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 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 Zygotic Expression of the Double-Stranded RNA Binding Motif Protein Drb2p Is Required for DNA Elimination in the Ciliate Tetrahymena thermophila

2011 ◽  
Vol 10 (12) ◽  
pp. 1648-1659 ◽  
Author(s):  
Jason A. Motl ◽  
Douglas L. Chalker
Keyword(s):  
Rna Binding ◽  
Tetrahymena Thermophila ◽  
Germ Line ◽  
Rna Binding Proteins ◽  
Chromosome Breakage ◽  
Binding Motif ◽  
Double Stranded Rna ◽  
Content Type ◽  
Dna Elimination ◽  
Genes Encoding

ABSTRACTDouble-stranded RNA binding motif (DSRM)-containing proteins play many roles in the regulation of gene transcription and translation, including some with tandem DSRMs that act in small RNA biogenesis. We report the characterization of the genes for double-stranded RNA binding proteins 1 and 2 (DRB1andDRB2), two genes encoding nuclear proteins with tandem DSRMs in the ciliateTetrahymena thermophila.Both proteins are expressed throughout growth and development but exhibit distinct peaks of expression, suggesting different biological roles. In support of this, we show that expression ofDRB2is essential for vegetative growth whileDRB1expression is not. During conjugation, Drb1p and Drb2p localize to distinct nuclear foci. Cells lacking allDRB1copies are able to produce viable progeny, although at a reduced rate relative to wild-type cells. In contrast, cells lacking germ lineDRB2copies, which thus cannot express Drb2p zygotically, fail to produce progeny, arresting late into conjugation. This arrest phenotype is accompanied by a failure to organize the essential DNA rearrangement protein Pdd1p into DNA elimination bodies and execute DNA elimination and chromosome breakage. These results implicate zygotically expressed Drb2p in the maturation of these nuclear structures, which are necessary for reorganization of the somatic genome.

scholarly journals RNA-Binding Protein Rnc1 Regulates Cell Length at Division and Acute Stress Response in Fission Yeast through Negative Feedback Modulation of the Stress-Activated Mitogen-Activated Protein Kinase Pathway

mBio ◽  
2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Francisco Prieto-Ruiz ◽  
Jero Vicente-Soler ◽  
Alejandro Franco ◽  
Elisa Gómez-Gil ◽  
Marta Sánchez-Marinas ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Fission Yeast ◽  
Binding Proteins ◽  
Rna Binding ◽  
Acute Stress ◽  
Rna Binding Proteins ◽  
Cell Length ◽  
Mitogen Activated Protein Kinase ◽  
Content Type ◽  
Mitogen Activated Protein

ABSTRACT RNA-binding proteins (RBPs) play a major role during control of mRNA localization, stability, and translation and are central to most cellular processes. In the fission yeast Schizosaccharomyces pombe, the multiple K homology (KH) domain RBP Rnc1 downregulates the activity of the cell integrity pathway (CIP) via stabilization of pmp1+ mRNA, which encodes the Pmp1 phosphatase that inactivates Pmk1, the mitogen-activated protein kinase (MAPK) component of this signaling cascade. However, Rnc1 likely regulates the half-life/stability of additional mRNAs. We show that Rnc1 downregulates the activity of Sty1, the MAPK of the stress-activated MAPK pathway (SAPK), during control of cell length at division and recovery in response to acute stress. Importantly, this control strictly depends on Rnc1’s ability to bind mRNAs encoding activators (Wak1 MAPKKK, Wis1 MAPKK) and downregulators (Atf1 transcription factor, Pyp1 and Pyp2 phosphatases) of Sty1 phosphorylation through its KH domains. Moreover, Sty1 is responsible for Rnc1 phosphorylation in vivo at multiple phosphosites during growth and stress, and these modifications trigger Rnc1 for proper binding and destabilization of the above mRNA targets. Phosphorylation by Sty1 prompts Rnc1-dependent mRNA destabilization to negatively control SAPK signaling, thus revealing an additional feedback mechanism that allows precise tuning of MAPK activity during unperturbed cell growth and stress. IMPORTANCE Control of mRNA localization, stability, turnover, and translation by RNA-binding proteins (RBPs) influences essential processes in all eukaryotes, including signaling by mitogen-activated protein kinase (MAPK) pathways. We describe that in the fission yeast Schizosaccharomyces pombe the RBP Rnc1 negatively regulates cell length at division during unperturbed growth and recovery after acute stress by reducing the activity of the MAPK Sty1, which regulates cell growth and differentiation during environmental cues. This mechanism relies on Rnc1 binding to specific mRNAs encoding both enhancers and negative regulators of Sty1 activity. Remarkably, multiple phosphorylation of Rnc1 by Sty1 favors RBP binding and destabilization of the above mRNAs. Thus, posttranscriptional modulation of MAP kinase signaling by RNA-binding proteins emerges as a major regulatory mechanism that dictates the growth cycle and cellular adaptation in response to the changing environment in eukaryotic organisms.

