Evidence For and Against a Pathogenic Role of Reduced γ-Secretase Activity in Familial Alzheimer's Disease

Tanya Jayne, Morgan Newman, Giuseppe Verdile, Greg Sutherland, Gerald Münch, Ian Musgrave, Seyyed Hani Moussavi Nik, Michael Lardelli, M. Paul Murphy
2016 Journal of Alzheimer's Disease  
The majority of mutations causing familial Alzheimer's disease (fAD) have been found in the gene PRESENILIN1 (PSEN1) with additional mutations in the related gene PRESENILIN2 (PSEN2). The best characterized function of PRESE-NILIN (PSEN) proteins is in ␥-secretase enzyme activity. One substrate of ␥-secretase is encoded by the gene AMYLOID BETA A4 PRECURSOR PROTEIN (A␤PP/APP) that is a fAD mutation locus. A␤PP is the source of the amyloid-␤ (A␤) peptide enriched in the brains of people with fAD
more » ... or the more common, late onset, sporadic form of AD, sAD. These observations have resulted in a focus on ␥-secretase activity and A␤ as we attempt to understand the molecular basis of AD pathology. In this paper we briefly review some of the history of research on ␥-secretase in AD. We then discuss the main ideas regarding the role of ␥-secretase and the PSEN genes in this disease. We examine the significance of the "fAD mutation reading frame preservation rule" that applies to PSEN1 and PSEN2 (and A␤PP) and look at alternative roles for A␤PP and A␤ in fAD. We present a case for an alternative interpretation of published data on the role of ␥-secretase activity and fAD-associated mutations in AD pathology. Evidence supports a "PSEN holoprotein multimer hypothesis" where PSEN
doi:10.3233/jad-151186 pmid:27060961 fatcat:esckn5ow75hcxdxrlwezsxvtcy