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Gallicchio L, Matias NR, Morales-Polanco F, Nava I, Stern S, Zeng Y, Fuller MT. A Developmental Mechanism to Regulate Alternative Polyadenylation in an Adult Stem Cell Lineage. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.18.585561. [PMID: 38562704 PMCID: PMC10983978 DOI: 10.1101/2024.03.18.585561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Alternative Cleavage and Polyadenylation (APA) often results in production of mRNA isoforms with either longer or shorter 3'UTRs from the same genetic locus, potentially impacting mRNA translation, localization and stability. Developmentally regulated APA can thus make major contributions to cell-type-specific gene expression programs as cells differentiate. During Drosophila spermatogenesis, approximately 500 genes undergo APA when proliferating spermatogonia differentiate into spermatocytes, producing transcripts with shortened 3' UTRs, leading to profound stage-specific changes in the proteins expressed. The molecular mechanisms that specify usage of upstream polyadenylation sites in spermatocytes are thus key to understanding the changes in cell state. Here, we show that upregulation of PCF11 and Cbc, the two components of Cleavage Factor II (CFII), orchestrates APA during Drosophila spermatogenesis. Knock down of PCF11 or cbc in spermatocytes caused dysregulation of APA, with many transcripts normally cleaved at a proximal site in spermatocytes now cleaved at their distal site, as in spermatogonia. Forced overexpression of CFII components in spermatogonia switched cleavage of some transcripts to the proximal site normally used in spermatocytes. Our findings reveal a developmental mechanism where changes in expression of specific cleavage factors can direct cell-type-specific APA at selected genes.
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Affiliation(s)
- Lorenzo Gallicchio
- Department of Developmental Biology, Stanford University School of Medicine, Stanford USA
| | - Neuza R. Matias
- Department of Developmental Biology, Stanford University School of Medicine, Stanford USA
| | - Fabian Morales-Polanco
- Department of Biology, Stanford University School of Humanities and Sciences, Stanford USA
- Department of Genetics, Stanford University School of Medicine, USA
| | - Iliana Nava
- Department of Developmental Biology, Stanford University School of Medicine, Stanford USA
| | - Sarah Stern
- Department of Developmental Biology, Stanford University School of Medicine, Stanford USA
| | - Yi Zeng
- Department of Genetics, Stanford University School of Medicine, USA
| | - Margaret T. Fuller
- Department of Developmental Biology, Stanford University School of Medicine, Stanford USA
- Department of Genetics, Stanford University School of Medicine, USA
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Cheng F, Chapman T, Zhang S, Morsch M, Chung R, Lee A, Rayner SL. Understanding age-related pathologic changes in TDP-43 functions and the consequence on RNA splicing and signalling in health and disease. Ageing Res Rev 2024; 96:102246. [PMID: 38401571 DOI: 10.1016/j.arr.2024.102246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 02/07/2024] [Accepted: 02/21/2024] [Indexed: 02/26/2024]
Abstract
TAR DNA binding protein-43 (TDP-43) is a key component in RNA splicing which plays a crucial role in the aging process. In neurodegenerative diseases such as amyotrophic lateral sclerosis, frontotemporal dementia and limbic-predominant age-related TDP-43 encephalopathy, TDP-43 can be mutated, mislocalised out of the nucleus of neurons and glial cells and form cytoplasmic inclusions. These TDP-43 alterations can lead to its RNA splicing dysregulation and contribute to mis-splicing of various types of RNA, such as mRNA, microRNA, and circular RNA. These changes can result in the generation of an altered transcriptome and proteome within cells, ultimately changing the diversity and quantity of gene products. In this review, we summarise the findings of novel atypical RNAs resulting from TDP-43 dysfunction and their potential as biomarkers or targets for therapeutic development.
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Affiliation(s)
- Flora Cheng
- Motor Neuron Disease Research Centre, Macquarie Medical School, Macquarie University, Sydney, Australia.
| | - Tyler Chapman
- Motor Neuron Disease Research Centre, Macquarie Medical School, Macquarie University, Sydney, Australia
| | - Selina Zhang
- Motor Neuron Disease Research Centre, Macquarie Medical School, Macquarie University, Sydney, Australia
| | - Marco Morsch
- Motor Neuron Disease Research Centre, Macquarie Medical School, Macquarie University, Sydney, Australia
| | - Roger Chung
- Motor Neuron Disease Research Centre, Macquarie Medical School, Macquarie University, Sydney, Australia
| | - Albert Lee
- Motor Neuron Disease Research Centre, Macquarie Medical School, Macquarie University, Sydney, Australia
| | - Stephanie L Rayner
- Motor Neuron Disease Research Centre, Macquarie Medical School, Macquarie University, Sydney, Australia.
