Genome-wide RNAi screen identifies ATPase inhibitory factor 1 (ATPIF1) as essential for PARK2 recruitment and mitophagy

Lefebvre, Valérie; Du, Qiujiang; Baird, Stephen; Ng, Andy Cheuk Him; Nascimento, Mirna; Campanella, Michelangelo; McBride, Heidi M.; Screaton, Robert A.

doi:10.4161/auto.25413

Cited by 71 publications

(57 citation statements)

References 40 publications

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“…37 In addition, IF1 has been identified as an essential factor for PARK2 recruitment and consequently mitophagy activation. 38 In accordance with the above described protective effect of TG2 on mitochondria, we detected a drastic reduction of IF1 protein level in TG2-null MEFs, untreated cells. Interestingly, we observed a very different IF1 protein turnover in the presence and absence of TG2 that is independent by autophagy ( Figure 5a).…”

Section: Resultssupporting

confidence: 89%

Transglutaminase 2 ablation leads to mitophagy impairment associated with a metabolic shift towards aerobic glycolysis

et al. 2014

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Macroautophagy selectively degrades dysfunctional mitochondria by a process known as mitophagy. Here we demonstrate the involvement of transglutaminase 2 (TG2) in the turnover and degradation of damaged mitochondria. In TG2-ablated cells we observed the presence of a large number of fragmented mitochondria that display decreased membrane potential, downregulation of IF1 along with increased Drp1 and PINK1 levels, two key proteins regulating the mitochondrial fission. Of note, we demonstrate that in healthy mitochondria, TG2 interacts with the dynamic proteins Drp1 and Fis1; interestingly, their interaction is largely reduced upon induction of the fission process by carbonyl cyanide m-chlorophenyl hydrazine (CCCP). In keeping with these findings, mitochondria lacking TG2 are more susceptible to CCCP treatment. As a consequence of accumulation of damaged mitochondria, cells lacking TG2 increased their aerobic glycolysis and became sensitive to the glycolytic inhibitor 2-deoxy-D-glucose (2-DG). In contrast, TG2-proficient cells are more resistant to 2-DG-induced apoptosis as the caspase 3 is inactivated through the enzyme's crosslinking activity. The data presented in this study show that TG2 plays a key role in cellular dynamics and consequently influences the energetic metabolism.

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Section: Resultssupporting

confidence: 89%

Transglutaminase 2 ablation leads to mitophagy impairment associated with a metabolic shift towards aerobic glycolysis

et al. 2014

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“…S4E). Second, ΔΨm could be restored by the reversal of ATP synthase, as was recently reported for ATPase inhibitory factor 1 (ATPIF1) (25). However, analysis using a potentiometric sensitive dye confirmed that ΔΨm was ablated in SREBF1 and FBXW7 knockdown cells (Fig.…”

Section: Rnai Screening Identified 20 Genes With a Conserved Role In supporting

confidence: 62%

Genome-wide RNAi screen identifies the Parkinson disease GWAS risk locusSREBF1as a regulator of mitophagy

Ivatt

Sánchez-Martínez

Godena

et al. 2014

Proc. Natl. Acad. Sci. U.S.A.

