Zhuravel, Arina2024-06-072024-06-072024-04-24Zhuravel, A. (2024). Spatiotemporal Organization Of Focal Adhesions In Migrating Cells. Nazarbayev University School of Sciences and Humanitieshttp://nur.nu.edu.kz/handle/123456789/7795Focal adhesions (FAs) are pivotal integrin-based macromolecular assemblies that orchestrate cell migration through traction force transmission by connecting cytoskeleton to extracellular matrix (Legerstee & Houtsmuller, 2021). While substantial progress has been made in understanding of the regulation of cell motility (Merino-Casallo et al., 2022), it remains elusive how considerable FA heterogeneity correlates with regional requirements to substrate adhesions intrinsic to cell migration. To evaluate FA dynamics, we employed live cell time-lapse microscopy with high spatial and temporal resolution, tracking FA size, lifetime, and intensity in cancer A549 cell line stably expressing Vinculin-RFP. We observed numerous small, short-living adhesions at the leading edge, which had formed both at large lamellae aligning with the vector of cell body translocation and smaller lateral lamellae. That contrasted with the presence of only a few large adhesions at the trailing edge. While FA maturation at the leading edge in response to tension generated by myosin II-decorated actin stress fibers has already been described, the origin of large FAs at the trailing edge remains poorly elucidated (Choi et al., 2008). Most FAs present at the trailing edge originated within lateral protrusions and only few of them formed directly there. During retraction of the trailing cell edge, a portion of FAs has already been disassembled before retraction has reached them. However, some FAs at the trailing edge were enlarging, either through merging with neighboring FAs or gradual increase in area and intensity as they slid along with the trailing edge relative to the substrate. As a result, relatively large FAs were forcibly detached and rapidly disassembled only upon retraction edge reached them. In summary, FA formation and maturation exhibited regionally regulated dynamics, and disassembly of FAs at the rear edge before retraction was not a prerequisite to edge retraction.enAttribution-NonCommercial-ShareAlike 3.0 United StatesType of access: Open AccessFocal adhesionsCell migrationCell motilityTime-lapse microscopyMaster's thesis