Severe muscle wasting and denervation in mice lacking the RNA-binding protein ZFP106

Innervation of skeletal muscle by motor neurons occurs through the neuromuscular junction, a cholinergic synapse essential for normal muscle growth and function. Defects in nerve–muscle signaling cause a variety of neuromuscular disorders with features of ataxia, paralysis, skeletal muscle wasting, and degeneration. Here we show that the nuclear zinc finger protein ZFP106 is highly enriched in skeletal muscle and is required for postnatal maintenance of myofiber innervation by motor neurons. Genetic disruption of Zfp106 in mice results in progressive ataxia and hindlimb paralysis associated with motor neuron degeneration, severe muscle wasting, and premature death by 6 mo of age. We show that ZFP106 is an RNA-binding protein that associates with the core splicing factor RNA binding motif protein 39 (RBM39) and localizes to nuclear speckles adjacent to spliceosomes. Upon inhibition of pre-mRNA synthesis, ZFP106 translocates with other splicing factors to the nucleolus. Muscle and spinal cord of Zfp106 knockout mice displayed a gene expression signature of neuromuscular degeneration. Strikingly, altered splicing of the Nogo (Rtn4) gene locus in skeletal muscle of Zfp106 knockout mice resulted in ectopic expression of NOGO-A, the neurite outgrowth factor that inhibits nerve regeneration and destabilizes neuromuscular junctions. These findings reveal a central role for Zfp106 in the maintenance of nerve–muscle signaling, and highlight the involvement of aberrant RNA processing in neuromuscular disease pathogenesis.

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RBM45 Modulates the Antioxidant Response in Amyotrophic Lateral Sclerosis through Interactions with KEAP1

Molecular and Cellular Biology ◽

10.1128/mcb.00087-15 ◽

2015 ◽

Vol 35 (14) ◽

pp. 2385-2399 ◽

Cited By ~ 12

Author(s):

Nadine Bakkar ◽

Arianna Kousari ◽

Tina Kovalik ◽

Yang Li ◽

Robert Bowser

Keyword(s):

Oxidative Stress ◽

Spinal Cord ◽

Amyotrophic Lateral Sclerosis ◽

Motor Neurons ◽

Rna Binding ◽

Binding Protein ◽

Rna Binding Protein ◽

Antioxidant Response ◽

Cytoplasmic Inclusions ◽

Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by the selective loss of motor neurons. Various factors contribute to the disease, including RNA binding protein dysregulation and oxidative stress, but their exact role in pathogenic mechanisms remains unclear. We have recently linked another RNA binding protein, RBM45, to ALS via increased levels of protein in the cerebrospinal fluid of ALS patients and its localization to cytoplasmic inclusions in ALS motor neurons. Here we show RBM45 nuclear exit in ALS spinal cord motor neurons compared to controls, a phenotype recapitulatedin vitroin motor neurons treated with oxidative stressors. We find that RBM45 binds and stabilizes KEAP1, the inhibitor of the antioxidant response transcription factor NRF2. ALS lumbar spinal cord lysates similarly show increased cytoplasmic binding of KEAP1 and RBM45. Binding of RBM45 to KEAP1 impedes the protective antioxidant response, thus contributing to oxidative stress-induced cellular toxicity. Our findings thus describe a novel link between a mislocalized RNA binding protein implicated in ALS (RBM45) and dysregulation of the neuroprotective antioxidant response seen in the disease.

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The RNA binding protein HuR influences skeletal muscle metabolic flexibility in rodents and humans

Metabolism ◽

10.1016/j.metabol.2019.05.010 ◽

2019 ◽

Vol 97 ◽

pp. 40-49 ◽

Cited By ~ 5

Author(s):

Randall L. Mynatt ◽

Robert C. Noland ◽

Carrie M. Elks ◽

Bolormaa Vandanmagsar ◽

David S. Bayless ◽

...

Keyword(s):

Skeletal Muscle ◽

Rna Binding ◽

Binding Protein ◽

Rna Binding Protein ◽

Metabolic Flexibility

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Suppression of C9orf72 RNA repeat-induced neurotoxicity by the ALS-associated RNA-binding protein Zfp106

eLife ◽

10.7554/elife.19032 ◽

2017 ◽

Vol 6 ◽

Cited By ~ 22

Author(s):

Barbara Celona ◽

John von Dollen ◽

Sarat C Vatsavayai ◽

Risa Kashima ◽

Jeffrey R Johnson ◽

...

