Abstract

Deposition of extracellular plaques, primarily consisting of amyloid beta peptide , in the brain is the confirmatory diagnostic of Alzheimer's disease ; however, the physiological and pathological role of Abeta is not fully understood. Herein, we demonstrate novel Abeta activity as a putative transcription factor upon AD-associated genes. We used oligomers from 5'-flanking regions of the apolipoprotein E , Abeta-precursor protein and beta-amyloid site cleaving enzyme-1 genes for electrophoretic mobility shift assay with different fragments of the Abeta peptide. Our results suggest that Abeta bound to an Abeta-interacting domain with a consensus of "KGGRKTGGGG". This peptide-DNA interaction was sequence specific, and mutation of the first "G" of the decamer's terminal "GGGG" eliminated peptide-DNA interaction. Furthermore, the cytotoxic Abeta25-35 fragment had greatest DNA affinity. Such specificity of binding suggests that the AbetaID is worth of further investigation as a site wherein the Abeta peptide may act as a transcription factor