scholarly journals Polymerase pausing induced by sequence-specific RNA binding protein drives heterochromatin assembly

2017 ◽  
Author(s):  
Jahan-Yar Parsa ◽  
Selim Boudoukha ◽  
Jordan Burke ◽  
Christina Homer ◽  
Hiten D. Madhani
Keyword(s):  
Genome Stability ◽  
Rna Binding ◽  
De Novo ◽  
Binding Protein ◽  
Rna Binding Protein ◽  
Heterochromatin Formation ◽  
Repressor Complex ◽  
Polymerase Pausing ◽  
Heterochromatin Assembly ◽  
Dependent Mechanism

Packaging of pericentromeric DNA into heterochromatin is crucial for genome stability, development and health, yet its endogenous triggers remain poorly understood1. A defining feature of pericentromeric heterochromatin is histone H3 lysine 9 methylation (H3K9me)2–4. In S. pombe, transcripts derived from the pericentromeric dg and dh repeat during S phase5–7 promote heterochromatin formation through two pathways: an RNAi-dependent mechanism involving recruitment of the Clr4 H3K9 methyltransferase complex (CLR-C) via the RITS complex8–13, and RNAi-independent mechanism involving an RNAPII-associated RNA-binding protein Seb1, the repressor complex SHREC, and RNA processing activities14–19. We show here that Seb1 promotes long-lived RNAPII pausing. Pause sites associated with sequence-specific Seb1 RNA binding events are significantly enriched in pericentromeric repeat regions and their presence correlates with the heterochromatin-triggering activities of the corresponding dg and dh DNA fragments. Remarkably, globally increasing RNAPII stalling by other means induces the formation of novel large ectopic heterochromatin domains. Such ectopic heterochromatin occurs even in cells lacking functional RITS, demonstrating that RNAPII pausing can be sufficient to trigger de novo heterochromatin independently of RNAi. These results uncover Seb1-mediated polymerase stalling as a new signal for nucleating heterochromatin assembly in repetitive DNA.

scholarly journals Polymerase pausing induced by sequence-specific RNA-binding protein drives heterochromatin assembly

2018 ◽  
Vol 32 (13-14) ◽  
pp. 953-964 ◽  
Author(s):  
Jahan-Yar Parsa ◽  
Selim Boudoukha ◽  
Jordan Burke ◽  
Christina Homer ◽  
Hiten D. Madhani
Keyword(s):  
Rna Binding ◽  
Binding Protein ◽  
Rna Binding Protein ◽  
Polymerase Pausing ◽  
Heterochromatin Assembly

scholarly journals PARP-1–dependent recruitment of cold-inducible RNA-binding protein promotes double-strand break repair and genome stability

2018 ◽  
Vol 115 (8) ◽  
pp. E1759-E1768 ◽  
Author(s):  
Jung-Kuei Chen ◽  
Wen-Ling Lin ◽  
Zhang Chen ◽  
Hung-wen Liu
Keyword(s):  
Dna Damage ◽  
Genome Stability ◽  
Rna Binding ◽  
Binding Protein ◽  
Rna Binding Protein ◽  
Strand Break ◽  
Double Strand Break ◽  
Dsb Repair ◽  
Active Involvement ◽  
Parp 1

Maintenance of genome integrity is critical for both faithful propagation of genetic information and prevention of mutagenesis induced by various DNA damage events. Here we report cold-inducible RNA-binding protein (CIRBP) as a newly identified key regulator in DNA double-strand break (DSB) repair. On DNA damage, CIRBP temporarily accumulates at the damaged regions and is poly(ADP ribosyl)ated by poly(ADP ribose) polymerase-1 (PARP-1). Its dissociation from the sites of damage may depend on its phosphorylation status as mediated by phosphatidylinositol 3-kinase-related kinases. In the absence of CIRBP, cells showed reduced γH2AX, Rad51, and 53BP1 foci formation. Moreover, CIRBP-depleted cells exhibited impaired homologous recombination, impaired nonhomologous end-joining, increased micronuclei formation, and higher sensitivity to gamma irradiation, demonstrating the active involvement of CIRBP in DSB repair. Furthermore, CIRBP depleted cells exhibited defects in DNA damage-induced chromatin association of the MRN complex (Mre11, Rad50, and NBS1) and ATM kinase. CIRBP depletion also reduced phosphorylation of a variety of ATM substrate proteins and thus impaired the DNA damage response. Taken together, these results reveal a previously unrecognized role for CIRBP in DSB repair.

scholarly journals α-Actinin TvACTN3 ofTrichomonas vaginalisIs an RNA-Binding Protein That Could Participate in Its Posttranscriptional Iron Regulatory Mechanism

