A Dock8-dependent mechanosensitive central actin pool maintains T cell shape and protects the nucleus during migration

knockout T cells. The appearance of the central actin pool is mechanoresponsive and emerges only when cells are very confined. We identified mammalian sterile 20-like (Mst1) as a necessary component in this mechanosensitive pathway in addition to Dock8, allowing for cell shape integrity and survival during migration through complex environments. Our work shows that loss of the central actin pool results in greater nuclear deformation, accrual of DNA damage, and premature cell senescence.