Mechanotransduction in Actin Stress Fibers

Mechanotransduction in actin stress fibers encompasses the processes by which contractile actomyosin bundles convert mechanical cues from the extracellular environment into biochemical signals that regulate cell behaviour. Actin stress fibers, composed of parallel arrays of actin filaments interspersed with non-muscle myosin II motors and cross-linking proteins, anchor at focal adhesions to transmit tensile forces. These forces inform cells about matrix stiffness, geometry and applied strain, driving adaptations in morphology, migration, proliferation and differentiation. Feedback between stress fiber contractility, adhesion maturation and cytoskeletal remodelling establishes tensional homeostasis, enabling cells to maintain integrity under external load. Dysregulation of this balance underlies pathological processes such as fibrosis, cancer invasion and impaired wound healing. Advances in imaging, biophysical measurement and computational modelling have elucidated how stress fiber subtypes—ventral, dorsal and transverse arc—differ in their assembly, force generation and mechanosensing roles, revealing a dynamic network that integrates mechanical and chemical signals across spatial and temporal scales.

Research from Nature Portfolio

Recent studies have uncovered how the interplay between actin stress fibers and adjacent cytoskeletal networks governs mechanical adaptation. One investigation demonstrated that a non-polarized spectrin meshwork in fibroblast cortices can reorganise into polarised clusters that are corralled by actin stress fibers, reducing local mechanical stress and turnover while preserving spectrin extension. By combining expansion microscopy, biophysical assays and computational modelling, this work highlighted a stress fiber–driven topological transition that protects and adapts the cell cortex under deformation.

Another advance identified Caldesmon as a pivotal dynamic cross-linker within non-muscle actomyosin bundles. Depletion of Caldesmon disrupted regular spacing of myosin II along actin–tropomyosin filaments, leading to irregular stress fiber architecture, compromised contractility and defects in cell morphogenesis, migration and mechanosensing. These findings establish how Caldesmon-mediated force balance ensures stress fiber network integrity and effective tension sensing in non-muscle cells.

Mechanotransduction in Actin Stress Fibers publication trend

The graph below shows the total number of articles in mechanotransduction in actin stress fibers across all publications each year (not limited to Nature Index journals).

Technical terms

Mechanotransduction: Conversion of mechanical stimuli into biochemical signals within cells.

Actin stress fibers: Contractile bundles of actin filaments and myosin II motors that generate and sense tensile forces.

Focal adhesions: Multi-protein complexes that link the actin cytoskeleton to the extracellular matrix and mediate force transduction.

Spectrin meshwork: A cytoskeletal network beneath the plasma membrane that provides structural support and adapts to mechanical stress.

Caldesmon: An actin-binding protein that cross-links myosin II filaments with tropomyosin–actin bundles, regulating force balance in stress fibers.

References

1. Mechanically induced topological transition of spectrin regulates its distribution in the mammalian cell cortex. Nature Communications (2024).
2. Caldesmon controls stress fiber force-balance through dynamic cross-linking of myosin II and actin-tropomyosin filaments. Nature Communications (2022).
3. The positioning of stress fibers in contractile cells minimizes internal mechanical stress. Journal of the Mechanics and Physics of Solids (2025).
4. Diffusion model predicts the geometry of actin cytoskeleton from cell morphology. PLOS Computational Biology (2024).
5. Actomyosin stress fiber mechanosensing in 2D and 3D. F1000Research (2016).
6. Actin stress fibre subtypes in mesenchymal-migrating cells. Open Biology (2013).