Manassantin A inhibits tumour growth under hypoxia through the activation of chaperone-mediated autophagy by modulating Hsp90 activity
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PROVIDER: PRJNA434512 | ENA |
REPOSITORIES: ENA
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Project description:Background: Chaperon-mediated autophagy (CMA) has taken on a new emphasis in cancer biology. However, the roles of CMA in hypoxic tumours are poorly understood. We investigated the anti-tumour effects of the natural product ManA through the activation of CMA in tumour progression under hypoxia. Methods: The effect of ManA on CMA activation was assessed in mouse xenograft models and cells. The gene expressions of HIF-1α, HSP90AA1, and transcription factor EB (TFEB) were analysed using The Cancer Genome Atlas (TCGA) datasets to assess the clinical relevance of CMA. Results: ManA activates photoswitchable CMA reporter activity and inhibits Hsp90 chaperone function by disrupting the Hsp90/F1F0-ATP synthase complex. Hsp90 inhibition enhances the interaction between CMA substrates and LAMP-2A and TFEB nuclear localisation, suggesting CMA activation by ManA. ManA-activated CMA retards tumour growth and displays cooperative anti-tumour activity with anti-PD-1 antibody. TCGA datasets show that a combined expression of HSP90AA1High/HIF1AHigh or TFEBLow/HIF1AHigh is strongly correlated with poor prognosis in patients with lung cancer. Conclusions: ManA-induced CMA activation by modulating Hsp90 under hypoxia induces HIF-1α degradation and reduces tumour growth. Thus, inducing CMA activity by targeting Hsp90 may be a promising therapeutic strategy against hypoxic tumours.
2024-01-22 | GSE110768 | GEO
Project description:The molecular chaperone Hsp90 is involved in the stability and activity of its client proteins which largely comprise of kinases. Phosphorylation of Hsp90 by these kinase clients provides a reciprocal regulatory mechanism between these proteins, however the mechanism of regulating the cellular pathway remains elusive. Here, we show that the serine/threonine kinase Atg1(yeast)/ULK1(mammalian) phosphorylates a conserved serine in the amino-domain of Hsp90 and reduces its ATPase activity hence lowers chaperone function. Broadly this modification negatively impacts the chaperoning of the kinase clients including Atg1/ULK1, yet enhances the activity of the non-kinase clients such as the heat shock factor and the steroid hormone receptors. Interestingly, ATG1/ULK1 mediated phosphorylation of the Hsp90 is essential for initiation of autophagy since yeast expressing a non-phosphorylatable Hsp90 were unable to undergo autophagy and the phosphomimetic Hsp90 mutants were underwent autophagy even in the absence of stimulus. Our findings provide a new paradigm where kinase client mediated phosphorylation of Hsp90 not only regulates the chaperone function but it is essential to initiate and regulate the relevant signaling pathway.
2023-09-08 | PXD038924 | Pride
Project description:The ability of Heat Shock Protein 90 (Hsp90) to hydrolyze ATP is essential for its chaperone function. The co-chaperone Aha1 stimulates Hsp90 ATPase activity tailoring the chaperone function to specific “client” proteins. The intracellular signaling mechanisms directly regulating Aha1 association with Hsp90 remain unknown. Here we show that c-Abl kinase phosphorylates Y223 in human Aha1 (hAha1) promoting its interaction with Hsp90. This also increases Hsp90 ATPase activity,enhancesHsp90 interaction with kinase clients,and compromises the chaperoning of non-kinase clients such as glucocorticoid receptor and CFTR. Suggesting a new regulatory paradigm, we find that Y223 phosphorylation leads to ubiquitination and degradation of hAha1 in the proteasome. Finally pharmacologic inhibition of c-Abl prevents hAha1 interaction with Hsp90 thereby, hypersensitizing cancer cells to Hsp90 inhibitors bothin vitro and ex vivo.
