Binding of alpha-synuclein to brain vesicles is abolished by familial Parkinson's disease mutation.

The presynaptic protein alpha-synuclein has been implicated in the pathogenesis of Parkinson's disease. First, two missense mutations A30P and A53T cause inheritable early onset Parkinson's disease in some families. Secondly, alpha-synuclein is present in Lewy bodies of affected nerve cells in the predominant sporadic type of Parkinson's disease as well as in dementia with Lewy bodies. We demonstrate in the rat optic system that a portion of alpha-synuclein is carried by the vesicle-moving fast component of axonal transport and that it binds to rat brain vesicles through its amino-terminal repeat region. We find alpha-synuclein with the A30P mutation of familial Parkinson's disease devoid of vesicle-binding activity and propose that mutant alpha-synuclein may accumulate, leading to assembly into Lewy body filaments.