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

細胞相互作用は、隣接する細胞間の物理的な接触点です。それらは、細胞を一緒に保持し、組織の協調的な機能に不可欠な膜貫通伝達を可能にするのに役立ちます。
安定した細胞相互作用は、内皮などの組織に見られ、そこで組織組織をサポートします。逆に、一過性の相互作用が弱いと、免疫細胞のように自由に動く細胞を動員するのに役立ちます。
これらの細胞相互作用は、細胞接着分子またはCAMと総称される特殊な細胞表面タンパク質を介して具体化されます。
CAMの4つの主要なファミリーのうち、インテグリンファミリーは細胞と細胞外マトリックスとの相互作用に関与していますが、他の3つのファミリーは細胞間相互作用に関与しています。
まず、カドヘリンは、他の細胞に発現したカドヘリンと結合することで安定した相互作用を形成します。
2つ目はセレクチンです。それらは他の細胞の表面上の特定の炭水化物に結合し、一過性の相互作用を形成します。
そして最後に、免疫グロブリンスーパーファミリーに属する免疫グロブリン様タンパク質も、他の類似タンパク質や他の細胞上のインテグリンと結合することにより、一過性の相互作用を形成します。

<ol>
	<li>「免疫および腫瘍微小環境における細胞接着分子とその役割および調節」 免疫学のフロンティア (2019):1078。</li>
</ol>

細胞接着分子 - 種類と機能

Cell Adhesion Molecules - Types and Functions

細胞接着分子 (CAM) は、多細胞性と組織および器官系の協調機能にとって極めて重要です。 これらは細胞間の物理的相互作用を可能にし、組織に機械的強度を与えます。 それらは、細胞膜を介したシグナル伝達の受容体としても機能します。 CAM は、インテグリン、カドヘリン、セレクチン、免疫グロブリン様 CAM (IgCAM) の 4 つのファミリーに大別されます。

CAM ファミリ

インテグリンファミリーのタンパク質は、主に細胞とその周囲のマトリックスとの相互作用に関与しています。 ただし、一部のインテグリンは別の細胞表面の CAM に結合し、直接の細胞間相互作用に関与することができます。 たとえば、免疫細胞上のインテグリンは、血管内皮上に発現する IgCAM に結合します。

カドヘリンは、主に強力な細胞接着の確立に関与するカルシウム依存性の糖タンパク質です。 それらは、上皮などの組織内の接着結合およびデスモソームを構成します。

セレクチンと IgCAM は一過性の細胞相互作用に関与し、細胞を標的部位に向けることに関与します。 例えば、それらは二次リンパ器官へのリンパ球の選択的補充に役立ちます。

CAMと多細胞性

CAM は、海綿動物や単純な線虫から複雑な無脊椎動物や脊椎動物に至るまで、事実上すべての多細胞生物にわたって見られます。 細胞相互作用の複雑さ、したがって CAM の複雑さは、生物の複雑さとともに増加します。 たとえば、ショウジョウバエ D.melanogaster には細胞接着に関与する遺伝子が約 500 個ありますが、哺乳類のような複雑な脊椎動物には、さまざまな種類の CAM をコードする遺伝子が 1,000 個以上あります。

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細胞接着分子(CAM)は、多細胞性や組織や臓器系の協調的な機能にとって極めて重要です。彼らは物理的な...

cell-adhesion-molecules-types-and-functions

Education

JoVE Core

Cell Biology

細胞生物学

Unit 1

ユニット1

Cell-Cell Interactions

細胞間相互作用

KEY TERMS AND CONCEPTS

主要用語と概念

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 細胞生物学は、複雑な細胞プロセスを、わかりやすく包括的なアニメーション ビデオ レッスンで説明します。このコレクションは、細胞小器官や膜、細胞輸送、細胞のエネルギー学など、細胞の必須コンポーネントと機能に焦点を当てています。これは、実際の研究実験における細胞生物学の応用を実証する科学者による実際のビデオによって補足されています。

Cell Adhesion Molecules in Tissues

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