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.

scholarly journals Spnr, a murine RNA-binding protein that is localized to cytoplasmic microtubules.

1995 ◽  
Vol 129 (4) ◽  
pp. 1023-1032 ◽  
Author(s):  
J M Schumacher ◽  
K Lee ◽  
S Edelhoff ◽  
R E Braun
Keyword(s):  
Translational Control ◽  
Rna Binding ◽  
Binding Protein ◽  
Rna Binding Protein ◽  
Translational Repression ◽  
Rna Transport ◽  
Binding Domains ◽  
Cytoplasmic Microtubules ◽  
Pachytene Spermatocytes ◽  
Expression Libraries

Previous studies in transgenic mice have established the importance of the 3' untranslated region (UTR) of the spermatid-specific protamine-1 (Prm-1) mRNA in its translational control during male germ cell development. To clone genes that mediate the translational repression or activation of the Prm-1 mRNA, we screened cDNA expression libraries made with RNA from pachytene spermatocytes and round spermatids, with an RNA probe corresponding to the 3' UTR of Prm-1. We obtained six independent clones that encode Spnr, a spermatid perinuclear RNA-binding protein. Spnr is a 71-kD protein that contains two previously described RNA binding domains. The Spnr mRNA is expressed at high levels in the testis, ovary, and brain, and is present in multiple forms in those tissues. Immunolocalization of the Spnr protein within the testis shows that it is expressed exclusively in postmeiotic germ cells and that it is localized to the manchette, a spermatid-specific microtubular array. Although the Spnr protein is expressed too late to be directly involved in the translational repression of Prm-1 specifically, we suggest that the Spnr protein may be involved in other aspects of spermatid RNA metabolism, such as RNA transport or translational activation.

scholarly journals The RNA binding protein Nab2 regulates the proteome of the developing Drosophila brain

2020 ◽  
Author(s):  
Edwin B. Corgiat ◽  
Sara M. List ◽  
J. Christopher Rounds ◽  
Anita H. Corbett ◽  
Kenneth H. Moberg
Keyword(s):  
Planar Cell Polarity ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Binding Protein ◽  
Transmembrane Protein ◽  
Rna Binding Protein ◽  
Brain Proteins ◽  
Brain Proteome ◽  
Drosophila Brain ◽  
And Function

AbstractThe human ZC3H14 gene, which encodes a ubiquitously expressed polyadenosine zinc finger RNA binding protein, is mutated in an inherited form of autosomal recessive, non-syndromic intellectual disability. To gain insight into ZC3H14 neurological functions, we previously developed a Drosophila melanogaster model of ZC3H14 loss by deleting the fly ortholog, Nab2. Studies in this invertebrate model reveal that Nab2 controls final patterns of neuron projection within fully developed adult brains. Here, we examine earlier pupal stages and define roles for Nab2 in controlling the dynamic growth of axons into the developing brain mushroom bodies (MBs), which support olfactory learning and memory, and in regulating abundance of a small fraction of the total brain proteome, a portion of which is rescued by overexpression of Nab2 specifically in brain neurons. The group of Nab2-regulated brain proteins, identified by quantitative proteomic analysis, includes the microtubule binding protein Futsch, the neuronal Ig-family transmembrane protein Turtle, the glial:neuron adhesion protein Contactin, the RacGAP Tumbleweed, and the planar cell polarity factor Van Gogh, which collectively link Nab2 to a the processes of brain morphogenesis, neuroblast proliferation, circadian sleep/wake cycles, and synaptic development. Overall, these data indicate that Nab2 controls abundance of a subset of brain proteins during the active process of wiring the pupal brain mushroom body, and thus provide a window into potentially conserved functions of the Nab2/ZC3H14 RNA binding proteins in neurodevelopment and function.

scholarly journals RNA-binding protein IGF2BP2/IMP2 is required for laminin-β2 mRNA translation and is modulated by glucose concentration

2012 ◽  
Vol 303 (1) ◽  
pp. F75-F82 ◽  
Author(s):  
Valerie Schaeffer ◽  
Kim M. Hansen ◽  
David R. Morris ◽  
Renée C. LeBoeuf ◽  
Christine K. Abrass
Keyword(s):  
Diabetic Nephropathy ◽  
Actin Cytoskeleton ◽  
Translational Control ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Binding Protein ◽  
Rna Binding Protein ◽  
Mrna Translation ◽  
Diabetic Rats ◽  
Laminin Β2

