scholarly journals Satellite DNA-containing gigantic introns in a unique gene expression program during Drosophila spermatogenesis

2018 ◽  
Author(s):  
Jaclyn M Fingerhut ◽  
Jessica V Moran ◽  
Yukiko Yamashita

Intron gigantism, where genes contain megabase-sized introns, is observed across species, yet little is known about its purpose or regulation. Here we identify a unique gene expression program utilized for the proper expression of genes with intron gigantism. We find that two Drosophila genes with intron gigantism, kl-3 and kl-5, are transcribed in a spatiotemporal manner over the course of spermatocyte differentiation, which spans ~90 hours. The introns of these genes contain megabases of simple satellite DNA repeats that comprise over 99% of the gene loci, and these satellite-DNA containing introns are transcribed. We identify two RNA-binding proteins that specifically localize to kl-3 and kl-5 transcripts and are needed for the successful transcription or processing of these genes. We propose that genes with intron gigantism require a unique gene expression program, which may serve as a platform to regulate gene expression during cellular differentiation.

PLoS Genetics ◽  
2019 ◽  
Vol 15 (5) ◽  
pp. e1008028 ◽  
Author(s):  
Jaclyn M. Fingerhut ◽  
Jessica V. Moran ◽  
Yukiko M. Yamashita

2018 ◽  
Vol 154 (6) ◽  
pp. S-585
Author(s):  
Sarah F. Andres ◽  
Kathy N. Williams ◽  
Kathryn E. Hamilton ◽  
Rei Mizuno ◽  
Jeff Headd ◽  
...  

2021 ◽  
Vol 11 (2) ◽  
Author(s):  
Dustin Haskell ◽  
Anna Zinovyeva

Abstract MicroRNAs (miRNAs) and RNA-binding proteins (RBPs) regulate gene expression at the post-transcriptional level, but the extent to which these key regulators of gene expression coordinate their activities and the precise mechanisms of this coordination are not well understood. RBPs often have recognizable RNA binding domains that correlate with specific protein function. Recently, several RBPs containing K homology (KH) RNA binding domains were shown to work with miRNAs to regulate gene expression, raising the possibility that KH domains may be important for coordinating with miRNA pathways in gene expression regulation. To ascertain whether additional KH domain proteins functionally interact with miRNAs during Caenorhabditis elegans development, we knocked down twenty-four genes encoding KH-domain proteins in several miRNA sensitized genetic backgrounds. Here, we report that a majority of the KH domain-containing genes genetically interact with multiple miRNAs and Argonaute alg-1. Interestingly, two KH domain genes, predicted splicing factors sfa-1 and asd-2, genetically interacted with all of the miRNA mutants tested, whereas other KH domain genes showed genetic interactions only with specific miRNAs. Our domain architecture and phylogenetic relationship analyses of the C. elegans KH domain-containing proteins revealed potential groups that may share both structure and function. Collectively, we show that many C. elegans KH domain RBPs functionally interact with miRNAs, suggesting direct or indirect coordination between these two classes of post-transcriptional gene expression regulators.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Vedrana Andric ◽  
Alicia Nevers ◽  
Ditipriya Hazra ◽  
Sylvie Auxilien ◽  
Alexandra Menant ◽  
...  

AbstractLong non-coding RNAs (lncRNAs) contribute to the regulation of gene expression in response to intra- or extracellular signals but the underlying molecular mechanisms remain largely unexplored. Here, we identify an uncharacterized lncRNA as a central player in shaping the meiotic gene expression program in fission yeast. We report that this regulatory RNA, termed mamRNA, scaffolds the antagonistic RNA-binding proteins Mmi1 and Mei2 to ensure their reciprocal inhibition and fine tune meiotic mRNA degradation during mitotic growth. Mechanistically, mamRNA allows Mmi1 to target Mei2 for ubiquitin-mediated downregulation, and conversely enables accumulating Mei2 to impede Mmi1 activity, thereby reinforcing the mitosis to meiosis switch. These regulations also occur within a unique Mmi1-containing nuclear body, positioning mamRNA as a spatially-confined sensor of Mei2 levels. Our results thus provide a mechanistic basis for the mutual control of gametogenesis effectors and further expand our vision of the regulatory potential of lncRNAs.