scholarly journals Interaction of SNF1 Protein Kinase with Its Activating Kinase Sak1

2011 ◽  
Vol 10 (3) ◽  
pp. 313-319 ◽  
Author(s):  
Yang Liu ◽  
Xinjing Xu ◽  
Marian Carlson
Keyword(s):  
Protein Kinase ◽  
Kinase Domain ◽  
Catalytic Subunit ◽  
Glucose Limitation ◽  
Content Type ◽  
Snf1 Kinase ◽  
Phosphorylation State ◽  
Glucose Depletion ◽  
C Terminus ◽  
Amp Activated Protein Kinase

ABSTRACT The Saccharomyces cerevisiae SNF1 protein kinase, a member of the SNF1/AMP-activated protein kinase (AMPK) family, is activated by three kinases, Sak1, Tos3, and Elm1, which phosphorylate the Snf1 catalytic subunit on Thr-210 in response to glucose limitation and other stresses. Sak1 is the primary Snf1-activating kinase and is associated with Snf1 in a complex. Here we examine the interaction of Sak1 with SNF1. We report that Sak1 coimmunopurifies with the Snf1 catalytic subunit from extracts of both glucose-replete and glucose-limited cultures and that interaction occurs independently of the phosphorylation state of Snf1 Thr-210, Snf1 catalytic activity, and other SNF1 subunits. Sak1 interacts with the Snf1 kinase domain, and nonconserved sequences C terminal to the Sak1 kinase domain mediate interaction with Snf1 and augment the phosphorylation and activation of Snf1. The Sak1 C terminus is modified in response to glucose depletion, dependent on SNF1 activity. Replacement of the C terminus of Elm1 (or Tos3) with that of Sak1 enhanced the ability of the Elm1 kinase domain to interact with and phosphorylate Snf1. These findings indicate that the C terminus of Sak1 confers its function as the primary Snf1-activating kinase and suggest that the physical association of Sak1 with SNF1 facilitates responses to environmental change.

Molecular dissection of a genome defense pathway in Neurospora crassa

2015 ◽  
Author(s):  
◽  
Erin C. Boone
Keyword(s):  
Neurospora Crassa ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Nuclear Periphery ◽  
Bimolecular Fluorescence Complementation ◽  
Proper Function ◽  
Rnai Pathway ◽  
Binding Motif ◽  
Perinuclear Region ◽  
A Genome

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] Meiotic silencing by unpaired DNA (MSUD) is an RNA interference (RNAi) pathway in Neurospora crassa that detects genes without a homologous partner and silences them for the duration of sexual development. In this study, we have further elucidated the function of known MSUD proteins, identified novel proteins that are required for MSUD, and demonstrated the conservation of RNAi-related processes at the nuclear periphery. We began by showing SAD-2 is crucial for the localization of other MSUD proteins in the perinuclear region. These data suggest that SAD-2 works as a scaffold protein and that proper function of MSUD, like other germline RNAi-like systems, is reliant on the presence of silencing proteins in the perinuclear region. An MSUD suppression assay identified two novel MSUD proteins, SAD-Y and SAD-B'. Even though SAD-Y and its homologs contain a conserved putative RNA- binding motif, they have yet to be assigned to a biochemical pathway. Our work here has linked silencing to SAD-Y-like proteins. SAD-Y has been shown to interact with other MSUD factors in both the nucleus and at the nuclear periphery. SAD-B's homolog has been found in the nuage, an epicenter for RNA-binding proteins involved in post-transcriptional regulation for Drosophila germline cells. SAD-B interacts with core MSUD proteins and has an especially intimate association with SMS-2, which requires it for localization. Furthermore, bimolecular fluorescence complementation (BiFC) revealed that SAD-B' interacts with a Golgi retrograde transport protein and an autophagy marker protein, suggesting the importance of the endomembrane system in this RNAi process.

scholarly journals Two functionally distinct RNA-binding motifs in the regulatory domain of the protein kinase DAI.

