Name: cell adhesion molecules in tissues
Uploaded: 2023-04-30T11:55:46.000Z
Duration: 1 min 20 s
Channel: JoVE

Las interacciones celulares son puntos físicos de contacto entre células adyacentes. Ayudan a mantener unidas las células y permiten la comunicación transmembrana, vital para el funcionamiento coordinado de los tejidos.
Las interacciones celulares estables se encuentran en los tejidos, como el endotelio, donde apoyan la organización de los tejidos. Por el contrario, las interacciones más débiles y transitorias ayudan a reclutar células que se mueven libremente, como las células inmunitarias.
Estas interacciones celulares se materializan a través de proteínas especiales de la superficie celular, llamadas colectivamente moléculas de adhesión celular o CAM.
De las cuatro familias principales de CAM, la familia de las integrinas está involucrada en la interacción de una célula con la matriz extracelular, mientras que las otras tres familias están involucradas en interacciones célula-célula.
Primero están las cadherinas, que forman interacciones estables al unirse a cadherinas expresadas en otras células.
En segundo lugar están los seleccionados. Se unen a carbohidratos específicos en la superficie de otras células y forman interacciones transitorias.
Y, por último, las proteínas similares a las inmunoglobulinas que pertenecen a la superfamilia de las inmunoglobulinas también forman interacciones transitorias al unirse a otras proteínas e integrinas similares en otras células.

<ol>
	<li>Harjunpää, Heidi, et al. "Moléculas de adhesión celular y sus funciones y regulación en el microambiente inmune y tumoral". Fronteras en inmunología (2019): 1078.</li>
</ol>

moléculas de adhesión celular: tipos y funciones

Cell Adhesion Molecules - Types and Functions

Las moléculas de adhesión celular (CAM) son fundamentales para la multicelularidad y el funcionamiento coordinado de tejidos y sistemas de órganos. Permiten interacciones físicas entre células y proporcionan resistencia mecánica a los tejidos. También funcionan como receptores para la transmisión de señales a través de la membrana plasmática. Las CAM se clasifican en términos generales en cuatro familias: integrinas, cadherinas, selectinas y CAM similares a inmunoglobulinas (IgCAM).

Familias CAM

La familia de proteínas Integrin participa principalmente en la interacción de una célula con la matriz circundante. Sin embargo, algunas integrinas pueden unirse a las CAM en la superficie de otra célula y participar en interacciones directas entre células. Por ejemplo, las integrinas de las células inmunitarias se unen a las IgCAM expresadas en el endotelio vascular.

Las cadherinas son una superfamilia de glicoproteínas dependientes del calcio implicadas principalmente en el establecimiento de fuertes adherencias celulares. Forman las uniones adherentes y los desmosomas en los tejidos, como el epitelio.

Las selectinas y las IgCAM participan en interacciones celulares transitorias y participan en la dirección de las células hacia los sitios objetivo. Por ejemplo, ayudan en el reclutamiento selectivo de linfocitos hacia los órganos linfoides secundarios.

CAM y multicelularidad

Las CAM se encuentran en prácticamente todos los organismos multicelulares, desde esponjas y nematodos simples hasta invertebrados y vertebrados complejos. La complejidad de las interacciones celulares, y por tanto de las CAM, aumenta con la complejidad de los organismos. Por ejemplo, mientras que la mosca de la fruta D.melanogaster tiene aproximadamente 500 genes implicados en la adhesión celular, los vertebrados complejos como los mamíferos tienen más de mil genes que codifican diferentes tipos de CAM.

Moléculas de adhesión celular: tipos y funciones

Las moléculas de adhesión celular (CAM) son fundamentales para la multicelularidad y el funcionamiento coordinado de los tejidos y sistemas de órganos. Permiten ...

cell-adhesion-molecules-types-and-functions

Education

Educación

JoVE Core

Cell Biology

Biología Celular

Unit 1

Unidad 1

Cell-Cell Interactions

Interacciones célula-célula

KEY TERMS AND CONCEPTS

TÉRMINOS Y CONCEPTOS CLAVE

cell adhesion molecules in tissues

Cell adhesion molecules help cells stick together and work as part of a tissue. They give multicellular organisms physical strength and also help cells send signals across the plasma membrane. These proteins are important for coordinated activity in tissues and organ systems.

CAMs are grouped into four main families: integrins, cadherins, selectins, and immunoglobulin-like CAMs, or IgCAMs. Each family supports cell interactions in a different way. Some CAMs help cells attach firmly, while others help cells make short-lived contacts and move to the right place.

Integrins mainly help a cell interact with the surrounding matrix, which is the material around cells. Some integrins can also bind CAMs on another cell and take part in direct cell-cell contact. For example, integrins on immune cells bind IgCAMs on the vascular endothelium, the inner lining of blood vessels.

Cadherins are calcium-dependent glycoproteins. They are known for strong cell adhesion and help form adherens junctions and desmosomes in tissues such as epithelium. Selectins and IgCAMs usually support transient cell interactions. They also help guide cells to target sites, such as the selective recruitment of lymphocytes to secondary lymphoid organs.

CAMs are found in nearly all multicellular organisms, from sponges and simple nematodes to complex invertebrates and vertebrates. As organisms become more complex, their cell interactions and CAM systems also become more complex. For example, D. melanogaster has about 500 genes involved in cell adhesion, while mammals have over a thousand genes that code for different CAMs.

Cell Adhesion Molecules in Tissues

cell adhesion molecules - types and functions

Cell adhesion molecules help cells stick together and work as part of a tissue. They give multicellular organisms physical strength and also help cells send signals across the plasma membrane. These proteins are important for coordinated activity in tissues and organ systems. CAMs are grouped into four main families: integrins, cadherins, selectins, and immunoglobulin-like CAMs, or IgCAMs. Each family supports cell interactions in a different way. Some CAMs help cells attach firmly, while...

structure of cadherins

Cadherins in Cell Junctions and Disease

Cadherins are cell adhesion proteins that help cells stick together and build tissues. Their name comes from their calcium-dependent binding. Early examples were named E-cadherin, P-cadherin, and N-cadherin after the epithelial, placental, and neuronal cells where they were first found. Classical cadherins share similar sequences and structures. Other cadherins, including those involved in cell signaling, are grouped as non-classical cadherins. This diversity comes from multiple cadherin genes...

cadherins in tissue organization

Cadherins Guide Cell Sorting in Tissues

Cadherins help cells sort into the right tissues during development. They are a large superfamily of cell adhesion molecules, with more than 180 variants. Different tissues express specific cadherin combinations, which helps cells recognize and stick to the right neighbors. Cadherins usually bind to the same or a closely related cadherin on another cell. This is called homophilic binding. Because of this matching behavior, cells of the same type tend to group together and form clusters that...

catenins

Catenins in Cell Junctions and Signaling

Catenins help cells stay connected and also support signaling inside the body. These proteins act as linker proteins in cell junction complexes because they have multiple binding domains and flexible structures. Most catenins contain a protein sequence called the armadillo repeat, so they are also known as armadillo proteins. Alpha-catenin is the main exception. Catenins bind to cell adhesion molecules such as cadherins. They then connect cadherins to cytoskeletal proteins, and the exact link...

selectins

Selectins in Immune Cell Capture

Selectins help cells make short, temporary contacts during immune responses. They are cell adhesion molecules that bind carbohydrate ligands on other cells. These rod-like proteins have a long outside region and end in a lectin domain, which binds carbohydrates only when calcium ions are present. Three main selectins are known: L-selectin, P-selectin, and E-selectin. Their names reflect where they are found and how long they are. This tissue specificity helps explain why selectins act in...

immunoglobulin-like cell adhesion molecules

immunoglobulin-like-cell-adhesion-molecules

Ig-CAMs in Neural Growth and Disease

Ig-CAMs, or immunoglobulin-like cell adhesion molecules, are cell surface glycoproteins in the immunoglobulin superfamily. They contain immunoglobulin domains, and some also have fibronectin type III domains. Their Ig domains can be glycosylated to different degrees. These molecules can bind to the same kind of Ig-CAM or to other ligands, such as integrins. Most Ig-CAMs help cells stick together only for a short time. The nectin class is different because it helps form stable junctions,...

overview of cell-cell junctions

Cell Junctions in Tissues

Cell junctions help hold tissues together and let neighboring cells communicate. In multicellular organisms, the three-dimensional shape of tissues depends on interactions between cells and the extracellular matrix. Cell-cell junctions are specialized structures made of multi-protein complexes on one cell that connect with similar complexes on another cell. These junctions are grouped into three main types based on function: occluding, anchoring, and gap junctions. Tight junctions, also called...

adherens junctions

Cell Adhesion in Tissues and Infection

Adherens junctions are strong cell-to-cell anchors that help tissues stay connected. These anchoring junctions work with desmosomes, another type of junction that holds adjacent cells together. In many epithelial and endothelial tissues, adherens junctions form a continuous adhesion belt. In heart muscle, they often appear as clusters that help cells work together for coordinated contraction. Adherens junctions are also dynamic, especially in the cells that line blood vessels. These...

tension response at adherens junctions

How Adherens Junctions Sense Force

Adherens junctions help cells stay attached while they respond to mechanical force. These multi-protein complexes can adapt to tensile force and shear stress. When the force changes, mechanosensory proteins in the junction can change shape. This process is called mechanotransduction. Alpha-catenin is one of the main force-sensing proteins in adherens junctions. It is an allosteric protein, which means its shape affects how it works. Alpha-catenin has three VH, or vinculin homology, domains...

desmosomes

Desmosomes and Cell Anchoring

Desmosomes are cell junctions that anchor cells together. They are button-like structures that create an interlinked network of intermediate filaments across cells. This strong link helps tissues resist mechanical stress and maintain tissue integrity. Desmosomes are built from multiple proteins. Their core includes desmosomal cadherins, which are adhesion proteins that bind to cadherins on neighboring cells. The two desmosomal cadherins are desmogleins and desmocollins. These transmembrane...

tight junctions

Tight Junction Proteins and Cell Barriers

Tight junction proteins form seals between neighboring cells. These molecular barriers help stop fluids, ions, and other small solutes from leaking across body cavities and tissue compartments in multicellular organisms. They are an important part of cell barriers in places where controlled movement matters. The main tight junction proteins are claudin and occludin. Other proteins include tricellulin and JAM, which stands for junctional adhesion molecule. Most of these proteins are 4-pass...

gap junctions

Cell Communication Through Gap Junctions

Gap junctions let adjacent animal cells share small molecules, ions, and secondary messengers. These communication channels connect the cytoplasm of neighboring cells. They are built from many molecular channels, often from a few hundred to thousands in one junction. Each channel is made of two halves called connexon hemichannels. A connexon is a hexamer, meaning it is formed by six transmembrane connexin proteins. The six proteins arrange in a ring and create a pore in the center. One...

key terms and concepts

Learn how cell adhesion molecules help tissues stay strong, guide immune cells, and support cell signaling through four major CAM families.

Cell Adhesion Molecules in Tissues | 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 Molecules in Tissues

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