3.2 Cell Adhesion Molecules and Receptors
2 min read•july 24, 2024
Cell adhesion molecules are crucial for tissue structure and function. These proteins, including integrins, , , and molecules, enable cells to stick together and interact with their environment.
Integrins play a key role in , forming that anchor cells and transmit signals. These adhesion complexes are vital for , differentiation, and tissue development, with implications for tissue engineering applications.
Cell Adhesion Molecules
Types of cell adhesion molecules
Top images from around the web for Types of cell adhesion molecules
Frontiers | Cell Adhesion Molecules and Protein Synthesis Regulation in Neurons View original
Is this image relevant?
Physics of cell adhesion: some lessons from cell-mimetic systems - Soft Matter (RSC Publishing ... View original
Is this image relevant?
Frontiers | Cadherins, Selectins, and Integrins in CAM-DR in Leukemia View original
Is this image relevant?
Frontiers | Cell Adhesion Molecules and Protein Synthesis Regulation in Neurons View original
Is this image relevant?
Physics of cell adhesion: some lessons from cell-mimetic systems - Soft Matter (RSC Publishing ... View original
Is this image relevant?
1 of 3
Top images from around the web for Types of cell adhesion molecules
Frontiers | Cell Adhesion Molecules and Protein Synthesis Regulation in Neurons View original
Is this image relevant?
Physics of cell adhesion: some lessons from cell-mimetic systems - Soft Matter (RSC Publishing ... View original
Is this image relevant?
Frontiers | Cadherins, Selectins, and Integrins in CAM-DR in Leukemia View original
Is this image relevant?
Frontiers | Cell Adhesion Molecules and Protein Synthesis Regulation in Neurons View original
Is this image relevant?
Physics of cell adhesion: some lessons from cell-mimetic systems - Soft Matter (RSC Publishing ... View original
Is this image relevant?
1 of 3
- Integrins form heterodimeric transmembrane proteins mediating cell-matrix and cell-cell adhesion composed of α and β subunits ()
- Cadherins facilitate calcium-dependent cell-cell adhesion primarily in epithelial tissues ( in skin)
- Selectins bind carbohydrates enabling leukocyte-endothelial cell interactions during inflammation ( on lymphocytes)
- Immunoglobulin superfamily (IgSF) adhesion molecules contain immunoglobulin-like domains involved in various cellular interactions ( in neural tissue)
Structure and function of integrins
- Extracellular domain binds specific ECM proteins transmitting forces between ECM and cytoskeleton (collagen, laminin)
- Transmembrane domain spans cell membrane anchoring the receptor
- Cytoplasmic domain interacts with intracellular proteins activating signaling pathways
- Activation occurs through inside-out signaling inducing conformational changes
- Outside-in signaling triggered by ligand binding initiates intracellular responses
- forms focal adhesions enhancing adhesion strength and signaling
Role of focal adhesions
- Composition includes integrins, , and signaling molecules (, )
- Anchor cells to ECM providing structural support
- Link ECM to actin cytoskeleton maintaining cell shape
- Act as signaling hubs activating pathways regulating survival and proliferation (, )
- Convert mechanical stimuli into biochemical signals through
- Respond to changes in ECM stiffness modulating cellular behavior
Importance of adhesion in development
- Cell migration relies on dynamic regulation of adhesion formation and disassembly
- Differentiation influenced by adhesion-dependent gene expression and stem cell fate decisions
- Tissue morphogenesis establishes architecture through cell sorting and boundary formation
- Embryonic development depends on adhesion for gastrulation and organ formation
- Tissue engineering applications utilize adhesion properties to control cell behavior in 3D scaffolds
Key Terms to Review (26)
Adaptor proteins: Adaptor proteins are molecules that facilitate interactions between different proteins, acting as a bridge to help transmit signals within cells. They play a crucial role in linking cell adhesion molecules and receptors to downstream signaling pathways, thereby influencing cellular responses and behaviors.
Adhesion regulation: Adhesion regulation refers to the complex biological processes that control the attachment and detachment of cells to each other and their surrounding extracellular matrix. This regulation is crucial for various cellular functions, including migration, proliferation, and tissue formation, ensuring that cells adhere appropriately during development and in response to environmental signals. Understanding adhesion regulation is fundamental to studying how cells interact with their environment through specific cell adhesion molecules and receptors.
