Dataset Information

Role of Ser129 phosphorylation of ?-synuclein in melanoma cells.

ABSTRACT: ?-Synuclein, a protein central to Parkinson's disease, is frequently expressed in melanoma tissues, but not in non-melanocytic cutaneous carcinoma and normal skin. Thus, ?-synuclein is not only related to Parkinson's disease, but also to melanoma. Recently, epidemiologists reported co-occurrence of melanoma and Parkinson's disease in patients, suggesting that these diseases could share common pathogenetic components and that ?-synuclein might be one of these. In Parkinson's disease, phosphorylation of ?-synuclein at Ser129 plays an important role in the pathobiology. However, its role in melanoma is not known. Here, we show the biological relevance of Ser129 phosphorylation in human melanoma cells. First, we have identified an antibody that reacts with Ser129-unphosphorylated ?-synuclein but not with Ser129-phosphorylated ?-synuclein. Using this and other antibodies to ?-synuclein, we investigated the role of Ser129 phosphorylation in human melanoma SK-MEL28 and SK-MEL5 cells. Our immunofluorescence microscopy showed that the Ser129-phosphorylated form, but not the Ser129-unphosphorylated form, of ?-synuclein localizes to dot-like structures at the cell surface and the extracellular space. Furthermore, immuno-electron microscopy showed that the melanoma cells release microvesicles in which Ser129-phosphorylated ?-synuclein localizes to the vesicular membrane. Taken together, our studies suggest that the phosphorylation of Ser129 leads to the cell surface translocation of ?-synuclein along the microtubule network and its subsequent vesicular release in melanoma cells.

SUBMITTER: Lee BR

PROVIDER: S-EPMC3613186 | biostudies-literature | 2013 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Role of Ser129 phosphorylation of α-synuclein in melanoma cells.

Lee Byung Rho BR Matsuo Yasuhiro Y Cashikar Anil G AG Kamitani Tetsu T

Journal of cell science 20121130 Pt 2

α-Synuclein, a protein central to Parkinson's disease, is frequently expressed in melanoma tissues, but not in non-melanocytic cutaneous carcinoma and normal skin. Thus, α-synuclein is not only related to Parkinson's disease, but also to melanoma. Recently, epidemiologists reported co-occurrence of melanoma and Parkinson's disease in patients, suggesting that these diseases could share common pathogenetic components and that α-synuclein might be one of these. In Parkinson's disease, phosphorylat ...[more]

PMID: 23203798

Similar Datasets

Project description:Parkinson's disease (PD) is characterized neuropathologically by intracellular aggregates of fibrillar α-synuclein, termed Lewy bodies (LBs). Approximately 90% of α-synuclein deposited as LBs is phosphorylated at Ser129 in brains with PD. In contrast, only 4% of total α-synuclein is phosphorylated at Ser129 in brains with normal individuals. It is unclear why extensive phosphorylation occurs in the pathological process of PD. To address this issue, we investigated a mechanism and role of Ser129-phosphorylation in regulating accumulation of α-synuclein. In CHO cells, the levels of Ser129-phosphorylated soluble α-synuclein were maintained constantly to those of total α-synuclein in intracellular and extracellular spaces. In SH-SY5Y cells and rat primary cortical neurons, mitochondrial impairment by rotenone or MPP+ enhanced Ser129-phosphorylation through increased influx of extracellular Ca2+. This elevation was suppressively controlled by targeting Ser129-phosphorylated α-synuclein to the proteasome pathway. Rotenone-induced insoluble α-synuclein was also targeted by Ser129-phosphoryation to the proteasome pathway. Experiments with epoxomicin and chloroquine showed that proteasomal targeting of insoluble Ser129-phosphorylated α-synuclein was enhanced under lysosome inhibition and it reduced accumulation of insoluble total α-synuclein. However, in a rat AAV-mediated α-synuclein overexpression model, there was no difference in the number of total α-synuclein aggregates between A53T mutant and A53T plus S129A double mutant α-synuclein, although Ser129-phosphorylated α-synuclein-positive aggregates were increased in rats expressing A53T α-synuclein. These findings suggest that Ser129-phosphorylation occurs against stress conditions, which increases influx of extracellular Ca2+, and it prevents accumulation of insoluble α-synuclein by evoking proteasomal clearance complementary to lysosomal one. However, Ser129-phosphorylation may provide an ineffective signal for degradation-resistant aggregates, causing extensive phosphorylation in aggregates.

Project description:Parkinson's disease is a neurodegenerative disorder characterized by motor and non-motor disturbances. Various pathogenic pathways drive disease progression including oxidative stress, mitochondrial dysfunction, α-synuclein aggregation and impairment of protein degradation systems. Dysfunction of the ubiquitin-proteasome system in the substantia nigra of Parkinson's disease patients is believed to be one of the causes of protein aggregation and cell death associated with this disorder. Lactacystin, a potent inhibitor of the proteasome, was previously delivered to the nigrostriatal pathway of rodents to model nigrostriatal degeneration. Although lactacystin-treated animals develop parkinsonian motor impairment, it is currently unknown whether they also develop non-motor symptoms characteristic of this disorder. In order to further describe the proteasome inhibition model of Parkinson's disease, we characterized the unilateral lactacystin model, performed by stereotaxic injection of the toxin in the substantia nigra of mice. We studied the degree of neurodegeneration and the behavioral phenotype 1 and 3 weeks after lactacystin lesion both in terms of motor impairment, as well as non-motor symptoms. We report that unilateral administration of 3 μg lactacystin to the substantia nigra of mice leads to partial (~40%) dopaminergic cell loss and concurrent striatal dopamine depletion, accompanied by increased expression of Ser129-phosphorylated α-synuclein. Behavioral characterization of the model revealed parkinsonian motor impairment, as well as signs of non-motor disturbances resembling early stage Parkinson's disease including sensitive and somatosensory deficits, anxiety-like behavior, and perseverative behavior. The consistent finding of good face validity, together with relevant construct validity, warrant a further evaluation of proteasome inhibition models of Parkinson's disease in pre-clinical research and validation of therapeutic targets.

Dataset Information

Role of Ser129 phosphorylation of ?-synuclein in melanoma cells.

Publications

Role of Ser129 phosphorylation of α-synuclein in melanoma cells.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets