Name: cell adhesion in anchoring junctions
Uploaded: 2023-04-30T11:54:35.000Z
Duration: 1 min 3 s
Channel: JoVE

Las células se conectan con la MEC y otras células a través de diferentes complejos de adhesión, denominados colectivamente uniones de anclaje.
En las células epiteliales, las adherencias focales y los hemidesmosomas conectan los filamentos de actina y los filamentos intermedios a una forma especializada de MEC llamada lámina basal.
Los hemidesmosomas contienen una placa densa en el lado citosólico de la membrana plasmática formada por la proteína citoenlazadora plectina.
Los filamentos intermedios que contienen queratina están conectados a esta placa a través de alfa seis, beta cuatro integrinas y otras proteínas como BP230 y BP180.
En la cara de la MEC, las integrinas se unen a la laminina, una glicoproteína que es un componente principal de la lámina basal.
Los hemidesmosomas resultantes pueden transmitir señales de ECM ayudando a la célula a responder a las fuerzas mecánicas y cambiar la forma, la polaridad y la dirección de la migración.

<ol>
	<li>Wei, Qi y Hayden Huang. "Perspectivas sobre el papel de las uniones célula-célula en la fisiología y la enfermedad". Revista internacional de biología celular y molecular 306 (2013): 187-221.</li>
	<li>Seetharaman, Shailaja y Sandrine Etienne-Manneville. "Diafonía del citoesqueleto en la migración celular". Trends in Cell Biology 30, no. 9 (2020): 720-735.</li>
	<li>https://www.mechanobio.info/what-is-mechanosignaling/what-are-cell-cell-adhesions/what-are-anchoring-junctions/</li>
</ol>

uniones de anclaje

Anchoring Junctions

Las uniones de anclaje son complejos multiproteicos que ayudan a las células a conectarse con otras células y con la matriz extracelular. Las uniones de anclaje están presentes en las superficies laterales y basales de las células, proporcionando conexiones fuertes y flexibles. Las adherencias focales a menudo se forman debido a interacciones celulares con los sustratos de la ECM, que inician la transducción de señales mediante cascadas de quinasas y otros mecanismos. Juntos, proporcionan estabilidad e integridad tisular. Hay tres tipos de uniones de anclaje: desmosomas, hemidesmosomas y adherentes.

Los desmosomas aparecen como placas densas, simétricas y en forma de disco en la membrana celular. Las proteínas de adhesión llamadas cadherinas participan en la formación de placas. La apariencia distintiva se debe a las proteínas estructurales de la superficie interna de la membrana celular.

Los hemidesmosomas parecen medio desmosoma y unen las células a la lámina basal. Si bien son similares en apariencia a los desmosomas, incluyen proteínas de adhesión llamadas integrinas en lugar de cadherinas. Estas conexiones son esenciales para mantener unidas las células.

Las uniones adherentes utilizan cadherinas o integrinas dependiendo de si se unen a otras células o a la matriz. Las uniones se caracterizan por la presencia de la proteína contráctil actina ubicada en la superficie citoplasmática de la membrana celular. La actina puede conectar parches aislados o formar una estructura similar a un cinturón dentro de la célula.

Las tres uniones de anclaje influyen en la forma y el plegamiento del tejido epitelial.

Uniones de anclaje

Las uniones de anclaje son complejos multiproteicos que ayudan a las células a conectarse con otras células y con la matriz extracelular. Las uniones de anclaje están presentes ...

Education

Educación

JoVE Core

Cell Biology

Biología Celular

Unit 1

Unidad 1

Cell-Matrix Interactions

Interacciones célula-matriz

KEY TERMS AND CONCEPTS

TÉRMINOS Y CONCEPTOS CLAVE

cell adhesion in anchoring junctions

Anchoring junctions are multiprotein complexes that help cells connect to other cells and to the extracellular matrix. They sit on the lateral and basal surfaces of cells. These junctions create strong, flexible links that help maintain tissue stability and integrity.

Focal adhesions often form when cells interact with the extracellular matrix, or ECM, substrata. These contacts can start signal transduction through kinase cascades and other pathways. Together, these junctions help cells stay attached and support the structure of tissues.

