scholarly journals Translational control of polyamine metabolism by CNBP is required for Drosophila locomotor function

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Sonia Coni ◽  
Federica A Falconio ◽  
Marta Marzullo ◽  
Marzia Munafò ◽  
Benedetta Zuliani ◽  
...  
Keyword(s):  
Translational Control ◽  
Rna Binding ◽  
Binding Protein ◽  
Polyamine Metabolism ◽  
Nucleic Acid Binding ◽  
Mammalian Development ◽  
Myotonic Dystrophy Type 2 ◽  
Evolutionarily Conserved ◽  
Toxic Rna

Microsatellite expansions of CCTG repeats in the cellular nucleic acid-binding protein (CNBP) gene leads to accumulation of toxic RNA and have been associated with myotonic dystrophy type 2 (DM2). However, it is still unclear whether the dystrophic phenotype is also linked to CNBP decrease, a conserved CCHC-type zinc finger RNA-binding protein that regulates translation and is required for mammalian development. Here, we show that depletion of Drosophila CNBP in muscles causes ageing-dependent locomotor defects that are correlated with impaired polyamine metabolism. We demonstrate that the levels of ornithine decarboxylase (ODC) and polyamines are significantly reduced upon dCNBP depletion. Of note, we show a reduction of the CNBP-polyamine axis in muscles from DM2 patients. Mechanistically, we provide evidence that dCNBP controls polyamine metabolism through binding dOdc mRNA and regulating its translation. Remarkably, the locomotor defect of dCNBP-deficient flies is rescued by either polyamine supplementation or dOdc1 overexpression. We suggest that this dCNBP function is evolutionarily conserved in vertebrates with relevant implications for CNBP-related pathophysiological conditions.

scholarly journals Translational control of polyamine metabolism by CNBP is required for Drosophila locomotor function

2021 ◽  
Author(s):  
Sonia Coni ◽  
Federica A. Falconio ◽  
Marta Marzullo ◽  
Marzia Munafò ◽  
Benedetta Zuliani ◽  
...  
Keyword(s):  
Translational Control ◽  
Muscle Function ◽  
Rna Binding ◽  
Polyamine Metabolism ◽  
List Type ◽  
Mammalian Development ◽  
Locomotor Function ◽  
Evolutionarily Conserved ◽  
Age Dependent ◽  
Toxic Rna

ABSTRACTMicrosatellite expansions of CCTG repeats in the CNBP gene leads to accumulation of toxic RNA and have been associated to DM2. However, it is still unclear whether the dystrophic phenotype is also linked to CNBP decrease, a conserved CCHC-type zinc finger RNA binding protein that regulates translation and is required for mammalian development.Here we show that depletion of Drosophila CNBP in muscles causes age-dependent locomotor defects that are correlated with impaired polyamine metabolism. We demonstrate that the levels of ornithine decarboxylase (ODC) and polyamines are significantly reduced upon dCNBP depletion. Of note, we show a reduction of the CNBP-polyamine axis in muscle from DM2 patients. Mechanistically, we provide evidence that dCNBP controls polyamine metabolism through binding dOdc mRNA and regulating its translation. Remarkably, the locomotor defect of dCNBP-deficient flies is rescued by either polyamine supplementation or dOdc1 overexpression. We suggest that this dCNBP function is evolutionarily conserved in vertebrates with relevant implications for CNBP-related pathophysiological conditions.GRAPHICAL ABSTRACTCNBP controls muscle function by regulating the polyamine metabolismLack of dCNBP impairs locomotor function through ODC-polyamine downregulationdCNBP binds dOdc mRNA and regulates its translationPolyamine supplementation or dOdc1 reconstitution rescues locomotor defectsCNBP-ODC-polyamine levels are reduced in muscle of DM2 patients

scholarly journals A Toxic RNA Catalyzes the Cellular Synthesis of Its Own Inhibitor, Shunting It to Endogenous Decay Pathways

2019 ◽  
Author(s):  
Raphael I. Benhamou ◽  
Alicia J. Angelbello ◽  
Eric T. Wang ◽  
Matthew D. Disney
Keyword(s):  
Small Molecules ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Intron Retention ◽  
Protein A ◽  
List Type ◽  
Nucleic Acid Binding ◽  
Myotonic Dystrophy Type 2 ◽  
Intron 1 ◽  
Toxic Rna