Laminin-β2 (LAMB2) is a critical component of the glomerular basement membrane as content of LAMB2 in part determines glomerular barrier permeability. Previously, we reported that high concentrations of glucose reduce expression of this laminin subunit at the translational level. The present studies were undertaken to further define systems that control Lamb2 translation and the effect of high glucose on those systems. Complementary studies were performed using in vitro differentiation of cultured podocytes and mesangial cells exposed to normal and elevated concentrations of glucose, and tissues from control and diabetic rats. Together, these studies provide evidence for regulation of Lamb2 translation by IMP2, an RNA binding protein that targets Lamb2 mRNA to the actin cytoskeleton. Expression of Imp2 itself is regulated by the transcription factor HMGA2, which in turn is regulated by the microRNA let-7b. Elevated concentrations of glucose increase let-7b, which reduces HMGA2 expression, in turn reducing IMP2 and LAMB2. Correlative changes in kidney tissues from control and streptozotocin-induced diabetic rats suggest these control mechanisms are operative in vivo and may contribute to proteinuria in diabetic nephropathy. To our knowledge, this is the first time that translation of Lamb2 mRNA has been linked to the actin cytoskeleton, as well as to specific RNA-binding proteins. These translational control points may provide new targets for therapy in proteinuric disorders such as diabetic nephropathy where LAMB2 levels are reduced.

scholarly journals An homeotic post-transcriptional network controlled by the RNA-binding protein RBMX

2018 ◽  
Author(s):  
Paola Zuccotti ◽  
Daniele Peroni ◽  
Valentina Potrich ◽  
Alessandro Quattrone ◽  
Erik Dassi
Keyword(s):  
Translational Control ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Binding Protein ◽  
Rna Binding Protein ◽  
Transcript Abundance ◽  
Homeotic Genes ◽  
Protein Levels ◽  
Functional Regions ◽  
Cellular Phenotypes

AbstractPost-transcriptional regulation (PTR) of gene expression is a powerful determinant of protein levels and cellular phenotypes. The 5’ and 3’ untranslated regions of the mRNA (UTRs) mediate this role through sequence and secondary structure elements bound by RNA-binding proteins (RBPs) and noncoding RNAs. While functional regions in the 3’UTRs have been extensively studied, the 5’UTRs are still relatively uncharacterized. To fill this gap, here we used a computational approach based on phylogenetic conservation to identify hyper-conserved elements in human 5’UTRs (5’HCEs). Our assumption, supported by the recovery of functionally characterized elements, was that 5’HCEs would represent evolutionarily stable and hence important PTR sites.We identified over 5000 short, clustered 5’HCEs occurring in approximately 10% of human protein-coding genes. Among these, homeotic genes were highly enriched. Indeed, 52 of the 258 characterized homeotic genes contained at least one 5’HCE, including members of all four Hox clusters and several other families. Homeotic genes are essential transcriptional regulators. They drive body plan and neuromuscular development, and the role of PTR in their expression is mostly unknown. By integrating computational and experimental approaches we then identified the RBMX RNA-binding protein as the initiator of a post-transcriptional cascade regulating many such homeotic genes. RBMX is known to control its targets by modulating transcript abundance and alternative splicing. Adding to that, we observed translational control as a novel mode of regulation by this RBP.This work thus establishes RBMX as a versatile master controller of homeotic genes and of the developmental processes they drive.

scholarly journals Phosphorylation of the RNA-binding protein Dazl by MAPKAP kinase 2 regulates spermatogenesis

2016 ◽  
Vol 27 (15) ◽  
pp. 2341-2350 ◽  
Author(s):  
Patrick A. Williams ◽  
Michael S. Krug ◽  
Emily A. McMillan ◽  
Jasmine D. Peake ◽  
Tara L. Davis ◽  
...  
Keyword(s):  
Translational Control ◽  
Binding Proteins ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Binding Protein ◽  
Rna Binding Protein ◽  
Negative Regulator ◽  
Transgenic Expression ◽  
Male Germline ◽  
Deleted In Azoospermia

