Neuronal mitochondria transport Pink1 mRNA via Synaptojanin 2 to support local mitophagy
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ABSTRACT:
PROVIDER: PRJNA796269 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| SRR17549355_1.fastq.gz | Fastqsanger.gz | |||
| SRR17549355_2.fastq.gz | Fastqsanger.gz | |||
| SRR17549356_1.fastq.gz | Fastqsanger.gz | |||
| SRR17549356_2.fastq.gz | Fastqsanger.gz | |||
| SRR17549357_1.fastq.gz | Fastqsanger.gz |
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Project description:PTEN-induced kinase 1 (PINK1) is a very short-lived protein that is required for the removal of damaged mitochondria through Parkin translocation and mitophagy. Because the short half-life of PINK1 limits its ability to be trafficked into neurites, local translation is required for this mitophagy pathway to be active far from the soma. The Pink1 transcript is associated with and cotransported with neuronal mitochondria. In concert with translation, the mitochondrial outer membrane protein Synaptojanin 2 Binding Protein (SYNJ2BP) and Synaptojanin 2 (SYNJ2) are required for tethering Pink1 mRNA to mitochondria via an RNA-binding domain in SYNJ2. This neuron-specific adaptation for local translation of PINK1 provides distal mitochondria with a continuous supply of PINK1 for activation of mitophagy.
2022-01-14 | GSE193443 | GEO
Project description:Mitochondrial quality control failure is frequently observed in neurodegenerative diseases. The detection of damaged mitochondria by stabilization of PTEN-induced kinase 1 (PINK1) requires transport of Pink1 mRNA by tethering it to the mitochondrial surface. Here, we report that inhibition of AMPK by activation of the insulin signaling cascade prevents Pink1 mRNA binding to mitochondria. Mechanistically, AMPK phosphorylates the RNA anchor complex subunit SYNJ2BP within its PDZ domain, a phosphorylation site that is necessary for its interaction with the RNA-binding protein SYNJ2. Interestingly, loss of mitochondrial Pink1 mRNA association upon insulin addition is required for PINK1 protein activation and its function as a ubiquitin kinase in the mitophagy pathway, thus placing PINK1 function under metabolic control. Induction of insulin-resistance in vitro by the key genetic Alzheimer-risk factor apolipoprotein E4 retains Pink1 mRNA at the mitochondria and prevents proper PINK1 activity especially in neurites. Our results thus identify a metabolic switch controlling Pink1 mRNA localization and PINK1 activity via insulin and AMPK signaling in neurons and propose a mechanistic connection between insulin resistance and mitochondrial dysfunction.
2024-02-23 | PXD045621 | Pride
Project description:Dysregulated inflammation is a key driver of disease following infection with the globally important human pathogens, Zika virus (ZIKV) and dengue virus. However, specific mechanisms of inflammation are not well defined. Here, we demonstrate that ZIKV antagonizes mitophagy, or the process of selective degradation of damaged mitochondria. The mechanism of antagonism was through interactions between NS5 and the host protein Ajuba to prevent Ajuba translocation to depolarized mitochondria. We further identify a role of Ajuba in mitophagy through augmenting PINK1 kinase activity. Mitophagy suppression in infected Ajuba-/- cells amplified the cellular integrated stress response (ISR) to promote ZIKV replication, and increased pro-inflammatory cytokine expression dependent on the ISR kinase, PKR. Thus, ZIKV suppresses mitophagy to favor replication and this failure of mitochondrial quality control is translated to inflammation by PKR, suggesting new therapeutic targets to treat flavivirus disease.
2021-09-08 | GSE162688 | GEO
Project description:The protein kinase PINK1 and ubiquitin ligase Parkin promote removal of damaged mitochondria via a feed-forward mechanism involving ubiquitin (Ub) phosphorylation (pUb), Parkin activation, and ubiquitylation of mitochondrial outer membrane proteins to support recruitment of mitophagy receptors. The ubiquitin ligase substrate receptor FBXO7/PARK15 is mutated in an early-onset parkinsonian-pyramidal syndrome. Previous studies have proposed a role for FBXO7 in promoting Parkin-dependent mitophagy. Here, we systematically examine the involvement of FBXO7 in depolarization and mtUPR-dependent mitophagy in the well-established HeLa and induced-neurons cell systems. We find that FBXO7-/- cells have no demonstrable defect in: 1) kinetics of pUb accumulation, 2) pUb puncta on mitochondria by super-resolution imaging, 3) recruitment of Parkin and autophagy machinery to damaged mitochondria, 4) mitophagic flux, and 5) mitochondrial clearance as quantified by global proteomics. Moreover, global proteomics of neurogenesis in the absence of FBXO7 reveals no obvious alterations in mitochondria or other organelles. These results argue against a general role for FBXO7 in Parkin-dependent mitophagy and point to the need for additional studies to define how FBXO7 mutations promote parkinsonian-pyramidal syndrome.
