scholarly journals Mitofusin2 cooperates with Nuage-associated proteins and involves mRNA translational machinery in controlling mRNA fates during spermatogenesis

2020 ◽  
Author(s):  
Xiaoli Wang ◽  
Yujiao Wen ◽  
Jin Zhang ◽  
Shuangshuang Guo ◽  
Congcong Cao ◽  
...  
Keyword(s):  
Germ Cell ◽  
Fusion Proteins ◽  
Rna Binding ◽  
Critical Role ◽  
Mrna Translation ◽  
Mitochondrial Fusion ◽  
Mitochondrial Morphology ◽  
Translational Machinery ◽  
Associated Proteins ◽  
Specific Mrna

AbstractMitochondria play a critical role in spermatogenesis and regulated by several mitochondrial fusion proteins. Its interaction with other organelles forms several unique structures, including mitochondria-associated ER membrane (MAM) and a specific type of Nuage close to mitochondria. However, the importance of mitochondria functions and mitochondrial fusion proteins in its associated-structure formation and mRNA translation during spermatogenesis remain unclear. Here, we show that Mitofusin 2 (MFN2), a mitochondrial fusion GTPase protein, cooperates with Nuage-associated proteins, including MIWI, DDX4, TDRKH and GASZ and involves translational machinery to control the fates of gamete-specific mRNAs in spermatogenesis. Conditional mutation of Mfn2 in postnatal germ cells results in male sterility due to germ cell developmental defects characterized by disruption of mitochondrial morphology, abnormal MAMs structure, aberrant mRNA translational processes, and anomalous splicing events. Moreover, MFN2 interacts with MFN1, another mitochondrial fusion protein with high-sequence similar to MFN2, in testes to facilitate spermatogenesis. Mutation of Mfn1 and Mfn2 simultaneously in testes causes very severe infertile phenotypes. Importantly, we further show that MFN2 is enriched in polysome fractions in testes and interacts with MSY2, a germ cell-specific DNA/RNA-binding protein, and eukaryotic elongation factor 1 alpha (eEF1A) to control gamete-specific mRNA translational delay during spermatogenesis. Collectively, our findings demonstrate that MFN2 works with Nuage-associated proteins and involves translational secession to regulate gamete-specific mRNA fates. Our data reveal a novel molecular link among Mitofusins, Nuage-associated proteins, and mRNA translational processes in controlling male germ cell development.

scholarly journals MFN2 interacts with Nuage-associated proteins and is essential for male germ cell development by controlling mRNA fate during spermatogenesis

Development ◽  
2021 ◽  
pp. dev.196295
Author(s):  
Xiaoli Wang ◽  
Yujiao Wen ◽  
Jin Zhang ◽  
Grace Swanson ◽  
Shuangshuang Guo ◽  
...  
Keyword(s):  
Fusion Protein ◽  
Germ Cell ◽  
Rna Binding ◽  
Cell Development ◽  
Mitochondrial Fusion ◽  
Male Germ Cell ◽  
Germ Cell Development ◽  
Associated Proteins ◽  
Mrna Fate ◽  
Specific Mrna

Mitochondria play a critical role in spermatogenesis and are regulated by several mitochondrial fusion proteins. However, their functional importance associated with their structure formation and mRNA fate regulation during spermatogenesis remains unclear. Here, we show that Mitofusin 2 (MFN2), a mitochondrial fusion protein, interacts with Nuage-associated proteins (including MIWI, DDX4, TDRKH, and GASZ). Conditional mutation of Mfn2 in postnatal germ cells results in male sterility due to germ cell developmental defects. Moreover, MFN2 interacts with MFN1, another mitochondrial fusion protein with a high-sequence similarity to MFN2, in testes to facilitate spermatogenesis. Simultaneous mutation of Mfn1 and Mfn2 in testes causes very severe infertile phenotypes. Importantly, we show that MFN2 is enriched in polysome fractions of testes and interacts with MSY2, a germ cell-specific DNA/RNA-binding protein to control gamete-specific mRNA (such as Spata19) translational activity during spermatogenesis. Collectively, our findings demonstrate that MFN2 interacts with Nuage-associated proteins and MSY2 to regulate male germ cell development by controlling several gamete-specific mRNA fates.

