Phylogenetic Analysis of Branchiostoma floridae APP-LP

Abstract

Alzheimer’s Disease (AD) is the most common type of dementia– affecting more than five million people in the United States. One of the histopathological hallmarks of AD is the presence of amyloid plaques in the brain. These plaques consist of Aβ peptide fibrils. Aβ is a small peptide derived from the proteolysis of a larger protein, APP, amyloid precursor protein (Figure 1). APP is a type I integral membrane protein that acts as a receptor for Kinesin-1 transport proteins. Phylogenetic analysis of genes implicated in pathological pathways can aid in the understanding of the disease origin. Amphioxus (Branchiostoma floridae) is a useful model system for the study of chordate evolution because it occupies a unique phylogenetic position as the closest, extant relative to vertebrates. Study Objective: The aim of this study was to clone an amphioxus APP cDNA, which then was phylogenetically analyzed to give insight into APP and Aβ origins.