Individual and combined presenilin 1 and 2 knockouts reveal that both have highly overlapping functions in HEK293T cells.

TitleIndividual and combined presenilin 1 and 2 knockouts reveal that both have highly overlapping functions in HEK293T cells.
Publication TypeJournal Article
Year of Publication2019
AuthorsLessard, CB, Rodriguez, E, Ladd, TB, Minter, LM, Osborne, BA, Miele, L, Golde, TE, Ran, Y
JournalJ Biol Chem
Date Published2019 07 19
KeywordsAlzheimer Disease, Amyloid Precursor Protein Secretases, Animals, CRISPR-Cas Systems, Gene Knockdown Techniques, HEK293 Cells, Humans, Hydrolysis, Mice, Presenilin-1, Presenilin-2, Substrate Specificity

Presenilins 1 and 2 (PS1 and 2) are the catalytic subunits of γ-secretase, a multiprotein protease that cleaves amyloid protein precursor and other type I transmembrane proteins. Previous studies with mouse models or cells have indicated differences in PS1 and PS2 functions. We have recently reported that clinical γ-secretase inhibitors (GSIs), initially developed to manage Alzheimer's disease and now being considered for other therapeutic interventions, are both pharmacologically and functionally distinct. Here, using CRISPR/Cas9-based gene editing, we established human HEK 293T cell lines in which endogenous PS1, PS2, or both have been knocked out. Using these knockout lines to examine differences in PS1- and PS2-mediated cleavage events, we confirmed that PS2 generates more intracellular β-amyloid than does PS1. Moreover, we observed subtle differences in PS1- and PS2-mediated cleavages of select substrates. In exploring the question of whether differences in activity among clinical GSIs could be attributed to differential inhibition of PS1 or PS2, we noted that select GSIs inhibit PS1 and PS2 activities on specific substrates with slightly different potencies. We also found that endoproteolysis of select PS1 FAD-linked variants in human cells is more efficient than what has been previously reported for mouse cell lines. Overall, these results obtained with HEK293T cells suggest that selective PS1 or PS2 inhibition by a given GSI does not explain the previously observed differences in functional and pharmacological properties among various GSIs.

Alternate JournalJ Biol Chem
PubMed ID31167792
PubMed Central IDPMC6643044
Grant ListP01 CA166009 / CA / NCI NIH HHS / United States
U54 GM104940 / GM / NIGMS NIH HHS / United States