scholarly journals Multiple Mechanisms Inactivate the LIN-41 RNA-Binding Protein to Ensure A Robust Oocyte-to-Embryo Transition in Caenorhabditis elegans

2018 ◽  
Author(s):  
Caroline A. Spike ◽  
Gabriela Huelgas-Morales ◽  
Tatsuya Tsukamoto ◽  
David Greenstein
Keyword(s):  
Caenorhabditis Elegans ◽  
Rna Binding ◽  
Binding Protein ◽  
Rna Binding Protein ◽  
Adaptor Protein ◽  
Protein Translation ◽  
Translational Repression ◽  
Meiotic Maturation ◽  
Oocyte Growth ◽  
Translational Repressor

ABSTRACTIn the nematode Caenorhabditis elegans, the conserved LIN-41 RNA-binding protein is a translational repressor that coordinately controls oocyte growth and meiotic maturation. LIN-41 exerts these effects, at least in part, by preventing the premature activation of the cyclin-dependent kinase CDK-1. Here we investigate the mechanism by which LIN-41 is rapidly eliminated upon the onset of meiotic maturation. Elimination of LIN-41 requires the activities of CDK-1 and multiple SCF-type ubiquitin ligase subunits, including the conserved substrate adaptor protein SEL-10/Fbw7/Cdc4, suggesting that LIN-41 is a target of ubiquitin-mediated protein degradation. Within the LIN-41 protein, two non-overlapping regions, Deg-A and Deg-B, are individually necessary for LIN-41 degradation; both contain several potential phosphodegron sequences, and at least one of these sites is required for LIN-41 degradation. Finally, Deg-A and Deg-B are sufficient, in combination, to mediate SEL-10-dependent degradation when transplanted into a different oocyte protein. Although LIN-41 is a potent inhibitor of protein translation and M-phase entry, the failure to eliminate LIN-41 from early embryos does not result in the continued translational repression of LIN-41 oocyte mRNA targets. Based on these observations, we propose a molecular model for the elimination of LIN-41 by SCFSEL-10 and suggest that LIN-41 is inactivated before it is degraded. Furthermore, we provide evidence that another RNA-binding protein, the GLD-1 tumor suppressor, is regulated similarly. Redundant mechanisms to extinguish translational repression by RNA-binding proteins may both control and provide robustness to irreversible developmental transitions, including meiotic maturation and the oocyte-to-embryo transition.

scholarly journals A testis cytoplasmic RNA-binding protein that has the properties of a translational repressor.

1996 ◽  
Vol 16 (6) ◽  
pp. 3023-3034 ◽  
Author(s):  
K Lee ◽  
M A Fajardo ◽  
R E Braun
Keyword(s):  
Germ Cell ◽  
Untranslated Region ◽  
Rna Binding ◽  
Binding Protein ◽  
Rna Binding Protein ◽  
Male Germ Cell ◽  
Translational Repression ◽  
Translational Repressor ◽  
Germ Cell Differentiation

Translation of the mouse protamine 1 (Prm-1) mRNA is repressed for several days during male germ cell differentiation. With the hope of cloning genes that regulate the translational repression of Prm-1, we screened male germ cell cDNA expression libraries with the 3' untranslated region of the Prm-1 RNA. From this screen we obtained two independent clones that encode Prbp, a Prm-1 RNA-binding protein. Prbp contains two copies of a double-stranded-RNA-binding domain. In vitro, the protein binds to a portion of the Prm-1 3' untranslated region previously shown to be sufficient for translational repression in transgenic mice, as well as to poly(I). poly(C). Prbp protein is present in multiple forms in cytoplasmic extracts prepared from wild-type mouse testes and is absent from testes of germ cell-deficient mouse mutants, suggesting that Prbp is restricted to the germ cells of the testis. Immunocytochemical localization confirmed that Prbp is present in the cytoplasmic compartment of late-stage meiotic cells and haploid round spermatids. Recombinant Prbp protein inhibits the translation of multiple mRNAs in a wheat germ lysate, suggesting that Prbp acts to repress translation in round spermatids. While this protein lacks complete specificity for Prm-1-containing RNAs in vitro, the properties of Prbp are consistent with it acting as a general repressor of translation.

scholarly journals RNA-binding protein GLD-1/quaking genetically interacts with the mir-35 and the let- 7 miRNA pathways in Caenorhabditis elegans

Open Biology ◽  
2013 ◽  
Vol 3 (11) ◽  
pp. 130151 ◽  
Author(s):  
Alper Akay ◽  
Ashley Craig ◽  
Nicolas Lehrbach ◽  
Mark Larance ◽  
Ehsan Pourkarimi ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Messenger Rna ◽  
Binding Proteins ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Binding Protein ◽  
Rna Binding Protein ◽  
Germline Development ◽  
Somatic Development ◽  
Translational Repressor

