scholarly journals Rbm24a Is Necessary for Hair Cell Development Through Regulating mRNA Stability in Zebrafish

Author(s):  
Yan Zhang ◽  
Yanfei Wang ◽  
Xuebo Yao ◽  
Changquan Wang ◽  
Fangyi Chen ◽  
...  

Hair cells in the inner ear and lateral lines are mechanosensitive receptor cells whose development and function are tightly regulated. Several transcription factors as well as splicing factors have been identified to play important roles in hair cell development, whereas the role of RNA stability in this process is poorly understood. In the present work, we report that RNA-binding motif protein 24a (Rbm24a) is indispensable for hair cell development in zebrafish. Rbm24a expression is detected in the inner ear as well as lateral line neuromasts. Albeit rbm24a deficient zebrafish do not survive beyond 9 days post fertilization (dpf) due to effects outside of the inner ear, rbm24a deficiency does not affect the early development of inner ear except for delayed otolith formation and semicircular canal fusion. However, hair cell development is severely affected and hair bundle is disorganized in rbm24a mutants. As a result, the auditory and vestibular function of rbm24a mutants are compromised. RNAseq analyses identified several Rbm24a-target mRNAs that are directly bound by Rbm24a and are dysregulated in rbm24a mutants. Among the identified Rbm24a-target genes, lrrc23, dfna5b, and smpx are particularly interesting as their dysregulation might contribute to the inner ear phenotypes in rbm24a mutants. In conclusion, our data suggest that Rbm24a affects hair cell development in zebrafish through regulating mRNA stability.

Genes ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 883
Author(s):  
Anna Gaertner ◽  
Julia Bloebaum ◽  
Andreas Brodehl ◽  
Baerbel Klauke ◽  
Katharina Sielemann ◽  
...  

A major cause of heart failure is cardiomyopathies, with dilated cardiomyopathy (DCM) as the most common form. Over 40 genes are linked to DCM, among them TTN and RBM20. Next Generation Sequencing in clinical DCM cohorts revealed truncating variants in TTN (TTNtv), accounting for up to 25% of familial DCM cases. Mutations in the cardiac splicing factor RNA binding motif protein 20 (RBM20) are also known to be associated with severe cardiomyopathies. TTN is one of the major RBM20 splicing targets. Most of the pathogenic RBM20 mutations are localized in the highly conserved arginine serine rich domain (RS), leading to a cytoplasmic mislocalization of mutant RBM20. Here, we present a patient with an early onset DCM carrying a combination of (likely) pathogenic TTN and RBM20 mutations. We show that the splicing of RBM20 target genes is affected in the mutation carrier. Furthermore, we reveal RBM20 haploinsufficiency presumably caused by the frameshift mutation in RBM20.


2020 ◽  
Vol 48 (7) ◽  
pp. 3869-3887 ◽  
Author(s):  
Linlin Hou ◽  
Yuanjie Wei ◽  
Yingying Lin ◽  
Xiwei Wang ◽  
Yiwei Lai ◽  
...  

Abstract Some transcription factors that specifically bind double-stranded DNA appear to also function as RNA-binding proteins. Here, we demonstrate that the transcription factor Sox2 is able to directly bind RNA in vitro as well as in mouse and human cells. Sox2 targets RNA via a 60-amino-acid RNA binding motif (RBM) positioned C-terminally of the DNA binding high mobility group (HMG) box. Sox2 can associate with RNA and DNA simultaneously to form ternary RNA/Sox2/DNA complexes. Deletion of the RBM does not affect selection of target genes but mitigates binding to pluripotency related transcripts, switches exon usage and impairs the reprogramming of somatic cells to a pluripotent state. Our findings designate Sox2 as a multi-functional factor that associates with RNA whilst binding to cognate DNA sequences, suggesting that it may co-transcriptionally regulate RNA metabolism during somatic cell reprogramming.


2010 ◽  
Vol 190 (1) ◽  
pp. 9-20 ◽  
Author(s):  
Martin Schwander ◽  
Bechara Kachar ◽  
Ulrich Müller

Mammals have an astonishing ability to sense and discriminate sounds of different frequencies and intensities. Fundamental for this process are mechanosensory hair cells in the inner ear that convert sound-induced vibrations into electrical signals. The study of genes that are linked to deafness has provided insights into the cell biological mechanisms that control hair cell development and their function as mechanosensors.


