Abstract
Endoplasmic reticulum-plasma membrane (ER-PM) junctions mediate crucial activities ranging from Ca2+signaling to lipid metabolism. Spatial organization of ER-PM junctions may modulate the extent and location of these cellular activities. However, the morphology and distribution of ER-PM junctions are not well characterized. Using photoactivated localization microscopy, we reveal that the contact area of single ER-PM junctions is mainly oblong with the dimensions of ∼120 nm × ∼80 nm in HeLa cells. Using total internal reflection fluorescence microscopy and structure illumination microscopy, we show that cortical actin contributes to spatial distribution and stability of ER-PM junctions. Further functional assays suggest that intact F-Actin architecture is required for phosphatidylinositol 4,5-bisphosphate homeostasis mediated by Nir2 at ER-PM junctions. Together, our study provides quantitative information on spatial organization of ER-PM junctions that is in part regulated by F-Actin. We envision that functions of ER-PM junctions can be differentially regulated through dynamic actin remodeling during cellular processes.
Original language | English (US) |
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Pages (from-to) | 3171-3180 |
Number of pages | 10 |
Journal | Molecular biology of the cell |
Volume | 28 |
Issue number | 23 |
DOIs | |
State | Published - Nov 7 2017 |
ASJC Scopus subject areas
- Molecular Biology
- Cell Biology