1995 ◽  
Vol 15 (1) ◽  
pp. 358-364 ◽  
Author(s):  
S R Green ◽  
L Manche ◽  
M B Mathews
Keyword(s):  
Amino Acid ◽  
Protein Kinase ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Alpha Helix ◽  
Binding Domain ◽  
Single Amino Acid ◽  
Double Stranded Rna ◽  
C Terminus ◽  
Rna Binding Domain

The RNA-binding domain of the protein kinase DAI, the double-stranded RNA inhibitor of translation, contains two repeats of a motif that is also found in a number of other RNA-binding proteins. This motif consists of 67 amino acid residues and is predicted to contain a positively charged alpha helix at its C terminus. We have analyzed the effects of equivalent single amino acid changes in three conserved residues distributed over each copy of the motif. Mutants in the C-terminal portion of either repeat were severely defective, indicating that both copies of the motif are essential for RNA binding. Changes in the N-terminal and central parts of the motif were more debilitating if they were made in the first motif than in the second, suggesting that the first motif is the more important for RNA binding and that the second motif is structurally more flexible. When the second motif was replaced by a duplicate of the first motif, the ectopic copy retained its greater sensitivity to mutation, implying that the two motifs have distinct functions with respect to the process of RNA binding. Furthermore, the mutations have the same effect on the binding of double-stranded RNA and VA RNA, consistent with the existence of a single RNA-binding domain for both activating and inhibitory RNAs.

scholarly journals A Posttranscriptional Mechanism That Controls Ptbp1 Abundance in the Xenopus Epidermis

2014 ◽  
Vol 35 (4) ◽  
pp. 758-768 ◽  
Author(s):  
Agnès Méreau ◽  
Vincent Anquetil ◽  
Hubert Lerivray ◽  
Justine Viet ◽  
Claire Schirmer ◽  
...  
Keyword(s):  
Rna Binding ◽  
Rna Binding Proteins ◽  
Fine Tuning ◽  
Splice Isoforms ◽  
Content Type ◽  
Splicing Pattern ◽  
Exon 11 ◽  
Splicing Patterns ◽  
Different Tissues

The output of alternative splicing depends on the cooperative or antagonistic activities of several RNA-binding proteins (RBPs), like Ptbp1 and Esrp1 inXenopus. Fine-tuning of the RBP abundance is therefore of prime importance to achieve tissue- or cell-specific splicing patterns. Here, we addressed the mechanisms leading to the high expression of theptbp1gene, which encodes Ptbp1, inXenopusepidermis. Two splice isoforms ofptbp1mRNA differ by the presence of an alternative exon 11, and only the isoform including exon 11 can be translated to a full-length protein.In vivominigene assays revealed that the nonproductive isoform was predominantly produced. Knockdown experiments demonstrated that Esrp1, which is specific to the epidermis, strongly stimulated the expression ofptbp1by favoring the productive isoform. Consequently, knocking downesrp1phenocopiedptbp1inactivation. Conversely, Ptbp1 repressed the expression of its own gene by favoring the nonproductive isoform. Hence, a complex posttranscriptional mechanism controls Ptbp1 abundance inXenopusepidermis: skipping of exon 11 is the default splicing pattern, but Esrp1 stimulatesptbp1expression by favoring the inclusion of exon 11 up to a level that is limited by Ptbp1 itself. These results decipher a posttranscriptional mechanism that achieves various abundances of the ubiquitous RBP Ptbp1 in different tissues.

scholarly journals Posttranscriptional regulation of human endogenous retroviruses by RNA-binding motif protein 4, RBM4

2020 ◽  
Vol 117 (42) ◽  
pp. 26520-26530
Author(s):  
Amir K. Foroushani ◽  
Bryan Chim ◽  
Madeline Wong ◽  
Andre Rastegar ◽  
Patrick T. Smith ◽  
...  
Keyword(s):  
Human Genome ◽  
Posttranscriptional Regulation ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Ectopic Expression ◽  
Transcript Level ◽  
Endogenous Retroviruses ◽  
Host Protein ◽  
Binding Motif ◽  
Sequencing Data