115

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Genetic analysis of Parkinson disease (PD) has identified several genes whose mutation causes inherited parkinsonism, as well as risk loci for sporadic PD. PTEN-induced kinase 1 (PINK1) and parkin, linked to autosomal recessive PD, act in a common genetic pathway regulating the autophagic degradation of mitochondria, termed mitophagy. We undertook a genome-wide RNAi screen as an unbiased approach to identify genes regulating the PINK1/Parkin pathway. We identified several genes that have a conserved function in promoting mitochondrial translocation of Parkin and subsequent mitophagy, most notably sterol regulatory element binding transcription factor 1 (SREBF1), Fbox and WD40 domain protein 7 (FBXW7), and other components of the lipogenesis pathway. The relevance of mechanisms of autosomal recessive parkinsonism to sporadic PD has long been debated. However, with the recent identification of SREBF1 as a risk locus for sporadic PD, our findings suggest a common mechanistic link between autosomal recessive and sporadic PD, and underscore the importance of mitochondrial homeostasis. P arkinson disease (PD) is an age-related neurodegenerative disease caused principally by the loss of midbrain dopaminergic neurons, resulting in motor disturbances, such as postural instability, resting tremor, and bradykinesia, as well as other nonmotor symptoms. Current therapeutic strategies alleviate symptoms by the replacement of dopamine, with variable efficacy and substantial side effects. However, there are currently no established curative, preventative, or disease-modifying interventions, stemming from a poor understanding of the molecular mechanisms of pathogenesis. Genetic analyses have identified causative mutations for autosomal dominant and recessive forms of familial parkinsonism. Functional studies of these genes have provided great insight into potential pathogenic mechanisms of inherited forms of PD; however, it is unclear how these may relate to the more common sporadic forms of PD. To gain insight into the genetic influence in sporadic PD, genome-wide association studies (GWASs) have revealed several loci that are significantly associated with the occurrence of PD, and so are considered potential risk factors. However, we lack mechanistic insight into how many of the associated risk loci may contribute to pathogenesis.Mitochondrial dysfunction has long been considered a key contributing factor in the pathogenesis of PD, with evidence from postmortem tissue, epidemiological studies, and genetics. In particular, a body of evidence indicates that two genes linked to recessive parkinsonism, PTEN-induced kinase 1 (PINK1) and parkin, act in a common pathway to regulate mitochondrial turnover, providing an attractive hypothesis for the impact of mitochondrial homeostasis on pathogenesis (1). The process of mitophagy to degrade dysfunctional mitochondria has been extensively studied using uncoupling agents to dissipate the mitochondrial membrane potential (ΔΨm) (2). Following loss of ΔΨm, PINK1 accumulates on the outer mit...

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“…UBE2A, UBE2C, UBE2D1, UBE2D2, UBE2D3, UBE2D4, UBE2L3, UBE2N, UBE2R1 (also known as CDC34), UBE2S and UBE2T]. Similar to recent studies (Hasson et al, 2013;Lefebvre et al, 2013;McCoy et al, 2014), we have established a High Content Imaging (HCI) assay that allows unbiased monitoring of PINK1-dependent Parkin recruitment from the cytosol onto chemically de-energized mitochondria. Using HeLa cells that stably expressed an enhanced green fluorescent protein (EGFP)-fusion, the distribution of Parkin within cells was quantified as a ratio of the intensity of cytoplasmic and nuclear GFP (Cyto:Nuc) (Fig.…”

Section: Identification Of E2 Enzymes That Regulate Activation and MImentioning

confidence: 87%

Select E2 enzymes differentially regulate parkin activation and mitophagy

Fiesel

Moussaud-Lamodière

Ando

et al. 2014

Journal of Cell Science

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Loss-of-function mutations in the genes encoding PINK1 and Parkin (also known as PARK2) are the most common causes of recessive Parkinson's disease. Both together mediate the selective degradation of mitochondrial proteins and whole organelles via the proteasome and the autophagy-lysosome pathway (mitophagy). The mitochondrial kinase PINK1 activates and recruits the E3 ubiquitin ligase Parkin to de-energized mitochondria. However, the cognate E2 co-enzymes of Parkin in this ubiquitin-dependent pathway have not been investigated. Here, we discovered a total of four E2s that either positively or negatively regulate the activation, translocation and enzymatic functions of Parkin during mitochondrial quality control. UBE2D family members and UBE2L3 redundantly charged the RING-HECT hybrid ligase Parkin with ubiquitin, resulting in its initial activation and translocation to mitochondria. UBE2N, however, primarily operated through a different mechanism in order to mediate the proper clustering of mitochondria, a prerequisite for degradation. Strikingly, in contrast to UBE2D, UBE2L3 and UBE2N, depletion of UBE2R1 resulted in enhanced Parkin translocation and clustering upon mitochondrial uncoupling. Our study uncovered redundant, cooperative or antagonistic functions of distinct E2 enzymes in the regulation of Parkin and mitophagy that might suggest a putative role in Parkinson's disease pathogenesis.

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Genome-wide RNAi screen identifies ATPase inhibitory factor 1 (ATPIF1) as essential for PARK2 recruitment and mitophagy

Cited by 71 publications

References 40 publications

Transglutaminase 2 ablation leads to mitophagy impairment associated with a metabolic shift towards aerobic glycolysis

Transglutaminase 2 ablation leads to mitophagy impairment associated with a metabolic shift towards aerobic glycolysis

Genome-wide RNAi screen identifies the Parkinson disease GWAS risk locusSREBF1as a regulator of mitophagy

Select E2 enzymes differentially regulate parkin activation and mitophagy

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