Investigating the in vivo Interactomes of BACE1 and APP

Type of Award: Catalyst
Award Number:
Award Period: December 2008 - November 2010
Amount Awarded: $ 200,000.00
PI(s): Sangram Sisodia, PhD, UChicago; Robert Vassar, PhD, NU;

Abstract: Alzheimer's disease is an incurable neurodegenerative disease characterized by the accumulation of amyloid plaques - deposits of protein in the brain whose main constituent is the Abeta peptide, which is itself derived from the metabolism of a larger protein called APP. Reducing the Abeta load in the brain is a major goal of Alzheimer's research, and to accomplish this, many strategies aim to inhibit the metabolism of APP. Cleavage of APP by the enzyme BACE1 is required to generate Abeta. Thus, understanding which proteins APP and BACE1 interact with is important because 1) this aids in the design of small molecule drugs, and 2) if APP metabolism or BACE1 activity are to be inhibited, an understanding of their natural function is critical. Although many studies have investigated the metabolism of APP in cultured cells, confirmation of these results in animal studies has not yet been achieved. Moreover, very little is known about BACE1 interacting proteins, and these proteins likely contribute to delivering BACE1 and APP into the same cellular compartment for cleavage of APP into Abeta. Thus, we aim to generate a transgenic mouse that expresses APP and BACE1 containing a peptide tag. By using these tagged proteins as "bait" in the living animal, we can subsequently purify them and those proteins with which they are bound. Analyzing the purified material and comparing it to a protein database will confirm binding partners identified by cell culture studies and identify new binding partners with new specific therapeutic targets.