synucleinopathies
Pathology
Parkinson disease
Pathogenesis
alpha-synuclein mutations and early-onset Parkinson disease
Alpha-synuclein is a highly conserved protein of 140 amino acids, that is expressed predominantly in neurons and is particularly abundant in presynaptic terminals. Alpha-synuclein might have a role in synaptic plasticity and might modulate DOPAMINERGIC neuro-transmission.
Two amino-acid substitutions in alpha-synuclein, A53T and A30P, are associated with autosomal-dominant, early-onset Parkinson disease. The mutant alpha-synuclein protein accumulates as intracytoplasmic inclusions in neurons to form the Lewy bodies that are characteristic of this condition.
Structural studies have shown that the A30P mutant favours the formation of oligomers rather than fibrils, and that these small intermediates could be the toxic species that cause cell death and the associated neurodegenerative disease.
References
Maries E, Dass B, Collier TJ, Kordower JH, Steece-Collier K. The role of alpha-synuclein in Parkinson?s disease: insights from animal models. Nat Rev Neurosci. 2003 Sep;4(9):727-38. PMID: 12951565
Lotharius J, Brundin P. Impaired dopamine storage resulting from alpha-synuclein mutations may contribute to the pathogenesis of Parkinson?s disease. Hum Mol Genet. 2002 Oct 1;11(20):2395-407. PMID: 12351575
Lomas DA, Carrell RW. Serpinopathies and the conformational dementias. Nat Rev Genet. 2002 Oct ;3(10):759-68. PMID : 12360234