2020 ◽  
Author(s):  
D Haskell ◽  
A Zinovyeva

ABSTRACTmicroRNAs (miRNAs) and RNA binding proteins (RBPs) regulate gene expression at the post-transcriptional level, but the extent to which these key regulators of gene expression coordinate and the precise mechanisms of their coordination are not well understood. RNA binding proteins often have recognizable RNA binding domains that correlate with specific protein function. Recently, several RBPs containing K Homology (KH) RNA binding domains were shown to work with miRNAs to regulate gene expression, raising the possibility that KH domains may be important for coordinating with miRNA pathways in gene expression regulation. To ascertain whether additional KH domain proteins functionally interact with miRNAs during Caenorhabditis elegans development, we knocked down twenty-four genes encoding KH-domain proteins in several miRNA sensitized genetic backgrounds. Here, we report that a majority of the KH domain-containing genes genetically interact with multiple miRNAs and Argonaute alg-1. Interestingly, two KH domain genes, predicted splicing factors sfa-1 and asd-2, genetically interacted with all of the miRNA mutants tested, while other KH domain genes exhibited functional interactions only with specific miRNAs. Our domain architecture and phylogenetic relationship analyses of the C. elegans KH domain-containing proteins revealed potential groups that may share both structure and function. Collectively, we show that many C. elegans KH domain RBPs functionally interact with miRNAs, suggesting direct or indirect coordination between these two classes of post-transcriptional gene expression regulators.


2020 ◽  
Author(s):  
Ryan S. Dhindsa ◽  
Anthony W. Zoghbi ◽  
Daniel K. Krizay ◽  
Chirag Vasavda ◽  
David B. Goldstein

AbstractAdvances in genetic discoveries have created substantial opportunities for precision medicine in neurodevelopmental disorders. Many of the genes implicated in these diseases encode proteins that regulate gene expression, such as chromatin associated proteins, transcription factors, and RNA-binding proteins. The identification of targeted therapeutics for individuals carrying mutations in these genes remains a challenge, as the encoded proteins can theoretically regulate thousands of downstream targets in a considerable number of cell types. Here, we propose the application of a drug discovery approach called “transcriptome reversal” for these disorders. This approach, originally developed for cancer, attempts to identify compounds that reverse gene-expression signatures associated with disease states.