scholarly journals RNA-binding proteins La and HuR cooperatively modulate translation repression of PDCD4 mRNA

2020 ◽  
pp. jbc.RA120.014894
Author(s):  
Ravi Kumar ◽  
Dipak Kumar Poria ◽  
Partho Sarothi Ray
Keyword(s):  
Inflammatory Response ◽  
Chronic Inflammation ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Critical Role ◽  
Regulation Of Gene Expression ◽  
Mrna Translation ◽  
Suppressor Gene ◽  
Cooperative Action ◽  
Translation Repression

Post-transcriptional regulation of gene expression plays a critical role in controlling the inflammatory response. An uncontrolled inflammatory response results in chronic inflammation, often leading to tumorigenesis. Programmed cell death 4 (PDCD4) is a pro-inflammatory tumor-suppressor gene which helps to prevent the transition from chronic inflammation to cancer. PDCD4 mRNA translation is regulated by an interplay between the oncogenic microRNA miR-21 and the RNA-binding protein (RBP) HuR in response to LPS stimulation, but the role of other regulatory factors remain unknown. Here we report that the RBP Lupus antigen (La) interacts with the 3’UTR of PDCD4 mRNA and prevents miR-21-mediated translation repression. While LPS causes nuclear-cytoplasmic translocation of HuR, it enhances cellular La expression. Remarkably, La and HuR were found to bind cooperatively to the PDCD4 mRNA and mitigate miR-21-mediated translation repression. The cooperative action of La and HuR reduced cell proliferation and enhanced apoptosis, reversing the pro-oncogenic function of miR-21. Together, these observations demonstrate a cooperative interplay between two RBPs, triggered differentially by the same stimulus, which exerts a synergistic effect on PDCD4 expression and thereby helps maintain a balance between inflammation and tumorigenesis.

scholarly journals A potential role for a novel ZC3H5 complex in regulating mRNA translation in Trypanosoma brucei

2020 ◽  
Vol 295 (42) ◽  
pp. 14291-14304
Author(s):  
Kathrin Bajak ◽  
Kevin Leiss ◽  
Christine Clayton ◽  
Esteban Erben
Keyword(s):  
Gene Expression ◽  
Trypanosoma Brucei ◽  
Binding Proteins ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Binding Protein ◽  
Affinity Purification ◽  
Critical Role ◽  
Rna Binding Protein ◽  
Mrna Translation

In Trypanosoma brucei and related kinetoplastids, gene expression regulation occurs mostly posttranscriptionally. Consequently, RNA-binding proteins play a critical role in the regulation of mRNA and protein abundance. Yet, the roles of many RNA-binding proteins are not understood. Our previous research identified the RNA-binding protein ZC3H5 as possibly involved in gene repression, but its role in controlling gene expression was unknown. We here show that ZC3H5 is an essential cytoplasmic RNA-binding protein. RNAi targeting ZC3H5 causes accumulation of precytokinetic cells followed by rapid cell death. Affinity purification and pairwise yeast two-hybrid analysis suggest that ZC3H5 forms a complex with three other proteins, encoded by genes Tb927.11.4900, Tb927.8.1500, and Tb927.7.3040. RNA immunoprecipitation revealed that ZC3H5 is preferentially associated with poorly translated, low-stability mRNAs, the 5′-untranslated regions and coding regions of which are enriched in the motif (U/A)UAG(U/A). As previously found in high-throughput analyses, artificial tethering of ZC3H5 to a reporter mRNA or other complex components repressed reporter expression. However, depletion of ZC3H5 in vivo caused only very minor decreases in a few targets, marked increases in the abundances of very stable mRNAs, an increase in monosomes at the expense of large polysomes, and appearance of “halfmer” disomes containing two 80S subunits and one 40S subunit. We speculate that the ZC3H5 complex might be implicated in quality control during the translation of suboptimal open reading frames.

scholarly journals Regulation of mitochondrial fusion by the F-box protein Mdm30 involves proteasome-independent turnover of Fzo1

