scholarly journals Separate Elements in the 3′ Untranslated Region of the Mouse Protamine 1 mRNA Regulate Translational Repression and Activation during Murine Spermatogenesis

1997 ◽  
Vol 191 (1) ◽  
pp. 42-52 ◽  
Author(s):  
Mark A. Fajardo ◽  
Harald S. Haugen ◽  
Christopher H. Clegg ◽  
Robert E. Braun
Development ◽  
1995 ◽  
Vol 121 (6) ◽  
pp. 1775-1785 ◽  
Author(s):  
E.P. Robbie ◽  
M. Peterson ◽  
E. Amaya ◽  
T.J. Musci

Early frog embryogenesis depends on a maternal pool of mRNA to execute critical intercellular signalling events. FGF receptor-1, which is required for normal development, is stored as a stable, untranslated maternal mRNA transcript in the fully grown immature oocyte, but is translationally activated at meiotic maturation. We have identified a short cis-acting element in the FGF receptor 3′ untranslated region that inhibits translation of synthetic mRNA. This inhibitory element is sufficient to inhibit translation of heterologous reporter mRNA in the immature oocyte without changing RNA stability. Deletion of the poly(A) tract or polyadenylation signal sequences does not affect translational inhibition by this element. At meiotic maturation, we observe the reversal of translational repression mediated by the inhibitory element, mimicking that seen with endogenous maternal FGF receptor mRNA at meiosis. In addition, the activation of synthetic transcripts at maturation does not appear to require poly(A) lengthening. We also show that an oocyte cytoplasmic protein specifically binds the 3′ inhibitory element, suggesting that translational repression of Xenopus FGF receptor-1 maternal mRNA in the oocytes is mediated by RNA-protein interactions. These data describe a mechanism of translational control that appears to be independent of poly(A) changes.


Development ◽  
1999 ◽  
Vol 126 (6) ◽  
pp. 1129-1138 ◽  
Author(s):  
Y.S. Lie ◽  
P.M. Macdonald

The product of the oskar gene directs posterior patterning in the Drosophila oocyte, where it must be deployed specifically at the posterior pole. Proper expression relies on the coordinated localization and translational control of the oskar mRNA. Translational repression prior to localization of the transcript is mediated, in part, by the Bruno protein, which binds to discrete sites in the 3′ untranslated region of the oskar mRNA. To begin to understand how Bruno acts in translational repression, we performed a yeast two-hybrid screen to identify Bruno-interacting proteins. One interactor, described here, is the product of the apontic gene. Coimmunoprecipitation experiments lend biochemical support to the idea that Bruno and Apontic proteins physically interact in Drosophila. Genetic experiments using mutants defective in apontic and bruno reveal a functional interaction between these genes. Given this interaction, Apontic is likely to act together with Bruno in translational repression of oskar mRNA. Interestingly, Apontic, like Bruno, is an RNA-binding protein and specifically binds certain regions of the oskar mRNA 3′ untranslated region.


2017 ◽  
Vol 8 (1) ◽  
Author(s):  
Jianqiang Shen ◽  
Juhong Liu ◽  
Kabin Xie ◽  
Feng Xing ◽  
Fang Xiong ◽  
...  

2008 ◽  
Vol 36 (6) ◽  
pp. 1224-1231 ◽  
Author(s):  
Ian G. Cannell ◽  
Yi Wen Kong ◽  
Martin Bushell

miRNAs (microRNAs) are short non-coding RNAs that regulate gene expression post-transcriptionally. They generally bind to the 3′-UTR (untranslated region) of their target mRNAs and repress protein production by destabilizing the mRNA and translational silencing. The exact mechanism of miRNA-mediated translational repression is yet to be fully determined, but recent data from our laboratory have shown that the stage of translation which is inhibited by miRNAs is dependent upon the promoter used for transcribing the target mRNA. This review focuses on understanding how miRNA repression is operating in light of these findings and the questions that still remain.


Development ◽  
1996 ◽  
Vol 122 (9) ◽  
pp. 2791-2800 ◽  
Author(s):  
E.R. Gavis ◽  
L. Lunsford ◽  
S.E. Bergsten ◽  
R. Lehmann

Correct formation of the Drosophila body plan requires restriction of nanos activity to the posterior of the embryo. Spatial regulation of nanos is achieved by a combination of RNA localization and localization-dependent translation such that only posteriorly localized nanos RNA is translated. Cis-acting sequences that mediate both RNA localization and translational regulation lie within the nanos 3′ untranslated region. We have identified a discrete translational control element within the nanos 3′ untranslated region that acts independently of the localization signal to mediate translational repression of unlocalized nanos RNA. Both the translational regulatory function of the nanos 3′UTR and the sequence of the translational control element are conserved between D. melanogaster and D. virilis. Furthermore, we show that the RNA helicase Vasa, which is required for nanos RNA localization, also plays a critical role in promoting nanos translation. Our results specifically exclude models for translational regulation of nanos that rely on changes in polyadenylation.


