RNA helicase MOV10 suppresses fear memory and dendritic arborization and regulates microtubule dynamics in hippocampal neurons [RNA-seq]
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ABSTRACT: RNA helicase MOV10 is highly expressed in postnatal brain and associates with FMRP and AGO2, suggesting a role in translation regulation in learning and memory. We generated a brain-specific knockout mouse (Mov10 Deletion) with greatly reduced MOV10 expression in cortex and hippocampus. Behavior testing revealed enhanced fear memory, similar to that observed in a mouse with reduced brain microRNA production, supporting MOV10’s reported role as an AGO2 cofactor. Cultured hippocampal neurons have elongated distal dendrites, a reported feature of augmin/HAUS over-expression in Drosophila da sensory neurons. In mitotic spindle formation, HAUS is antagonized by the microtubule bundling protein NUMA1. Numa1 mRNA is a MOV10 CLIP target and is among the genes significantly decreased in Mov10 Deletion hippocampus. Restoration of NUMA1 expression and knockdown of HAUS rescued microtubule comet formation in dendritic growth cones. This is the first evidence of translation regulation of NUMA1 as a control point in dendritogenesis.
Project description:RNA helicase MOV10 is highly expressed in postnatal brain and associates with FMRP and AGO2, suggesting a role in translation regulation in learning and memory. We generated a brain-specific knockout mouse (Mov10 Deletion) with greatly reduced MOV10 expression in cortex and hippocampus. Behavior testing revealed enhanced fear memory, similar to that observed in a mouse with reduced brain microRNA production, supporting MOV10’s reported role as an AGO2 cofactor. Cultured hippocampal neurons have elongated distal dendrites, a reported feature of augmin/HAUS over-expression in Drosophila da sensory neurons. In mitotic spindle formation, HAUS is antagonized by the microtubule bundling protein NUMA1. Numa1 mRNA is a MOV10 CLIP target and is among the genes significantly decreased in Mov10 Deletion hippocampus. Restoration of NUMA1 expression and knockdown of HAUS rescued microtubule comet formation in dendritic growth cones. This is the first evidence of translation regulation of NUMA1 as a control point in dendritogenesis.
Project description:MOV10 is an RNA helicase that is required for organismal development and is highly expressed in postnatal brain. MOV10 was identified as an AGO2 associated protein that is also necessary for AGO2-mediated silencing. MOV10 has been shown to be ubiquitinated, leading to its degradation and release from bound mRNAs but no other post-translational modifications with functional implications have been described. Using mass spectrometry, we show that MOV10 is phosphorylated in cells at the C-terminus, specifically at serine 970 (S970). Substitution of S970 to phospho-mimic aspartic acid (S970D) blocked unfolding of an RNA G-quadruplex, similar to when the helicase domain was mutated (K531A). In contrast, the alanine substitution (S970A) of MOV10 unfolded the model RNA G-quadruplex. To examine its role in cells, RNA-seq analysis showed that the expression of S970D causes decreased expression of MOV10 eCLIP targets compared to WT. Introduction of S970A had an intermediate effect, suggesting that S970 was protective of mRNAs. In whole cell extracts, MOV10 and its substitutions bound AGO2 comparably; however, knockdown of AGO2 abrogated the S970D-induced mRNA degradation. Thus, MOV10 activity protects mRNA from AGO2; phosphorylation of S970 restricts this activity resulting in AGO2-mediated mRNA degradation. S970 is positioned C-terminal to the defined MOV10-AGO2 interaction site and is proximal to a disordered region that likely modulates AGO2 interaction with target mRNAs upon phosphorylation. In summary, we provide evidence for a model whereby MOV10 phosphorylation facilitates AGO2 association with the 3’UTR of translating mRNAs that leads to their degradation.
Project description:MOV10 is an RNA helicase that is required for organismal development and is highly expressed in postnatal brain. MOV10 was identified as an AGO2 associated protein that is also necessary for AGO2-mediated silencing. MOV10 has been shown to be ubiquitinated, leading to its degradation and release from bound mRNAs but no other post-translational modifications with functional implications have been described. Using mass spectrometry, we show that MOV10 is phosphorylated in cells at the C-terminus, specifically at serine 970 (S970). Substitution of S970 to phospho-mimic aspartic acid (S970D) blocked unfolding of an RNA G-quadruplex, similar to when the helicase domain was mutated (K531A). In contrast, the alanine substitution (S970A) of MOV10 unfolded the model RNA G-quadruplex. To examine its role in cells, RNA-seq analysis showed that the expression of S970D causes decreased expression of MOV10 eCLIP targets compared to WT. Introduction of S970A had an intermediate effect, suggesting that S970 was protective of mRNAs. In whole cell extracts, MOV10 and its substitutions bound AGO2 comparably; however, knockdown of AGO2 abrogated the S970D-induced mRNA degradation. Thus, MOV10 activity protects mRNA from AGO2; phosphorylation of S970 restricts this activity resulting in AGO2-mediated mRNA degradation. S970 is positioned C-terminal to the defined MOV10-AGO2 interaction site and is proximal to a disordered region that likely modulates AGO2 interaction with target mRNAs upon phosphorylation. In summary, we provide evidence for a model whereby MOV10 phosphorylation facilitates AGO2 association with the 3’UTR of translating mRNAs that leads to their degradation.