2021 ◽  
Author(s):  
Juan-Juan Wang ◽  
Ding-Xiong Chen ◽  
Yu Zhang ◽  
Xin Xu ◽  
Yan Cai ◽  
...  

Abstract BackgroundMetastasis are mainly responsible for the death of patients with advanced esophageal squamous cell carcinoma (ESCC). At present, there is no targeted drug for the treatment of ESCC in clinic practice. The present study aims to investigate the roles and implication of IGF2BP1 overexpression in ESCC.MethodsIGF2BP1 protein expression was assessed by immunohistochemistry (IHC), and the mRNA abundance of IGF2BP1 and INHBA were analyzed with TCGA datasets and by RNA in situ hybridization (RISH). Cell viability, migration, invasion and in vivo metastasis assays were performed to explore the roles of IGF2BP1 in ESCC. RNA immunoprecipitation sequencing (RIP-seq) and mass spectrometry were applied to identify the targets and interacting proteins of IGF2BP1, respectively. RIP-PCR, RNA-pulldown, immunofluorescence (IF), gene specific m6A PCR and RNA stability assay were used to uncover the molecular mechanism of IGF2BP1 dysregulation. The methylation level of IGF2BP1 promoter region was detected by MSP-PCR. BTYNB, a small molecular inhibitor which could block the binding of IGF2BP1 to c-Myc mRNA, was evaluated for the inhibition effect on the malignant phenotypes of ESCC cells.ResultsIGF2BP1 overexpression was detected in ESCC tissues and associated with depth of tumor invasion. Knockdown of IGF2BP1 inhibited ESCC cell invasion and migration as well as tumor metastasis. Importantly, INHBA was identified as a direct target of IGF2BP1 in ESCC cells, which had a role in promoting the malignant phenotypes. TCGA data and RISH analyses showed that the mRNA level of INHBA was upregaluted in ESCC tissues as well. Mechanistically, IGF2BP1 bound and stabilized INHBA mRNA and then enhanced its translation, leading to an activation of Smad2/3 signaling. Ras GTPase-activating protein-binding protein 1 (G3BP1) was recruited by IGF2BP1 to participate in activating the signaling process, which was inhibited by the IGF2BP1 inhibitor BTYNB. Of note, IGF2BP1 mRNA expression in ESCC cells was negatively correlated with the level of its promoter methylation.ConclusionsIGF2BP1 overexpression promotes the invasion and migration of ESCC cells by up-regulating TGF-β-Smad2/3 pathway through enhancing INHBA mRNA stability and translation, providing a potential therapeutic target for ESCC treatment.


2020 ◽  
Author(s):  
Yue-Wei Yin ◽  
Kai-Long Liu ◽  
Bao-Sai Lu ◽  
Wei Li ◽  
Ya-Lin Niu ◽  
...  

Abstract Background: RNA-binding motif protein 24 (RBM24) acts as a multifunctional determinant of cell fate, proliferation, apoptosis, and differentiation during development through regulation of pre-mRNA splicing and mRNA stability. It is also implicated in carcinogenesis, but the functions of RBM24 in bladder cancer (BC) remains unclear.Methods: Cell viability was examined by colony forming and MTT assays. Real-time quantitative PCR (RT-qPCR) and western blot analysis were used to detect the protein and mRNA levels. Co-immunoprecipitation (CoIP) and proximity ligation assay (PLA) were used to determine the protein-protein interaction. Chromatin immunoprecipitation (ChIP), RNA immunoprecipitation (RIP), and oligo pull-down assays were used to verify DNA/RNA–protein interactions. Luciferase assay analysis was used to detect effects on transcription factor activity.Results: In the present study, we revealed that RBM24 was upregulated in BC tissues. Importantly, we found that higher level of RBM24 was correlated with poor prognosis in BC patients. Overexpression of RBM24 promoted while depletion of RBM24 inhibited BC cell proliferation in vivo and in vitro. Mechanically, RBM24 positively regulated Runx1t1 expression in BC cells by binding to and enhancing Runx1t1 mRNA stability. Runx1t1 in turn promoted RBM24 expression by interacting with TCF4. Furthermore, Runx1t1 in turn promoted RBM24 expression by interacting with the transcription factor TCF4 and depressing transcription of miR-625-5p, which directly targets and normally suppresses RBM24 expression. RBM24-regulated BC cells proliferation was moderated via the Runx1t1/TCF4/miR-625-5p feedback loop.Conclusions: In summary, these results indicate that a RBM24/Runx1t1/TCF4/miR-625-5p positive feedback loop plays a key role in BC oncogenesis. Disruption of this pathway may be a potential therapeutic strategy for BC treatment.


