Two Faced Members of the Family: The Synucleins pp. 225-238
Authors: (Andrei Surguchov, VA Medical Center Kansas City, Kansas City, Missouri, USA and others)
Abstract: ,- - and -Synucleins are highly homologous small proteins implicated in neurodegenerative diseases and some forms of cancer. These proteins attracted attention of many investigators, because of their role in human pathology. Certain soluble -synuclein oligomers share a common structure with oligomers of other amyloidogenic proteins and peptides, for example, beta-amyloid (Aβ) and prion protein, implying a common mechanism of pathogenesis for several illnesses. -Synuclein also can form toxic protein inclusions, although the mechanism of its pathological action is not investigated in such details as for -synuclein. -Synuclein prevents aggregation of -synuclein and possesses neuroprotective effect. Here we give a brief overview of the structural features of synucleins which may explain why two members of the family (- and -synucleins) can be easily converted into oligomeric toxic species, whereas -synuclein has cytoprotective properties. Among important factors which cause transition of synucleins into pathological molecules are mutations, increased gene dosage (for -synuclein), post-translational modifications (PTM) and binding to other proteins (for -synuclein). Oxidative conditions cause the formation of prefibrillar annular -synuclein oligomers which can induce aggregation of -synuclein thus manifesting the property of antichaperone. Substances specifically preventing deleterious protein-protein interactions can be tested as potential drugs for the treatment of neurodegenerative diseases.