SUMMARYMyotonic dystrophy type 2 (DM2) is a genetically defined muscular dystrophy caused by a toxic expanded repeat of r(CCUG) [heretofore (CCUG)exp], harbored in intron 1 of CHC-Type Zinc Finger Nucleic Acid Binding Protein (CNBP) pre-mRNA. This r(CCUG)exp causes DM2 via a gain-of-function mechanism that results in three hallmarks of its pathology: (i) binding to RNA-binding proteins (RBPs) that aggregate into nuclear foci; (ii) sequestration of muscleblind-like-1 (MBNL1) protein, a regulator of alternative pre-mRNA splicing, leading to splicing defects; and (iii) retention of intron 1 in the CNBP mRNA. Here, we find that CNBP intron retention is caused by the r(CCUG)exp-MBNL1 complex and can be rescued by small molecules. We studied two types of small molecules with different modes of action, ones that simply bind and ones that can be synthesized by a r(CCUG)exp-templated reaction in cells, that is the RNA synthesizes its own drug. Indeed, our studies completed in DM2 patient-derived fibroblasts show that the compounds disrupt the r(CCUG)exp-MBNL1 complex, reduce intron retention, subjecting the liberated intronic r(CCUG)exp to native decay pathways, and rescue other DM2-associated cellular defects. Collectively, this study shows that small molecules can affect RNA biology by shunting toxic transcripts towards native decay pathways.HIGHLIGHTSIntron retention in RNA repeat expansions can be due to repeats binding to proteinsSmall molecules that bind RNA repeats and inhibit protein binding can trigger decayA toxic RNA repeat can catalyze the synthesis of its own inhibitor on-siteOn-site drug synthesis most potently affects disease biologyeTOC BLURBThe most common way to target RNA is to use antisense oligonucleotides to target unstructured RNAs for destruction. Here, we show for the first time that small molecules targeting structured, disease-causing RNAs can shunt them towards native decay pathways by affecting their processing.

scholarly journals Structural basis of nucleic acid binding byNicotiana tabacumglycine-rich RNA-binding protein: implications for its RNA chaperone function

2014 ◽  
Vol 42 (13) ◽  
pp. 8705-8718 ◽  
Author(s):  
Fariha Khan ◽  
Mark A. Daniëls ◽  
Gert E. Folkers ◽  
Rolf Boelens ◽  
S. M. Saqlan Naqvi ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Rna Binding ◽  
Binding Protein ◽  
Rna Binding Protein ◽  
Structural Basis ◽  
Nucleic Acid Binding ◽  
Rna Chaperone ◽  
Chaperone Function

scholarly journals Reduction of Cellular Nucleic Acid Binding Protein Encoded by a Myotonic Dystrophy Type 2 Gene Causes Muscle Atrophy

2018 ◽  
Vol 38 (14) ◽  
Author(s):  
Christina Wei ◽  
Lauren Stock ◽  
Christiane Schneider-Gold ◽  
Claudia Sommer ◽  
Nikolai A. Timchenko ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Nucleic Acid ◽  
Myotonic Dystrophy ◽  
Muscle Atrophy ◽  
Myotonic Dystrophy Type ◽  
Nucleic Acid Binding ◽  
Myotonic Dystrophy Type 2 ◽  
Nucleic Acid Binding Protein ◽  
Acid Binding Protein

ABSTRACT Myotonic dystrophy type 2 (DM2) is a neuromuscular disease caused by an expansion of intronic CCTG repeats in the CNBP gene, which encodes a protein regulating translation and transcription. To better understand the role of cellular nucleic acid binding protein (CNBP) in DM2 pathology, we examined skeletal muscle in a new model of Cnbp knockout (KO) mice. This study showed that a loss of Cnbp disturbs myofibrillar sarcomeric organization at birth. Surviving homozygous Cnbp KO mice develop muscle atrophy at a young age. The skeletal muscle phenotype in heterozygous Cnbp KO mice was milder, but they developed severe muscle wasting at an advanced age. Several proteins that control global translation and muscle contraction are altered in muscle of Cnbp KO mice. A search for CNBP binding proteins showed that CNBP interacts with the α subunit of the dystroglycan complex, a core component of the multimeric dystrophin-glycoprotein complex, which regulates membrane stability. Whereas CNBP is reduced in cytoplasm of DM2 human fibers, it is a predominantly membrane protein in DM2 fibers, and its interaction with α-dystroglycan is increased in DM2. These findings suggest that alterations of CNBP in DM2 might cause muscle atrophy via CNBP-mediated translation and via protein-protein interactions affecting myofiber membrane function.

