Related Experiment Video
Updated: Aug 14, 2026
09:56
Tension Gauge Tether Probes for Quantifying Growth Factor Mediated Integrin Mechanics and Adhesion
Published on: February 11, 2022
Rigidity sensing at the leading edge through alphavbeta3 integrins and RPTPalpha
Guoying Jiang1, Angela H Huang, Yunfei Cai
1Department of Biological Sciences, Columbia University, New York, New York 11027, USA.
Biophysical Journal
|December 13, 2005
Summary
Cells sense matrix rigidity through RPTPalpha and alphavbeta3 integrins at the leading edge, influencing cell spreading and function. This mechanism is crucial for normal cell behavior and differentiation.
Area of Science:
- Cell Biology
- Biophysics
- Mechanobiology
Background:
- Cellular function and differentiation depend on optimal substrate stiffness.
- Mechanisms of matrix rigidity sensing and durotaxis are not fully understood.
Purpose of the Study:
- To investigate the roles of RPTPalpha and alphavbeta3 integrins in sensing fibronectin (FN) matrix rigidity.
- To elucidate the signaling pathways involved in rigidity sensing and durotaxis.
Main Methods:
- Utilized genetically modified cell lines (Shp2-/-, integrin beta1-/-, talin1-/-, RPTPalpha-/-) to assess cell spreading on substrates of varying stiffness.
- Employed laser traps to measure cytoskeletal bond formation with fibronectin beads at the leading edge.
- Investigated the effect of antibodies to alphavbeta3 on FN rigidity sensing.
Main Results:
- RPTPalpha-/- cells showed impaired rigidity sensing on FN but retained it on collagen IV.
- Antibodies to alphavbeta3 blocked FN rigidity sensing.
- A force of 10 pN generated within 1 second was sufficient to activate the rigidity response.
- Stronger cytoskeletal bonds formed with rigid FN beads at the leading edge.
Conclusions:
- RPTPalpha and alphavbeta3 integrins at the leading edge are critical for sensing FN matrix rigidity.
- SFK activation at the leading edge may mediate rigidity sensing and downstream signaling.
- Understanding these mechanisms is key to comprehending cell behavior and differentiation.
Related Concept Videos
01:31Mechanism of Lamellipodia Formation
Cells migrating in response to external stimuli form lamellipodia, which are thin membrane protrusions supported by a mesh of linked, branched, or unbranched actin filaments. These actin filaments interact with myosin motor proteins, creating the dynamic actomyosin complex within the cytoskeleton. Contractility, or the ability to generate contractile stress, is inherent to the actomyosin complex. It helps cells detect the stiffness of the surrounding ECM and exert contractile force for...
01:26Tension Response at Adherens Junctions
The adherens junctions that anchor cells together are multi-protein complexes that dynamically adapt to mechanical stimuli such as tensile forces and shear stress. Mechanosensory proteins in these junctions can sense such mechanical stimuli and undergo a shift in their conformation, resulting in an altered function — a process called mechanotransduction.
α-Catenin as a Mechanosensory Protein
The α-catenin of adherens junctions is an allosteric protein with three VH (vinculin homology) domains...
α-Catenin as a Mechanosensory Protein
The α-catenin of adherens junctions is an allosteric protein with three VH (vinculin homology) domains...
01:17Intracellular Signaling Affects Focal Adhesions
Integrins act both as extracellular input receivers and as intracellular processing activators. As their name suggests, integrins are entirely integrated into the membrane structure. Their hydrophobic membrane-spanning regions interact with the phospholipid bilayer's hydrophobic region. These membrane receptors provide extracellular attachment sites for effectors like hormones and growth factors. They activate intracellular response cascades when their effectors are bound and active.
Some...
Some...
01:39Mechanism of Filopodia Formation
Filopodia are thin, actin-rich cellular protrusions that play an important role in many fundamental cellular functions. They vary in their occurrence, length, and positioning in different cell types, suggesting their diverse roles.
Their main function is to guide migrating cells during normal tissue morphogenesis or cancer metastasis by recognizing and making initial contacts with the extracellular matrix. However, they can also act as stationary cell anchors or help to establish communication...
Their main function is to guide migrating cells during normal tissue morphogenesis or cancer metastasis by recognizing and making initial contacts with the extracellular matrix. However, they can also act as stationary cell anchors or help to establish communication...
01:15Activation of Integrins
Integrins bind ligands and transmit information from outside the cell to inside or vice-versa through an "outside-in signaling" or "inside-out signaling."
In "outside-in signaling," external factors in the extracellular space bind to exposed ligand binding sites on integrins. This causes the inactive protein to undergo a conformational change to become active. Integrins are often clustered on the cell membrane. Repetitive and regularly spaced ligand binding events provide an effective stimulus.
In "outside-in signaling," external factors in the extracellular space bind to exposed ligand binding sites on integrins. This causes the inactive protein to undergo a conformational change to become active. Integrins are often clustered on the cell membrane. Repetitive and regularly spaced ligand binding events provide an effective stimulus.
01:10Integrins
Animal and protozoan cells do not have cell walls to help maintain shape and provide structural stability. Instead, these eukaryotic cells secrete a sticky mass of carbohydrates and proteins into the spaces between adjacent cells. This network of proteins and molecules is called an extracellular matrix or ECM.
Some ECM proteins assemble into a basement membrane to which the remaining components adhere. Proteoglycans typically form the bulk of the ECM while fibrous proteins, like collagen,...
Some ECM proteins assemble into a basement membrane to which the remaining components adhere. Proteoglycans typically form the bulk of the ECM while fibrous proteins, like collagen,...