The dynamic interaction of AMBRA1 with the dynein motor complex regulates mammalian autophagy

Bartolomeo, Sabrina Di; Corazzari, Marco; Nazio, Francesca; Oliverio, Serafina; Lisi, Gaia; Antonioli, Manuela; Pagliarini, Vittoria; Matteoni, Silvia; Fuoco, Claudia; Giunta, Luigi; D’Amelio, Marcello; Nardacci, Roberta; Romagnoli, Alessandra; Piacentini, Mauro; Cecconi, Francesco; Fimia, Gian María

doi:10.1083/jcb.201002100

Cited by 442 publications

(389 citation statements)

References 59 publications

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“…Results were recorded as percentage of p62-positive cells with p62 punctate as previously described. 53 A minimum of 50-100 cells per sample was counted for triplicate samples per condition per experiment.…”

Section: Methodsmentioning

confidence: 99%

Oncogenic BRAF induces chronic ER stress condition resulting in increased basal autophagy and apoptotic resistance of cutaneous melanoma

et al. 2014

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The notorious unresponsiveness of metastatic cutaneous melanoma to current treatment strategies coupled with its increasing incidence constitutes a serious worldwide clinical problem. Moreover, despite recent advances in targeted therapies for patients with BRAF V600E mutant melanomas, acquired resistance remains a limiting factor and hence emphasises the acute need for comprehensive pre-clinical studies to increase the biological understanding of such tumours in order to develop novel effective and longlasting therapeutic strategies. Autophagy and ER stress both have a role in melanoma development/progression and chemoresistance although their real impact is still unclear. Here, we show that BRAF V600E induces a chronic ER stress status directly increasing basal cell autophagy. BRAF V600E -mediated p38 activation stimulates both the IRE1/ASK1/JNK and TRB3 pathways. Bcl-XL/Bcl-2 phosphorylation by active JNK releases Beclin1 whereas TRB3 inhibits the Akt/mTor axes, together resulting in an increase in basal autophagy. Furthermore, we demonstrate chemical chaperones relieve the BRAF V600E -mediated chronic ER stress status, consequently reducing basal autophagic activity and increasing the sensitivity of melanoma cells to apoptosis. Taken together, these results suggest enhanced basal autophagy, typically observed in BRAF V600E melanomas, is a consequence of a chronic ER stress status, which ultimately results in the chemoresistance of such tumours. Targeted therapies that attenuate ER stress may therefore represent a novel and more effective therapeutic strategy for BRAF mutant melanoma.

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Section: Methodsmentioning

confidence: 99%

Oncogenic BRAF induces chronic ER stress condition resulting in increased basal autophagy and apoptotic resistance of cutaneous melanoma

et al. 2014

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“…77,78 AMBRA1 plays a positive role in autophagy presumably by regulating the BECN1-PIK3C3 interaction. 79,80 AMBRA1 also acts as a tether controlling BECN1-PIK3C3 subcellular localization. Under normal conditions, AMBRA1 anchors the BECN1-PIK3C3 core complex to microtubules by interacting with dynein light chains 1/2; upon induction of autophagy, ULK1 phosphorylates AMBRA1 and releases the core complex, enabling the latter to translocate to the ER and initiate autophagosome formation.…”

Section: Regulation Of Autophagy By Pik3c3 Via Other Interacting Partmentioning

confidence: 99%

“…133 Thus, AKT modulates the indirect interaction of BECN1 with intermediate filaments, mirroring the AMBRA1-regulated subcellular localization of BECN1-PIK3C3 to another kind of cytoskeleton, microtubules (to be discussed below). 80 In addition, DAPK1 (death-associated protein kinase 1) phosphorylates BECN1 at its BH3 domain and releases BECN1 from BCL2, which promotes autophagy. 134 EGFR can also phosphorylate BECN1, but is inhibitory for PIK3C3 activity and autophagy.…”