There are three main types of anchoring junctions: desmosomes, hemidesmosomes, and adherens junctions. Desmosomes appear as dense, symmetrical, disc-shaped plaques on the cell membrane. Adhesion proteins called cadherins help form these plaques, and structural proteins on the inner surface of the membrane give them their distinct look.

Hemidesmosomes look like half a desmosome. They link cells to the basal lamina. Unlike desmosomes, hemidesmosomes use integrins instead of cadherins.

Adherens junctions can use cadherins or integrins, depending on whether they connect cells to other cells or to the matrix. These junctions are marked by actin, a contractile protein on the cytoplasmic side of the cell membrane. Actin may form isolated patches or a belt-like structure inside the cell.

Together, these three anchoring junctions help shape epithelial tissue and influence how it folds. They are essential for holding cells together and preserving tissue form.

Cell Adhesion in Anchoring Junctions

overview of cell-matrix interactions

ECM Proteins and Cell Signaling

The extracellular matrix, or ECM, is the material that helps hold cells together in a tissue. It also lets cells in that tissue communicate with one another. The ECM contains proteins such as fibronectin, collagen, and laminin. Collagen is the most abundant protein in this space. Collagen fibers are woven together with proteoglycans, which are protein molecules with carbohydrates attached. This mix gives the ECM its structure. It also supports cell migration and provides a scaffold for cell...

integrins

Integrins in Cell Adhesion

Integrins help animal and protozoan cells attach to the extracellular matrix, or ECM. These cells do not have cell walls, so the ECM helps maintain shape and provide structural stability. The ECM is a sticky network of carbohydrates and proteins found between adjacent cells. Some ECM proteins form a basement membrane, and other ECM parts adhere to it. Proteoglycans make up much of the ECM, while fibrous proteins such as collagen give it strength. Fibronectin connects proteoglycans and collagen...

activation of integrins

How Integrins Link Cells to Their Environment

Integrins help cells connect with their environment and send signals across the cell membrane. They can carry information from outside the cell to the inside, or from inside the cell to the outside. These two paths are called outside-in signaling and inside-out signaling. In outside-in signaling, molecules in the extracellular space bind to exposed ligand-binding sites on integrins. A ligand is a molecule that binds to a protein. This binding makes the inactive integrin change shape and become...

intracellular signaling affects focal adhesions

intracellular-signaling-affects-focal-adhesions

Integrins Trigger Focal Adhesion Signaling

Integrins trigger focal adhesion signaling at the cell membrane. These membrane receptors sit in the phospholipid bilayer with hydrophobic regions that match the membrane interior. They provide attachment sites for outside signals such as hormones and growth factors. When these effectors bind and become active, integrins can start response pathways inside the cell. Some integrin-driven pathways support cell growth and help cells survive. The signal begins at the membrane, but G-proteins and...

anchoring junctions

Anchoring junctions are multiprotein complexes that help cells connect to other cells and to the extracellular matrix. They sit on the lateral and basal surfaces of cells. These junctions create strong, flexible links that help maintain tissue stability and integrity. Focal adhesions often form when cells interact with the extracellular matrix, or ECM, substrata. These contacts can start signal transduction through kinase cascades and other pathways. Together, these junctions help cells stay...

cell-matrix's response to mechanical forces

cell-matrix-s-response-to-mechanical-forces

Focal Adhesions and Cell Mechanics

Focal adhesions help animal cells connect to the extracellular matrix and sense mechanical forces. The extracellular matrix, or ECM, sits outside cells and helps tissues withstand stress. It also sends signals from outside the cell to the inside. The ECM is large and its makeup changes from one tissue to another. In loose connective tissue, reticular fibers and ground substance form the ECM. In bone tissue, collagen and bone minerals make up the ECM. Anchoring junctions hold a cell to the...

key terms and concepts

Explore how desmosomes, hemidesmosomes, and adherens junctions connect cells to each other and the ECM to support tissue strength and shape.

Cell Adhesion in Anchoring Junctions | JoVE K12

cell biology

JoVE Core Biología Celular ilustra procesos celulares complejos mediante completos vídeos animados fáciles de entender. Esta colección se centra en los componentes esenciales de las células y su funcionamiento, incluyendo los orgánulos y las membranas, el transporte celular y el metabolismo energético celular. Todo este material se complementa con los vídeos de científicos en acción, que muestran la aplicación de la biología celular en experimentos reales de investigación.

Cell Adhesion in Anchoring Junctions

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