scholarly journals Regulation of gene expression in trypanosomatids: living with polycistronic transcription

Open Biology ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 190072 ◽  
Author(s):  
Christine Clayton
Keyword(s):  
Rna Polymerase Ii ◽  
Binding Proteins ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Regulation Of Gene Expression ◽  
Translation Initiation Factor ◽  
Initiation Factor ◽  
Transcription Control ◽  
Individual Gene ◽  
Polycistronic Transcription

In trypanosomes, RNA polymerase II transcription is polycistronic and individual mRNAs are excised by trans -splicing and polyadenylation. The lack of individual gene transcription control is compensated by control of mRNA processing, translation and degradation. Although the basic mechanisms of mRNA decay and translation are evolutionarily conserved, there are also unique aspects, such as the existence of six cap-binding translation initiation factor homologues, a novel decapping enzyme and an mRNA stabilizing complex that is recruited by RNA-binding proteins. High-throughput analyses have identified nearly a hundred regulatory mRNA-binding proteins, making trypanosomes valuable as a model system to investigate post-transcriptional regulation.

eIF4E-binding proteins: new factors, new locations, new roles

2014 ◽  
Vol 42 (4) ◽  
pp. 1238-1245 ◽  
Author(s):  
Anastasiia Kamenska ◽  
Clare Simpson ◽  
Nancy Standart
Keyword(s):  
Binding Proteins ◽  
Rna Binding ◽  
Gene Expression Regulation ◽  
Rna Binding Proteins ◽  
Ribosomal Subunit ◽  
Translation Initiation Factor ◽  
Initiation Factor ◽  
Eukaryotic Initiation Factor 4E ◽  
New Locations ◽  
Specific Mrnas

The cap-binding translation initiation factor eIF4E (eukaryotic initiation factor 4E) is central to protein synthesis in eukaryotes. As an integral component of eIF4F, a complex also containing the large bridging factor eIF4G and eIF4A RNA helicase, eIF4E enables the recruitment of the small ribosomal subunit to the 5′ end of mRNAs. The interaction between eIF4E and eIF4G via a YXXXXLϕ motif is regulated by small eIF4E-binding proteins, 4E-BPs, which use the same sequence to competitively bind eIF4E thereby inhibiting cap-dependent translation. Additional eIF4E-binding proteins have been identified in the last 10–15 years, characterized by the YXXXXLϕ motif, and by interactions (many of which remain to be detailed) with RNA-binding proteins, or other factors in complexes that recognize the specific mRNAs. In the present article, we focus on the metazoan 4E-T (4E-transporter)/Cup family of eIF4E-binding proteins, and also discuss very recent examples in yeast, fruitflies and humans, some of which predictably inhibit translation, while others may result in mRNA decay or even enhance translation; altogether considerably expanding our understanding of the roles of eIF4E-binding proteins in gene expression regulation.

scholarly journals PTBP1 mRNA isoforms and regulation of their translation

2018 ◽  
Author(s):  
Luisa M Arake de Tacca ◽  
Mia C Pulos ◽  
Stephen N Floor ◽  
Jamie Cate
Keyword(s):  
Cell Cycle ◽  
Alternative Splicing ◽  
Binding Proteins ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Translation Initiation Factor ◽  
Protein Isoforms ◽  
Initiation Factor ◽  
Dependent Manner ◽  
Mrna Isoforms

Polypyrimidine tract-binding proteins (PTBPs) are RNA binding proteins that regulate a number of post-transcriptional events. Human PTBP1 transits between the nucleus and cytoplasm and is thought to regulate RNA processes in both. However, information about PTBP1 mRNA isoforms and regulation of PTPB1 expression remain incomplete. Here we mapped the major PTBP1 mRNA isoforms in HEK293T cells, and identified alternative 5' and 3' untranslated regions (5' UTRs, 3' UTRs) as well as alternative splicing patterns in the protein coding region. We also assessed how the observed PTBP1 mRNA isoforms contribute to PTBP1 expression in different phases of the cell cycle. Previously, PTBP1 mRNAs were shown to crosslink to eukaryotic translation initiation factor 3 (eIF3). We find that eIF3 binds differently to each PTBP1 mRNA isoform in a cell cycle-dependent manner. We also observe a strong correlation between eIF3 binding to PTBP1 mRNAs and repression of PTBP1 levels during the S phase of the cell cycle. Our results provide evidence of translational regulation of PTBP1 protein levels during the cell cycle, which may affect downstream regulation of alternative splicing and translation mediated by PTBP1 protein isoforms.

scholarly journals The DAZL and PABP families: RNA-binding proteins with interrelated roles in translational control in oocytes