2014 ◽  
Vol 2014 ◽  
pp. 1-20 ◽  
Author(s):  
Jaeson Santos Calla-Choque ◽  
Elisa Elvira Figueroa-Angulo ◽  
Leticia Ávila-González ◽  
Rossana Arroyo
Keyword(s):  
Trichomonas Vaginalis ◽  
Rna Binding ◽  
Regulatory Mechanism ◽  
De Novo ◽  
Binding Protein ◽  
Regulation Of Gene Expression ◽  
Iron Concentration ◽  
Rna Binding Protein ◽  
Cross Linking ◽  
Cytoplasmic Protein

Trichomonas vaginalisis a sexually transmitted flagellated protist parasite responsible for trichomoniasis. This parasite is dependent on high levels of iron, favoring its growth and multiplication. Iron also differentially regulates some trichomonad virulence properties by unknown mechanisms. However, there is evidence to support the existence of gene regulatory mechanisms at the transcriptional and posttranscriptional levels that are mediated by iron concentration inT. vaginalis. Thus, the goal of this study was to identify an RNA-binding protein inT. vaginalisthat interacts with the tvcp4 RNA stem-loop structure, which may participate in a posttranscriptional iron regulatory mechanism mediated by RNA-protein interactions. We performed RNA electrophoretic mobility shift assay (REMSA) and supershift, UV cross-linking, Northwestern blot, and western blot (WB) assays using cytoplasmic protein extracts fromT. vaginaliswith the tvcp4 RNA hairpin structure as a probe. We identified a 135-kDa protein isolated by the UV cross-linking assays asα-actinin 3 (TvACTN3) by MALDI-TOF-MS that was confirmed by LS-MS/MS andde novosequencing. TvACTN3 is a cytoplasmic protein that specifically binds to hairpin RNA structures from trichomonads and humans when the parasites are grown under iron-depleted conditions. Thus, TvACTN3 could participate in the regulation of gene expression by iron inT. vaginalisthrough a parallel posttranscriptional mechanism similar to that of the IRE/IRP system.

scholarly journals Su1862 RNA Binding Protein Musashi-1 Regulates Tumorigenesis and Angiogenesis via MicroRNA-Dependent Mechanism

2014 ◽  
Vol 146 (5) ◽  
pp. S-488
Author(s):  
Sripathi M. Sureban ◽  
Randal May ◽  
Dongfeng Qu ◽  
Parthasarathy Chandrakesan ◽  
Nathaniel Weygant ◽  
...  
Keyword(s):  
Rna Binding ◽  
Binding Protein ◽  
Rna Binding Protein ◽  
Dependent Mechanism

scholarly journals The Fission Yeast RNA-Binding Protein Meu5 Is Involved in Outer Forespore Membrane Breakdown during Spore Formation

2020 ◽  
Vol 6 (4) ◽  
pp. 284
Author(s):  
Bowen Zhang ◽  
Erika Teraguchi ◽  
Kazuki Imada ◽  
Yuhei O. Tahara ◽  
Shuko Nakamura ◽  
...  
Keyword(s):  
Molecular Mechanism ◽  
Target Genes ◽  
Rna Binding ◽  
De Novo ◽  
Binding Protein ◽  
Rna Binding Protein ◽  
Biological Significance ◽  
Spore Wall ◽  
Spore Formation ◽  
Membrane Breakdown

In Schizosaccharomyces pombe, the spore wall confers strong resistance against external stress. During meiosis II, the double-layered intracellular forespore membrane (FSM) forms de novo and encapsulates the nucleus. Eventually, the inner FSM layer becomes the plasma membrane of the spore, while the outer layer breaks down. However, the molecular mechanism and biological significance of this membrane breakdown remain unknown. Here, by genetic investigation of an S. pombe mutant (E22) with normal prespore formation but abnormal spores, we showed that Meu5, an RNA-binding protein known to bind to and stabilize more than 80 transcripts, is involved in this process. We confirmed that the E22 mutant does not produce Meu5 protein, while overexpression of meu5+ in E22 restores the sporulation defect. Furthermore, electron microscopy revealed that the outer membrane of the FSM persisted in meu5∆ spores. Investigation of the target genes of meu5+ showed that a mutant of cyc1+ encoding cytochrome c also showed a severe defect in outer FSM breakdown. Lastly, we determined that outer FSM breakdown occurs coincident with or after formation of the outermost Isp3 layer of the spore wall. Collectively, our data provide novel insights into the molecular mechanism of spore formation.

scholarly journals Kaposi's Sarcoma-Associated Herpesvirus K8 Is an RNA Binding Protein That Regulates Viral DNA Replication in Coordination with a Noncoding RNA

2018 ◽  
Vol 92 (7) ◽  
Author(s):  
Dongcheng Liu ◽  
Yan Wang ◽  
Yan Yuan
Keyword(s):  
Dna Replication ◽  
Noncoding Rna ◽  
Rna Binding ◽  
De Novo ◽  
Binding Protein ◽  
Rna Binding Protein ◽  
Noncoding Rnas ◽  
Viral Dna ◽  
Viral Dna Replication