2017 ◽  
Vol 45 (15) ◽  
pp. 8957-8967 ◽  
Author(s):  
Birgit Märtens ◽  
Kundan Sharma ◽  
Henning Urlaub ◽  
Udo Bläsi

2002 ◽  
Vol 445 (2) ◽  
pp. 176-198
Author(s):  
Kenji Kondo ◽  
Hiroshi Sagara ◽  
Kazushige Hirosawa ◽  
Kimitaka Kaga ◽  
Satsuki Matsushima ◽  
...  

2021 ◽  
Author(s):  
Gabrielle Perron ◽  
Pouria Jandaghi ◽  
Maryam Rajaee ◽  
Rached Alkallas ◽  
Yasser Riazalhosseini ◽  
...  

AbstractRNA stability is a crucial and often overlooked determinant of gene expression. Some of the regulators of mRNA stability are long known as key oncogenic or tumour suppressor factors. Nonetheless, the extent to which mRNA stability contributes to transcriptome remodeling in cancer is unknown, and the factors that modulate mRNA stability during cancer development and progression are largely uncharacterized. Here, by decoupling transcriptional and post-transcriptional effects in RNA-seq data of 7760 samples from 18 cancer types, we present a pan-cancer view of the mRNA stability changes that accompany tumour development and progression. We show that thousands of genes are dysregulated at the mRNA stability level, and identify the potential factors that drive these changes, including >80 RNA-binding proteins (RBPs) and microRNAs (miRNAs). Most RBPs and miRNAs have cancer type-specific activities, but a few show recurrent inactivation across multiple cancers, including the RBFOX family of RBPs and miR-29. Analysis of cell lines with phenotypic activation or inhibition of RBFOX1 and miR-29 confirms their role in modulation of genes that are dysregulated across multiple cancers, with functions in calcium signaling, extracellular matrix organization, and stemness. Overall, our study highlights the critical role of mRNA stability in shaping the tumour transcriptome, with recurrent post-transcriptional changes that are ~30% as frequent as transcriptional events. These results provide a resource for systematic interrogation of cancer-associated stability drivers and pathways.


2021 ◽  
Vol 15 ◽  
Author(s):  
Michael R. Deans

Planar polarity describes the organization and orientation of polarized cells or cellular structures within the plane of an epithelium. The sensory receptor hair cells of the vertebrate inner ear have been recognized as a preeminent vertebrate model system for studying planar polarity and its development. This is principally because planar polarity in the inner ear is structurally and molecularly apparent and therefore easy to visualize. Inner ear planar polarity is also functionally significant because hair cells are mechanosensors stimulated by sound or motion and planar polarity underlies the mechanosensory mechanism, thereby facilitating the auditory and vestibular functions of the ear. Structurally, hair cell planar polarity is evident in the organization of a polarized bundle of actin-based protrusions from the apical surface called stereocilia that is necessary for mechanosensation and when stereociliary bundle is disrupted auditory and vestibular behavioral deficits emerge. Hair cells are distributed between six sensory epithelia within the inner ear that have evolved unique patterns of planar polarity that facilitate auditory or vestibular function. Thus, specialized adaptations of planar polarity have occurred that distinguish auditory and vestibular hair cells and will be described throughout this review. There are also three levels of planar polarity organization that can be visualized within the vertebrate inner ear. These are the intrinsic polarity of individual hair cells, the planar cell polarity or coordinated orientation of cells within the epithelia, and planar bipolarity; an organization unique to a subset of vestibular hair cells in which the stereociliary bundles are oriented in opposite directions but remain aligned along a common polarity axis. The inner ear with its complement of auditory and vestibular sensory epithelia allows these levels, and the inter-relationships between them, to be studied using a single model organism. The purpose of this review is to introduce the functional significance of planar polarity in the auditory and vestibular systems and our contemporary understanding of the developmental mechanisms associated with organizing planar polarity at these three cellular levels.


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