CHMP2B regulates TDP-43 phosphorylation and cytotoxicity independent of autophagy via CK1

2021 ◽  
Vol 221 (1) ◽  
Author(s):  
Xue Deng ◽  
Xing Sun ◽  
Wenkai Yue ◽  
Yongjia Duan ◽  
Rirong Hu ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Rna Binding ◽  
Binding Protein ◽  
Rna Binding Protein ◽  
Down Regulation ◽  
Protein Levels ◽  
Modifying Effect

The ESCRT protein CHMP2B and the RNA-binding protein TDP-43 are both associated with ALS and FTD. The pathogenicity of CHMP2B has mainly been considered a consequence of autophagy–endolysosomal dysfunction, whereas protein inclusions containing phosphorylated TDP-43 are a pathological hallmark of ALS and FTD. Intriguingly, TDP-43 pathology has not been associated with the FTD-causing CHMP2BIntron5 mutation. In this study, we identify CHMP2B as a modifier of TDP-43–mediated neurodegeneration in a Drosophila screen. Down-regulation of CHMP2B reduces TDP-43 phosphorylation and toxicity in flies and mammalian cells. Surprisingly, although CHMP2BIntron5 causes dramatic autophagy dysfunction, disturbance of autophagy does not alter TDP-43 phosphorylation levels. Instead, we find that inhibition of CK1, but not TTBK1/2 (all of which are kinases phosphorylating TDP-43), abolishes the modifying effect of CHMP2B on TDP-43 phosphorylation. Finally, we uncover that CHMP2B modulates CK1 protein levels by negatively regulating ubiquitination and the proteasome-mediated turnover of CK1. Together, our findings propose an autophagy-independent role and mechanism of CHMP2B in regulating CK1 abundance and TDP-43 phosphorylation.

Cold-induced RNA-binding protein (CIRBP) regulates the expression of Src-associated during mitosis of 68 kDa (Sam68) and extracellular signal-regulated kinases (ERK) during heat stress-induced testicular injury

2020 ◽  
Vol 32 (18) ◽  
pp. 1357
Author(s):  
Chengcheng Xu ◽  
Dandan Ke ◽  
Liping Zou ◽  
Nianyu Li ◽  
Yingying Wang ◽  
...  
Keyword(s):  
Gene Expression ◽  
Heat Stress ◽  
Protein Expression ◽  
Rna Binding ◽  
Cell Model ◽  
Binding Protein ◽  
Rna Binding Protein ◽  
Protein Levels ◽  
Extracellular Signal ◽  
Testicular Injury

In this study, the ability of cold-induced RNA-binding protein (CIRBP) to regulate the expression of Src-associated during mitosis of 68 kDa (Sam68) and extracellular signal-regulated kinases (ERK) in the mouse testis and mouse primary spermatocytes (GC-2spd cell line) before and after heat stress was examined to explore the molecular mechanism by which CIRBP decreases testicular injury. A mouse testicular hyperthermia model, a mouse primary spermatocyte hyperthermia model and a low CIRBP gene-expression cell model were constructed and their relevant parameters were analysed. The mRNA and protein levels of CIRBP and Sam68 were significantly decreased in the 3-h and 12-h testicular heat-stress groups, extracellular signal-regulated kinase 1/2 (ERK1/2) protein expression was not significantly affected but phospho-ERK1/2 protein levels were significantly decreased. GC-2spd cellular heat-stress results showed that the mRNA and protein concentrations of CIRBP and Sam68 were reduced 48h after heat stress. In the low CIRBP gene-expression cell model, CIRBP protein expression was significantly decreased. Sam68 mRNA expression was significantly decreased only at the maximum transfection concentration of 50nM and Sam68 protein expression was not significantly affected. These findings suggest that CIRBP may regulate the expression of Sam68 at the transcriptional level and the expression of phospho-ERK1/2 protein, both of which protect against heat-stress-induced testicular injury in mice.