2006 ◽  
Vol 173 (5) ◽  
pp. 645-650 ◽  
Author(s):  
Mafalda Escobar-Henriques ◽  
Benedikt Westermann ◽  
Thomas Langer
Keyword(s):  
Outer Membrane ◽  
Outer Membrane Proteins ◽  
Critical Role ◽  
Mitochondrial Fusion ◽  
Yeast Cells ◽  
Mitochondrial Outer Membrane ◽  
Central Component ◽  
Mitochondrial Morphology ◽  
Proteolytic Pathway ◽  
F Box Protein

Mitochondrial morphology depends on balanced fusion and fission events. A central component of the mitochondrial fusion apparatus is the conserved GTPase Fzo1 in the outer membrane of mitochondria. Mdm30, an F-box protein required for mitochondrial fusion in vegetatively growing cells, affects the cellular Fzo1 concentration in an unknown manner. We demonstrate that mitochondrial fusion requires a tight control of Fzo1 levels, which is ensured by Fzo1 turnover. Mdm30 binds to Fzo1 and, dependent on its F-box, mediates proteolysis of Fzo1. Unexpectedly, degradation occurs along a novel proteolytic pathway not involving ubiquitylation, Skp1–Cdc53–F-box (SCF) E3 ubiquitin ligase complexes, or 26S proteasomes, indicating a novel function of an F-box protein. This contrasts to the ubiquitin- and proteasome-dependent turnover of Fzo1 in α-factor–arrested yeast cells. Our results therefore reveal not only a critical role of Fzo1 degradation for mitochondrial fusion in vegetatively growing cells but also the existence of two distinct proteolytic pathways for the turnover of mitochondrial outer membrane proteins.

scholarly journals The Cell Fate Determinant Musashi Is Controlled Through Dynamic Protein:Protein Interactions

2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. A555-A555
Author(s):  
Katherine Bronson ◽  
Meenakshisundaram Balasubramaniam ◽  
Linda Hardy ◽  
Gwen V Childs ◽  
Melanie C MacNicol ◽  
...  
Keyword(s):  
Cell Fate ◽  
Oocyte Maturation ◽  
Rna Binding ◽  
Mrna Translation ◽  
Hormone Production ◽  
Target Mrna ◽  
Associated Proteins ◽  
Specific Regulation ◽  
Partner Proteins

Abstract The Musashi RNA-binding protein functions as a gatekeeper of cell maturation and plasticity through the control of target mRNA translation. It is understood that Musashi promotes stem cell self-renewal and opposes differentiation. While Musashi is best characterized as a repressor of target mRNA translation, we have shown that Musashi can activate target mRNA translation in a cell context specific manner via regulatory phosphorylation on two evolutionarily conserved C-terminal serine residues. Our recent work has found that Musashi is expressed in pituitary stem cells as well as in differentiated hormone producing cell lineages in the adult pituitary. We hypothesize that Musashi maintains cell fate plasticity in the adult pituitary to allow the gland to modulate hormone production in response to changing organismal needs. Here, we seek to understand the regulation of Musashi function. Both Musashi isoforms (Musashi1 and Musashi2) contain two RNA-recognition motifs (RRMs) that bind to specific sequences in the 3’-UTR of target mRNA transcripts; however, neither isoform has enzymatic properties and thus functions through interactions with other proteins to regulate translational outcomes, but the identity and role of Musashi partner proteins is largely unknown. In this study, we have identified co-associated partner proteins that functionally contribute to Musashi-dependent mRNA translational activation during the maturation of Xenopus oocytes. Using mass spectrometry, we identified 29 co-associated proteins that interact specifically with Musashi1 during oocyte maturation and determined that the Musashi co-associated proteins ePABP, PABP4, LSM14A/B, CELF2, PUM1, ELAV1, ELAV2, and DDX6 attenuated oocyte maturation through individual antisense DNA oligo knockdowns. An assessment of the role of these cofactors in the control of Musashi-dependent target mRNA translation is in progress. In addition to studying co-associated proteins, we have created a computational 3D model of the Musashi1 molecule to assist in our investigation Musashi dimerization. This model has indicated that both Musashi1 dimerization and Musashi1:Musashi2 heterodimerization are energetically favorable, and co-pulldown studies have verified both Musashi1 homo-dimerization and Musashi1:Musashi2 heterodimerization in vivo. Computational modeling of Musashi dimer complexes has also identified the key amino acids necessary for these interactions. The contribution of each co-associated protein’s influence on Musashi-dependent translation, relative to the requirement for Musashi:Musashi dimerization, is expected to provide unparalleled insight into regulation of Musashi action. Moreover, cell type specific regulation of association of Musashi co-factors would directly influence Musashi target mRNA translation in oocyte maturation and during pituitary cell plasticity.

