1. Super-resolution microscopy reveals majorly mono- and dimeric presenilin1/γ-secretase at the cell surface.
- Author
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Escamilla-Ayala AA, Sannerud R, Mondin M, Poersch K, Vermeire W, Paparelli L, Berlage C, Koenig M, Chavez-Gutierrez L, Ulbrich MH, Munck S, Mizuno H, and Annaert W
- Subjects
- Amyloid Precursor Protein Secretases metabolism, Animals, Cell Line, Cell Membrane metabolism, Fibroblasts, Humans, Membrane Proteins genetics, Membrane Proteins metabolism, Mice, Microscopy, Presenilin-1 metabolism, Amyloid Precursor Protein Secretases genetics, Presenilin-1 genetics
- Abstract
γ-Secretase is a multi-subunit enzyme whose aberrant activity is associated with Alzheimer's disease and cancer. While its structure is atomically resolved, γ-secretase localization in the membrane in situ relies mostly on biochemical data. Here, we combined fluorescent tagging of γ-secretase subunits with super-resolution microscopy in fibroblasts. Structured illumination microscopy revealed single γ-secretase complexes with a monodisperse distribution and in a 1:1 stoichiometry of PSEN1 and nicastrin subunits. In living cells, sptPALM revealed PSEN1/γ-secretase mainly with directed motility and frequenting 'hotspots' or high track-density areas that are sensitive to γ-secretase inhibitors. We visualized γ-secretase association with substrates like amyloid precursor protein and N-cadherin, but not with its sheddases ADAM10 or BACE1 at the cell surface, arguing against pre-formed megadalton complexes. Nonetheless, in living cells PSEN1/γ-secretase transiently visits ADAM10 hotspots. Our results highlight the power of super-resolution microscopy for the study of γ-secretase distribution and dynamics in the membrane., Competing Interests: AE, RS, MM, KP, WV, LP, LC, MU, SM, HM, WA No competing interests declared, CB Associated to PicoQuant, MK Works for PicoQuant, (© 2020, Escamilla-Ayala et al.)
- Published
- 2020
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