Background

Synaptic vesicle membrane docking and fusion is mediated by soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNARE) complex which is located on the vesicle membrane (v-SNAREs) and the target membrane (t-SNAREs). Other than VAMP2 and STX1A, SNAP25 is another key component of SNARE core complex, and is known to be involved in regulating neurotransmitter release. Its palmitoylation domain is located in the middle of the molecule that contains four cysteine residues and mutation of the cysteines abolishes palmitoylation and its membrane binding activity. As an important presynaptic plasma membrane protein, SNAP25 has been linked to memory and learning by its effect on long term potentiation in the hippocampus, thus playing a critical role in the synaptic function of specific neuronal systems. It has been reported that SNAP25 levels were were significantly decreased in brain tissue homogenates of patients with later stages of Alzheimer's disease compared with the controls, while the levels of SNAP25 were significantly increased in cerebrospinal fluid (CSF) of the group with an Alzheimer's disease biomarker profile than in the group with a control biomarker profile.