scholarly journals Sam68 regulates translation of target mRNAs in male germ cells, necessary for mouse spermatogenesis

2009 ◽  
Vol 185 (2) ◽  
pp. 235-249 ◽  
Author(s):  
Maria Paola Paronetto ◽  
Valeria Messina ◽  
Enrica Bianchi ◽  
Marco Barchi ◽  
Gillian Vogel ◽  
...  
Keyword(s):  
Germ Cells ◽  
Male Fertility ◽  
Essential Role ◽  
Rna Binding ◽  
Mrna Translation ◽  
Male Gamete ◽  
Essential Requirement ◽  
Translational Machinery ◽  
Heterologous System ◽  
Specific Mrnas

Sam68 is a KH-type RNA-binding protein involved in several steps of RNA metabolism with potential implications in cell differentiation and cancer. However, its physiological roles are still poorly understood. Herein, we show that Sam68−/− male mice are infertile and display several defects in spermatogenesis, demonstrating an essential role for Sam68 in male fertility. Sam68−/− mice produce few spermatozoa, which display dramatic motility defects and are unable to fertilize eggs. Expression of a subset of messenger mRNAs (mRNAs) is affected in the testis of knockout mice. Interestingly, Sam68 is associated with polyadenylated mRNAs in the cytoplasm during the meiotic divisions and in round spermatids, when it interacts with the translational machinery. We show that Sam68 is required for polysomal recruitment of specific mRNAs and for accumulation of the corresponding proteins in germ cells and in a heterologous system. These observations demonstrate a novel role for Sam68 in mRNA translation and highlight its essential requirement for the development of a functional male gamete.

scholarly journals The RNA-binding protein RBP42 regulates cellular energy metabolism in mammalian-infective Trypanosoma brucei

2021 ◽  
Author(s):  
Anish Das ◽  
Tong Liu ◽  
Hong Li ◽  
Seema Husain
Keyword(s):  
Energy Metabolism ◽  
Rna Binding ◽  
Binding Protein ◽  
Critical Role ◽  
Rna Binding Protein ◽  
Mrna Translation ◽  
Cellular Energy ◽  
Target Mrna ◽  
Cellular Energy Metabolism ◽  
Central Carbon

AbstractRNA-binding proteins are key players in coordinated post-transcriptional regulation of functionally related genes, defined as RNA regulons. RNA regulons play particularly critical roles in parasitic trypanosomes, which exhibit unregulated co-transcription of long arrays of unrelated genes. In this report, we present a systematic analysis of an essential RNA-binding protein, RBP42, in the mammalian-infective slender bloodstream form of African trypanosome, and we show that RBP42 is a key regulator of parasite’s central carbon and energy metabolism. Using individual-nucleotide resolution UV cross-linking and immunoprecipitation (iCLIP) to identify genome-wide RBP42-RNA interactions, we show that RBP42 preferentially binds within the coding region of mRNAs encoding core metabolic enzymes. Using global quantitative transcriptomic and proteomic analyses, we also show that loss of RBP42 reduces the abundance of target mRNA-encoded proteins, but not target mRNA, suggesting a plausible role of RBP42 as a positive regulator of target mRNA translation. Analysis reveals significant changes in central carbon metabolic intermediates following loss of RBP42, further supporting its critical role in cellular energy metabolism.

scholarly journals The Dynamic Regulation of mRNA Translation and Ribosome Biogenesis During Germ Cell Development and Reproductive Aging

2021 ◽  
Vol 9 ◽  
Author(s):  
Marianne Mercer ◽  
Seoyeon Jang ◽  
Chunyang Ni ◽  
Michael Buszczak
Keyword(s):  
Germ Cell ◽  
Germ Cells ◽  
Ribosome Biogenesis ◽  
Binding Proteins ◽  
Rna Binding ◽  
Mrna Translation ◽  
Cell Development ◽  
Reproductive Aging ◽  
Germ Cell Development ◽  
And Function