Cadherins: Cadherins are a class of type-1 transmembrane proteins that play a crucial role in cell adhesion, helping cells stick to one another to form tissues. They are important for maintaining the structural integrity of tissues and are involved in signaling pathways that affect cell behavior, such as proliferation, differentiation, and apoptosis.
Calcium-dependent adhesion: Calcium-dependent adhesion refers to the process by which certain cell adhesion molecules (CAMs) require calcium ions to mediate the binding between cells. This mechanism is critical for various biological functions, including tissue development, immune response, and wound healing. Calcium acts as a signaling molecule that triggers conformational changes in these adhesion proteins, facilitating their interaction with other cells or the extracellular matrix.
Cell migration: Cell migration refers to the movement of cells from one location to another within the body, a process that is essential for various physiological events such as tissue development, wound healing, and immune responses. Understanding cell migration is crucial for designing scaffolds in tissue engineering, where the scaffold must support cell movement and attachment, and for developing effective 2D and 3D culture methods that mimic the natural environment of cells. Additionally, cell migration is influenced by the interactions between cells and their microenvironment, particularly through cell adhesion molecules and receptors.
Cell signaling pathways: Cell signaling pathways are complex networks of molecular interactions that govern cellular responses to external signals, enabling cells to communicate and coordinate their activities. These pathways play a crucial role in regulating various cellular processes, such as growth, differentiation, and metabolism, ensuring that cells can adapt to changes in their environment. By involving specific molecules like receptors, second messengers, and transcription factors, these pathways influence how cells behave and respond to stimuli.
Cell-matrix adhesion: Cell-matrix adhesion refers to the process by which cells attach to the extracellular matrix (ECM), a network of proteins and carbohydrates that provide structural and biochemical support to surrounding cells. This interaction is crucial for maintaining tissue integrity, facilitating communication between cells and their environment, and influencing various cellular functions such as migration, proliferation, and differentiation.
Clustering: Clustering refers to the process by which cell adhesion molecules and receptors group together on the surface of cells, forming aggregates that can influence various cellular functions. This phenomenon is crucial for the regulation of signaling pathways, as the clustering of these molecules can enhance their interactions, facilitate communication between cells, and modulate responses to external stimuli. Clustering is essential for processes like tissue formation, immune responses, and the development of various diseases.
E-cadherin: e-cadherin is a type of cell adhesion molecule that plays a critical role in the formation and maintenance of adherens junctions, which are crucial for cell-cell adhesion in epithelial tissues. It is a transmembrane protein that helps cells stick together, contributing to the integrity and structure of tissues while regulating important cellular processes such as signaling, proliferation, and differentiation.
Extracellular matrix: The extracellular matrix (ECM) is a complex network of proteins and carbohydrates that provide structural and biochemical support to surrounding cells. This matrix plays a critical role in tissue organization, cell adhesion, communication, and regulating cellular functions, making it essential for various biological processes.
Fak: Focal adhesion kinase (FAK) is a non-receptor tyrosine kinase that plays a critical role in the regulation of cell adhesion and signaling pathways. It is primarily found at focal adhesions, where cells connect to the extracellular matrix, and is essential for various cellular processes such as migration, proliferation, and survival. FAK's activation is triggered by integrin binding and growth factor receptors, linking cell adhesion to signaling cascades that influence cell behavior.
Fibronectin receptor: The fibronectin receptor is a type of cell adhesion molecule that plays a crucial role in the attachment of cells to the extracellular matrix through binding to fibronectin. This receptor is part of a larger family known as integrins, which facilitate various cellular processes, including migration, proliferation, and differentiation by enabling cells to interact with their surrounding environment.
Focal Adhesions: Focal adhesions are specialized structures that connect cells to the extracellular matrix (ECM), playing a critical role in cell signaling and mechanical stability. These dynamic junctions anchor cells to their surroundings while facilitating communication between the cell's interior and its external environment, impacting processes like migration, proliferation, and differentiation.
Heterodimeric proteins: Heterodimeric proteins are composed of two different polypeptide chains that are linked together to form a functional unit. These proteins play critical roles in various biological processes, including cell signaling, immune responses, and cell adhesion. By having distinct subunits, heterodimeric proteins can exhibit diverse functional properties, allowing them to interact specifically with other molecules such as receptors or adhesion molecules.
