Membrane to cytosol redistribution of αII‐spectrin drives extracellular vesicle biogenesis in malignant breast cells. Issue 13 (19th May 2021)

• Record Type: Journal Article
• Authors: Taylor, Jack; Patio, Kevin; De Rubis, Gabriele; Morris, Micheal B.; Evenhuis, Christian; Johnson, Michael; Bebawy, Mary
• Other Names: Greening David guestEditor.; Simpson Richard guestEditor.
• Is Part Of: Proteomics. Volume 21:Issue 13/14(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-05-19
• Subjects: calcium -- cancer -- cytoskeleton -- extracellular vesicles -- spectrin; Proteins -- Separation -- Periodicals; Bioinformatics -- Periodicals; Proteomics -- Periodicals; Genomes -- Periodicals; Molecular genetics -- Periodicals; 572.605
• DOI: 10.1002/pmic.202000091
• Languages: English
• ISSNs: 1615-9853

Abstract

Abstract: Spectrin is a ubiquitous cytoskeletal protein that provides structural stability and supports membrane integrity. In erythrocytes, spectrin proteolysis leads to the biogenesis of plasma membrane extracellular vesicles (EVs). However, its role in non‐erythroid or cancer‐derived plasma membrane EVs biogenesis is unknown. This study aims to examine the role of αII‐spectrin in malignant and non‐malignant plasma membrane vesiculation. We developed a custom, automated cell segmentation plugin for the image processor, Fiji, that provides an unbiased assessment of high resolution confocal microscopy images of the subcellular distribution of αII‐spectrin. We show that, in low vesiculating non‐malignant MBE‐F breast cells, prominent cortical spectrin localises to the cell periphery at rest. In comparison, cortical spectrin is diminished in high vesiculating malignant MCF‐7 breast cells at rest. A cortical distribution of spectrin correlates with increased biomechanical stiffness as measured by Atomic Force Microscopy. Furthermore, cortical spectrin can be induced in malignant MCF‐7 cells by treatment with known vesiculation modulators including the calcium chelator, BAPTA‐AM or the calpain inhibitor II (ALLM). These results demonstrate that the subcellular localisation of spectrin is distinctly different in malignant and non‐malignant cells at rest and shows that the redistribution of cortical αII‐spectrin to the cytoplasm supports plasma membrane‐derived EV biogenesis in malignant cells.