2017-03-28 | MSV000080713 | MassIVE
Project description:Here we demonstrate that inactivation of the essential autophagy genes, Atg5, Atg14, or Atg16L1 results in tumour rejection. Despite a significant reduction in the total number of CD8+ tumour infiltrating lymphocytes (TILs), loss of Atg5 causes a profound shift toward IFNg and TNF producing effector memory cells. Consistent with this, adoptive transfer with Atg5-/- T cells promotes tumour control. Mechanistically, CD8+ T cells lacking autophagy exhibit enhanced glucose metabolism resulting in global changes in histone trimethylation and increased transcriptional activation of effector target genes. Restricting glucose is sufficient to suppress autophagy-dependent increases in effector function and reverse alterations in histone trimethylation. These findings identify autophagy as a cell-autonomous negative regulator of CD8+ T cell anti-tumour immunity with implications on T cell-based immunotherapy.
2019-04-09 | GSE117757 | GEO
Project description:BackgroundChaperon-mediated autophagy (CMA) has taken on a new emphasis in cancer biology. However, the roles of CMA in hypoxic tumours are poorly understood. We investigated the anti-tumour effects of the natural product ManA through the activation of CMA in tumour progression under hypoxia.MethodsThe effect of ManA on CMA activation was assessed in mouse xenograft models and cells. The gene expressions of HIF-1α, HSP90AA1, and transcription factor EB (TFEB) were analysed using The Cancer Genome Atlas (TCGA) datasets to assess the clinical relevance of CMA.ResultsManA activates photoswitchable CMA reporter activity and inhibits Hsp90 chaperone function by disrupting the Hsp90/F1F0-ATP synthase complex. Hsp90 inhibition enhances the interaction between CMA substrates and LAMP-2A and TFEB nuclear localisation, suggesting CMA activation by ManA. ManA-activated CMA retards tumour growth and displays cooperative anti-tumour activity with anti-PD-1 antibody. TCGA datasets show that a combined expression of HSP90AA1High/HIF1AHigh or TFEBLow/HIF1AHigh is strongly correlated with poor prognosis in patients with lung cancer.ConclusionsManA-induced CMA activation by modulating Hsp90 under hypoxia induces HIF-1α degradation and reduces tumour growth. Thus, inducing CMA activity by targeting Hsp90 may be a promising therapeutic strategy against hypoxic tumours.
| S-EPMC10070431 | biostudies-literature
Project description:The essential stress-responsive chaperone Hsp90 impacts development and adaptation from microbes to humans. Yet despite evidence of its role in evolution, pathogenesis, and oncogenic transformation, the molecular mechanisms by which Hsp90 alters the consequences of mutations remain vigorously debated. Here we exploit the power of nucleotide-resolution genetic mapping in Saccharomyces cerevisiae to uncover more than 1,000 natural variant-to-phenotype associations governed by this molecular chaperone. Strikingly, Hsp90 more frequently modified the phenotypic effects of cis-regulatory variation than variants that altered protein sequence. Moreover, these interactions made the largest contribution to Hsp90-dependent heredity. Nearly all interacting variants—both regulatory and protein-coding—fell within clients of Hsp90 or targets of its direct binding partners. Hsp90 activity affected mutations in evolutionarily young genes, segmental deletions, and heterozygotes, highlighting its influence on variation central to evolutionary novelty. Reconciling the diverse epistatic effects of this chaperone, synthetic transcriptional regulation and reconstructions of natural alleles by genome editing revealed a central role for Hsp90 in regulating the fundamental relationship between activity and phenotype. Our findings establish that non-coding variation is a core driver of Hsp90’s influence on heredity, offering a mechanistic explanation for the chaperone’s strong effects on evolution and development across species.