Reproduction ◽  
2009 ◽  
Vol 137 (4) ◽  
pp. 595-617 ◽  
Author(s):  
Matthew Brook ◽  
Joel W S Smith ◽  
Nicola K Gray
Keyword(s):  
Gene Expression ◽  
Germ Cells ◽  
Translational Control ◽  
Translational Regulation ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Regulation Of Gene Expression ◽  
Mrna Translation ◽  
Translation Initiation Factor ◽  
Initiation Factor

Gametogenesis is a highly complex process that requires the exquisite temporal, spatial and amplitudinal regulation of gene expression at multiple levels. Translational regulation is important in a wide variety of cell types but may be even more prevalent in germ cells, where periods of transcriptional quiescence necessitate the use of post-transcriptional mechanisms to effect changes in gene expression. Consistent with this, studies in multiple animal models have revealed an essential role for mRNA translation in the establishment and maintenance of reproductive competence. While studies in humans are less advanced, emerging evidence suggests that translational regulation plays a similarly important role in human germ cells and fertility. This review highlights specific mechanisms of translational regulation that play critical roles in oogenesis by activating subsets of mRNAs. These mRNAs are activated in a strictly determined temporal manner via elements located within their 3′UTR, which serve as binding sites fortrans-acting factors. While we concentrate on oogenesis, these regulatory events also play important roles during spermatogenesis. In particular, we focus on the deleted in azoospermia-like (DAZL) family of proteins, recently implicated in the translational control of specific mRNAs in germ cells; their relationship with the general translation initiation factor poly(A)-binding protein (PABP) and the process of cytoplasmic mRNA polyadenylation.

PUB1: a major yeast poly(A)+ RNA-binding protein

1993 ◽  
Vol 13 (10) ◽  
pp. 6114-6123
Author(s):  
M J Matunis ◽  
E L Matunis ◽  
G Dreyfuss
Keyword(s):  
Rna Polymerase Ii ◽  
Binding Proteins ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Uv Light ◽  
Binding Protein ◽  
Gene Replacement ◽  
Yeast Saccharomyces Cerevisiae ◽  
Binding Domains ◽  
Development And Differentiation

The expression of RNA polymerase II transcripts can be regulated at the posttranscriptional level by RNA-binding proteins. Although extensively characterized in metazoans, relatively few RNA-binding proteins have been characterized in the yeast Saccharomyces cerevisiae. Three major proteins are cross-linked by UV light to poly(A)+ RNA in living S. cerevisiae cells. These are the 72-kDa poly(A)-binding protein and proteins of 60 and 50 kDa (S.A. Adam, T.Y. Nakagawa, M.S. Swanson, T. Woodruff, and G. Dreyfuss, Mol. Cell. Biol. 6:2932-2943, 1986). Here, we describe the 60-kDa protein, one of the major poly(A)+ RNA-binding proteins in S. cerevisiae. This protein, PUB1 [for poly(U)-binding protein 1], was purified by affinity chromatography on immobilized poly(rU), and specific monoclonal antibodies to it were produced. UV cross-linking demonstrated that PUB1 is bound to poly(A)+ RNA (mRNA or pre-mRNA) in living cells, and it was detected primarily in the cytoplasm by indirect immunofluorescence. The gene for PUB1 was cloned and sequenced, and the sequence was found to predict a 51-kDa protein with three ribonucleoprotein consensus RNA-binding domains and three glutamine- and asparagine-rich auxiliary domains. This overall structure is remarkably similar to the structures of the Drosophila melanogaster elav gene product, the human neuronal antigen HuD, and the cytolytic lymphocyte protein TIA-1. Each of these proteins has an important role in development and differentiation, potentially by affecting RNA processing. PUB1 was found to be nonessential in S. cerevisiae by gene replacement; however, further genetic analysis should reveal important features of this class of RNA-binding proteins.

scholarly journals Interaction of yeast RNA-binding proteins Nrd1 and Nab3 with RNA polymerase II terminator elements

RNA ◽  
2007 ◽  
Vol 13 (3) ◽  
pp. 361-373 ◽  
Author(s):  
K. L. Carroll ◽  
R. Ghirlando ◽  
J. M. Ames ◽  
J. L. Corden
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Binding Proteins ◽  
Rna Binding ◽  
Rna Binding Proteins

scholarly journals Identification of hemicatenane-specific binding proteins by fractionation of HeLa nuclei extracts