2009 ◽  
Vol 187 (1) ◽  
pp. 33-42 ◽  
Author(s):  
Wei Li ◽  
Leah R. DeBella ◽  
Tugba Guven-Ozkan ◽  
Rueyling Lin ◽  
Lesilee S. Rose

In Caenorhabditis elegans, the MEI-1–katanin microtubule-severing complex is required for meiosis, but must be down-regulated during the transition to embryogenesis to prevent defects in mitosis. A cullin-dependent degradation pathway for MEI-1 protein has been well documented. In this paper, we report that translational repression may also play a role in MEI-1 down-regulation. Reduction of spn-2 function results in spindle orientation defects due to ectopic MEI-1 expression during embryonic mitosis. MEL-26, which is both required for MEI-1 degradation and is itself a target of the cullin degradation pathway, is present at normal levels in spn-2 mutant embryos, suggesting that the degradation pathway is functional. Cloning of spn-2 reveals that it encodes an eIF4E-binding protein that localizes to the cytoplasm and to ribonucleoprotein particles called P granules. SPN-2 binds to the RNA-binding protein OMA-1, which in turn binds to the mei-1 3′ untranslated region. Thus, our results suggest that SPN-2 functions as an eIF4E-binding protein to negatively regulate translation of mei-1.


2000 ◽  
Vol 20 (6) ◽  
pp. 2129-2137 ◽  
Author(s):  
Sunnie R. Thompson ◽  
Elizabeth B. Goodwin ◽  
Marvin Wickens

ABSTRACT The 3′ untranslated region (3′UTR) of many eukaryotic mRNAs is essential for their control during early development. Negative translational control elements in 3′UTRs regulate pattern formation, cell fate, and sex determination in a variety of organisms.tra-2 mRNA in Caenorhabditis elegans is required for female development but must be repressed to permit spermatogenesis in hermaphrodites. Translational repression oftra-2 mRNA in C. elegans is mediated by tandemly repeated elements in its 3′UTR; these elements are called TGEs (for tra-2 and GLI element). To examine the mechanism of TGE-mediated repression, we first demonstrate that TGE-mediated translational repression occurs in Xenopus embryos and thatXenopus egg extracts contain a TGE-specific binding factor. Translational repression by the TGEs requires that the mRNA possess a poly(A) tail. We show that in C. elegans, the poly(A) tail of wild-type tra-2 mRNA is shorter than that of a mutant mRNA lacking the TGEs. To determine whether TGEs regulate poly(A) length directly, synthetic tra-2 3′UTRs with and without the TGEs were injected into Xenopus embryos. We find that TGEs accelerate the rate of deadenylation and permit the last 15 adenosines to be removed from the RNA, resulting in the accumulation of fully deadenylated molecules. We conclude that TGE-mediated translational repression involves either interference with poly(A)'s function in translation and/or regulated deadenylation.


2021 ◽  
Author(s):  
Simone G. Moro ◽  
Cedric Hermans ◽  
Jorge Ruiz-Orera ◽  
M. Mar Albà

Abstract Background: A large fraction of genes contain upstream ORFs (uORFs) in the 5' untranslated region (5'UTR). The translation of uORFs can inhibit the translation of the main coding sequence, for example by causing premature dissociation of the two ribosomal units or ribosome stalling. However, it is currently unknown if most uORFs are inhibitory or if this activity is restricted to specific cases. Here we interrogate ribosome profiling data from three different stress experiments in yeast to address this question. Results: By comparing ribosome occupancies in different conditions and experiments we obtain strong evidence that, in comparison to primary coding sequences (CDS), which undergo translational arrest during stress, the translation of uORFs is mostly unaffected by changes in the environment. As a result the relative abundance of uORF-encoded peptides increases during stress. In general, the changes in the translational efficiency of regions containing uORFs do not seem to affect downstream translation. The exception are uORFs found in a subset of genes that are strongly up-regulated at the level of translation during stress; these uORFs tend to be translated at lower levels during stress than in optimal growth conditions, facilitating the translation of the CDS during stress. We find new examples of uORF-mediated regulation of translation, including the Gcn4 functional homologue fil1 and ubi4 genes in S. pombe.Conclusion: We find evidence that the relative amount of uORF-encoded peptides increases during stress. The increased translation of uORFs is however uncoupled from the general CDS translational repression observed during stress. In a subset of genes that encode proteins that need to be rapidly synthesized upon stress uORFs act as translational switches.


2001 ◽  
Vol 21 (20) ◽  
pp. 7010-7019 ◽  
Author(s):  
Flaviano Giorgini ◽  
Holly G. Davies ◽  
Robert E. Braun

ABSTRACT Y-box proteins are major constituents of ribonucleoprotein particles (RNPs) which contain translationally silent mRNAs in gametic cells. We have recently shown that a sequence-specific RNA binding activity present in spermatogenic cells contains the two Y-box proteins MSY2 and MSY4. We show here that MSY2 and MSY4 bind a sequence, 5′-UCCAUCA-3′, present in the 3′ untranslated region of the translationally repressed protamine 1 (Prm1) mRNA. Using pre- and post-RNase T1-digested substrate RNAs, it was determined that MSY2 and MSY4 can bind an RNA of eight nucleotides containing the MSY2 and MSY4 binding site. Single nucleotide mutations in the sequence eliminated the binding of MSY2 and MSY4 in an electrophoretic mobility shift assay, and the resulting mutants failed to compete for binding in a competition assay. A consensus site of UACCACAUCCACU(subscripts indicate nucleotides which do not disrupt YRS binding by MSY2 and MSY4), denoted the Y-box recognition site (YRS), was defined from this mutational analysis. These mutations in the YRS were further characterized in vivo using a novel application of the yeast three-hybrid system. Experiments with transgenic mice show that disruption of the YRS in vivo relieves Prm1-like repression of a reporter gene. The conservation of the RNA binding motifs among Y-box protein family members raises the possibility that other Y-box proteins may have previously unrecognized sequence-specific RNA binding activities.


1996 ◽  
Vol 16 (6) ◽  
pp. 3023-3034 ◽  
Author(s):  
K Lee ◽  
M A Fajardo ◽  
R E Braun

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.


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