[The role of alpha-synuclein in Parkinson's disease].

α-synuclein, a small protein (140 amino acids) encoded by the SNCA gene is the best known isoform of the synuclein protein family. Though its physiological role is still not fully clarified, there is growing experimental evidence for a causal role of α-synuclein in the so-called conformational-neurodegenerative diseases. Conformational changes in the structure of the native soluble protein form insoluble neurotoxic aggregates and finally contribute to the formation of inclusion Lewy-bodies and Lewy-neurites.

[The role of parkin in Parkinson's disease].

Parkin (Parkinson juvenile disease protein 2) is a ~52 kDa (426 amino acid) enzyme protein, encoded by PARK2 gene and located on the 6q chromosome. It plays an important role in the ubiquitin-proteasome system and acts as a regulator of protein breakdown. Parkin is located in the cytoplasma until a sustained depolarization occurs as a result of which it is translocated to the mitochondrial surface and induces the degradation of various membrane proteins which are candidates for mitophagia.