2020 ◽  
Vol 477 (2) ◽  
pp. 509-524
Author(s):  
Oumayma Rouis ◽  
Cédric Broussard ◽  
François Guillonneau ◽  
Jean-Baptiste Boulé ◽  
Emmanuelle Delagoutte
Keyword(s):  
Spatial Organization ◽  
Binding Proteins ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Specific Binding ◽  
Regulation Of Gene Expression ◽  
Double Stranded Dna ◽  
Nuclear Extracts ◽  
Interesting Possibility

DNA hemicatenanes (HCs) are four-way junctions in which one strand of a double-stranded helix is catenated with one strand of another double-stranded DNA. Frequently mentioned as DNA replication, recombination and repair intermediates, they have been proposed to participate in the spatial organization of chromosomes and in the regulation of gene expression. To explore potential roles of HCs in genome metabolism, we sought to purify proteins capable of binding specifically HCs by fractionating nuclear extracts from HeLa cells. This approach identified three RNA-binding proteins: the Tudor-staphylococcal nuclease domain 1 (SND1) protein and two proteins from the Drosophila behavior human splicing family, the paraspeckle protein component 1 and the splicing factor proline- and glutamine-rich protein. Since these proteins were partially pure after fractionation, truncated forms of these proteins were expressed in Escherichia coli and purified to near homogeneity. The specificity of their interaction with HCs was re-examined in vitro. The two truncated purified SND1 proteins exhibited specificity for HCs, opening the interesting possibility of a link between the basic transcription machinery and HC structures via SND1.

scholarly journals RNA-Binding Proteins as Regulators of Migration, Invasion and Metastasis in Oral Squamous Cell Carcinoma

2020 ◽  
Vol 21 (18) ◽  
pp. 6835
Author(s):  
Jonas Weiße ◽  
Julia Rosemann ◽  
Vanessa Krauspe ◽  
Matthias Kappler ◽  
Alexander W. Eckert ◽  
...  
Keyword(s):  
Gene Expression ◽  
Binding Proteins ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Regulation Of Gene Expression ◽  
Invasion And Metastasis ◽  
Protein Coding ◽  
Oral Cancers ◽  
Cellular Processes ◽  
Post Transcriptional Regulation

Nearly 7.5% of all human protein-coding genes have been assigned to the class of RNA-binding proteins (RBPs), and over the past decade, RBPs have been increasingly recognized as important regulators of molecular and cellular homeostasis. RBPs regulate the post-transcriptional processing of their target RNAs, i.e., alternative splicing, polyadenylation, stability and turnover, localization, or translation as well as editing and chemical modification, thereby tuning gene expression programs of diverse cellular processes such as cell survival and malignant spread. Importantly, metastases are the major cause of cancer-associated deaths in general, and particularly in oral cancers, which account for 2% of the global cancer mortality. However, the roles and architecture of RBPs and RBP-controlled expression networks during the diverse steps of the metastatic cascade are only incompletely understood. In this review, we will offer a brief overview about RBPs and their general contribution to post-transcriptional regulation of gene expression. Subsequently, we will highlight selected examples of RBPs that have been shown to play a role in oral cancer cell migration, invasion, and metastasis. Last but not least, we will present targeting strategies that have been developed to interfere with the function of some of these RBPs.

scholarly journals The Tristetraprolin Family of RNA-Binding Proteins in Cancer: Progress and Future Prospects

Cancers ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1539 ◽  
Author(s):  
Yogesh Saini ◽  
Jian Chen ◽  
Sonika Patial
Keyword(s):  
Gene Expression ◽  
Transcriptional Regulation ◽  
Zinc Finger ◽  
Binding Proteins ◽  
Rna Binding ◽  
Zinc Finger Protein ◽  
Rna Binding Proteins ◽  
Regulation Of Gene Expression ◽  
Finger Protein ◽  
Post Transcriptional Regulation

Post-transcriptional regulation of gene expression plays a key role in cellular proliferation, differentiation, migration, and apoptosis. Increasing evidence suggests dysregulated post-transcriptional gene expression as an important mechanism in the pathogenesis of cancer. The tristetraprolin family of RNA-binding proteins (RBPs), which include Zinc Finger Protein 36 (ZFP36; commonly referred to as tristetraprolin (TTP)), Zinc Finger Protein 36 like 1 (ZFP36L1), and Zinc Finger Protein 36 like 2 (ZFP36L2), play key roles in the post-transcriptional regulation of gene expression. Mechanistically, these proteins function by binding to the AU-rich elements within the 3′-untranslated regions of their target mRNAs and, in turn, increasing mRNA turnover. The TTP family RBPs are emerging as key regulators of multiple biological processes relevant to cancer and are aberrantly expressed in numerous human cancers. The TTP family RBPs have tumor-suppressive properties and are also associated with cancer prognosis, metastasis, and resistance to chemotherapy. Herein, we summarize the various hallmark molecular traits of cancers that are reported to be regulated by the TTP family RBPs. We emphasize the role of the TTP family RBPs in the regulation of trait-associated mRNA targets in relevant cancer types/cell lines. Finally, we highlight the potential of the TTP family RBPs as prognostic indicators and discuss the possibility of targeting these TTP family RBPs for therapeutic benefits.

scholarly journals Functional reconstruction of NANOS3 expression in the germ cell lineage by a novel transgenic reporter reveals distinct subcellular localizations of NANOS3

Reproduction ◽  
2010 ◽  
Vol 139 (2) ◽  
pp. 381-393 ◽  
Author(s):  
Masashi Yamaji ◽  
Takashi Tanaka ◽  
Mayo Shigeta ◽  
Shinichiro Chuma ◽  
Yumiko Saga ◽  
...  
Keyword(s):  
Germ Cell ◽  
Germ Cells ◽  
Binding Proteins ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Primordial Germ Cells ◽  
Cell Lineage ◽  
Regulatory Elements ◽  
Initiation Factor ◽  
Processing Bodies

Mutations of RNA-binding proteins such as NANOS3, TIAL1, and DND1 in mice have been known to result in the failure of survival and/or proliferation of primordial germ cells (PGCs) soon after their fate is specified (around embryonic day (E) 8.0), leading to the infertility of these animals. However, the mechanisms of actions of these RNA-binding proteins remain largely unresolved. As a foundation to explore the role of these RNA-binding proteins in germ cells, we established a novel transgenic reporter strain that expresses NANOS3 fused with EGFP under the control of Nanos3 regulatory elements. NANOS3–EGFP exhibited exclusive expression in PGCs as early as E7.25, and continued to be expressed in female germ cells until around E14.5 and in male germ cells throughout the fetal period with declining expression levels after E16.5. NANOS3–EGFP resumed strong expression in postnatal spermatogonia and continued to be expressed in undifferentiated spermatogonial cells in adults. Importantly, the Nanos3–EGFP transgene rescued the sterile phenotype of Nanos3 homozygous mutants, demonstrating the functional equivalency of NANOS3–EGFP with endogenous NANOS3. We found that throughout germ cell development, a predominant amount of  NANOS3–EGFP co-localized with TIAL1 (also known as TIAR) and phosphorylated eukaryotic initiation factor 2α, markers for the stress granules, whereas a fraction of it showed co-localization with DCP1A, a marker for the processing bodies. On the other hand, NANOS3–EGFP did not co-localize with Tudor domain-containing protein 1, a marker for the intermitochondrial cements, in spermatogenic cells. These findings unveil the presence of distinct posttranscriptional regulations in PGCs soon after their specification, for which RNA-binding proteins such as NANOS3 and TIAL1 would play critical functions.

At the Interface of Three Nucleic Acids: The Role of RNA-Binding Proteins and Poly(ADP-ribose) in DNA Repair

Acta Naturae ◽  
2017 ◽  
Vol 9 (2) ◽  
pp. 4-16 ◽  
Author(s):  
E. E. Alemasova ◽  
O. I. Lavrik
Keyword(s):  
Dna Damage ◽  
Dna Repair ◽  
Binding Proteins ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Binding Protein ◽  
Regulation Of Gene Expression ◽  
Rna Granules ◽  
Dna And Rna ◽  
Cytoplasmic Rna

RNA-binding proteins (RBPs) regulate RNA metabolism, from synthesis to decay. When bound to RNA, RBPs act as guardians of the genome integrity at different levels, from DNA damage prevention to the post-transcriptional regulation of gene expression. Recently, RBPs have been shown to participate in DNA repair. This fact is of special interest as DNA repair pathways do not generally involve RNA. DNA damage in higher organisms triggers the formation of the RNA-like polymer - poly(ADP-ribose) (PAR). Nucleic acid-like properties allow PAR to recruit DNA- and RNA-binding proteins to the site of DNA damage. It is suggested that poly(ADP-ribose) and RBPs not only modulate the activities of DNA repair factors, but that they also play an important role in the formation of transient repairosome complexes in the nucleus. Cytoplasmic biomolecules are subjected to similar sorting during the formation of RNA assemblages by functionally related mRNAs and promiscuous RBPs. The Y-box-binding protein 1 (YB-1) is the major component of cytoplasmic RNA granules. Although YB-1 is a classic RNA-binding protein, it is now regarded as a non-canonical factor of DNA repair.

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