The human genome encodes for over 1,500 RNA-binding proteins (RBPs), which coordinate regulatory events on RNA transcripts. Most studies of RBPs have concentrated on their action on host protein-encoding mRNAs, which constitute a minority of the transcriptome. A widely neglected subset of our transcriptome derives from integrated retroviral elements, termed endogenous retroviruses (ERVs), that comprise ∼8% of the human genome. Some ERVs have been shown to be transcribed under physiological and pathological conditions, suggesting that sophisticated regulatory mechanisms to coordinate and prevent their ectopic expression exist. However, it is unknown how broadly RBPs and ERV transcripts directly interact to provide a posttranscriptional layer of regulation. Here, we implemented a computational pipeline to determine the correlation of expression between individual RBPs and ERVs from single-cell or bulk RNA-sequencing data. One of our top candidates for an RBP negatively regulating ERV expression was RNA-binding motif protein 4 (RBM4). We used photoactivatable ribonucleoside-enhanced cross-linking and immunoprecipitation to demonstrate that RBM4 indeed bound ERV transcripts at CGG consensus elements. Loss of RBM4 resulted in an elevated transcript level of bound ERVs of the HERV-K and -H families, as well as increased expression of HERV-K envelope protein. We pinpointed RBM4 regulation of HERV-K to a CGG-containing element that is conserved in the LTRs of HERV-K-10, -K-11, and -K-20, and validated the functionality of this site using reporter assays. In summary, we systematically identified RBPs that may regulate ERV function and demonstrate a role for RBM4 in controlling ERV expression.

scholarly journals Fitting Pieces into the Puzzle ofPseudomonas aeruginosaType III Secretion System Gene Expression

2019 ◽  
Vol 201 (13) ◽  
Author(s):  
Emily A. Williams McMackin ◽  
Louise Djapgne ◽  
Jodi M. Corley ◽  
Timothy L. Yahr
Keyword(s):  
Gene Expression ◽  
Protein Delivery ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Binding Activity ◽  
Secretion Systems ◽  
Content Type ◽  
Global Regulators ◽  
Dna Binding Activity ◽  
Host Pathogen

ABSTRACTType III secretion systems (T3SS) are widely distributed in Gram-negative microorganisms and critical for host-pathogen and host-symbiont interactions with plants and animals. Central features of the T3SS are a highly conserved set of secretion and translocation genes and contact dependence wherein host-pathogen interactions trigger effector protein delivery and serve as an inducing signal for T3SS gene expression. In addition to these conserved features, there are pathogen-specific properties that include a unique repertoire of effector genes and mechanisms to control T3SS gene expression. ThePseudomonas aeruginosaT3SS serves as a model system to understand transcriptional and posttranscriptional mechanisms involved in the control of T3SS gene expression. The central regulatory feature is a partner-switching system that controls the DNA-binding activity of ExsA, the primary regulator of T3SS gene expression. Superimposed upon the partner-switching mechanism are cyclic AMP and cyclic di-GMP signaling systems, two-component systems, global regulators, and RNA-binding proteins that have positive and negative effects on ExsA transcription and/or synthesis. In the present review, we discuss advances in our understanding of how these regulatory systems orchestrate the activation of T3SS gene expression in the context of acute infections and repression of the T3SS asP. aeruginosaadapts to and colonizes the cystic fibrosis airways.

scholarly journals Concurrent binding to DNA and RNA facilitates the pluripotency reprogramming activity of Sox2

2020 ◽  
Vol 48 (7) ◽  
pp. 3869-3887 ◽  
Author(s):  
Linlin Hou ◽  
Yuanjie Wei ◽  
Yingying Lin ◽  
Xiwei Wang ◽  
Yiwei Lai ◽  
...  
Keyword(s):  
Dna Sequences ◽  
Target Genes ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
High Mobility ◽  
Binding Motif ◽  
Dna And Rna ◽  
Somatic Cell Reprogramming ◽  
Double Stranded Dna

Abstract Some transcription factors that specifically bind double-stranded DNA appear to also function as RNA-binding proteins. Here, we demonstrate that the transcription factor Sox2 is able to directly bind RNA in vitro as well as in mouse and human cells. Sox2 targets RNA via a 60-amino-acid RNA binding motif (RBM) positioned C-terminally of the DNA binding high mobility group (HMG) box. Sox2 can associate with RNA and DNA simultaneously to form ternary RNA/Sox2/DNA complexes. Deletion of the RBM does not affect selection of target genes but mitigates binding to pluripotency related transcripts, switches exon usage and impairs the reprogramming of somatic cells to a pluripotent state. Our findings designate Sox2 as a multi-functional factor that associates with RNA whilst binding to cognate DNA sequences, suggesting that it may co-transcriptionally regulate RNA metabolism during somatic cell reprogramming.

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