Basement membrane turnover controls cell shape.

Basement membrane stress relaxation time can regulate 3D cell shape, according to mathematical modeling. Molecular dynamics simulations show the stress relaxation time of a collagen IV network can be inferred from collagen IV molecule lifetime, and a new fluorescent timer reporter measures that lifetime in vivo, revealing that perlecan modifies it. The work establishes a multiscale framework linking matrix turnover to cell shape control.