Synucleins are small cytosolic proteins of uncertain function, normally expressed at high levels in the vertebrate nervous system. Increased expression of synuclein proteins, especially γ-synuclein, is associated with progression of a variety of tumors.
The precise function of the synuclein proteins is not well understood. All family members (α-synuclein, SNCA; β-synuclein, SNCB; and γ-synuclein, SNCG) share a conserved domain related to the lipid-binding domains of the exchangeable apolipoproteins, the major lipid transporters in blood. This conserved domain mediates reversible interactions with lipid membranes. α-Synuclein regulates the uptake and incorporation of fatty acids into phospholipids, and mutations in α-synuclein alter the composition of cellular membranes.
Each of the synuclein isoforms possesses a unique tail domain, which may mediate distinct physiological actions. α-Synuclein and β-synuclein are normally expressed in the central nervous...