Developing male germ cells are exquisitely sensitive to environmental insults such as heat and oxidative stress. An additional characteristic of these cells is their unique dependence on RNA-binding proteins for regulating posttranscriptional gene expression and translational control. Here we provide a mechanistic link unifying these two features. We show that the germ cell–specific RNA-binding protein deleted in azoospermia-like (Dazl) is phosphorylated by MAPKAP kinase 2 (MK2), a stress-induced protein kinase activated downstream of p38 MAPK. We demonstrate that phosphorylation of Dazl by MK2 on an evolutionarily conserved serine residue inhibits its interaction with poly(A)-binding protein, resulting in reduced translation of Dazl-regulated target RNAs. We further show that transgenic expression of wild-type human Dazl but not a phosphomimetic form in the Drosophila male germline can restore fertility to flies deficient in boule, the Drosophila orthologue of human Dazl. These results illuminate a novel role for MK2 in spermatogenesis, expand the repertoire of RNA-binding proteins phosphorylated by this kinase, and suggest that signaling by the p38-MK2 pathway is a negative regulator of spermatogenesis via phosphorylation of Dazl.

scholarly journals RNA-binding Motif Protein 45 (Rbm45)/Developmentally Regulated RNA-binding Protein-1 (Drbp1): Association with Neurodegenerative Disorders

2018 ◽  
Vol 7 (2) ◽  
pp. 33-37
Author(s):  
Andrew G. Eck ◽  
Kevin J. Lopez ◽  
Jeffrey O. Henderson
Keyword(s):  
Neural Development ◽  
Neurodegenerative Disorders ◽  
Inclusion Bodies ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Binding Protein ◽  
Rna Binding Protein ◽  
Future Research ◽  
Binding Motif ◽  
Developmentally Regulated

Neurodegenerative disorders are caused by the progressive loss of the structure and/or function of neurons, often through cell death, contributing significantly to morbidity and mortality. Cytoplasmic aggregation of proteins into inclusion bodies is a pathological characteristic of amyotrophic lateral sclerosis (ALS), frontotemporal lobar degeneration (FTLD), and Alzheimer’s disorder (AD). These inclusion bodies have been shown to contain RNA-binding proteins participating in RNA-dependent and RNA–independent protein:protein interactions. RNA-binding motif protein 45 (RBM45), also known as developmentally regulated RNA-binding protein-1 (Drbp1), was first identified as a novel RNA binding protein in rat that functions in neural development. Advancing research has indicated a connection between the presence of human RBM45 protein cytosolic aggregates and degenerative neurological diseases. This review considers the structure, function, and distribution of RBM45 along with a look into potential future research on this multifunctional RNA-binding protein.

scholarly journals The Interplay of RNA Binding Proteins, Oxidative Stress and Mitochondrial Dysfunction in ALS

Antioxidants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 552
Author(s):  
Jasmine Harley ◽  
Benjamin E. Clarke ◽  
Rickie Patani
Keyword(s):  
Oxidative Stress ◽  
Gene Expression ◽  
Mitochondrial Dysfunction ◽  
Binding Proteins ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Binding Protein ◽  
Rna Binding Protein ◽  
Therapeutic Strategies ◽  
Lateral Sclerosis

RNA binding proteins fulfil a wide number of roles in gene expression. Multiple mechanisms of RNA binding protein dysregulation have been implicated in the pathomechanisms of several neurodegenerative diseases including amyotrophic lateral sclerosis (ALS). Oxidative stress and mitochondrial dysfunction also play important roles in these diseases. In this review, we highlight the mechanistic interplay between RNA binding protein dysregulation, oxidative stress and mitochondrial dysfunction in ALS. We also discuss different potential therapeutic strategies targeting these pathways.

scholarly journals The RNA-binding protein ELAVL1/HuR is essential for mouse spermatogenesis, acting both at meiotic and postmeiotic stages

2011 ◽  
Vol 22 (16) ◽  
pp. 2875-2885 ◽  
Author(s):  
Mai Nguyen Chi ◽  
Jacques Auriol ◽  
Bernard Jégou ◽  
Dimitris L. Kontoyiannis ◽  
James M.A. Turner ◽  
...  
Keyword(s):  
Germ Cells ◽  
Posttranscriptional Regulation ◽  
Target Gene ◽  
Molecular Mechanisms ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Binding Protein ◽  
Rna Binding Protein ◽  
Female Sterility ◽  
Targeted Deletion