2023-06-19 | PXD037797 | Pride
Project description:Down syndrome (DS), a complex genetic disorder caused by chromosome 21 trisomy, is associated with mitochondrial dysfunction leading to the accumulation of damaged mitochondria. Here we report that mitophagy, a form of selective autophagy activated to clear damaged mitochondria is deficient in primary human fibroblasts derived from individuals with DS leading to accumulation of damaged mitochondria with consequent increases in oxidative stress. We identified two molecular bases for this mitophagy deficiency: PINK1/PARKIN impairment and abnormal suppression of macroautophagy. First, strongly downregulated PARKIN and the mitophagic adaptor protein SQSTM1/p62 delays PINK1 activation to impair mitophagy induction after mitochondrial depolarization by CCCP or antimycin A plus oligomycin. Secondly, mTOR is strongly hyper-activated, which globally suppresses macroautophagy induction and the transcriptional expression of proteins critical for autophagosome formation such as ATG7, ATG3 and FOXO1. Notably, inhibition of mTOR complex 1 (mTORC1) and complex 2 (mTORC2) using AZD8055 (AZD) restores autophagy flux, PARKIN/PINK initiation of mitophagy, and the clearance of damaged mitochondria by mitophagy. These results recommend mTORC1-mTORC2 inhibition as a promising candidate therapeutic strategy for Down Syndrome.
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Project description:Age-related macular degeneration (AMD), the leading cause of blindness among the elderly, is without effective treatment for early, dry disease. Retinal pigment epithelial (RPE) cell degeneration is a cardinal feature of dry AMD. Given the reliance of photoreceptors on the RPE for maintaining health and vision, rejuvenating dysfunctional RPE is a logical treatment strategy. Here, the interplay between two cytoprotective pathways, Pink1 mediated mitophagy and the Nrf2 stress-response, was studied in human AMD tissue samples, RPE cells, and relevant mouse models. Pink1 immunolabeling was decreased in the RPE of early AMD eyes. The RPE from Pink1-/- mice and Pink1 deficient cultured human RPE cells displayed impaired mitophagy, decreased aerobic respiration, and increased mitochondrial reactive oxygen species (ROS) generation, and coincidently, developed morphological, molecular, and functional features of epithelial-mesenchymal transition (EMT). This change was triggered by novel retrograde mitochondrial to nuclear signaling that was initiated by mitochondrial ROS, which activated Nrf2 to induce TXNRD1, PI3K/AKT, and canonical EMT transcription factors Zeb1 and Snail. Nrf2 signaling was pivotal since its deficiency prevented EMT and increased cell death. A dendrimer containing N-acetyl cysteine that is tropic for the RPE and contains the mitochondrial targeting ligand Triphenyl phosphinium abrogates EMT in human RPE cells in vitro and in Pink1-/- mice. This study describes a novel interdependency of mitophagy and the Nrf2 antioxidant response in determining cell fate and introduces an RPE and mitochondrial specific ROS reducing dendrimer that can rescue RPE cells in EMT, a change recognized in early AMD.
2022-01-01 | GSE186751 | GEO
Project description:Enhancing mitophagy, a naturally-occurring cellular process for elimination of damaged mitochondria, holds great promise for the intervention of many human diseases. Proteolysis-targeting chimeras (PROTACs) are heterobifunctional molecules that induce ubiquitination and subsequent proteasome-mediated degradation of a target protein through simultaneously binding to the target protein and an E3 ubiquitin ligase. However, the narrow cavity of the proteasome prevents the degradation of mitochondria. Here we show that the E3 ubiquitin ligase MAP3K1, when recruited to the outer mitochondria membrane (OMM) protein TSPO by our PROTAC-designed molecules (termed “mitophagy-enhancing chimeras”, or MECs), induced extensive K63 ubiquitination of TSPO and other OMM proteins, reminiscent of the PINK1-activated Parkin, without triggering proteasome-mediated degradation of TSPO. Aided by NBR1 and Nur77, this increased K63 ubiquitination of OMM proteins triggered mitophagy exclusively for damaged mitochondria, leading to improved mitochondria function and diminished cellular ROS. With the capability to enhance mitophagy at low nanomolar concentrations, MECs effectively inhibited NLRP3 inflammasome activation, abrogated acetaminophen-induced acute liver injury and mitigated high-fat diet-induced obesity in mice. Our work provided a proof-of-concept for developing unconventionally-acting PROTACs to achieve degradation of damaged mitochondria and possibly other organelles.
