An in vivo assay for the identification of target proteases which cleave membrane-associated substrates

Proteases not only play a fundamental role in numerous physiological processes, but are also involved in several human diseases including Alzheimer's disease (AD), A key protease implicated in AD is the so far unidentified gamma-secretase, which cleaves the membrane-bound beta-amyloid precursor protein (beta APP) at the C-terminus of its amyloid domain within the membrane to release the neurotoxic amyloid beta-peptide, In order to allow the isolation of proteases, which specifically cleave membrane-bound substrates within or in the vicinity of a transmembrane domain, we developed a reporter gene assay in Saccharomyces cerevisiae. This assay may allow the identification of genes encoding target proteases that specifically cleave membrane bound substrates by transforming expression libraries. (C) 1999 Federation of European Biochemical Societies.