Abstract: The present invention provides a method of decreasing the level of ubiquitylated protein in a subject, the method comprising administering a heterocyclic compound disclosed herein or a pharmaceutically acceptable salt, hydrate or prodrug thereof to a subject in need thereof.

Abstract: The present invention provides a method of decreasing the level of pro-ADAM10 and/or BACE protein in a subject, the method comprising administering a heterocyclic compound or a pharmaceutically acceptable salt, hydrate or prodrug thereof to a subject in need thereof.

Abstract: The present invention provides a method of inducing cleavage of amyloid precursor protein to produce an approximately 17 kilodalton carboxy-terminal fragment of amyloid precursor protein in a subject, the method comprising administering a heterocyclic compound or a pharmaceutically acceptable salt, hydrate or prodrug thereof to a subject in need thereof, wherein the approximately 17 kilodalton fragment includes the carboxyterminal amino acid sequence of amyloid precursor protein and amyloid-beta amino acid sequence. Also provided is a screening method for identifying compounds induce cleavage of amyloid precursor protein to produce the approximately 17 kilodalton carboxy-terminal fragment of amyloid precursor protein.