Posttranscriptional mechanisms are crucial to regulate spermatogenesis. Accurate protein synthesis during germ cell development relies on RNA binding proteins that control the storage, stability, and translation of mRNAs in a tightly and temporally regulated manner. Here, we focused on the RNA binding protein Embryonic Lethal Abnormal Vision (ELAV) L1/Human antigen R (HuR) known to be a key regulator of posttranscriptional regulation in somatic cells but the function of which during gametogenesis has never been investigated. In this study, we have used conditional loss- and gain-of-function approaches to address this issue in mice. We show that targeted deletion of HuR specifically in germ cells leads to male but not female sterility. Mutant males are azoospermic because of the extensive death of spermatocytes at meiotic divisions and failure of spermatid elongation. The latter defect is also observed upon HuR overexpression. To elucidate further the molecular mechanisms underlying spermatogenesis defects in HuR-deleted and -overexpressing testes, we undertook a target gene approach and discovered that heat shock protein (HSP)A2/HSP70-2, a crucial regulator of spermatogenesis, was down-regulated in both situations. HuR specifically binds hspa2 mRNA and controls its expression at the translational level in germ cells. Our study provides the first genetic evidence of HuR involvement during spermatogenesis and reveals Hspa2 as a target for HuR.

scholarly journals The control of inflammation via the phosphorylation and dephosphorylation of tristetraprolin: a tale of two phosphatases

2016 ◽  
Vol 44 (5) ◽  
pp. 1321-1337 ◽  
Author(s):  
Andrew R. Clark ◽  
Jonathan L.E. Dean
Keyword(s):  
Inflammatory Mediators ◽  
Knockout Mouse ◽  
Rna Binding ◽  
Binding Protein ◽  
Rna Binding Protein ◽  
Human Orthologue ◽  
And Function ◽  
Detailed Picture ◽  
Lines Of Evidence

Twenty years ago, the first description of a tristetraprolin (TTP) knockout mouse highlighted the fundamental role of TTP in the restraint of inflammation. Since then, work from several groups has generated a detailed picture of the expression and function of TTP. It is a sequence-specific RNA-binding protein that orchestrates the deadenylation and degradation of several mRNAs encoding inflammatory mediators. It is very extensively post-translationally modified, with more than 30 phosphorylations that are supported by at least two independent lines of evidence. The phosphorylation of two particular residues, serines 52 and 178 of mouse TTP (serines 60 and 186 of the human orthologue), has profound effects on the expression, function and localisation of TTP. Here, we discuss the control of TTP biology via its phosphorylation and dephosphorylation, with a particular focus on recent advances and on questions that remain unanswered.

scholarly journals The Putative RNA-Binding Protein Nrp1 Promotes the Loading of Kinesin-14/Klp2 to the Mitotic Spindle and Is Sequestered Into Heat-Induced Protein Aggregates in Fission Yeast

2021 ◽  
Author(s):  
Masashi Yukawa ◽  
Mitsuki Ohishi ◽  
Yusuke Yamada ◽  
Takashi Toda
Keyword(s):  
Fission Yeast ◽  
Rna Binding ◽  
Binding Protein ◽  
Rna Binding Protein ◽  
Protein Aggregates ◽  
Associated Proteins ◽  
Spindle Microtubules ◽  
The Stability ◽  
And Function ◽  
Post Transcriptional Regulation

Cells form a bipolar spindle during mitosis to ensure accurate chromosome segregation. Proper spindle architecture is established by a set of kinesin motors and microtubule-associated proteins. In most eukaryotes, kinesin-5 motors are essential for this process, and genetic or chemical inhibition of their activity leads to the emergence of monopolar spindles and cell death. However, these deficiencies can be rescued by simultaneous inactivation of kinesin-14 motors, as they counteract kinesin-5. We conducted detailed genetic analyses in fission yeast to understand the mechanisms driving spindle assembly in the absence of kinesin-5. Here we show that deletion of the nrp1 gene, which encodes a putative RNA-binding protein with unknown function, can rescue temperature sensitivity caused by cut7-22, a fission yeast kinesin-5 mutant. Interestingly, kinesin-14/Klp2 levels on the spindles in the cut7 mutants were significantly reduced by the nrp1 deletion, although the total levels of Klp2 and the stability of spindle microtubules remained unaffected. Moreover, RNA-binding motifs of Nrp1 are essential for its cytoplasmic localization and function. We have also found that a portion of Nrp1 is spatially and functionally sequestered by chaperone-based protein aggregates upon mild heat stress and limits cell division at high temperatures. We propose that Nrp1 might be involved in post-transcriptional regulation through its RNA-binding ability to promote the loading of Klp2 on the spindle microtubules.

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