Translational control in early development: CPEB, P-bodies and germinal granules

2008 ◽  
Vol 36 (4) ◽  
pp. 671-676 ◽  
Author(s):  
Nancy Standart ◽  
Nicola Minshall
Keyword(s):  
Early Development ◽  
Translational Control ◽  
Binding Proteins ◽  
Rna Binding ◽  
Binding Protein ◽  
Initiation Factor ◽  
Dependent Manner ◽  
Cytoplasmic Polyadenylation ◽  
P Bodies ◽  
Germinal Granules

Selective protein synthesis in oocytes, eggs and early embryos of many organisms drives several critical aspects of early development, including meiotic maturation and entry into mitosis, establishment of embryonic axes and cell fate determination. mRNA-binding proteins which (usually) recognize 3′-UTR (untranslated region) elements in target mRNAs influence the recruitment of the small ribosomal subunit to the 5′ cap. Probably the best studied such protein is CPEB (cytoplasmic polyadenylation element-binding protein), which represses translation in the oocyte in a cap-dependent manner, and activates translation in the meiotically maturing egg, via cytoplasmic polyadenylation. Co-immunoprecipitation and gel-filtration assays revealed that CPEB in Xenopus oocytes is in a very large RNP (ribonucleoprotein) complex and interacts with other RNA-binding proteins including Xp54 RNA helicase, Pat1, RAP55 (RNA-associated protein 55) and FRGY2 (frog germ cell-specific Y-box protein 2), as well as the eIF4E (eukaryotic initiation factor 4E)-binding protein 4E-T (eIF4E-transporter) and an ovary-specific eIF4E1b, which binds the cap weakly. Functional tests which implicate 4E-T and eIF4E1b in translational repression in oocytes led us to propose a model for the specific inhibition of translation of a target mRNA by a weak cap-binding protein. The components of the CPEB RNP complex are common to P-bodies (processing bodies), neuronal granules and germinal granules, suggesting that a highly conserved ‘masking’ complex operates in early development, neurons and somatic cells.

scholarly journals Dynamic regulation of immunity through post-translational control of defense transcript splicing

2019 ◽  
Author(s):  
Keini Dressano ◽  
Philipp R Weckwerth ◽  
Elly Poretsky ◽  
Yohei Takahashi ◽  
Carleen Villarreal ◽  
...  
Keyword(s):  
Immune Responses ◽  
Translational Control ◽  
Rna Binding ◽  
Binding Protein ◽  
Rna Binding Protein ◽  
Negative Regulator ◽  
Signaling Proteins ◽  
Receptor Signaling ◽  
Post Translational Modification ◽  
Defense Signaling

AbstractSurvival of all living organisms requires the ability to detect attack and swiftly counter with protective immune responses. Despite considerable mechanistic advances, interconnectivity of signaling circuits often remains unclear. A newly-characterized protein, IMMUNOREGULATORY RNA-BINDING PROTEIN (IRR), negatively regulates immune responses in both maize and Arabidopsis, with disrupted function resulting in enhanced disease resistance. IRR physically interacts with, and promotes canonical splicing of, transcripts encoding defense signaling proteins, including the key negative regulator of pattern recognition receptor signaling complexes, CALCIUM-DEPENDENT PROTEIN KINASE 28 (CPK28). Upon immune activation by Plant Elicitor Peptides (Peps), IRR is dephosphorylated, disrupting interaction withCPK28transcripts and resulting in accumulation of an alternative splice variant encoding a truncated CPK28 protein with impaired kinase activity and diminished function as a negative regulator. We demonstrate a novel circuit linking Pep-induced post-translational modification of IRR with post-transcriptionally-mediated attenuation of CPK28 function to dynamically amplify Pep signaling and immune output.One Sentence SummaryPlant innate immunity is promoted by post-translational modification of a novel RNA-binding protein that regulates alternative splicing of transcripts encoding defense signaling proteins to dynamically increase immune receptor signaling capacity through deactivation of a key signal-buffering circuit.

