Related Experiment Video
Updated: May 18, 2026
18:11
Quantifying Synapses: an Immunocytochemistry-based Assay to Quantify Synapse Number
Published on: November 16, 2010
Interactions between ICAM-5 and β1 integrins regulate neuronal synapse formation
Lin Ning1, Li Tian, Sergei Smirnov
1Division of Biochemistry and Biotechnology, Faculty of Biological and Environmental Sciences, University of Helsinki, Finland.
Journal of Cell Science
|September 28, 2012
Summary
Intercellular adhesion molecule-5 (ICAM-5) regulates dendritic spine maturation. Its interaction with β1 integrins is crucial for forming functional synapses.
Area of Science:
- Neuroscience
- Cell Biology
- Molecular Biology
Background:
- Intercellular adhesion molecule-5 (ICAM-5) is a dendrite-specific adhesion molecule involved in immune and nervous system functions.
- ICAM-5 is the sole identified negative regulator of dendritic spine maturation, with its ectodomain shedding promoting spine maturation and synaptic activity.
Purpose of the Study:
- To elucidate the poorly understood mechanism by which ICAM-5 regulates spine development.
- To investigate the role of ICAM-5 and its interaction with β1 integrins in synaptic formation and maturation.
Main Methods:
- Ablation of ICAM5 expression in mice.
- Immunoprecipitation assays to identify binding partners of ICAM-5.
- Antibody-mediated modulation of ICAM-5 and β1 integrin interactions.
- Microscopy to analyze spine morphology and synaptic structures.
Main Results:
- ICAM5 ablation led to increased synaptic contact formation and miniature excitatory post-synaptic current frequency.
- β1 integrins were identified as binding partners for ICAM-5, with binding localized to the first two Ig domains.
- Antibodies targeting ICAM-5 and β1 integrins affected spine maturation.
- Altered β1 integrin localization and affected post-synaptic structure morphology were observed.
- Modulating the ICAM-5/β1 integrin interaction influenced ICAM-5 ectodomain cleavage.
Conclusions:
- The interaction between ICAM-5 and β1 integrins is essential for the formation of functional synapses.
- β1 integrins play a significant role in synaptic development, from initial formation to mature spine structures.
- ICAM-5's regulation of spine maturation is mediated, in part, through its interaction with β1 integrins.
More Related Videos
07:51Inhibitory Synapse Formation in a Co-culture Model Incorporating GABAergic Medium Spiny Neurons and HEK293 Cells Stably Expressing GABAA Receptors
Published on: November 14, 2014
11:10Antibody Binding Specificity for Kappa (Vκ) Light Chain-containing Human (IgM) Antibodies: Polysialic Acid (PSA) Attached to NCAM as a Case Study
Published on: June 29, 2016
Related Concept Videos
01:31Immunoglobulin-like Cell Adhesion Molecules
Immunoglobulin-like cell adhesion molecules or Ig-CAMs are a versatile group of cell surface glycoproteins belonging to the immunoglobulin protein superfamily. Ig-CAMs possess the characteristic immunoglobulin protein domains and other domains such as the fibronectin type III domain. The Ig domains are glycosylated to varying degrees in different Ig-CAMs.
Ig-CAMs exhibit either homophilic binding (to other Ig-CAMs) or heterophilic binding (to other ligands such as integrins). While most Ig-CAMs...
Ig-CAMs exhibit either homophilic binding (to other Ig-CAMs) or heterophilic binding (to other ligands such as integrins). While most Ig-CAMs...
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...
01:15Activation 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,...
01:20Cell Adhesion Molecules - Types and Functions
Cell adhesion molecules (CAMs) are pivotal to multicellularity and the coordinated functioning of tissues and organ systems. They enable physical interactions between cells and provide mechanical strength to tissues. They also function as receptors for signal transmission across the plasma membrane. The CAMs are broadly classified into four families - integrins, cadherins, selectins, and immunoglobulin-like CAMs (IgCAMs).
CAM Families
The Integrin family of proteins is primarily involved in a...
CAM Families
The Integrin family of proteins is primarily involved in a...
01:28Integration of Synaptic Events
Synaptic integration mainly includes the summation of graded potentials. Graded potentials, regardless of their type, cause subtle alterations in membrane voltage, resulting in either depolarization or hyperpolarization. These incremental changes, when combined or summed, can propel the neuron toward its threshold. Consider, for example, a membrane experiencing a +15 mV shift, causing it to depolarize from -70 mV to -55 mV. In this scenario, graded potentials govern the membrane's ability to...