Messenger RNA translation is regulated by RNA-binding proteins and small non-coding RNAs called microRNAs. Even though we know the majority of RNA-binding proteins and microRNAs that regulate messenger RNA expression, evidence of interactions between the two remain elusive. The role of the RNA-binding protein GLD-1 as a translational repressor is well studied during Caenorhabditis elegans germline development and maintenance. Possible functions of GLD-1 during somatic development and the mechanism of how GLD-1 acts as a translational repressor are not known. Its human homologue, quaking (QKI), is essential for embryonic development. Here, we report that the RNA-binding protein GLD-1 in C. elegans affects multiple microRNA pathways and interacts with proteins required for microRNA function. Using genome-wide RNAi screening, we found that nhl-2 and vig-1 , two known modulators of miRNA function, genetically interact with GLD-1. gld-1 mutations enhance multiple phenotypes conferred by mir-35 and let-7 family mutants during somatic development. We used stable isotope labelling with amino acids in cell culture to globally analyse the changes in the proteome conferred by let-7 and gld-1 during animal development. We identified the histone mRNA-binding protein CDL-1 to be, in part, responsible for the phenotypes observed in let-7 and gld-1 mutants. The link between GLD-1 and miRNA-mediated gene regulation is further supported by its biochemical interaction with ALG-1, CGH-1 and PAB-1, proteins implicated in miRNA regulation. Overall, we have uncovered genetic and biochemical interactions between GLD-1 and miRNA pathways.

scholarly journals Regulation of Motility in Erwinia carotovora subsp. carotovora: Quorum-Sensing Signal Controls FlhDC, the Global Regulator of Flagellar and Exoprotein Genes, by Modulating the Production of RsmA, an RNA-Binding Protein

2010 ◽  
Vol 23 (10) ◽  
pp. 1316-1323 ◽  
Author(s):  
Asita Chatterjee ◽  
Yaya Cui ◽  
Pranjib Chakrabarty ◽  
Arun K. Chatterjee
Keyword(s):  
Quorum Sensing ◽  
Rna Binding ◽  
Binding Protein ◽  
Rna Binding Protein ◽  
Erwinia Carotovora ◽  
Translational Repression ◽  
Global Regulator ◽  
Acylhomoserine Lactone ◽  
Σ Factor ◽  
Regulatory Effects

Erwinia carotovora subsp. carotovora causes soft-rotting (tissue-macerating) disease in many plants and plant organs. Although pectinases are the primary determinants of virulence, several ancillary factors that augment bacterial virulence have also been identified. One such factor is bacterial motility. Flagellum formation and bacterial movement are regulated in many enterobacteria, including E. carotovora subsp. carotovora, by FlhDC, the master regulator of flagellar genes and FliA, a flagellum-specific σ factor. We document here that motility of E. carotovora subsp. carotovora is positively regulated by the quorum-sensing signal, N-acylhomoserine lactone (AHL), and negatively regulated by RsmA, a post-transcriptional regulator. RsmA, an RNA-binding protein, causes translational repression and promotes RNA decay. Our data show that RsmA negatively regulates flhDC and fliA expression. Moreover, the chemical stabilities of transcripts of these genes are greater in an RsmA– mutant than in RsmA+ bacteria. These observations contrast with positive regulation of flhDC and motility by CsrA (= RsmA) in Escherichia coli. In the absence of AHL, the AHL receptors ExpR1/ExpR2 (= AhlR) in Erwinia carotovora subsp. carotovora negatively regulate motility and expression of flhDC and fliA by activating RsmA production. In the presence of AHL, regulatory effects of ExpR1/ExpR2 are neutralized, resulting in reduced levels of rsmA expression and enhanced motility.

FOG-2, a novel F-box containing protein, associates with the GLD-1 RNA binding protein and directs male sex determination in the C. elegans hermaphrodite germline

Development ◽  
2000 ◽  
Vol 127 (24) ◽  
pp. 5265-5276 ◽  
Author(s):  
R. Clifford ◽  
M.H. Lee ◽  
S. Nayak ◽  
M. Ohmachi ◽  
F. Giorgini ◽  
...  
Keyword(s):  
Sex Determination ◽  
Rna Binding ◽  
Binding Protein ◽  
Rna Binding Protein ◽  
Translational Repression ◽  
Specific Substrate ◽  
Interaction Domain ◽  
C Elegans ◽  
Male Sex ◽  
F Box Protein

Male sex determination in the Caenorhabditis elegans hermaphrodite germline requires translational repression of tra-2 mRNA by the GLD-1 RNA binding protein. We cloned fog-2 by finding that its gene product physically interacts with GLD-1, forming a FOG-2/GLD-1/tra-2 3′untranslated region ternary complex. FOG-2 has an N-terminal F-box and a novel C-terminal domain called FTH. Canonical F-box proteins act as bridging components of the SCF ubiquitin ligase complex; the N-terminal F-box binds a Skp1 homolog, recruiting ubiquination machinery, while a C-terminal protein-protein interaction domain binds a specific substrate for degradation. However, since both fog-2 and gld-1 are necessary for spermatogenesis, FOG-2 cannot target GLD-1 for ubiquitin-mediated degradation. We propose that FOG-2 also acts as a bridge, bringing GLD-1 bound to tra-2 mRNA into a multiprotein translational repression complex, thus representing a novel function for an F-box protein. fog-2 is a member of a large, apparently rapidly evolving, C. elegans gene family that has expanded, in part, by local duplications; fog-2 related genes have not been found outside nematodes. fog-2 may have arisen during evolution of self-fertile hermaphroditism from an ancestral female/male species.

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 Translational repression by an RNA-binding protein promotes differentiation to infective forms in Trypanosoma cruzi

2018 ◽  
Vol 14 (6) ◽  
pp. e1007059 ◽  
Author(s):  
Maria Albertina Romaniuk ◽  
Alberto Carlos Frasch ◽  
Alejandro Cassola
Keyword(s):  
Trypanosoma Cruzi ◽  
Rna Binding ◽  
Binding Protein ◽  
Rna Binding Protein ◽  
Translational Repression
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