Section: Regulation Of Autophagy By Pik3c3 Via Becn1mentioning

confidence: 99%

“…2). The stratification can be viewed based on their interaction and stability: PIK3C3-PIK3R4-BECN1, the most stable and prevalent complex, constitutes the core; while ATG14 and UVRAG (UV radiation resistance associated) are combined with the core in PtdIns3K complex I (PtdIns3K-C1; ATG14-containing PtdIns3K complex) and PtdIns3K complex II (PtdIns3K-C2; UVRAG-containing PtdIns3K complex), respectively; 75-78 KIAA0226/Rubicon is a regulatory subunit that is thought to stably bind to UVRAGcontaining complexes; 77,78 AMBRA1, NRBF2 (nuclear receptor binding factor 2) and other accessory factors transiently or unstably interact with either BECN1 (e.g., AMBRA1) 79,80 or ATG14 (e.g., NRBF2), [81][82][83] thus comprising the peripheral components. 84,85 UVRAG also exists in a separate complex excluding ATG14, which holds an important role in the regulation of autophagy at the maturation step.…”

Section: Regulation Of Autophagy By Class III Ptdins3kmentioning

confidence: 99%

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Differential regulatory functions of three classes of phosphatidylinositol and phosphoinositide 3-kinases in autophagy

2015

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Abbreviations: 3-MA, 3-methyladenine; AMBRA1, autophagy/Beclin 1 regulator 1; ATG, autophagy related; ATM, ATM serine/threonine kinase; ATR, ATR serine/threonine kinase; BH3, Bcl-2 homology 3; CCD, coiled-coil domain; CDK, cyclin-dependent kinase; CISD2, CDGSH iron sulfur domain 2; class I/II PI3K, class I/II phosphoinositide 3-kinase; class III PtdIns3K, class III phosphatidylinositol 3-kinase; DAPK1, death-associated protein kinase 1; DDR, DNA damage response; EIF4EBP1, eukaryotic translation initiation factor 4E binding protein 1; ER, endoplasmic reticulum; FOXO, forkhead box O; FYCO1, FYVE and coiledcoil domain containing 1; GAP, GTPase-activating protein; HMGB1, high mobility group box 1; HSPA1A, heat shock 70kDa protein 1A; IR, ionizing radiation; MAPK8, mitogen-activated protein kinase 8; MEFs, mouse embryonic fibroblasts; MTMR, myotubularin-related protein; MTOR, mechanistic target of rapamycin (serine/threonine kinase); MTORC1, mechanistic target of rapamycin complex 1; MVBs, spherical multivesicular bodies; NRBF2, nuclear receptor binding factor 2; PAS, phagophore assembly site; PDPK1, 3-phosphoinositide dependent protein kinase 1; PE, phosphatidylethanolamine; PIKFYVE, phosphoinositide kinase, FYVE finger containing; PINK1, PTEN-induced putative kinase 1; PtdIns3K-C1, class III phosphatidylinositol 3-kinase complex I; PtdIns3K-C2, class III phosphatidylinositol 3-kinase complex II; PKB, protein kinase B; PRKA, protein kinase, AMP-activated; PRKD1, protein kinase D1; PRKDC, protein kinase, DNA-activated, catalytic polypeptide; PtdIns5P, phosphatidylinositol 5-phosphate; PtdIns4P, phosphatidylinositol 4-phosphate; PtdIns(4,5)P 2 , phosphatidylinositol 4,5-bisphosphate; PtdIns3P, phosphatidylinositol 3-phosphate; PtdIns(3,5)P 2 , phosphatidylinositol 3,5-bisphosphate; PtdIns(3,4,5)P 3 , phosphatidylinositol 3,4,5-trisphosphate; RHEB, Ras homolog enriched in brain; RPS6KB1, ribosomal protein S6 kinase, 70kDa, polypeptide 1; SQSTM1, sequestosome 1; TECPR1, tectonin b-propeller repeat containing 1; TFEB, transcription factor EB; TRIM28, tripartite motif containing 28; TSC, tuberous sclerosis; UV, ultraviolet; UVRAG, UV radiation resistance associated; WDFY3, WD repeat and FYVE domain containing 3; WIPI, WD repeat domain, phosphoinositide interacting; ZFYVE1, zinc finger, FYVE domain containing 1.Autophagy is an evolutionarily conserved and exquisitely regulated self-eating cellular process with important biological functions. Phosphatidylinositol 3-kinases (PtdIns3Ks) and phosphoinositide 3-kinases (PI3Ks) are involved in the autophagic process. Here we aim to recapitulate how 3 classes of these lipid kinases differentially regulate autophagy. Generally, activation of the class I PI3K suppresses autophagy, via the well-established PI3K-AKT-MTOR (mechanistic target of rapamycin) complex 1 (MTORC1) pathway. In contrast, the class III PtdIns3K catalytic subunit PIK3C3/Vps34 forms a protein complex with BECN1 and PIK3R4 and produces phosphatidylinositol 3-phosphate (PtdIns3P), which is required for the initiati...