2024-02-08 | GSE255354 | GEO
Project description:Mitophagy is essential to maintain mitochondrial function and prevent diseases. It activates upon mitochondria depolarization, which causes PINK1 stabilization on the mitochondrial outer membrane. Strikingly, a number of conditions, including mitochondrial protein misfolding, can induce mitophagy without a loss in membrane potential. The underlying molecular details remain unclear. Here, we report that a loss of mitochondrial protein import, mediated by the pre-sequence translocase-associated motor complex PAM, is sufficient to induce mitophagy in polarized mitochondria. A genome-wide CRISPR/Cas9 screen for mitophagy inducers identifies components of the PAM complex. Protein import defects are able to induce mitophagy without a need for depolarization. Upon mitochondrial protein misfolding, PAM dissociates from the import machinery resulting in decreased protein import and mitophagy induction. Our findings extend the current mitophagy model to explain mitophagy induction upon conditions that do not affect membrane polarization, such as mitochondrial protein misfolding.
2022-08-04 | GSE207212 | GEO
Project description:Clearance of damaged mitochondria via mitophagy is crucial for cellular homeostasis. While the role of ubiquitin (Ub) ligase PARKIN in mitophagy has been extensively studied, increasing evidence suggests the existence of PARKIN-independent mitophagy in highly metabolically active organs such as the heart. Here, we identify a crucial role for Cullin-RING Ub ligase 5 (CRL5) in basal mitochondrial turnover in cardiomyocytes. CRL5 is a multi-subunit Ub ligase comprised by the catalytic RING box protein RBX2 (also known as SAG), scaffold protein Cullin 5 (CUL5), and a substrate-recognizing receptor. Analysis of the mitochondrial outer membrane-interacting proteome uncovered a robust association of CRLs with mitochondria. Subcellular fractionation, immunostaining, and immunogold electron microscopy established that RBX2 and Cul5, two core components of CRL5, localizes to mitochondria. Depletion of RBX2 inhibited mitochondrial ubiquitination and turnover, impaired mitochondrial membrane potential and respiration, and increased cell death in cardiomyocytes. In vivo, deletion of the Rbx2 gene in adult mouse hearts suppressed mitophagic activity, provoked accumulation of damaged mitochondria in the myocardium, and disrupted myocardial metabolism, leading to rapid development of dilated cardiomyopathy and heart failure. Similarly, ablation of RBX2 in the developing heart resulted in dilated cardiomyopathy and heart failure. Notably, the action of RBX2 in mitochondria is not dependent on PARKIN, and PARKIN gene deletion had no impact on the onset and progression of cardiomyopathy in RBX2-deficient hearts. Furthermore, RBX2 controls the stability of PINK1 in mitochondria. Proteomics and biochemical analyses further revealed a global impact of RBX2 deficiency on the mitochondrial proteome and identified several mitochondrial proteins as its putative substrates. These findings identify RBX2-CRL5 as a mitochondrial Ub ligase that controls mitophagy under physiological conditions in a PARKIN-independent, PINK1-dependent manner, thereby regulating cardiac homeostasis.
2024-04-28 | GSE265777 | GEO
Project description:O-linked N-acetylglucosamine (O-GlcNAc) transferase (OGT) catalyzes post-translational modification of target proteins by introducing O-GlcNAc moiety on serine or threonine residues. OGT critically regulates various cellular functions in many cell types. However, its roles in hematopoietic stem and progenitor cells (HSPCs) are totally unknown. Here we report critical roles of OGT in homeostasis of HSPCs. Ogt is highly expressed in HSPCs and its disruption led to their rapid loss with increased reactive oxygen species and apoptosis. In particular, Ogt-deficient HSCs lost quiescence and showed severe defects in self-renewal and long-term repopulation capacities. Interestingly, Ogt-deficient HSCs accumulated defective mitochondria due to impaired mitophagy with decreased key mitophagy regulators, Pink1 and Bnip3, through dysregulation of host cell factor 1 (HCF1)-H3K4me3 pathway, and overexpression of Pink1 rescued impaired mitophagy and numbers of Ogt-deficient HSCs. In summary, our results revealed that OGT plays an essential role in HSC maintenance by assuring mitochondrial quality through mitophagy.
2020-12-09 | GSE116433 | GEO