scholarly journals Makorin 1 controls embryonic patterning by alleviating Bruno1-mediated repression ofoskartranslation

2018 ◽  
Author(s):  
Annabelle Dold ◽  
Hong Han ◽  
Niankun Liu ◽  
Andrea Hildebrandt ◽  
Mirko Brüggemann ◽  
...  
Keyword(s):  
Binding Site ◽  
Rna Binding ◽  
Binding Protein ◽  
Protein A ◽  
Cell Formation ◽  
Posterior Pole ◽  
Embryonic Patterning ◽  
Translational Repressor ◽  
Translational Activation ◽  
Translational Activator

AbstractMakorins are evolutionary conserved proteins that contain C3H-type zinc finger modules and a RING E3 ubiquitin ligase domain. InDrosophilamaternal Makorin 1 (Mkrn1) has been linked to embryonic patterning but the mechanism remained unsolved. Here, we show that Mkrn1 is essential for axis specification and pole plasm assembly by translational activation ofoskar. We demonstrate that Mkrn1 interacts with poly(A) binding protein (pAbp) and bindsosk3’ UTR in a region adjacent to A-rich sequences. This binding site overlaps with Bruno1 (Bru1) responsive elements (BREs), which regulateosktranslation. We observe increased association of the translational repressor Bru1 withoskmRNA upon depletion of Mkrn1, indicating that both proteins compete foroskbinding. Consistently, reducing Bru1 dosage partially rescues viability and Osk protein level in ovaries fromMkrn1females. We conclude that Mkrn1 controls embryonic patterning and germ cell formation by specifically activatingosktranslation by displacing Bru1 from its 3’ UTR.Author SummaryTo ensure accurate development of theDrosophilaembryo, proteins and mRNAs are positioned at specific sites within the embryo. Many of these proteins and mRNAs are produced and localized during the development of the egg in the mother. One protein essential for this process that has been heavily studied is Oskar (Osk), which is positioned at the posterior pole. During the localization ofoskmRNA, its translation is repressed by the RNA-binding protein Bruno1 (Bru1), ensuring that Osk protein is not present outside of the posterior where it is harmful. At the posterior pole,oskmRNA is activated through mechanisms that are not yet understood. In this work, we show that the conserved protein Makorin 1 (Mkrn1) is a novel factor involved in the translational activation ofosk. Mkrn1 binds specifically tooskmRNA in a region that overlaps with the binding site of Bru1, thus alleviating the association of Bru1 withosk. Moreover, Mkrn1 is stabilized by poly(A) binding protein, a translational activator that bindsoskmRNA in close proximity to Mkrn1. Our work thus helps to answer a long-standing question in the field, providing insight about the function of Mkrn1 and more generally into embryonic patterning in animals.

scholarly journals Progesterone Receptor Membrane Component-1 (PGRMC1) Is the Mediator of Progesterone’s Antiapoptotic Action in Spontaneously Immortalized Granulosa Cells As Revealed by PGRMC1 Small Interfering Ribonucleic Acid Treatment and Functional Analysis of PGRMC1 Mutations

Endocrinology ◽  
2007 ◽  
Vol 149 (2) ◽  
pp. 534-543 ◽  
Author(s):  
John J. Peluso ◽  
Jonathan Romak ◽  
Xiufang Liu
Keyword(s):  
Binding Site ◽  
Rna Binding ◽  
Transmembrane Domain ◽  
Binding Protein ◽  
Plasminogen Activator Inhibitor ◽  
Membrane Receptor ◽  
Membrane Component ◽  
Plasminogen Activator Inhibitor 1 ◽  
Receptor Membrane ◽  
C Terminus

Progesterone (P4) receptor membrane component-1 (PGRMC1) and its binding partner, plasminogen activator inhibitor 1 RNA binding protein (PAIRBP1) are thought to form a complex that functions as membrane receptor for P4. The present investigations confirm PGRMC1’s role in this membrane receptor complex by demonstrating that depleting PGMRC1 with PGRMC1 small interfering RNA results in a 60% decline in [3H]P4 binding and the loss of P4’s antiapoptotic action. Studies conducted on partially purified GFP-PGRMC1 fusion protein indicate that [3H]P4 specifically binds to PGRMC1 at a single site with an apparent Kd of about 35 nm. In addition, experiments using various deletion mutations reveal that the entire PGRMC1 molecule is required for maximal [3H]P4 binding and P4 responsiveness. Analysis of the binding data also suggests that the P4 binding site is within a segment of PGRMC1 that is composed of the transmembrane domain and the initial segment of the C terminus. Interestingly, PAIRBP1 appears to bind to the C terminus between amino acids 70–130, which is distal to the putative P4 binding site. Taken together, these data provide compelling evidence that PGRMC1 is the P4 binding protein that mediates P4’s antiapoptotic action. Moreover, the deletion mutation studies indicate that each domain of PGRMC1 plays an essential role in modulating PGRMC1’s capacity to both bind and respond to P4. Additional studies are required to more precisely delineate the role of each PGRMC1 domain in transducing P4’s antiapoptotic action.