Keyword(s):

Motor Neurons ◽

Binding Proteins ◽

Rna Binding ◽

Zinc Finger Protein ◽

Rna Binding Proteins ◽

Binding Protein ◽

Affinity Purification ◽

Rna Binding Protein ◽

Severe Motor ◽

Affinity Purification Mass Spectrometry

Expanded GGGGCC repeats in the first intron of the C9orf72 gene represent the most common cause of familial amyotrophic lateral sclerosis (ALS), but the mechanisms underlying repeat-induced disease remain incompletely resolved. One proposed gain-of-function mechanism is that repeat-containing RNA forms aggregates that sequester RNA binding proteins, leading to altered RNA metabolism in motor neurons. Here, we identify the zinc finger protein Zfp106 as a specific GGGGCC RNA repeat-binding protein, and using affinity purification-mass spectrometry, we show that Zfp106 interacts with multiple other RNA binding proteins, including the ALS-associated factors TDP-43 and FUS. We also show that Zfp106 knockout mice develop severe motor neuron degeneration, which can be suppressed by transgenic restoration of Zfp106 specifically in motor neurons. Finally, we show that Zfp106 potently suppresses neurotoxicity in a Drosophila model of C9orf72 ALS. Thus, these studies identify Zfp106 as an RNA binding protein with important implications for ALS.

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Nuclear depletion of RNA binding protein ELAVL3 (HuC) in sporadic and familial amyotrophic lateral sclerosis

10.1101/2021.06.03.446017 ◽

2021 ◽

Author(s):

Sandra Diaz-Garcia ◽

Vivian I. Ko ◽

Sonia Vazquez-Sanchez ◽

Ruth Chia ◽

Olubankole Aladesuyi Arogundade ◽

...

Keyword(s):

Amyotrophic Lateral Sclerosis ◽

Motor Neurons ◽

Rna Binding ◽

Binding Protein ◽

Rna Binding Protein ◽

Loss Of Function ◽

Cryptic Exon ◽

Protein Levels ◽

Sporadic Als ◽

Lateral Sclerosis

Amyotrophic lateral sclerosis is a progressive fatal neurodegenerative disease caused by loss of motor neurons and characterized neuropathologically in almost all cases by nuclear depletion and cytoplasmic aggregation of TDP-43, a nuclear RNA binding protein (RBP). We identified ELAVL3 as one of the most downregulated genes in our transcriptome profiles of laser captured microdissection of motor neurons from sporadic ALS nervous systems and the top dysregulated RBPs. Neuropathological characterizations showed ELAVL3 nuclear depletion in a great percentage of remnant motor neurons, sometimes accompanied by cytoplasmic accumulations. These abnormalities were common in sporadic cases with and without intermediate expansions in ATXN2 and familial cases carrying mutations in C9orf72 and SOD1. Depletion of ELAVL3 occurred at both the RNA and protein levels and a short protein isoform was identified but it is not related to a TDP-43-dependent cryptic exon in intron 3. Strikingly, ELAVL3 abnormalities were more frequent than TDP-43 abnormalities and occurred in motor neurons still with normal nuclear TDP-43 present, but all neurons with abnormal TDP-43 also had abnormal ELAVL3. In a neuron-like cell culture model using SH-SY5Y cells, ELAVL3 mislocalization occurred weeks before TDP-43 abnormalities were seen. We interrogated genetic databases but did not identify association of ELAVL3 genetic structure associated with ALS. Taken together, these findings suggest that ELAVL3 is an important RBP in ALS pathogenesis acquired early and the neuropathological data suggest it is involved by loss of function rather than cytoplasmic toxicity.

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The Nuclear RNA-binding Protein Sam68 Translocates to the Cytoplasm and Associates with the Polysomes in Mouse Spermatocytes

Molecular Biology of the Cell ◽

10.1091/mbc.e05-06-0548 ◽

2006 ◽

Vol 17 (1) ◽

pp. 14-24 ◽

Cited By ~ 60

Author(s):

Maria Paola Paronetto ◽

Francesca Zalfa ◽

Flavia Botti ◽

Raffaele Geremia ◽

Claudia Bagni ◽

...

Keyword(s):

Translational Control ◽

Rna Binding ◽

Rna Binding Proteins ◽

Binding Protein ◽

Rna Binding Protein ◽

Male Meiosis ◽

Binding Motif ◽

Mitogen Activated Protein ◽

Pachytene Spermatocytes ◽

And Function

Translational control plays a crucial role during gametogenesis in organisms as different as worms and mammals. Mouse knockout models have highlighted the essential function of many RNA-binding proteins during spermatogenesis. Herein we have investigated the expression and function during mammalian male meiosis of Sam68, an RNA-binding protein implicated in several aspects of RNA metabolism. Sam68 expression and localization within the cells is stage specific: it is expressed in the nucleus of spermatogonia, it disappears at the onset of meiosis (leptotene/zygotene stages), and it accumulates again in the nucleus of pachytene spermatocytes and round spermatids. During the meiotic divisions, Sam68 translocates to the cytoplasm where it is found associated with the polysomes. Translocation correlates with serine/threonine phosphorylation and it is blocked by inhibitors of the mitogen activated protein kinases ERK1/2 and of the maturation promoting factor cyclinB-cdc2 complex. Both kinases associate with Sam68 in pachytene spermatocytes and phosphorylate the regulatory regions upstream and downstream of the Sam68 RNA-binding motif. Molecular cloning of the mRNAs associated with Sam68 in mouse spermatocytes reveals a subset of genes that might be posttranscriptionally regulated by this RNA-binding protein during spermatogenesis. We also demonstrate that Sam68 shuttles between the nucleus and the cytoplasm in secondary spermatocytes, suggesting that it may promote translation of specific RNA targets during the meiotic divisions.

