Related Experiment Video
Updated: May 29, 2026
04:15
A Flow Cytometry-Based High-Throughput Technique for Screening Integrin-Inhibitory Drugs
Published on: February 2, 2024
Overview: structural biology of integrins
Guanyuan Fu1, Wei Wang, Bing-Hao Luo
1Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, USA.
Methods in Molecular Biology (Clifton, N.J.)
|September 13, 2011
Summary
Integrins are key cell adhesion molecules. Recent advances reveal how their structure changes to regulate cell signaling and binding, impacting various biological processes.
Area of Science:
- Molecular Biology
- Cell Biology
- Biochemistry
Background:
- Integrins are crucial cell adhesion molecules involved in hemostasis, immunity, development, and cancer.
- Their function is regulated by inside-out signaling, altering adhesiveness.
- Ligand binding initiates outside-in signaling, transmitting information to the cell interior.
Purpose of the Study:
- To elucidate the structural mechanisms underlying integrin regulation and signaling.
- To understand the relationship between ectodomain reorientations and ligand-binding affinity.
- To connect ectodomain conformational changes to transmembrane and cytoplasmic domain alterations.
Main Methods:
- Structural biology techniques (e.g., cryo-EM, X-ray crystallography) to visualize integrin conformations.
- Biochemical assays to measure integrin-ligand binding affinities.
- Cell-based assays to study integrin signaling pathways.
Main Results:
- Detailed structural insights into how large-scale ectodomain reorientations modulate integrin activation.
- Demonstration of how inter-domain and intra-domain movements within the ectodomain affect ligand-binding affinity.
- Evidence linking extracellular conformational changes to coordinated shifts in transmembrane and cytoplasmic domains of integrin subunits.
Conclusions:
- The structural basis for integrin inside-out and outside-in signaling is increasingly understood.
- Conformational dynamics of the integrin ectodomain are critical for regulating cell adhesion and signaling.
- These findings provide a framework for understanding integrin function in health and disease.
Related Concept Videos
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,...
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.
01:17Intracellular 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...
01:56Structural Protein Function
Structural proteins are a category of proteins responsible for functions ranging from cell shape and movement to providing support to major structures such as bones, cartilage, hair, and muscles. This group includes proteins such as collagen, actin, myosin, and keratin.
Collagen, the most abundant protein in mammals, is found throughout the body. In connective tissue, such as skin, ligaments, and tendons, it provides tensile strength and elasticity. In bones and teeth, it mineralizes to form...
Collagen, the most abundant protein in mammals, is found throughout the body. In connective tissue, such as skin, ligaments, and tendons, it provides tensile strength and elasticity. In bones and teeth, it mineralizes to form...
01:56Structural Protein Function
Structural proteins are a category of proteins responsible for functions ranging from cell shape and movement to providing support to major structures such as bones, cartilage, hair, and muscles. This group includes proteins such as collagen, actin, myosin, and keratin.
Collagen, the most abundant protein in mammals, is found throughout the body. In connective tissue, such as skin, ligaments, and tendons, it provides tensile strength and elasticity. In bones and teeth, it mineralizes to form...
Collagen, the most abundant protein in mammals, is found throughout the body. In connective tissue, such as skin, ligaments, and tendons, it provides tensile strength and elasticity. In bones and teeth, it mineralizes to form...
01:03Anchoring Junctions
Anchoring junctions are multiprotein complexes that help cells connect to other cells and the extracellular matrix. Anchoring junctions are present on the lateral and basal surfaces of cells, providing strong and flexible connections. Focal adhesions are often formed due to cell interactions with the ECM substrata, which initiate signal transduction via kinase cascades and other mechanisms. Together, they provide stability and tissue integrity. There are three types of anchoring junctions:...