APBA1 (amyloid beta precursor protein binding family A member 1) is a neuronal adaptor protein that plays critical roles in synaptic function and APP metabolism. The protein functions in synaptic vesicle exocytosis by binding to Munc18-1, and participates in the LIN-10-LIN-2-LIN-7 complex for NMDA receptor trafficking along microtubules 1. APBA1 directly interacts with amyloid precursor protein (APP) and overexpression reduces amyloid-β (Aβ) generation, ameliorating memory deficits in Alzheimer's disease models 1. Transcription of APBA1 is regulated by the Sp3 transcription factor, with Sp3 inhibition reducing endogenous X11α expression and promoting Aβ generation 1. Beyond Alzheimer's disease, emerging evidence indicates APBA1 mutations contribute to adult-onset obesity through disrupted synaptic communication in feeding circuits 234. Rare loss-of-function variants in APBA1 confer substantial obesity risk and show significant ancestral heterogeneity 4. APBA1 expression is altered in type 2 diabetes, with significant downregulation observed across diabetes populations 5. The protein is also involved in cognitive functioning and is regulated by HIV-Tat in the context of neuroAIDS pathogenesis 67. These findings position APBA1 as a multifunctional synaptic protein bridging neurodegeneration, metabolic dysfunction, and cognitive impairment.