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Converging pathways involving microRNA-206 and the RNA-binding protein KSRP control post-transcriptionally utrophin A expression in skeletal muscle

Nucleic Acids Research ◽

10.1093/nar/gkt1350 ◽

2013 ◽

Vol 42 (6) ◽

pp. 3982-3997 ◽

Cited By ~ 17

Author(s):

Adel Amirouche ◽

Helina Tadesse ◽

Pedro Miura ◽

Guy Bélanger ◽

John A. Lunde ◽

...

Keyword(s):

Skeletal Muscle ◽

Rna Binding ◽

Binding Protein ◽

Rna Binding Protein ◽

Control Post

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The RNA-binding protein Staufen1 is increased in DM1 skeletal muscle and promotes alternative pre-mRNA splicing

The Journal of Cell Biology ◽

10.1083/jcb.201108113 ◽

2012 ◽

Vol 196 (6) ◽

pp. 699-712 ◽

Cited By ~ 72

Author(s):

Aymeric Ravel-Chapuis ◽

Guy Bélanger ◽

Ramesh S. Yadava ◽

Mani S. Mahadevan ◽

Luc DesGroseillers ◽

...

Keyword(s):

Skeletal Muscle ◽

Alternative Splicing ◽

Nuclear Export ◽

Rna Binding ◽

Rna Binding Proteins ◽

Binding Protein ◽

Rna Binding Protein ◽

Splicing Regulation ◽

Ribonucleic Acids ◽

Dystrophia Myotonica Protein Kinase

In myotonic dystrophy type 1 (DM1), dystrophia myotonica protein kinase messenger ribonucleic acids (RNAs; mRNAs) with expanded CUG repeats (CUGexp) aggregate in the nucleus and become toxic to cells by sequestering and/or misregulating RNA-binding proteins, resulting in aberrant alternative splicing. In this paper, we find that the RNA-binding protein Staufen1 is markedly and specifically increased in skeletal muscle from DM1 mouse models and patients. We show that Staufen1 interacts with mutant CUGexp mRNAs and promotes their nuclear export and translation. This effect is critically dependent on the third double-stranded RNA–binding domain of Staufen1 and shuttling of Staufen1 into the nucleus via its nuclear localization signal. Moreover, we uncover a new role of Staufen1 in splicing regulation. Overexpression of Staufen1 rescues alternative splicing of two key pre-mRNAs known to be aberrantly spliced in DM1, suggesting its increased expression represents an adaptive response to the pathology. Altogether, our results unravel a novel function for Staufen1 in splicing regulation and indicate that it may positively modulate the complex DM1 phenotype, thereby revealing its potential as a therapeutic target.

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Loss of the multifunctional RNA-binding protein RBM47 as a source of selectable metastatic traits in breast cancer

eLife ◽

10.7554/elife.02734 ◽

2014 ◽

Vol 3 ◽

Cited By ~ 57

Author(s):

Sakari Vanharanta ◽

Christina B Marney ◽

Weiping Shu ◽

Manuel Valiente ◽

Yilong Zou ◽

...

Keyword(s):

Breast Cancer ◽

Cancer Progression ◽

Rna Binding ◽

Binding Protein ◽

Rna Binding Protein ◽

Wnt Signaling Pathway ◽

Experimental Models ◽

Breast Cancer Progression ◽

Binding Motif ◽

Clinical Breast

The mechanisms through which cancer cells lock in altered transcriptional programs in support of metastasis remain largely unknown. Through integrative analysis of clinical breast cancer gene expression datasets, cell line models of breast cancer progression, and mutation data from cancer genome resequencing studies, we identified RNA binding motif protein 47 (RBM47) as a suppressor of breast cancer progression and metastasis. RBM47 inhibited breast cancer re-initiation and growth in experimental models. Transcriptome-wide HITS-CLIP analysis revealed widespread RBM47 binding to mRNAs, most prominently in introns and 3′UTRs. RBM47 altered splicing and abundance of a subset of its target mRNAs. Some of the mRNAs stabilized by RBM47, as exemplified by dickkopf WNT signaling pathway inhibitor 1, inhibit tumor progression downstream of RBM47. Our work identifies RBM47 as an RNA-binding protein that can suppress breast cancer progression and demonstrates how the inactivation of a broadly targeted RNA chaperone enables selection of a pro-metastatic state.

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