The regulation of mRNA translation, both globally and at the level of individual transcripts, plays a central role in the development and function of germ cells across species. Genetic studies using flies, worms, zebrafish and mice have highlighted the importance of specific RNA binding proteins in driving various aspects of germ cell formation and function. Many of these mRNA binding proteins, including Pumilio, Nanos, Vasa and Dazl have been conserved through evolution, specifically mark germ cells, and carry out similar functions across species. These proteins typically influence mRNA translation by binding to specific elements within the 3′ untranslated region (UTR) of target messages. Emerging evidence indicates that the global regulation of mRNA translation also plays an important role in germ cell development. For example, ribosome biogenesis is often regulated in a stage specific manner during gametogenesis. Moreover, oocytes need to produce and store a sufficient number of ribosomes to support the development of the early embryo until the initiation of zygotic transcription. Accumulating evidence indicates that disruption of mRNA translation regulatory mechanisms likely contributes to infertility and reproductive aging in humans. These findings highlight the importance of gaining further insights into the mechanisms that control mRNA translation within germ cells. Future work in this area will likely have important impacts beyond germ cell biology.

Translational control mechanisms in metabolic regulation: critical role of RNA binding proteins, microRNAs, and cytoplasmic RNA granules

2011 ◽  
Vol 301 (6) ◽  
pp. E1051-E1064 ◽  
Author(s):  
Khosrow Adeli
Keyword(s):  
Protein Synthesis ◽  
Translational Control ◽  
Metabolic Regulation ◽  
Binding Proteins ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Critical Role ◽  
Mrna Translation ◽  
Rna Granules

Regulated cell metabolism involves acute and chronic regulation of gene expression by various nutritional and endocrine stimuli. To respond effectively to endogenous and exogenous signals, cells require rapid response mechanisms to modulate transcript expression and protein synthesis and cannot, in most cases, rely on control of transcriptional initiation that requires hours to take effect. Thus, co- and posttranslational mechanisms have been increasingly recognized as key modulators of metabolic function. This review highlights the critical role of mRNA translational control in modulation of global protein synthesis as well as specific protein factors that regulate metabolic function. First, the complex lifecycle of eukaryotic mRNAs will be reviewed, including our current understanding of translational control mechanisms, regulation by RNA binding proteins and microRNAs, and the role of RNA granules, including processing bodies and stress granules. Second, the current evidence linking regulation of mRNA translation with normal physiological and metabolic pathways and the associated disease states are reviewed. A growing body of evidence supports a key role of translational control in metabolic regulation and implicates translational mechanisms in the pathogenesis of metabolic disorders such as type 2 diabetes. The review also highlights translational control of apolipoprotein B (apoB) mRNA by insulin as a clear example of endocrine modulation of mRNA translation to bring about changes in specific metabolic pathways. Recent findings made on the role of 5′-untranslated regions (5′-UTR), 3′-UTR, RNA binding proteins, and RNA granules in mediating insulin regulation of apoB mRNA translation, apoB protein synthesis, and hepatic lipoprotein production are discussed.

Neuronal mRNA Translation in Addiction

2018 ◽  
Author(s):  
Emma Puighermanal ◽  
Emmanuel Valjent
Keyword(s):  
Structural Changes ◽  
Drugs Of Abuse ◽  
Mrna Translation ◽  
Cell Types ◽  
Behavioral Changes ◽  
Translational Machinery ◽  
Addictive Drugs ◽  
Specific Mrnas ◽  
Cell Type Specific ◽  
Future Work

Addictive drugs trigger persistent synaptic and structural changes in the neuronal reward circuits that are thought to underlie the development of drug-adaptive behavior. While transcriptional and epigenetic modifications are known to contribute to these circuit changes, accumulating evidence indicates that altered mRNA translation is also a key molecular mechanism. This chapter reviews recent studies demonstrating how addictive drugs alter protein synthesis and/or the translational machinery and how this leads to neuronal circuit remodeling and behavioral changes. Future work will determine precisely which neuronal circuits and cell types participate in these changes. The chapter summarizes current methodologies for identifying cell type-specific mRNAs whose translation is affected by drugs of abuse and gives recent examples of the mechanistic insights into addiction they provide.

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