2019 ◽  
Author(s):  
Li Li ◽  
Isana Veksler-Lublinsky ◽  
Anna Y. Zinovyeva

AbstractmicroRNAs (miRNAs) are potent regulators of gene expression that function in diverse developmental and physiological processes. Argonaute proteins loaded with miRNAs form the miRNA Induced Silencing Complexes (miRISCs) that repress gene expression at the post-transcriptional level. miRISCs target genes through partial sequence complementarity between the miRNA and the target mRNA’s 3’ UTR. In addition to being targeted by miRNAs, these mRNAs are also extensively regulated by RNA-binding proteins (RBPs) through RNA processing, transport, stability, and translation regulation. While the degree to which RBPs and miRISCs functionally interact to regulate gene expression is likely extensive, we have only begun to unravel these functional interactions. An RNAi-based screen of putative ALG-1 Argonaute interactors has identified a role for a conserved RNA binding protein, HRPK-1, in modulating miRNA activity during C. elegans development. Here, we report the physical and genetic interaction between HRPK-1 and ALG-1/miRNAs. Specifically, we report the genetic and molecular characterizations of hrpk-1 and its role in C. elegans development and miRNA-mediated target repression. We show that loss of hrpk-1 causes numerous developmental defects and enhances the mutant phenotypes associated with reduction of miRNA activity, including those of lsy-6, mir-35-family, and let-7-family miRNAs. In addition to hrpk-1 genetic interaction with these miRNA families, hrpk-1 is required for efficient regulation of lsy-6 target cog-1. We report that hrpk-1 may play a role in miRNA processing but is not globally required for mature miRNA biogenesis or ALG-1/AIN-1 miRISC assembly and confirm HRPK-1 ability to co-precipitate with ALG-1. We suggest that HRPK-1 may functionally interact with miRNAs on multiple levels to enhance miRNA/miRISC gene regulatory activity and present several models for its activity.Author summarymicroRNAs are small non-coding RNAs that regulate gene expression at the post-transcriptional level. The core microRNA Induced Silencing Complex (miRISC), composed of Argonaute, mature microRNA, and GW182 protein effector, assembles on the target messenger RNA and inhibits translation or leads to messenger RNA degradation. RNA binding proteins interface with miRNA pathways on multiple levels to coordinate gene expression regulation. Here, we report identification and characterization of HRPK-1, a conserved RNA binding protein, as a physical and functional interactor of miRNAs. We confirm the physical interaction between HRPK-1, an hnRNPK homolog, and Argonaute ALG-1. We report characterizations of hrpk-1 role in development and its functional interactions with multiple miRNA families. We suggest that HRPK-1 promotes miRNA activity on multiple levels in part by contributing to miRNA processing and by coordinating with miRISC at the level of target RNAs. This work contributes to our understanding of how RNA binding proteins and auxiliary miRNA cofactors may interface with miRNA pathways to modulate miRNA gene regulatory activity.


2020 ◽  
Vol 21 (11) ◽  
pp. 3757 ◽  
Author(s):  
Hui Zhang ◽  
R. Dale Brown ◽  
Kurt R. Stenmark ◽  
Cheng-Jun Hu

Pulmonary hypertension (PH) is a life-threatening disease characterized by significant vascular remodeling and aberrant expression of genes involved in inflammation, apoptosis resistance, proliferation, and metabolism. Effective therapeutic strategies are limited, as mechanisms underlying PH pathophysiology, especially abnormal expression of genes, remain unclear. Most PH studies on gene expression have focused on gene transcription. However, post-transcriptional alterations have been shown to play a critical role in inflammation and metabolic changes in diseases such as cancer and systemic cardiovascular diseases. In these diseases, RNA-binding proteins (RBPs) have been recognized as important regulators of aberrant gene expression via post-transcriptional regulation; however, their role in PH is less clear. Identifying RBPs in PH is of great importance to better understand PH pathophysiology and to identify new targets for PH treatment. In this manuscript, we review the current knowledge on the role of dysregulated RBPs in abnormal mRNA gene expression as well as aberrant non-coding RNA processing and expression (e.g., miRNAs) in PH.


Development ◽  
2021 ◽  
Author(s):  
Hui Tian ◽  
Petko M. Petkov

Spermatogenesis is precisely controlled by complex gene-expression programs. During mammalian male germ-cell development, a crucial feature is the repression of transcription before spermatid elongation. Previously, we discovered that the RNA-binding protein EWSR1 plays an important role in meiotic recombination in mouse, and showed that EWSR1 is highly expressed in late meiotic cells and post-meiotic cells. Here, we used an Ewsr1 pachytene stage-specific knockout mouse model to study the roles of Ewsr1 in late meiotic prophase I and in spermatozoa maturation. We show that loss of EWSR1 in late meiotic prophase I does not affect proper meiosis completion, but does result in defective spermatid elongation and chromocenter formation in the developing germ cells. As a result, male mice lacking EWSR1 after pachynema are sterile. We found that in Ewsr1 CKO round spermatids, transition from a meiotic gene-expression program to a post-meiotic and spermatid gene expression program related to DNA condensation is impaired, suggesting that EWSR1 plays an important role in regulation of spermiogenesis-related mRNA synthesis necessary for spermatid differentiation into mature sperm.


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