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α4β7 Integrin
Integrin α4β7 (Lymphocyte Peyer’s patch adhesion molecule-1) is an integrin heterodimer composed of CD49d (alpha-4) subunit and beta-7 subunit noncovalently linked. LPAM-1 is expressed on the cell surface of leukocytes. This receptor is involved in lymphocyte trafficking pathway to site of inflammation in intestinal tissues. Structure LPAM-1 α and β subunits are composed of a large extracellular domain, a short transmembrane region Cell surface receptors (membrane receptors, transmembrane receptors) are receptors that are embedded in the plasma membrane of cells. They act in cell signaling by receiving (binding to) extracellular molecules. They are specialized integral me ... and a cytoplasmic tail. Its ligand specificity depends on both α4 and β7 subunits. The binding head of the β7 chain has three metal-binding sites that contributes to the cation-dependent (Ca2+, Mg2+ and Mn2+) allosteric conformational activation of the integrin α4β7. These three sites ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Integrin
Integrins are transmembrane receptors that help cell–cell and cell–extracellular matrix (ECM) adhesion. Upon ligand binding, integrins activate signal transduction pathways that mediate cellular signals such as regulation of the cell cycle, organization of the intracellular cytoskeleton, and movement of new receptors to the cell membrane. The presence of integrins allows rapid and flexible responses to events at the cell surface (''e.g''. signal platelets to initiate an interaction with coagulation factors). Several types of integrins exist, and one cell generally has multiple different types on its surface. Integrins are found in all animals while integrin-like receptors are found in plant cells. Integrins work alongside other proteins such as cadherins, the immunoglobulin superfamily cell adhesion molecules, selectins and syndecans, to mediate cell–cell and cell–matrix interaction. Ligands for integrins include fibronectin, vitronectin, collagen and laminin. Stru ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heterodimer
In biochemistry, a protein dimer is a macromolecular complex or multimer formed by two protein monomers, or single proteins, which are usually non-covalently bound. Many macromolecules, such as proteins or nucleic acids, form dimers. The word ''dimer'' has roots meaning "two parts", '' di-'' + '' -mer''. A protein dimer is a type of protein quaternary structure. A protein homodimer is formed by two identical proteins while a protein heterodimer is formed by two different proteins. Most protein dimers in biochemistry are not connected by covalent bonds. An example of a non-covalent heterodimer is the enzyme reverse transcriptase, which is composed of two different amino acid chains. An exception is dimers that are linked by disulfide bridges such as the homodimeric protein NEMO. Some proteins contain specialized domains to ensure dimerization (dimerization domains) and specificity. The G protein-coupled cannabinoid receptors have the ability to form both homo- and hetero ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Integrin Alpha 4
CD49d is an integrin alpha subunit. It makes up half of the α4β1 lymphocyte homing receptor. Function The product of this gene belongs to the integrin alpha chain family of proteins. Integrins are heterodimeric integral membrane proteins composed of an alpha chain and a beta chain. This gene encodes an alpha 4 chain. Unlike other integrin alpha chains, alpha 4 neither contains an I-domain, nor undergoes disulfide-linked cleavage. Alpha 4 chain associates with either beta 1 chain or beta 7 chain. Interactions CD49d has been shown to interact with LGALS8 and Paxillin Paxillin is a protein that in humans is encoded by the ''PXN'' gene. Paxillin is expressed at focal adhesions of non-striated cells and at costameres of striated muscle cells, and it functions to adhere cells to the extracellular matrix. Mutati .... See also * Carotegrast methyl, an integrin alpha 4 antagonist used for the treatment of ulcerative colitis References Further reading * * * * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Integrin Beta 7
Integrin beta-7 is an integrin protein that in humans is encoded by the ''ITGB7'' gene. It can pair with ITGA4 (CD49d) to form the heterodimeric integrin receptor αβ, or with ITGAE (CD103) to form αβ. Structure Like all integrin subunits, β is a highly flexible, membrane-bound, extracellular protein that must pair with an α subunit for stability. The molecule's flexibility allows it to dynamically regulate its affinity for ligand through conformational changes. Beginning with the apical end of the protein, farthest from the cell membrane, the β is composed of a head and upper legs, collectively known as the headpiece, lower legs, a transmembrane domain and a cytoplasmic tail. The top of the head is the I-like domain, sometimes called the βI domain, which, in combination with the α subunit, binds ligand. Just below this is the hybrid domain, a portion of which is N-terminal to the I-like domain. Below the hybrid domain is the PSI domain, which completes the headpiece ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extracellular Domain
An ectodomain is the domain of a membrane protein that extends into the extracellular space (the space outside a cell). Ectodomains are usually the parts of proteins that initiate contact with surfaces, which leads to signal transduction. A notable example of an ectodomain is the S protein, commonly known as the spike protein, of the viral particle responsible for the COVID-19 pandemic. The ectodomain region of the spike protein (S) is essential for attachment and eventual entry of the viral protein into the host cell. Ectodomains play a crucial part in the signaling pathways of viruses. Recent findings have indicated that certain antibodies including the anti-receptor binding domain (anti-RBD) or anti-spike ectodomain (anti-ECD) IgG titers can act as virus neutralization titers (VN titers) which can be identified in individuals with diseases, dyspnea and hospitalizations. In perspective of severe acute respiratory syndrome corona virus 2 (SARS-Cov-2) these specific ectodomains m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transmembrane Region
Cell surface receptors (membrane receptors, transmembrane receptors) are receptors that are embedded in the plasma membrane of cells. They act in cell signaling by receiving (binding to) extracellular molecules. They are specialized integral membrane proteins that allow communication between the cell and the extracellular space. The extracellular molecules may be hormones, neurotransmitters, cytokines, growth factors, cell adhesion molecules, or nutrients; they react with the receptor to induce changes in the metabolism and activity of a cell. In the process of signal transduction, ligand binding affects a cascading chemical change through the cell membrane. Structure and mechanism Many membrane receptors are transmembrane proteins. There are various kinds, including glycoproteins and lipoproteins. Hundreds of different receptors are known and many more have yet to be studied. Transmembrane receptors are typically classified based on their tertiary (three-dimensional) struc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein Complexes
A protein complex or multiprotein complex is a group of two or more associated polypeptide chains. Protein complexes are distinct from multidomain enzymes, in which multiple catalytic domains are found in a single polypeptide chain. Protein complexes are a form of quaternary structure. Proteins in a protein complex are linked by non-covalent protein–protein interactions. These complexes are a cornerstone of many (if not most) biological processes. The cell is seen to be composed of modular supramolecular complexes, each of which performs an independent, discrete biological function. Through proximity, the speed and selectivity of binding interactions between enzymatic complex and substrates can be vastly improved, leading to higher cellular efficiency. Many of the techniques used to enter cells and isolate proteins are inherently disruptive to such large complexes, complicating the task of determining the components of a complex. Examples of protein complexes include the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
