Load-dependent RGD-context sensing via αV-class integrins reprograms cell adhesion and mechanics
- Upnishad Sharma
- Jakob M. Reber
- Jonne Helenius
- Cara Buchholz
- Reinhard Fässler
- Nico Strohmeyer
- Daniel J. Müller
2026-08-24
The biochemical and mechanical properties of extracellular matrix proteins govern cell adhesion, mechanics, and migration. How cells use integrins to discriminate between the arginine-glycine-aspartic acid motifs presented by different extracellular matrix proteins, a process central to tissue homeostasis and disease, has remained unclear. Here we show that mammalian cells mount a distinct “biphasic” mechanical response through αV-class integrins to the arginine-glycine-aspartic acid motif of vitronectin compared with fibronectin, osteopontin, and cyclic arginine-glycine-aspartic acid. Within seconds of contact with vitronectin, we find that αV-class integrins strengthen cell adhesion through two load-dependent mechanotransduction pathways in which αVβ3 and αVβ5 integrins take complementary roles. Under low load, we demonstrate that the first phase requires both integrins together with an intact, pre-tensed actomyosin cortex, talin, paxillin, and focal adhesion kinase activity, with αVβ5 integrin additionally engaging clathrin-mediated endocytosis. Under higher load, we show that the second phase is dominated by αVβ3 integrin–directed actin-related protein 2/3, cellular Src kinase, and phosphatidyl inositol-3-kinase signaling, which organizes the consensus adhesome, while αVβ5 integrin concurrently drives cellular stiffening. Taken together, we find that αV-class integrins rapidly deploy arginine-glycine-aspartic acid -motif- and β-subunit-specific programs that cooperatively tune cell adhesion and mechanics according to the extracellular matrix composition.