Format

Send to

Choose Destination
Neurobiol Dis. 2019 Apr;124:248-262. doi: 10.1016/j.nbd.2018.11.015. Epub 2018 Nov 22.

Pα-syn* mitotoxicity is linked to MAPK activation and involves tau phosphorylation and aggregation at the mitochondria.

Author information

1
Department of Immunology and Microbiology, The Scripps Research Institute, Scripps Florida, Jupiter, FL 33458, United States; Department of Neuroscience, The Scripps Research Institute, Scripps Florida, Jupiter, FL 33458, United States.
2
Palm Beach Gardens, FL 33418, United States.
3
Center for Neurodegeneration and Experimental Therapeutics, University of Alabama at Birmingham, Birmingham, AL 35294, United States.
4
Department of Immunology and Microbiology, The Scripps Research Institute, Scripps Florida, Jupiter, FL 33458, United States; Department of Neuroscience, The Scripps Research Institute, Scripps Florida, Jupiter, FL 33458, United States. Electronic address: lasmezas@scripps.edu.

Abstract

We recently identified a truncated and phosphorylated form of α-synuclein, pα-syn*, as a key neurotoxic α-synuclein species found in cultured neurons, as well as in mouse and Parkinson's disease patients' brains. Small pα-syn* aggregates localize to mitochondria and induce mitochondrial damage and fragmentation. Herein, we investigated the molecular basis of pα-syn*-induced toxicity. By immunofluorescence, we found phosphorylated MKK4, JNK, ERK5 and p38 MAPKs in pα-syn* inclusions. pJNK colocalized with pα-syn* at mitochondria and mitochondria-associated ER membranes where it was associated with BiP and pACC1, markers for the ER and energy deprivation, respectively. We also found that pα-syn* aggregates are tightly associated with small ptau aggregates of similar size. Pα-syn*/ptau inclusions localized to areas of mitochondrial damage and to mitophagic vesicles, showing their role in mitochondrial toxicity, mitophagy induction and their removal along with damaged mitochondrial fragments. Several MAPKs may act cooperatively to phosphorylate tau, notably JNK, p38 and GSK3β, a non-MAPK that was also found phosphorylated in the vicinity of pα-syn*/ptau aggregates. These results add insight into the mechanisms by which pα-syn* exerts its toxic effects that include the phosphorylation of several kinases of the MAPK pathway, as well as the formation of ptau at the mitochondrial membrane, likely contributing to mitotoxicity. Thus pα-syn* appears to be the trigger of a series of kinase mediated pathogenic events and a link between α-syn pathology and tau, another protein known to aggregate in Parkinson's disease and other synucleinopathies.

KEYWORDS:

Alpha-synuclein; Kinases; Mitochondria; Mitophagy; Neurotoxicity; Parkinson's disease; Primary neurons; Tau

PMID:
30472299
DOI:
10.1016/j.nbd.2018.11.015

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center