scholarly journals Conserved and clustered RNA recognition sequences are a critical feature of signals directing RNA localization in Xenopus oocytes

2004 ◽  
Vol 121 (1) ◽  
pp. 101-109 ◽  
Author(s):  
Raymond A. Lewis ◽  
Tracy L. Kress ◽  
Colette A. Cote ◽  
Denise Gautreau ◽  
Megan E. Rokop ◽  
...  
Keyword(s):  
Xenopus Oocytes ◽  
Rna Localization ◽  
Rna Recognition ◽  
Critical Feature

scholarly journals A Sponge-like Structure Involved in the Association and Transport of Maternal Products during Drosophila Oogenesis

1997 ◽  
Vol 139 (3) ◽  
pp. 817-829 ◽  
Author(s):  
Michaela Wilsch-Bräuninger ◽  
Heinz Schwarz ◽  
Christiane Nüsslein-Volhard
Keyword(s):  
Xenopus Oocytes ◽  
Polar Granule ◽  
Rna Localization ◽  
Drosophila Embryo ◽  
Fibrillar Structure ◽  
Subcellular Structure ◽  
Cytoplasmic Bridges ◽  
Dense Mass ◽  
Mitochondrial Cloud ◽  
Surrounding Membrane

Localization of maternally provided RNAs during oogenesis is required for formation of the antero–posterior axis of the Drosophila embryo. Here we describe a subcellular structure in nurse cells and oocytes which may function as an intracellular compartment for assembly and transport of maternal products involved in RNA localization. This structure, which we have termed “sponge body,” consists of ER-like cisternae, embedded in an amorphous electron-dense mass. It lacks a surrounding membrane and is frequently associated with mitochondria. The sponge bodies are not identical to the Golgi complexes. We suggest that the sponge bodies are homologous to the mitochondrial cloud in Xenopus oocytes, a granulo-fibrillar structure that contains RNAs involved in patterning of the embryo. Exuperantia protein, the earliest factor known to be required for the localization of bicoid mRNA to the anterior pole of the Drosophila oocyte, is highly enriched in the sponge bodies but not an essential structural component of these. RNA staining indicates that sponge bodies contain RNA. However, neither the intensity of this staining nor the accumulation of Exuperantia in the sponge bodies is dependent on the amount of bicoid mRNA present in the ovaries. Sponge bodies surround nuage, a possible polar granule precursor. Microtubules and microfilaments are not present in sponge bodies, although transport of the sponge bodies through the cells is implied by their presence in cytoplasmic bridges. We propose that the sponge bodies are structures that, by assembly and transport of included molecules or associated structures, are involved in localization of mRNAs in Drosophila oocytes.

scholarly journals PTB/hnRNP I Is Required for RNP Remodeling during RNA Localization in Xenopus Oocytes

2007 ◽  
Vol 28 (2) ◽  
pp. 678-686 ◽  
Author(s):  
Raymond A. Lewis ◽  
James A. Gagnon ◽  
Kimberly L. Mowry
Keyword(s):  
Protein Interactions ◽  
Xenopus Oocytes ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Rna Localization ◽  
Rna Transport ◽  
Rna Sequences ◽  
Cytoplasmic Rna ◽  
Embryonic Polarity ◽  
Specific Mrnas

ABSTRACT Transport of specific mRNAs to defined regions within the cell cytoplasm is a fundamental mechanism for regulating cell and developmental polarity. In the Xenopus oocyte, Vg1 RNA is transported to the vegetal cytoplasm, where localized expression of the encoded protein is critical for embryonic polarity. The Vg1 localization pathway is directed by interactions between key motifs within Vg1 RNA and protein factors recognizing those RNA sequences. We have investigated how RNA-protein interactions could be modulated to trigger distinct steps in the localization pathway and found that the Vg1 RNP is remodeled during cytoplasmic RNA transport. Our results implicate two RNA-binding proteins with key roles in Vg1 RNA localization, PTB/hnRNP I and Vg1RBP/vera, in this process. We show that PTB/hnRNP I is required for remodeling of the interaction between Vg1 RNA and Vg1RBP/vera. Critically, mutations that block this remodeling event also eliminate vegetal localization of the RNA, suggesting that RNP remodeling is required for localization.

scholarly journals Evidence for common machinery utilized by the early and late RNA localization pathways in Xenopus oocytes

2005 ◽  
Vol 278 (1) ◽  
pp. 103-117 ◽  
Author(s):  
Soheun Choo ◽  
Bianca Heinrich ◽  
J. Nicholas Betley ◽  
Zhao Chen ◽  
James O. Deshler
Keyword(s):  
Xenopus Oocytes ◽  
Rna Localization

scholarly journals Visualizing RNA Localization in Xenopus Oocytes

10.3791/1704 ◽  
2010 ◽  
Author(s):  
James A. Gagnon ◽  
Kimberly L. Mowry
Keyword(s):  
Xenopus Oocytes ◽  
Rna Localization

Two copies of a subelement from the Vg1 RNA localization sequence are sufficient to direct vegetal localization in Xenopus oocytes

Development ◽  
1997 ◽  
Vol 124 (24) ◽  
pp. 5013-5020 ◽  
Author(s):  
D. Gautreau ◽  
C.A. Cote ◽  
K.L. Mowry
Keyword(s):  
Xenopus Oocytes ◽  
Rna Localization ◽  
Sequence Motifs ◽  
Sequence Element ◽  
Cis Acting ◽  
Vegetal Cortex ◽  
Sequence Elements ◽  
Localization Sequence ◽  
Localization Signal ◽  
Localization Element

Localization of mRNA has emerged as a fundamental mechanism for generating polarity during development. In vertebrates, one example of this phenomenon is Vg1 RNA, which is localized to the vegetal cortex of Xenopus oocytes. Vegetal localization of Vg1 RNA is directed by a 340-nt sequence element contained within its 3′ untranslated region. To investigate how such cis-acting elements function in the localization process, we have undertaken a detailed analysis of the precise sequence requirements for vegetal localization within the 340-nt localization element. We present evidence for considerable redundancy within the localization element and demonstrate that critical sequences lie at the ends of the element. Importantly, we show that a subelement from the 5′ end of the Vg1 localization element is, when duplicated, sufficient to direct vegetal localization. We suggest that the Vg1 localization element is composed of smaller, redundant sequence motifs and identify one such 6-nt motif as essential for localization. These results allow insight into what constitutes an RNA localization signal and how RNA sequence elements may act in the localization process.

scholarly journals RNA localization in Xenopus oocytes uses a core group of trans-acting factors irrespective of destination

RNA ◽  
2013 ◽  
Vol 19 (7) ◽  
pp. 889-895 ◽  
Author(s):  
D. D. Snedden ◽  
M. M. Bertke ◽  
D. Vernon ◽  
P. W. Huber
Keyword(s):  
Xenopus Oocytes ◽  
Rna Localization ◽  
Core Group

Identification of vegetal RNA-localization elements in Xenopus oocytes

Methods ◽  
2010 ◽  
Vol 51 (1) ◽  
pp. 146-151 ◽  
Author(s):  
Maike Claußen ◽  
Tomas Pieler
Keyword(s):  
Xenopus Oocytes ◽  
Rna Localization ◽  
Localization Elements
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