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Krus KL, Benitez AM, Strickland A, Milbrandt J, Bloom AJ, DiAntonio A. Reduced STMN2 and pathogenic TDP-43, two hallmarks of ALS, synergize to accelerate motor decline in mice. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.19.585052. [PMID: 38562780 PMCID: PMC10983882 DOI: 10.1101/2024.03.19.585052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Pathological TDP-43 loss from the nucleus and cytoplasmic aggregation occurs in almost all cases of ALS and half of frontotemporal dementia patients. Stathmin2 (Stmn2) is a key target of TDP-43 regulation and aberrantly spliced Stmn2 mRNA is found in patients with ALS, frontotemporal dementia, and Alzheimer's Disease. STMN2 participates in the axon injury response and its depletion in vivo partially replicates ALS-like symptoms including progressive motor deficits and distal NMJ denervation. The interaction between STMN2 loss and TDP-43 dysfunction has not been studied in mice because TDP-43 regulates human but not murine Stmn2 splicing. Therefore, we generated trans-heterozygous mice that lack one functional copy of Stmn2 and express one mutant TDP-43Q331K knock-in allele to investigate whether reduced STMN2 function exacerbates TDP-43-dependent pathology. Indeed, we observe synergy between these two alleles, resulting in an early onset, progressive motor deficit. Surprisingly, this behavioral defect is not accompanied by detectable neuropathology in the brain, spinal cord, peripheral nerves or at neuromuscular junctions (NMJs). However, the trans-heterozygous mice exhibit abnormal mitochondrial morphology in their distal axons and NMJs. As both STMN2 and TDP-43 affect mitochondrial dynamics, and neuronal mitochondrial dysfunction is a cardinal feature of many neurodegenerative diseases, this abnormality likely contributes to the observed motor deficit. These findings demonstrate that partial loss of STMN2 significantly exacerbates TDP-43-associated phenotypes, suggesting that STMN2 restoration could ameliorate TDP-43 related disease before the onset of degeneration.
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Affiliation(s)
- Kelsey L. Krus
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, United States, 63110
| | - Ana Morales Benitez
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, United States, 63110
| | - Amy Strickland
- Department of Genetics, Washington University School of Medicine, St. Louis, United States, 63110
| | - Jeffrey Milbrandt
- Department of Genetics, Washington University School of Medicine, St. Louis, United States, 63110
- McDonnell Genome Institute, Washington University School of Medicine, St. Louis, United States, 63110
- Needleman Center for Neurometabolism and Axonal Therapeutics, St. Louis, United States, 63110
| | - A. Joseph Bloom
- Department of Genetics, Washington University School of Medicine, St. Louis, United States, 63110
- Needleman Center for Neurometabolism and Axonal Therapeutics, St. Louis, United States, 63110
| | - Aaron DiAntonio
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, United States, 63110
- Needleman Center for Neurometabolism and Axonal Therapeutics, St. Louis, United States, 63110
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Arnold FJ, Cui Y, Michels S, Colwin MR, Stockford C, Ye W, Tam OH, Menon S, Situ WG, Ehsani KCK, Howard S, Hammell MG, Li W, La Spada AR. TDP-43 dysregulation of polyadenylation site selection is a defining feature of RNA misprocessing in ALS/FTD and related disorders. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.22.576709. [PMID: 38328178 PMCID: PMC10849549 DOI: 10.1101/2024.01.22.576709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
Nuclear clearance and cytoplasmic aggregation of the RNA-binding protein TDP-43 are observed in many neurodegenerative disorders, including amyotrophic lateral sclerosis (ALS) and fronto- temporal dementia (FTD). Although TDP-43 dysregulation of splicing has emerged as a key event in these diseases, TDP-43 can also regulate polyadenylation; yet, this has not been adequately studied. Here, we applied the dynamic analysis of polyadenylation from RNA-seq (DaPars) tool to ALS/FTD transcriptome datasets, and report extensive alternative polyadenylation (APA) upon TDP-43 alteration in ALS/FTD cell models and postmortem ALS/FTD neuronal nuclei. Importantly, many identified APA genes highlight pathways implicated in ALS/FTD pathogenesis. To determine the functional significance of APA elicited by TDP-43 nuclear depletion, we examined microtubule affinity regulating kinase 3 (MARK3). Nuclear loss of TDP-43 yielded increased expression of MARK3 transcripts with longer 3'UTRs, resulting in greater transcript stability and elevated MARK3 protein levels, which promotes increased neuronal tau S262 phosphorylation. Our findings define changes in polyadenylation site selection as a previously unrecognized feature of TDP-43-driven disease pathology in ALS/FTD and highlight a potentially novel mechanistic link between TDP-43 dysfunction and tau regulation.
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