Heterophilic binding: Heterophilic binding refers to the interaction between different types of molecules, typically involving cell adhesion molecules that bind specifically to distinct receptors on adjacent cells. This type of binding is crucial in mediating various biological processes, such as tissue formation, immune responses, and cellular signaling, by ensuring that cells communicate and adhere correctly to one another.
Homophilic binding: Homophilic binding is a type of cell adhesion process where identical or similar molecules on adjacent cells interact with each other. This mechanism is crucial for establishing strong connections between cells, allowing them to maintain their structure and communicate effectively. It plays an important role in various biological processes, including tissue formation, immune responses, and the maintenance of cellular organization.
Immunoglobulin superfamily: The immunoglobulin superfamily is a large group of proteins that share common structural features, particularly the immunoglobulin (Ig) domain, and are involved in various cellular functions such as cell adhesion, recognition, and signaling. These proteins play crucial roles in the immune response, but they are also important in processes like neural development and tissue formation, as they facilitate interactions between cells and the extracellular matrix.
L-selectin: l-selectin is a cell adhesion molecule that plays a crucial role in the immune system by facilitating the adhesion of leukocytes to the endothelium of blood vessels. It is primarily expressed on the surface of naive lymphocytes and plays a key role in their trafficking to lymphoid tissues, enabling them to respond effectively to pathogens.
Leukocyte-endothelial interactions: Leukocyte-endothelial interactions refer to the dynamic processes that involve the binding and movement of leukocytes (white blood cells) across the endothelial cell layer of blood vessels during immune responses. These interactions are crucial for the recruitment of leukocytes to sites of inflammation, injury, or infection, facilitating their migration into tissues to perform various immune functions.
Mapk: MAPK, or Mitogen-Activated Protein Kinase, refers to a family of protein kinases that play a crucial role in signaling pathways related to cell growth, differentiation, and response to stress. These kinases are activated by various extracellular signals and are involved in the transmission of these signals from cell surface receptors to the nucleus, influencing cellular functions and behaviors.
Mechanotransduction: Mechanotransduction is the process by which cells sense and respond to mechanical stimuli from their environment, translating physical forces into biochemical signals. This ability is crucial for cells to adapt to changes in their mechanical surroundings, influencing functions such as proliferation, differentiation, and tissue remodeling.
NCAM: NCAM, or Neural Cell Adhesion Molecule, is a cell adhesion molecule that plays a crucial role in neural development and synaptic plasticity. It helps cells stick to each other, particularly in the nervous system, facilitating neuron-neuron interactions and influencing cell migration, growth, and differentiation. By promoting adhesion between neurons, NCAM contributes to the formation and stabilization of neural networks.
PI3K: Phosphoinositide 3-kinases (PI3Ks) are a family of enzymes involved in cellular functions such as growth, proliferation, differentiation, and survival. These enzymes play a key role in signaling pathways, particularly those initiated by cell adhesion molecules and receptors, by phosphorylating phosphatidylinositol, leading to the generation of important lipid second messengers that activate downstream signaling cascades.
Selectins: Selectins are a family of cell adhesion molecules that play a crucial role in the process of cell-cell interactions, particularly in the immune response and inflammation. They are expressed on the surface of endothelial cells and leukocytes, mediating the initial steps of leukocyte rolling along blood vessel walls and subsequent adhesion to tissues during inflammatory responses.
Signal transduction: Signal transduction is the process by which cells convert external signals into functional responses, involving a series of molecular events that lead to cellular changes. This pathway allows cells to communicate and respond to their environment, regulating essential functions such as cell growth, differentiation, and movement. Understanding how these signaling pathways work is crucial for grasping the mechanisms that control the cell cycle and how cells adhere and interact with each other.
Talin: Talin is a cytoskeletal protein that plays a critical role in cell adhesion by linking integrins to the actin cytoskeleton. It is essential for forming focal adhesions, which are complexes that connect cells to the extracellular matrix, enabling cellular communication and mechanical stability. Talin's structure allows it to act as a molecular switch, activating integrins in response to mechanical forces, which is vital for cellular mechanotransduction.