scholarly journals A new crystal structure and small-angle X-ray scattering analysis of the homodimer of human SFPQ

2019 ◽  
Vol 75 (6) ◽  
pp. 439-449 ◽  
Author(s):  
Thushara Welwelwela Hewage ◽  
Sofia Caria ◽  
Mihwa Lee
Keyword(s):  
Crystal Structure ◽  
Small Angle ◽  
Solution Structure ◽  
Rna Binding ◽  
Binding Protein ◽  
Coiled Coil ◽  
Scattering Data ◽  
Nucleic Acid Binding ◽  
Dimerization Domain ◽  
Orthorhombic Space Group

Splicing factor proline/glutamine-rich (SFPQ) is an essential RNA-binding protein that is implicated in many aspects of nuclear function. The structures of SFPQ and two paralogs, non-POU domain-containing octamer-binding protein and paraspeckle component 1, from theDrosophilabehavior human splicing protein family have previously been characterized. The unusual arrangement of the four domains, two RNA-recognition motifs (RRMs), a conserved region termed the NonA/paraspeckle (NOPS) domain and a C-terminal coiled coil, in the intertwined dimer provides a potentially unique RNA-binding surface. However, the molecular details of how the four RRMs in the dimeric SFPQ interact with RNA remain to be characterized. Here, a new crystal structure of the dimerization domain of human SFPQ in theC-centered orthorhombic space groupC2221with one monomer in the asymmetric unit is presented. Comparison of the new crystal structure with the previously reported structure of SFPQ and analysis of the solution small-angle X-scattering data revealed subtle domain movements in the dimerization domain of SFPQ, supporting the concept of multiple conformations of SFPQ in equilibrium in solution. The domain movement of RRM1, in particular, may reflect the complexity of the RNA substrates of SFPQ. Taken together, the crystal and solution structure analyses provide a molecular basis for further investigation into the plasticity of nucleic acid binding by SFPQ in the absence of the structure in complex with its cognate RNA-binding partners.

scholarly journals The Nuclear RNA-binding Protein Sam68 Translocates to the Cytoplasm and Associates with the Polysomes in Mouse Spermatocytes

2006 ◽  
Vol 17 (1) ◽  
pp. 14-24 ◽  
Author(s):  
Maria Paola Paronetto ◽  
Francesca Zalfa ◽  
Flavia Botti ◽  
Raffaele Geremia ◽  
Claudia Bagni ◽  
...  
Keyword(s):  
Translational Control ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Binding Protein ◽  
Rna Binding Protein ◽  
Male Meiosis ◽  
Binding Motif ◽  
Mitogen Activated Protein ◽  
Pachytene Spermatocytes ◽  
And Function

Translational control plays a crucial role during gametogenesis in organisms as different as worms and mammals. Mouse knockout models have highlighted the essential function of many RNA-binding proteins during spermatogenesis. Herein we have investigated the expression and function during mammalian male meiosis of Sam68, an RNA-binding protein implicated in several aspects of RNA metabolism. Sam68 expression and localization within the cells is stage specific: it is expressed in the nucleus of spermatogonia, it disappears at the onset of meiosis (leptotene/zygotene stages), and it accumulates again in the nucleus of pachytene spermatocytes and round spermatids. During the meiotic divisions, Sam68 translocates to the cytoplasm where it is found associated with the polysomes. Translocation correlates with serine/threonine phosphorylation and it is blocked by inhibitors of the mitogen activated protein kinases ERK1/2 and of the maturation promoting factor cyclinB-cdc2 complex. Both kinases associate with Sam68 in pachytene spermatocytes and phosphorylate the regulatory regions upstream and downstream of the Sam68 RNA-binding motif. Molecular cloning of the mRNAs associated with Sam68 in mouse spermatocytes reveals a subset of genes that might be posttranscriptionally regulated by this RNA-binding protein during spermatogenesis. We also demonstrate that Sam68 shuttles between the nucleus and the cytoplasm in secondary spermatocytes, suggesting that it may promote translation of specific RNA targets during the meiotic divisions.

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