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

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.

scholarly journals New Insights into the Interplay between Non-Coding RNAs and RNA-Binding Protein HnRNPK in Regulating Cellular Functions

Cells ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 62 ◽  
Author(s):  
Yongjie Xu ◽  
Wei Wu ◽  
Qiu Han ◽  
Yaling Wang ◽  
Cencen Li ◽  
...  
Keyword(s):  
Gene Expression ◽  
Mammalian Cells ◽  
Rna Binding ◽  
Binding Protein ◽  
Genomic Structure ◽  
Rna Binding Protein ◽  
Stem Cell Differentiation ◽  
Cellular Functions ◽  
Non Coding Rnas ◽  
Conserved Gene

The emerging data indicates that non-coding RNAs (ncRNAs) epresent more than the “junk sequences” of the genome. Both miRNAs and long non-coding RNAs (lncRNAs) are involved in fundamental biological processes, and their deregulation may lead to oncogenesis and other diseases. As an important RNA-binding protein (RBP), heterogeneous nuclear ribonucleoprotein K (hnRNPK) is known to regulate gene expression through the RNA-binding domain involved in various pathways, such as transcription, splicing, and translation. HnRNPK is a highly conserved gene that is abundantly expressed in mammalian cells. The interaction of hnRNPK and ncRNAs defines the novel way through which ncRNAs affect the expression of protein-coding genes and form autoregulatory feedback loops. This review summarizes the interactions of hnRNPK and ncRNAs in regulating gene expression at transcriptional and post-transcriptional levels or by changing the genomic structure, highlighting their involvement in carcinogenesis, glucose metabolism, stem cell differentiation, virus infection and other cellular functions. Drawing connections between such discoveries might provide novel targets to control the biological outputs of cells in response to different stimuli.

scholarly journals The Neural RNA-Binding Protein Musashi1 Translationally Regulates Mammalian numb Gene Expression by Interacting with Its mRNA

2001 ◽  
Vol 21 (12) ◽  
pp. 3888-3900 ◽  
Author(s):  
Takao Imai ◽  
Akinori Tokunaga ◽  
Tetsu Yoshida ◽  
Mitsuhiro Hashimoto ◽  
Katsuhiko Mikoshiba ◽  
...  
Keyword(s):  
Notch Signaling ◽  
In Vitro Selection ◽  
Neural Progenitor Cells ◽  
Rna Binding ◽  
Binding Protein ◽  
Mrna Level ◽  
Rna Binding Protein ◽  
Down Regulation

ABSTRACT Musashi1 (Msi1) is an RNA-binding protein that is highly expressed in neural progenitor cells, including neural stem cells. In this study, the RNA-binding sequences for Msi1 were determined by in vitro selection using a pool of degenerate 50-mer sequences. All of the selected RNA species contained repeats of (G/A)U n AGU (n = 1 to 3) sequences which were essential for Msi1 binding. These consensus elements were identified in some neural mRNAs. One of these, mammaliannumb (m-numb), which encodes a membrane-associated antagonist of Notch signaling, is a likely target of Msi1. Msi1 protein binds in vitro-transcribed m-numb RNA in its 3′-untranslated region (UTR) and binds endogenousm-numb mRNA in vivo, as shown by affinity precipitation followed by reverse transcription-PCR. Furthermore, adenovirus-induced Msi1 expression resulted in the down-regulation of endogenous m-Numb protein expression. Reporter assays using a chimeric mRNA that combined luciferase and the 3′-UTR of m-numb demonstrated that Msi1 decreased the reporter activity without altering the reporter mRNA level. Thus, our results suggested that Msi1 could regulate the expression of its target gene at the translational level. Furthermore, we found that Notch signaling activity was increased by Msi1 expression in connection with the posttranscriptional down-regulation of them-numb gene.

Vaccinia virus double-stranded RNA-binding protein E3 does not interfere with siRNA-mediated gene silencing in mammalian cells

2007 ◽  
Vol 126 (1-2) ◽  
pp. 1-8 ◽  
Author(s):  
Markus Lantermann ◽  
Astrid Schwantes ◽  
Katja Sliva ◽  
Gerd Sutter ◽  
Barbara S. Schnierle
Keyword(s):  
Gene Silencing ◽  
Vaccinia Virus ◽  
Mammalian Cells ◽  
Rna Binding ◽  
Binding Protein ◽  
Rna Binding Protein ◽  
Double Stranded Rna

scholarly journals SUMO Modification of the RNA-Binding Protein La Regulates Cell Proliferation and STAT3 Protein Stability

2017 ◽  
Vol 38 (2) ◽  
Author(s):  
Venkatesh Kota ◽  
Gunhild Sommer ◽  
E. Starr Hazard ◽  
Gary Hardiman ◽  
Jeffery L. Twiss ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Rna Binding ◽  
Fluorescent Protein ◽  
Binding Protein ◽  
Rna Binding Protein ◽  
Hek293 Cells ◽  
Sequencing Data ◽  
Protein Levels ◽  
Specific Mrnas ◽  
Green Fluorescent