Project description:RNA helicase MOV10 participates in RNA-induced gene silencing, nonsense-mediated decay and suppression of retrotransposition in cultured cells. We describe a critical role for MOV10 in early postnatal brain, where there is an ~40 fold increase in MOV10 protein levels along with a nucleo-cytoplasmic localization pattern. The isolation of MOV10-associated RNAs from this stage showed a preponderance of retrotransposon encoded RNAs along with messenger RNAs. Furthermore, reduced MOV10 expression led to an increase in genomic L1 levels in P2 brain. We show that MOV10 likely suppresses retrotransposition by binding to the LINE1 reverse transcriptase and blocking cDNA synthesis. MOV10 also binds cytoskeletal mRNAs and is required for normal neurite outgrowth in both Neuro2A and cultured hippocampal neurons. Finally, standard MOV10 levels in brain are required for normal mouse behavior. We provide the first evidence of a role for MOV10 in retrotransposon control in brain and in neuronal development and function.
Project description:The fragile X mental retardation protein FMRP is an RNA binding protein that regulates translation of its bound mRNAs through incompletely defined mechanisms. FMRP has been linked to the microRNA pathway and we show here that it is associated with MOV10, a putative helicase that is also associated with the microRNA pathway. We show that FMRP associates with MOV10 in an RNA-dependent manner and facilitates MOV10-association with RNAs in brain. We identified the RNA sequences recognized by MOV10 using iCLIP and found an increased number of G-quadruplexes in the CLIP sites. We provide evidence that MOV10 facilitates microRNA-mediated translation regulation and also has the novel role of increasing the expression of a subset of RNAs by sterically hindering Argonaute2 association. In summary, we have identified a new mechanism for FMRP-mediated translational regulation through its association with MOV10. Comparison of MOV10 siRNA knockdown, irrelevant siRNA control and MOV10 overexpression on total RNA levels
Project description:RNA helicase MOV10 suppresses fear memory and dendritic arborization and regulates microtubule dynamics in hippocampal neurons [eCLIP-seq]
Project description:RNA helicase MOV10 suppresses fear memory and dendritic arborization and regulates microtubule dynamics in hippocampal neurons [RNA-seq]
Project description:The fragile X mental retardation protein FMRP is an RNA binding protein that regulates translation of its bound mRNAs through incompletely defined mechanisms. FMRP has been linked to the microRNA pathway and we show here that it is associated with MOV10, a putative helicase that is also associated with the microRNA pathway. We show that FMRP associates with MOV10 in an RNA-dependent manner and facilitates MOV10-association with RNAs in brain. We identified the RNA sequences recognized by MOV10 using iCLIP and found an increased number of G-quadruplexes in the CLIP sites. We provide evidence that MOV10 facilitates microRNA-mediated translation regulation and also has the novel role of increasing the expression of a subset of RNAs by sterically hindering Argonaute2 association. In summary, we have identified a new mechanism for FMRP-mediated translational regulation through its association with MOV10.
Project description:Transposable elements constitute nearly half of the mammalian genome and play important roles in genome evolution. While a multitude of both transcriptional and post-transcriptional mechanisms exist to silence transposable elements, control of transposition in vivo remains poorly understood. MOV10, an RNA helicase, is an inhibitor of mobilization of retrotransposons and retroviruses in cell culture assays. Here we report that MOV10 restricts LINE1 retrotransposition in mice. Although MOV10 is broadly expressed, its loss causes only incomplete penetrance of embryonic lethality, and the surviving MOV10-deficient mice are healthy and fertile. Biochemically, MOV10 forms a complex with UPF1, a key component of the nonsense-mediated mRNA decay pathway, and primarily binds to the 3' UTR of somatically expressed transcripts in testis. Consequently, loss of MOV10 results in an altered transcriptome in testis. Analyses using a LINE1 reporter transgene reveal that loss of MOV10 leads to increased LINE1 retrotransposition in somatic and reproductive tissues from both embryos and adult mice. Moreover, the degree of LINE1 retrotransposition inhibition is dependent on the Mov10 gene dosage. Furthermore, MOV10 deficiency reduces reproductive fitness over successive generations. Our findings demonstrate that MOV10 attenuates LINE1 retrotransposition in a dosage-dependent manner in mice.
Project description:Using the iCLIP protocol we have identified the cellular RNA entities that are bound by MOV10. We report the location and sequence of the MOV10 binding region on each RNA entity. To identify the RNAs that bound MOV10, we UV-cross-linked HEK293F cells and immunoprecipitated with an irrelevant antibody (ir or "control") followed by a MOV10-specific antibody (MOV10) to isolate associated RNAs after stringent washing.