ABSTRACTKaposi's sarcoma-associated herpesvirus (KSHV) lytic replication and constant primary infection of fresh cells are crucial for viral tumorigenicity. The virus-encoded bZIP family protein K8 plays an important role in viral DNA replication in both viral reactivation andde novoinfection. The mechanism underlying the functional role of K8 in the viral life cycle is elusive. Here, we report that K8 is an RNA binding protein that also associates with many other proteins, including other RNA binding proteins. Many protein-protein interactions involving K8 are mediated by RNA. Using a UVcross-linking andimmunoprecipitation (CLIP) procedure combined with high-throughput sequencing, RNAs that are associated with K8 in BCBL-1 cells were identified, including both viral (PAN, T1.4, T0.7, etc.) and cellular (MALAT-1, MRP, 7SK, etc.) RNAs. An RNA binding motif in K8 was defined, and mutation of the motif abolished the ability of K8 to bind to many noncoding RNAs, as well as viral DNA replication duringde novoinfection, suggesting that the K8 functions in viral replication are carried out through RNA association. The functions of K8 and associated T1.4 RNA were investigated in detail, and the results showed that T1.4 mediates the binding of K8 to ori-Lyt DNA. The T1.4-K8 complex physically bound to KSHV ori-Lyt DNA and recruited other proteins and cofactors to assemble a replication complex. Depletion of T1.4 abolished DNA replication in primary infection. These findings provide mechanistic insights into the role of K8 in coordination with T1.4 RNA in regulating KSHV DNA replication duringde novoinfection.IMPORTANCEGenomewide analyses of the mammalian transcriptome revealed that a large proportion of sequence previously annotated as noncoding regions is actually transcribed and gives rise to stable RNAs. The emergence of a large number of noncoding RNAs suggests that functional RNA-protein complexes, e.g., ribosomes or spliceosomes, are not ancient relics of the last ribo-organism but would be well adapted to a regulatory role in biology. K8 has been puzzling because of its unique characteristics, such as multiple regulatory roles in gene expression and DNA replication without DNA binding capability. This study reveals the mechanism underlying its regulatory role by demonstrating that K8 is an RNA binding protein that binds to DNA and initiates DNA replication in coordination with a noncoding RNA. It is suggested that many K8 functions, if not all, are carried out through its associated RNAs.

scholarly journals Global cataloguing of variations in untranslated regions of viral genome and prediction of key host RNA binding protein-microRNA interactions modulating genome stability in SARS-CoV2

2020 ◽  
Author(s):  
Moumita Mukherjee ◽  
Srikanta Goswami
Keyword(s):  
Genome Stability ◽  
Rna Binding ◽  
Binding Protein ◽  
Rna Binding Protein ◽  
Untranslated Regions ◽  
Global Changes ◽  
Sequence Information ◽  
Coding Region ◽  
High Coverage ◽  
Geographical Regions

AbstractBackgroundThe world is going through the critical phase of COVID-19 pandemic, caused by human coronavirus, SARS-CoV2. Worldwide concerted effort to identify viral genomic changes across different sub-types has identified several strong changes in the coding region. However, there have not been many studies focusing on the variations in the 5’ and 3’ untranslated regions and their consequences. Considering the possible importance of these regions in host mediated regulation of viral RNA genome, we wanted to explore the phenomenon.MethodsTo have an idea of the global changes in 5’ and 3’-UTR sequences, we downloaded 8595 complete and high-coverage SARS-CoV2 genome sequence information from human host in FASTA format from Global Initiative on Sharing All Influenza Data (GISAID) from 15 different geographical regions. Next, we aligned them using Clustal Omega software and investigated the UTR variants. We also looked at the putative host RNA binding protein (RBP) and microRNA binding sites in these regions by ‘RBPmap’ and ‘RNA22 v2’ respectively. Expression status of selected RBPs and microRNAs were checked in lungs tissue.ResultsWe identified 28 unique variants in SARS-CoV2 UTR region based on a minimum variant percentage cut-off of 0.5. Along with 241C>T change the important 5’-UTR change identified was 187A>G, while 29734G>C, 29742G>A/T and 29774C>T were the most familiar variants of 3’UTR among most of the continents. Furthermore, we found that despite of the variations in the UTR regions, binding of host RBP to them remains mostly unaltered, which further influenced the functioning of specific miRNAs.ConclusionOur results, shows for the first time in SARS-Cov2 infection, a possible cross-talk between host RBPs-miRNAs and viral UTR variants, which ultimately could explain the mechanism of escaping host RNA decay machinery by the virus. The knowledge might be helpful in developing anti-viral compounds in future.

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