ABSTRACTThe cancer-associated RNA-binding protein La is posttranslationally modified by phosphorylation and sumoylation. Sumoylation of La regulates not only the trafficking of La in neuronal axons but also its association with specific mRNAs. Depletion of La in various types of cancer cell lines impairs cell proliferation; however, the molecular mechanism whereby La supports cell proliferation is not clearly understood. In this study, we address the question of whether sumoylation of La contributes to cell proliferation of HEK293 cells. We show that HEK293 cells stably expressing green fluorescent protein (GFP)-tagged wild-type La (GFP-LaWT) grow faster than cells expressing a sumoylation-deficient mutant La (GFP-LaSD), suggesting a proproliferative function of La in HEK293 cells. Further, we found that STAT3 protein levels were reduced in GFP-LaSDcells due to an increase in STAT3 ubiquitination and that overexpression of STAT3 partially restored cell proliferation. Finally, we present RNA sequencing data from RNA immunoprecipitations (RIPs) and report that mRNAs associated with the cell cycle and ubiquitination are preferentially bound by GFP-LaWTand are less enriched in GFP-LaSDRIPs. Taken together, results of our study support a novel mechanism whereby sumoylation of La promotes cell proliferation by averting ubiquitination-mediated degradation of the STAT3 protein.

scholarly journals Identification of a novel enhancer that binds Sp1 and contributes to induction of cold-inducible RNA-binding protein (cirp) expression in mammalian cells

2012 ◽  
Vol 12 (1) ◽  
pp. 72 ◽  
Author(s):  
Yasuhiko Sumitomo ◽  
Hiroaki Higashitsuji ◽  
Hisako Higashitsuji ◽  
Yu Liu ◽  
Takanori Fujita ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Rna Binding ◽  
Binding Protein ◽  
Rna Binding Protein ◽  
Expression In Mammalian Cells

scholarly journals Polyamines Regulate the Stability of Activating Transcription Factor-2 mRNA through RNA-binding Protein HuR in Intestinal Epithelial Cells

2007 ◽  
Vol 18 (11) ◽  
pp. 4579-4590 ◽  
Author(s):  
Lan Xiao ◽  
Jaladanki N. Rao ◽  
Tongtong Zou ◽  
Lan Liu ◽  
Bernard S. Marasa ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Rna Binding ◽  
Binding Protein ◽  
Critical Role ◽  
Rna Binding Protein ◽  
Gene Promoter ◽  
Protein Levels ◽  
Ribonucleoprotein Complexes ◽  
Activating Transcription Factor ◽  
The Stability

Maintenance of intestinal mucosal epithelial integrity requires polyamines that modulate the expression of various genes involved in cell proliferation and apoptosis. Recently, polyamines were shown to regulate the subcellular localization of the RNA-binding protein HuR, which stabilizes its target transcripts such as nucleophosmin and p53 mRNAs. The activating transcription factor-2 (ATF-2) mRNA encodes a member of the ATF/CRE-binding protein family of transcription factors and was computationally predicted to be a target of HuR. Here, we show that polyamines negatively regulate ATF-2 expression posttranscriptionally and that polyamine depletion stabilizes ATF-2 mRNA by enhancing the interaction of the 3′-untranslated region (UTR) of ATF-2 with cytoplasmic HuR. Decreasing cellular polyamines by inhibiting ornithine decarboxylase (ODC) with α-difluoromethylornithine increased the levels of ATF-2 mRNA and protein, whereas increasing polyamines by ectopic ODC overexpression repressed ATF-2 expression. Polyamine depletion did not alter transcription via the ATF-2 gene promoter but increased the stability of ATF-2 mRNA. Increased cytoplasmic HuR in polyamine-deficient cells formed ribonucleoprotein complexes with the endogenous ATF-2 mRNA and specifically bound to 3′-UTR of ATF-2 mRNA on multiple nonoverlapping 3′-UTR segments. Adenovirus-mediated HuR overexpression elevated ATF-2 mRNA and protein levels, whereas HuR silencing rendered the ATF-2 mRNA unstable and prevented increases in ATF-2 mRNA and protein. Furthermore, inhibition of ATF-2 expression prevented the increased resistance of polyamine-deficient cells to apoptosis induced by treatment with tumor necrosis factor-α and cycloheximide. These results indicate that polyamines modulate the stability of ATF-2 mRNA by altering cytoplasmic HuR levels and that polyamine-modulated ATF-2 expression plays a critical role in regulating epithelial apoptosis.

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