Amyloid beta A4 precursor protein-binding family A member 1, also known as Mint1 or X11alpha, is a neuronal adaptor protein that binds to the intracellular domain of the amyloid precursor protein (APP) []. It belongs to the X11/Mint family of adaptor proteins []. It has been shown to modulate processing of APP and accumulation of Abeta (hallmark pathologies of Alzheimer's disease), making it a potential therapeutic target for Alzheimer's disease []. It may also affect Alzheimer's disease pathogenesis through its interaction with transcription factor FSBP (fibrinogen silencer binding protein), forming a complex that represses glycogen synthase kinase-3beta (GSK3beta) transcription. GSK3beta is a candidate kinase for the phosphorylation of tau in Alzheimer's disease [].X11alpha participates in a brain-specific heterotrimeric complex containing two other PDZ domain proteins, Lin-2/CASK and mLin-7, involved in synaptic vesicle exocytosis and synaptic junctions []. Additional proteins can bind, forming a neuronal multiprotein complex predicted to be involved in receptor localisation []. The X11/Mint family members are multidomain proteins typically composed of a conserved PTB domain and two C-terminal PDZ domains. They are adaptor proteins that possess several functions, such as trafficking and transport, synaptic function and regulation of ion channel []. Two of the family members, X11alpha and X11beta, are expressed primarily in neurones [].
There are three mammalian LIN7 homologues, LIN7A/B/C []. LIN7 contains single L27 and PDZ domains. Protein lin-7 plays a role in establishing and maintaining the asymmetric distribution of channels and receptors at the plasma membrane of polarized cells []. The three components LIN7A, B and C form a complex with CASK and APBA1 which is thought to have roles in neurone synapses [].
