Name: desmosomes and cell anchoring
Uploaded: 2025-05-22T09:05:46.000Z
Duration: 1 min 5 s
Channel: JoVE

Desmozomlar, kalp kası ve bağırsak epiteli gibi mekanik stres yaşayan dokularda daha bol bulunan ankraj bağlantılarıdır.
Desmozomlarda hücre yapışması, hücre dışı alanlarının heterofilik etkileşimleri yoluyla yapışan desmozomal kaderinler, yani desmokolin ve desmoglein tarafından kolaylaştırılır.
Kaderinlerin sitoplazmik alanı, sitoplazmik tarafta yoğun bir plak oluşturan plakoglobinler ve plakofiller adı verilen kateninleri bağlar.
Kateninler, ara filamentleri doğrudan bağlayamazlar ve bunlara, plakin ailesine ait bir hücre iskeleti bağlayıcı proteini olan desmoplakin ile bağlanırlar.
Desmoplakin'in N-terminal alanı kateninleri bağlar ve C-terminal plakin tekrarları ara filamentleri bağlar.
Böylece, desmozom, bitişik hücrelerin ara filamentlerini sabitleyerek doku boyunca bir hücre içi iskelet ağı oluşturur.

<ol>
	<li>Delva, Emmanuella, Dana K. Tucker ve Andrew P. Kowalczyk. "Desmosome." Biyolojide Cold Spring Harbor perspektifleri 1.2 (2009): a002543.</li>
	<li>Garrod, David ve Martyn Chidgey. "Desmozom yapısı, bileşimi ve işlevi." Biochimica ve Biophysica Acta (BBA)-Biyomembranlar 1778.3 (2008): 572-587.</li>
	<li>Nekrasova, Oxana ve Kathleen J. Green. "Desmosome montajı ve dinamikleri." Hücre biyolojisindeki eğilimler 23.11 (2013): 537-546.</li>
</ol>

dezmozomlar

Desmosomes

Dezmozom terimi, "yapışma cisimleri" anlamına gelen Yunanca "desmo" ve "soma" kelimelerinden türemiştir. Bu yapı ilk kez 1800'lü yılların sonlarında gözlemlendi ve epidermiste küçük, yoğun nodüller olarak tanımlandı. Dezmozomlar, hücreler boyunca birbirine bağlı bir ara filament ağı oluşturmaya yardımcı olan düğme benzeri yapılardır. Bu bağlantılar, hücreleri mekanik stres altında bir arada tutmak ve doku bütünlüğünü korumak için gereklidir. Dezmozomlar, çeşitli adaptör proteinler yoluyla ara filamentlere bağlanan dezmozomal kaderinlerden oluşan çoklu protein kompleksleridir. Dezmozomal Kaderinler Kaderinler, bir desmozomun hücre dışı çekirdek bölgesini oluşturur ve bitişik hücredeki kaderinleri bağlar. Dezmozomlarda iki tip kaderin vardır; desmogleinler ve desmokolinler. Bu transmembran glikoproteinler, dört kaderin tekrarından ve bu proteinleri hücre membranına bağlayan bir hücre dışı ankor alanından oluşan büyük bir hücre dışı kısma sahiptir. Heterodimerik desmoglein ve desmokollin çiftleri, aynı hücre üzerindeki cis-etkileşimleri ve bitişik hücreler arasındaki trans-etkileşimleri yoluyla kümeler oluşturur. Sitoplazmik alanlarının uzunluğu, alternatif birleştirme nedeniyle farklı izoformlar arasında değişebilir - örneğin, insanlarda bulunan dört desmoglein izoformu ve üç desmokollin izoformu vardır. Desmozomlardaki Adaptör Proteinleri Dezmozomal kaderinlerin sitoplazmik alanları, yoğun bir plak oluşturan plakoglobin ve plakophilin adı verilen armadillo protein ailesine bağlanır. Bu proteinler, desmoplakin gibi farklı bağlayıcı proteinler için kenetlenme bölgesi olarak işlev gören karakteristik kol tekrarlarına sahiptir. Desmoplakin, desmozomal komplekste en bol bulunan proteindir. Karboksi terminalleri, ara filamenti bağlayan plakin tekrarlarını içerir, böylece desmozomal plak ile hücre iskeleti arasında bir bağlantı oluşturur. Dezmozom Disfonksiyonu Hastalıkları Dezmozomal disfonksiyon genellikle kalp ve cilt bozuklukları olarak ortaya çıkar; dokular tipik olarak yüksek düzeyde mekanik gerilime maruz kalır. Örneğin desmoglein genlerindeki mutasyonlar epidermal kalınlaşmaya ve aritmojenik sağ ventriküler kardiyomiyopatiye (ARVC) neden olabilir. Ek olarak, dezmozomal kaderinleri hedef alan otoantikorlar, hastaların zayıf hücre-hücre yapışması nedeniyle epidermal kabarcıklar sergilediği otoimmün hastalık pemfigus vulgarise neden olur.

Dezmozomlar

Desmozom terimi, Yunanca "yapışma cisimleri" anlamına gelen "desmo" ve "soma" kelimelerinden türemiştir. Bu yapı ilk olarak gözlendi ...

Education

JoVE Core

Cell Biology

Hücre Biyolojisi

Unit 1

Ünite 1

Cell-Cell Interactions

Hücre-Hücre Etkileşimleri

KEY TERMS AND CONCEPTS

TEMEL TERİMLER VE KAVRAMLAR

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 glycoproteins have a large extracellular region with four cadherin repeats and one anchor domain that holds them in the cell membrane.

Desmogleins and desmocollins can pair as heterodimers. They form clusters through cis-interactions on the same cell and trans-interactions between adjacent cells. In humans, there are four desmoglein isoforms and three desmocollin isoforms, and their cytoplasmic domains can differ in length because of alternative splicing.

Inside the cell, the cadherins bind armadillo family proteins called plakoglobin and plakophilin. These proteins form a dense plaque. The plaque then recruits desmoplakin, the most abundant protein in a desmosomal complex. Desmoplakin uses its carboxy-terminal plakin repeats to bind intermediate filaments, which connects the desmosome to the cytoskeleton.

Problems with desmosomes often show up in the heart and skin, where cells face high mechanical strain. Mutations in desmoglein genes can cause epidermal thickening and arrhythmogenic right ventricular cardiomyopathy, or ARVC. Autoantibodies against desmosomal cadherins can also cause pemphigus vulgaris, an autoimmune disease that leads to epidermal blisters because cell-cell adhesion becomes weak.

Desmosomes and Cell Anchoring

cell adhesion molecules - types and functions

cell-adhesion-molecules-types-and-functions

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...

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 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 desmosomes hold cells together, link to intermediate filaments, and why defects can affect skin and heart tissue in humans.

Desmosomes and Cell Anchoring | JoVE K12

cell biology

JoVE Core Hücre Biyolojisi, anlaşılması kolay ancak kapsamlı animasyonlu video derslerde karmaşık hücresel süreçleri gösterir. Bu koleksiyon, organeller ve zarlar, hücresel taşıma ve hücre enerjileri dahil olmak üzere hücrelerin temel bileşenlerine ve işlevlerine odaklanır. Gerçek dünya araştırma deneylerinde hücre biyolojisinin uygulanmasını gösteren bilim insanı eylem videoları ile tamamlanmaktadır.

Desmosomes and Cell Anchoring

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