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

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.

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Modeling the binding specificity of the RNA-binding protein GLD-1 suggests a function of coding region-located sites in translational repression

RNA ◽

10.1261/rna.037531.112 ◽

2013 ◽

Vol 19 (10) ◽

pp. 1317-1326 ◽

Cited By ~ 16

Author(s):

A. Brummer ◽

S. Kishore ◽

D. Subasic ◽

M. Hengartner ◽

M. Zavolan

Keyword(s):

Rna Binding ◽

Binding Protein ◽

Rna Binding Protein ◽

Binding Specificity ◽

Translational Repression ◽

Coding Region

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

10.1101/378398 ◽

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.

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The overexpression of the trypanosomatid-exclusive TcRBP19 RNA-binding protein affects cellular infection by Trypanosoma cruzi

Memórias do Instituto Oswaldo Cruz ◽

10.1590/s0074-02762012000800021 ◽

2012 ◽

Vol 107 (8) ◽

pp. 1076-1079 ◽

Cited By ~ 6

Author(s):

Leticia Pérez-Díaz ◽

Alejandro Correa ◽

Mariana P Moretão ◽

Samuel Goldenberg ◽

Bruno Dallagiovanna ◽

...

Keyword(s):

Trypanosoma Cruzi ◽

Rna Binding ◽

Binding Protein ◽

Rna Binding Protein

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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 ◽

10.1242/dev.127.24.5265 ◽

2000 ◽

Vol 127 (24) ◽

pp. 5265-5276 ◽

Cited By ~ 9

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.

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

The Journal of Cell Biology ◽

10.1083/jcb.129.4.1023 ◽

1995 ◽

Vol 129 (4) ◽

pp. 1023-1032 ◽

Cited By ~ 67

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.

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Molecular characterization of the Trypanosoma cruzi specific RNA binding protein TcRBP40 and its associated mRNAs

Biochemical and Biophysical Research Communications ◽

10.1016/j.bbrc.2012.02.154 ◽

2012 ◽

Vol 420 (2) ◽

pp. 302-307 ◽

Cited By ~ 11

Author(s):

Eloise P. Guerra-Slompo ◽

Christian M. Probst ◽

Daniela P. Pavoni ◽

Samuel Goldenberg ◽

Marco A. Krieger ◽

...

Keyword(s):

Trypanosoma Cruzi ◽

Molecular Characterization ◽

Rna Binding ◽

Binding Protein ◽

Rna Binding Protein

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