Dataset Information

Role of chaperone mediated autophagy (CMA) in the degradation of misfolded N-CoR protein in non-small cell lung cancer (NSCLC) cells.

ABSTRACT: Nuclear receptor co-repressor (N-CoR) plays important role in transcriptional control mediated by several tumor suppressor proteins. Recently, we reported a role of misfolded-conformation dependent loss (MCDL) of N-CoR in the activation of oncogenic survival pathway in acute promyelocytic leukemia (APL). Since N-CoR plays important role in cellular homeostasis in various tissues, therefore, we hypothesized that an APL like MCDL of N-CoR might also be involved in other malignancy. Indeed, our initial screening of N-CoR status in various leukemia and solid tumor cells revealed an APL like MCDL of N-CoR in primary and secondary tumor cells derived from non-small cell lung cancer (NSCLC). The NSCLC cell specific N-CoR loss could be blocked by Kaletra, a clinical grade protease inhibitor and by genistein, an inhibitor of N-CoR misfolding previously characterized by us. The misfolded N-CoR presented in NSCLC cells was linked to the amplification of ER stress and was subjected to degradation by NSCLC cell specific aberrant protease activity. In NSCLC cells, misfolded N-CoR was found to be associated with Hsc70, a molecular chaperone involved in chaperone mediated autophagy (CMA). Genetic and chemical inhibition of Lamp2A, a rate limiting factor of CMA, significantly blocked the loss of N-CoR in NSCLC cells, suggesting a crucial role of CMA in N-CoR degradation. These findings identify an important role of CMA-induced degradation of misfolded N-CoR in the neutralization of ER stress and suggest a possible role of misfolded N-CoR protein in the activation of oncogenic survival pathway in NSCLC cells.

SUBMITTER: Ali AB

PROVIDER: S-EPMC3179509 | biostudies-literature | 2011

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Role of chaperone mediated autophagy (CMA) in the degradation of misfolded N-CoR protein in non-small cell lung cancer (NSCLC) cells.

Ali Azhar Bin AB Nin Dawn Sijin DS Tam John J Khan Matiullah M

PloS one 20110923 9

Nuclear receptor co-repressor (N-CoR) plays important role in transcriptional control mediated by several tumor suppressor proteins. Recently, we reported a role of misfolded-conformation dependent loss (MCDL) of N-CoR in the activation of oncogenic survival pathway in acute promyelocytic leukemia (APL). Since N-CoR plays important role in cellular homeostasis in various tissues, therefore, we hypothesized that an APL like MCDL of N-CoR might also be involved in other malignancy. Indeed, our ini ...[more]

PMID: 21966475

Similar Datasets

Project description:Parkinson disease (PD) is an age-related neurodegenerative disorder associated with misfolded SNCA/α-synuclein accumulation in brain. Impaired catabolism of SNCA potentiates formation of its toxic oligomers. LRRK2 (leucine-rich repeat kinase-2) mutations predispose to familial and sporadic PD. Mutant LRRK2 perturbs chaperone-mediated-autophagy (CMA) to degrade SNCA. We showed greater age-dependent accumulation of oligomeric SNCA in striatum and cortex of aged LRRK2R1441G knockin (KI) mice, compared to age-matched wildtype (WT) by 53% and 31%, respectively. Lysosomal clustering and accumulation of CMA-specific LAMP2A and HSPA8/HSC70 proteins were observed in aged mutant striatum along with increased GAPDH (CMA substrate) by immunohistochemistry of dorsal striatum and flow cytometry of ventral midbrain cells. Using our new reporter protein clearance assay, mutant mouse embryonic fibroblasts (MEFs) expressing either SNCA or CMA recognition 'KFERQ'-like motif conjugated with photoactivated-PAmCherry showed slower cellular clearance compared to WT by 28% and 34%, respectively. However, such difference was not observed after the 'KFERQ'-motif was mutated. LRRK2 mutant MEFs exhibited lower lysosomal degradation than WT indicating lysosomal dysfunction. LAMP2A-knockdown reduced total lysosomal activity and clearance of 'KFERQ'-substrate in WT but not in mutant MEFs, indicating impaired CMA in the latter. A CMA-specific activator, AR7, induced neuronal LAMP2A transcription and lysosomal activity in MEFs. AR7 also attenuated the progressive accumulation of both intracellular and extracellular SNCA oligomers in prolonged cultures of mutant cortical neurons (DIV21), indicating that oligomer accumulation can be suppressed by CMA activation. Activation of autophagic pathways to reduce aged-related accumulation of pathogenic SNCA oligomers is a viable disease-modifying therapeutic strategy for PD.Abbreviations: 3-MA: 3-methyladenine; AR7: 7-chloro-3-(4-methylphenyl)-2H-1,4-benzoxazine; CMA: chaperone-mediated autophagy; CQ: chloroquine; CSF: cerebrospinal fluid; DDM: n-dodecyl β-D-maltoside; DIV: days in vitro; ELISA: enzyme-linked immunosorbent assay; FACS: fluorescence-activated cell sorting; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; GWAS: genome-wide association studies; HSPA8/HSC70: heat shock protein 8; KFERQ: CMA recognition pentapeptide; KI: knockin; LAMP1: lysosomal-associated membrane protein 1; LAMP2A: lysosomal-associated membrane protein 2A; LDH: lactate dehydrogenase; LRRK2: leucine-rich repeat kinase 2; MEF: mouse embryonic fibroblast; NDUFS4: NADH:ubiquinone oxidoreductase core subunit S4; NE: novel epitope; PD: Parkinson disease; RARA/RARα: retinoic acid receptor, alpha; SNCA: synuclein, alpha; TUBB3/TUJ1: tubulin, beta 3 class III; WT: wild-type.

Dataset Information

Role of chaperone mediated autophagy (CMA) in the degradation of misfolded N-CoR protein in non-small cell lung cancer (NSCLC) cells.

Publications

Role of chaperone mediated autophagy (CMA) in the degradation of misfolded N-CoR protein in non-small cell lung cancer (NSCLC) cells.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets