PXD028656

PXD028656 is an original dataset announced via ProteomeXchange.

Title	Mutant glucocerebrosidase impairs -synuclein degradation by blockade of chaperone-mediated autophagy
Description	The most common genetic risk factors for Parkinson’s disease (PD) are a set of heterozygous mutant (MT) alleles of the GBA1 gene that encodes -glucocerebrosidase (GCase), an enzyme that is normally trafficked from the endoplasmic reticulum and Golgi apparatus to the lysosomal lumen. We examined isolated lysosomes from anterior cingulate cortex, a region of high alpha-synuclein accumulation in GBA-PD, and found that while lysosomal GCase is entirely luminal in healthy controls, half of the lysosomal GBA-PD GCase was present on the lysosomal surface. This lysosomal mislocalization is dependent on a pentapeptide motif in GCase used for targeting of cytosolic proteins to lysosomes for degradation by chaperone-mediated autophagy (CMA), a type of autophagy inhibited by PD-related pathogenic proteins including -synuclein and LRRK2. Single cell transcriptional analysis and comparative proteomics of brains from GBA-PD patients demonstrated reduced CMA activity and overall proteome changes similar to those observed in mouse models with CMA blockage. We found that the delivery of unfolded mutant GCase to lysosomes decreased CMA due to recognition of unfolded mutant GCase to the chaperone hsc70, and the resulting complex binds the CMA receptor LAMP2A at the lysosomal surface. Unfolded mutant GCase is a poor substrate for translocation into the lysosomal lumen, and by interfering with LAMP2A multimerization, blocks the translocation and causes cytosolic accumulation of other CMA substrates including -synuclein and tau. In primary substantia nigra dopamine neurons, MT GCase led to neuronal death, while loss of the GCase CMA motif or deletion of -synuclein rescued the neurons. These results indicate how MT GCase alleles may converge with other PD proteins to block CMA function and produce -synuclein accumulation.
HostingRepository	PRIDE
AnnounceDate	2022-02-03
AnnouncementXML	Submission_2022-02-03_07:36:45.658.xml
DigitalObjectIdentifier
ReviewLevel	Peer-reviewed dataset
DatasetOrigin	Original dataset
RepositorySupport	Unsupported dataset by repository
PrimarySubmitter	Pilar Ximenez-Embun
SpeciesList	scientific name: Homo sapiens (Human); NCBI TaxID: 9606;
ModificationList	iTRAQ8plex-116 reporter+balance reagent acylated residue; iodoacetamide derivatized residue
Instrument	Q Exactive

Revision	Datetime	Status	ChangeLog Entry
0	2021-09-20 07:00:46	ID requested
⏵ 1	2022-02-03 07:36:46	announced

Dataset with its publication pending

submitter keyword: GBA, CMA, brain, iTRAQ

Javier Munoz
contact affiliation	Spanish National Cancer Research Centre (CNIO) Address: Melchor Férnandez Almagro, 3. 28029 Madrid. SPAIN Phone: +34 917 328 000 Ext. 3110
contact email	jmunozpe@cnio.es
lab head
Pilar Ximenez-Embun
contact affiliation	Proteomics Group
contact email	mpximenez@cnio.es
dataset submitter

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PRIDE project URI

• PRIDE
  1. PXD028656
     1. Label: PRIDE project
     2. Name: Mutant glucocerebrosidase impairs -synuclein degradation by blockade of chaperone-mediated autophagy