members of the lin-12/Notch gene family encode receptors for intercellular signals and are found throughout the animal kingdom. In many animals, the presence of at least two lin-12/Notch genes raises the issue of the significance of this duplication and divergence. In Caenorhabditis elegans, two lin-12/Notch genes, lin-12 and glp-1, encode proteins that are 50% identical, with different numbers of epidermal growth factor-like motifs in their extracellular domains. Many of the cell fate decisions mediated by lin-12 and glp-1 are distinct. Here, we express glp-1 protein under the control of lin-12 regulatory sequences in animals lacking endogenous lin-12 activity and find that glp-1 can substitute for lin-12 in mediating cell fate decisions. These results imply that the lin-12 and glp-1 proteins are biochemically interchangeable, sharing common ligand and effector proteins, and that the discrete lin-12 and glp-1 mutant phenotypes result from differential gene expression. In addition, these results suggest that the duplicate lin-12/Notch genes found in vertebrates may also be biochemically interchangeable.


Biomolecules ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1475
Author(s):  
Veronica Ruta ◽  
Vittoria Pagliarini ◽  
Claudio Sette

Signal transduction pathways transmit the information received from external and internal cues and generate a response that allows the cell to adapt to changes in the surrounding environment. Signaling pathways trigger rapid responses by changing the activity or localization of existing molecules, as well as long-term responses that require the activation of gene expression programs. All steps involved in the regulation of gene expression, from transcription to processing and utilization of new transcripts, are modulated by multiple signal transduction pathways. This review provides a broad overview of the post-translational regulation of factors involved in RNA processing events by signal transduction pathways, with particular focus on the regulation of pre-mRNA splicing, cleavage and polyadenylation. The effects of several post-translational modifications (i.e., sumoylation, ubiquitination, methylation, acetylation and phosphorylation) on the expression, subcellular localization, stability and affinity for RNA and protein partners of many RNA-binding proteins are highlighted. Moreover, examples of how some of the most common signal transduction pathways can modulate biological processes through changes in RNA processing regulation are illustrated. Lastly, we discuss challenges and opportunities of therapeutic approaches that correct RNA processing defects and target signaling molecules.


2021 ◽  
Vol 8 ◽  
Author(s):  
Gustavo D. Campagnaro ◽  
Edward Nay ◽  
Michael J. Plevin ◽  
Angela K. Cruz ◽  
Pegine B. Walrad

A large number of eukaryotic proteins are processed by single or combinatorial post-translational covalent modifications that may alter their activity, interactions and fate. The set of modifications of each protein may be considered a “regulatory code”. Among the PTMs, arginine methylation, catalyzed by protein arginine methyltransferases (PRMTs), can affect how a protein interacts with other macromolecules such as nucleic acids or other proteins. In fact, many RNA-binding (RBPs) proteins are targets of PRMTs. The methylation status of RBPs may affect the expression of their bound RNAs and impact a diverse range of physiological and pathological cellular processes. Unlike most eukaryotes, Kinetoplastids have overwhelmingly intronless genes that are arranged within polycistronic units from which mature mRNAs are generated by trans-splicing. Gene expression in these organisms is thus highly dependent on post-transcriptional control, and therefore on the action of RBPs. These genetic features make trypanosomatids excellent models for the study of post-transcriptional regulation of gene expression. The roles of PRMTs in controlling the activity of RBPs in pathogenic kinetoplastids have now been studied for close to 2 decades with important advances achieved in recent years. These include the finding that about 10% of the Trypanosoma brucei proteome carries arginine methylation and that arginine methylation controls Leishmania:host interaction. Herein, we review how trypanosomatid PRMTs regulate the activity of RBPs, including by modulating interactions with RNA and/or protein complex formation, and discuss how this impacts cellular and biological processes. We further highlight unique structural features of trypanosomatid PRMTs and how it contributes to their singular functionality.


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