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“…Briefly, bronchial cells were grown to 70% confluency in six‐well culture dishes and treated with 50 nmol/L wortmannin for 30 min, while control cells were incubated with DMSO vehicle (Di Bartolomeo et al. 2010). After changing the medium, cells were thoroughly washed with prewarmed media and then treated with nanoparticle suspension and rrRSV.…”

Section: Methodsmentioning

confidence: 99%

Nanoparticles increase human bronchial epithelial cell susceptibility to respiratory syncytial virus infection via nerve growth factor-induced autophagy

et al. 2017

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Cytotoxic and neuroinflammatory effects of TiO2 nanoparticles (TiO2‐NP) in human airways are mediated by nerve growth factor (NGF), which is also implicated in the pathophysiology of respiratory syncytial virus (RSV) infection. We tested the hypothesis that exposure to TiO2‐NP results in increased susceptibility to RSV infection and exacerbation of airway inflammation via NGF‐mediated induction of autophagy in lower respiratory tract cells. Human primary bronchial epithelial cells were exposed to TiO2‐NP for 24 h prior to infection with recombinant red RSV (rrRSV). Expression of NGF and its TrkA and p75NTR receptors was measured by real‐time PCR and fluorescence‐activated cell sorting (FACS). Autophagy was assessed by beclin‐1 expression analysis. Cell death was studied by FACS after annexin V/propidium iodide staining. rrRSV infection efficiency more than doubled in human bronchial cells pre‐exposed to TiO2‐NP compared to controls. NGF and its TrkA receptor were upregulated in RSV‐infected bronchial cells pre‐exposed to TiO2‐NP compared to controls exposed to either rrRSV or TiO2‐NP alone. Silencing NGF gene expression with siRNA significantly inhibited rrRSV infection. rrRSV‐infected cells pre‐exposed to TiO2‐NP also showed increase in necrotic cell death and reduction in apoptosis, together with 4.3‐fold increase in expression of the early autophagosomal gene beclin‐1. Pharmacological inhibition of beclin‐1 by wortmannin resulted in increased apoptotic rate along with lower viral load. This study shows that TiO2‐NP exposure enhances the infectivity of RSV in human bronchial epithelial cells by upregulating the NGF/TrkA axis. The mechanism of this interaction involves induction of autophagy promoting viral replication and necrotic cell death.

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The dynamic interaction of AMBRA1 with the dynein motor complex regulates mammalian autophagy

Abstract: When autophagy is induced, ULK1 phosphorylates AMBRA1, releasing the autophagy core complex from the cytoskeleton and allowing its relocalization to the ER membrane to nucleate autophagosome formation.

Cited by 442 publications

References 59 publications

Oncogenic BRAF induces chronic ER stress condition resulting in increased basal autophagy and apoptotic resistance of cutaneous melanoma

Oncogenic BRAF induces chronic ER stress condition resulting in increased basal autophagy and apoptotic resistance of cutaneous melanoma

Differential regulatory functions of three classes of phosphatidylinositol and phosphoinositide 3-kinases in autophagy

Nanoparticles increase human bronchial epithelial cell susceptibility to respiratory syncytial virus infection via nerve growth factor-induced autophagy

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