Super-resolution microscopy reveals majorly mono- and dimeric presenilin1/γ-secretase at the cell surface

eLife

Marcelle Koenig¹  Maximilian H Ulbrich¹  Karin Poersch¹  Ragna Sannerud¹  Sebastian Munck²  Wendy Vermeire³  Hideaki Mizuno⁴  Laura Paparelli⁵  Abril Angélica Escamilla-Ayala⁶  Caroline Berlage⁶  Magali Mondin⁶  Lucia Chavez-Gutierrez⁶  Wim Annaert⁷ 

[1] Department of Neurosciences, KU Leuven, Leuven, Belgium;VIB Bio Imaging Core, Leuven, Belgium;Bordeaux Imaging Center, UMS 3420, CNRS-University of Bordeaux, US4 INSERM, Bordeaux, France;Einstein Center for Neurosciences, NeuroCure Cluster of Excellence, Charité-Universitätsmedizin Berlin, Berlin, Germany;Faculty of Biology, University of Freiburg, Freiburg, Germany;Laboratory for Membrane Trafficking, VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium;PicoQuant GmbH, Berlin, Germany;

关键词: Alzheimer's disease;    gamma-secretase;    presenilin1;    super-resolution microscopy;    single-particle tracking;   

DOI  :  10.7554/eLife.56679

来源: DOAJ

【 摘 要 】

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.

【 授权许可】

Unknown