2023-10-30 | GSE242925 | GEO
Project description:SUMMARY Mps1 protein kinase is required for accurate chromosome segregation during the mitotic checkpoint. The molecular chaperone Heat Shock Protein 90 (Hsp90) has been linked to Mps1 activity, however the molecular mechanismsunderlying this regulatory process remain elusive. We report that Mps1 directly phosphorylates a conserved threonine residue (T101 in yeast Hsp90 and T115 in human Hsp90) in the N domain of Hsp90. This phosphorylation regulates chaperone function by reducingHsp90 ATPase activity andfosteringits association with kinase client proteins including Mps1. Phosphorylation of T101is also essential for the mitotic checkpoint because it confers Mps1 stability and activity.Additionally,Mps1 phosphorylation of Hsp90 sensitizes cells to Hsp90 inhibitors and elevated Mps1 levels confer tumor selectivity on Hsp90 drugs.Finally,we identified Cdc14 as the phosphatasethat dephosphorylatesT101 and disruptsthe Mps1-Hsp90 interaction. This leads to degradation of Mps1,thusproviding a mechanism for its inactivation and mitotic exit.
2016-01-27 | PXD001969 | Pride
Project description:Heat shock protein-90 chaperone machinery is involved in the stability and activity of its client proteins. The chaperone function of Hsp90 is regulated by co-chaperones and post-translational modifications. Although structural evidence exists for Hsp90 interaction with clients, our understanding of the impact of Hsp90 chaperone function towards client activity in cells remains elusive. Here, we dissected the impact of newly identified co-chaperones in higher eukaryotes, FNIP1/2 (FNIPs) and Tsc1, towards Hsp90 client activity. Our data show that Tsc1 and FNIP2 form mutually exclusive complexes with FNIP1 and that unlike Tsc1, FNIP1/2 interact with the catalytic residue of Hsp90. Functionally, these co-chaperone complexes increase the affinity of the steroid hormone receptors glucocorticoid receptor and estrogen receptor to their ligands in vivo. Here, we provide a model for the responsiveness of the steroid hormone receptor activation upon ligand binding as a consequence of their association with specific Hsp90:co-chaperone subpopulations.
2023-05-30 | PXD030486 | Pride
Project description:The ability of Heat Shock Protein 90 (Hsp90) to hydrolyze ATP is essential for its chaperone function. The co-chaperone Aha1 stimulates Hsp90 ATPase activity tailoring the chaperone function to specific “client” proteins. The intracellular signaling mechanisms directly regulating Aha1 association with Hsp90 remain unknown. Here we show that c-Abl kinase phosphorylates Y223 in human Aha1 (hAha1) promoting its interaction with Hsp90. This also increases Hsp90 ATPase activity,enhancesHsp90 interaction with kinase clients,and compromises the chaperoning of non-kinase clients such as glucocorticoid receptor and CFTR. Suggesting a new regulatory paradigm, we find that Y223 phosphorylation leads to ubiquitination and degradation of hAha1 in the proteasome. Finally pharmacologic inhibition of c-Abl prevents hAha1 interaction with Hsp90 thereby, hypersensitizing cancer cells to Hsp90 inhibitors bothin vitro and ex vivo.
2015-08-06 | PXD001737 | Pride
Project description:Cdc37 is a core cochaperone of the Hsp90 machinery. It is involved in an early stage of the chaperone cycle to activate nascent forms of protein kinases as well as to stabilize mature forms of a subset of protein kinases. Overall, the chaperone cycle is quite complex and involves several steps. Progression, through these steps is regulated by the incorporation of several other cochaperones, ATP hydrolysis and posttranslational modifications on both Cdc37 and Hsp90. We show that phosphorylation of Cdc37 at Y298 by Yes kinase results in partial unfolding of its C-terminal domain, without affecting its ability to form binary or ternary complexes with kinases and Hsp90. Unfolding, unmasks a phosphopeptide sequence that exhibits high affinity for SH2 domains of non-receptor tyrosine kinases (nRTKs), resulting in their recruitment in the chaperone complex. In turn, the high local concentration of nRTKs potentiates Hsp90 phosphorylation at Y197, which results in dissociation of this early kinase-recruitment complex
2018-01-22 | PXD008375 | Pride