Apontic binds the translational repressor Bruno and is implicated in regulation of oskar mRNA translation

Development ◽  
1999 ◽  
Vol 126 (6) ◽  
pp. 1129-1138 ◽  
Author(s):  
Y.S. Lie ◽  
P.M. Macdonald
Keyword(s):  
Translational Control ◽  
Untranslated Region ◽  
Rna Binding ◽  
Mrna Translation ◽  
Posterior Pole ◽  
Translational Repression ◽  
Yeast Two Hybrid ◽  
Functional Interaction ◽  
Translational Repressor ◽  
Two Hybrid

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.

scholarly journals NMR structure and dynamics of the RNA-binding site for the histone mRNA stem-loop binding protein

RNA ◽  
2002 ◽  
Vol 8 (1) ◽  
pp. 83-96 ◽  
Author(s):  
ERIC S. DEJONG ◽  
WILLIAM F. MARZLUFF ◽  
EDWARD P. NIKONOWICZ
Keyword(s):  
Binding Site ◽  
Rna Binding ◽  
Binding Protein ◽  
Nmr Structure ◽  
Histone Mrna ◽  
Stem Loop ◽  
Structure And Dynamics

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 An RNA-binding protein specifically interacts with a functionally important domain of the downstream element of the simian virus 40 late polyadenylation signal.

1991 ◽  
Vol 11 (10) ◽  
pp. 5312-5320 ◽  
Author(s):  
Z W Qian ◽  
J Wilusz
Keyword(s):  
Binding Site ◽  
Rna Binding ◽  
Specific Binding ◽  
Binding Protein ◽  
Rna Binding Protein ◽  
Simian Virus 40 ◽  
Simian Virus ◽  
Polyadenylation Signal ◽  
Band Shift

We have identified an RNA-binding protein which interacts with the downstream element of the simian virus 40 late polyadenylation signal in a sequence-specific manner. A partially purified 50-kDa protein, which we have named DSEF-1, retains RNA-binding specificity as assayed by band shift and UV cross-linking analyses. RNA footprinting assays, using end-labeled RNA ladder fragments in conjunction with native gel electrophoresis, have identified the DSEF-1 binding site as 5'-GGGGGAGGUGUGGG-3'. This 14-base sequence serves as an efficient DSEF-1 binding site when placed within a GEM4 polylinker-derived RNA. Finally, the DSEF-1 binding site restored efficient in vitro 3' end processing to derivatives of the simian virus 40 late polyadenylation signal in which it substituted for the entire downstream region. DSEF-1, therefore, may be a sequence-specific binding factor which regulates the efficiency of polyadenylation site usage.

scholarly journals Association of Guide RNA Binding Protein gBP21 with Active RNA Editing Complexes in Trypanosoma brucei

1998 ◽  
Vol 18 (10) ◽  
pp. 6014-6022 ◽  
Author(s):  
Thomas E. Allen ◽  
Stefan Heidmann ◽  
RoseMary Reed ◽  
Peter J. Myler ◽  
H. Ulrich Göringer ◽  
...  
Keyword(s):  
Trypanosoma Brucei ◽  
Rna Editing ◽  
Rna Binding ◽  
Binding Protein ◽  
Protein A ◽  
Mitochondrial Fraction ◽  
Macromolecular Complex ◽  
Guide Rna ◽  
Ribonucleoprotein Complexes

