Reena Kumari, Katharina Ven, Megan Chastney, Shrikant B Kokate, Johan Peränen, Jesse Aaron, Konstantin Kogan, Leonardo Almeida-Souza, Elena Kremneva, Renaud Poincloux, Teng-Leong Chew, Peter W Gunning, Johanna Ivaska, Pekka Lappalainen
Focal adhesions (FAs) connect inner workings of cell to the extracellular matrix to control cell adhesion, migration and mechanosensing. Previous studies demonstrated that FAs contain three vertical layers, which connect extracellular matrix to the cytoskeleton. By using super-resolution iPALM microscopy, we identify two additional nanoscale layers within FAs, specified by actin filaments bound to tropomyosin isoforms Tpm1.6 and Tpm3.2. The Tpm1.6-actin filaments, beneath the previously identified α-actinin cross-linked actin filaments, appear critical for adhesion maturation and controlled cell motility, whereas the adjacent Tpm3...
March 21, 2024: Nature Communications