ABSTRACT RNA editing in Trypanosoma brucei mitochondria produces mature mRNAs by a series of enzyme-catalyzed reactions that specifically insert or delete uridylates in association with a macromolecular complex. Using a mitochondrial fraction enriched for in vitro RNA editing activity, we produced several monoclonal antibodies that are specific for a 21-kDa guide RNA (gRNA) binding protein initially identified by UV cross-linking. Immunofluorescence studies localize the protein to the mitochondrion, with a preference for the kinetoplast. The antibodies cause a supershift of previously identified gRNA-specific ribonucleoprotein complexes and immunoprecipitate in vitro RNA editing activities that insert and delete uridylates. The immunoprecipitated material also contains gRNA-specific endoribonuclease, terminal uridylyltransferase, and RNA ligase activities as well as gRNA and both edited and unedited mRNA. The immunoprecipitate contains numerous proteins, of which the 21-kDa protein, a 90-kDa protein, and novel 55- and 16-kDa proteins can be UV cross-linked to gRNA. These studies indicate that the 21-kDa protein associates with the ribonucleoprotein complex (or complexes) that catalyze RNA editing.

scholarly journals LINE-1 ORF1 Protein Localizes in Stress Granules with Other RNA-Binding Proteins, Including Components of RNA Interference RNA-Induced Silencing Complex

2007 ◽  
Vol 27 (18) ◽  
pp. 6469-6483 ◽  
Author(s):  
John L. Goodier ◽  
Lili Zhang ◽  
Melissa R. Vetter ◽  
Haig H. Kazazian
Keyword(s):  
Binding Proteins ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Binding Protein ◽  
Protein A ◽  
Rna Binding Protein ◽  
Stress Granules ◽  
Plasminogen Activator Inhibitor ◽  
Cellular Damage ◽  
Activator Inhibitor

ABSTRACT LINE-1 retrotransposons constitute one-fifth of human DNA and have helped shape our genome. A full-length L1 encodes a 40-kDa RNA-binding protein (ORF1p) and a 150-kDa protein (ORF2p) with endonuclease and reverse transcriptase activities. ORF1p is distinctive in forming large cytoplasmic foci, which we identified as cytoplasmic stress granules. A phylogenetically conserved central region of the protein is critical for wild-type localization and retrotransposition. Yeast two-hybrid screens revealed several RNA-binding proteins that coimmunoprecipitate with ORF1p and colocalize with ORF1p in foci. Two of these proteins, YB-1 and hnRNPA1, were previously reported in stress granules. We identified additional proteins associated with stress granules, including DNA-binding protein A, 9G8, and plasminogen activator inhibitor RNA-binding protein 1 (PAI-RBP1). PAI-RBP1 is a homolog of VIG, a part of the Drosophila melanogaster RNA-induced silencing complex (RISC). Other RISC components, including Ago2 and FMRP, also colocalize with PAI-RBP1 and ORF1p. We suggest that targeting ORF1p, and possibly the L1 RNP, to stress granules is a mechanism for controlling retrotransposition and its associated genetic and cellular damage.

scholarly journals Functioning of the Drosophila orb gene in gurken mRNA localization and translation

Development ◽  
2001 ◽  
Vol 128 (16) ◽  
pp. 3169-3177 ◽  
Author(s):  
Jacqueline S. Chang ◽  
Lihua Tan ◽  
Melisande R. Wolf ◽  
Paul Schedl
Keyword(s):  
Signaling Pathway ◽  
Rna Binding ◽  
Binding Protein ◽  
Growth Factor Receptor ◽  
Follicle Cell ◽  
Posterior Pole ◽  
Rna Recognition Motif ◽  
Cytoplasmic Polyadenylation ◽  
Element Binding Protein ◽  
Translational Regulators

The orb gene encodes an RNA recognition motif (RRM)-type RNA-binding protein that is a member of the cytoplasmic polyadenylation element binding protein (CPEB) family of translational regulators. Early in oogenesis, orb is required for the formation and initial differentiation of the egg chamber, while later in oogenesis it functions in the determination of the dorsoventral (DV) and anteroposterior axes of egg and embryo. In the studies reported here, we have examined the role of theorb gene in the gurken (grk)-Drosophila epidermal growth factor receptor (DER) signaling pathway. During the previtellogenic stages of oogenesis, the grk-DER signaling pathway defines the posterior pole of the oocyte by specifying posterior follicle cell identity. This is accomplished through the localized expression of Grk at the very posterior of the oocyte. Later in oogenesis, thegrk-DER pathway is used to establish the DV axis. Grk protein synthesized at the dorsal anterior corner of the oocyte signals dorsal fate to the overlying follicle cell epithelium. We show that orb functions in both the early and late grk-DER signaling pathways, and in each case is required for the localized expression of Grk protein. We have found thatorb is also required to promote the synthesis of a key component of the DV polarity pathway, K(10). Finally, we present evidence that Orb protein expression during the mid- to late stages of oogenesis is, in turn, negatively regulated by K(10).

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