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Immunoreceptor Tyrosine Activation Motif
An immunoreceptor tyrosine-based activation motif (ITAM) is a conserved sequence of four amino acids that is repeated twice in the cytoplasmic tails of non-catalytic tyrosine-phosphorylated receptors, cell-surface proteins found mainly on immune cells. Its major role is being an integral component for the initiation of a variety of signaling pathway and subsequently the activation of immune cells, although different functions have been described, for example an osteoclast maturation. Structure The motif contains a tyrosine separated from a leucine or isoleucine by any two other amino acids, giving the signature YxxL/I. Two of these signatures are typically separated by between 6 and 8 amino acids in the cytoplasmic tail of the molecule (YxxL/Ix(6-8)YxxL/I). However, it is worth noting that in various sources, this consensus sequence differs, mainly in the number of amino acids between individual signatures. Apart from ITAMs which have the structure described above, there is also ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amino Acid
Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although hundreds of amino acids exist in nature, by far the most important are the alpha-amino acids, which comprise proteins. Only 22 alpha amino acids appear in the genetic code. Amino acids can be classified according to the locations of the core structural functional groups, as Alpha and beta carbon, alpha- , beta- , gamma- or delta- amino acids; other categories relate to Chemical polarity, polarity, ionization, and side chain group type (aliphatic, Open-chain compound, acyclic, aromatic, containing hydroxyl or sulfur, etc.). In the form of proteins, amino acid '' residues'' form the second-largest component (water being the largest) of human muscles and other tissues. Beyond their role as residues in proteins, amino acids participate in a number of processes such as neurotransmitter transport and biosynthesis. It is thought that they played a key role in enabling l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ligand
In coordination chemistry, a ligand is an ion or molecule ( functional group) that binds to a central metal atom to form a coordination complex. The bonding with the metal generally involves formal donation of one or more of the ligand's electron pairs, often through Lewis bases. The nature of metal–ligand bonding can range from covalent to ionic. Furthermore, the metal–ligand bond order can range from one to three. Ligands are viewed as Lewis bases, although rare cases are known to involve Lewis acidic "ligands". Metals and metalloids are bound to ligands in almost all circumstances, although gaseous "naked" metal ions can be generated in a high vacuum. Ligands in a complex dictate the reactivity of the central atom, including ligand substitution rates, the reactivity of the ligands themselves, and redox. Ligand selection requires critical consideration in many practical areas, including bioinorganic and medicinal chemistry, homogeneous catalysis, and environment ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CD64 (biology)
CD64 (Cluster of Differentiation 64) is a type of integral membrane glycoprotein known as an Fc receptor that binds monomeric IgG-type antibodies with high affinity. It is more commonly known as Fc-gamma receptor 1 (FcγRI). After binding IgG, CD64 interacts with an accessory chain known as the common γ chain (γ chain), which possesses an ITAM motif that is necessary for triggering cellular activation. Structurally CD64 is composed of a signal peptide that allows its transport to the surface of a cell, three extracellular immunoglobulin domains of the C2-type that it uses to bind antibody, a hydrophobic transmembrane domain, and a short cytoplasmic tail. CD64 is constitutively found on only macrophages and monocytes, but treatment of polymorphonuclear leukocytes with cytokines like IFNγ and G-CSF can induce CD64 expression on these cells. There are three distinct (but highly similar) genes in humans for CD64 called FcγRIA (CD64A), FcγRIB (CD64B), and FcγRIC (CD64 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FCAR
Fc fragment of IgA receptor (''FCAR'') is a human gene that codes for the transmembrane receptor FcαRI, also known as CD89 (Cluster of Differentiation 89). FcαRI binds the heavy-chain constant region of Immunoglobulin A (IgA) antibodies. FcαRI is present on the cell surface of myeloid lineage cells, including neutrophils, monocytes, macrophages, and eosinophils, though it is notably absent from intestinal macrophages and does not appear on mast cells. FcαRI plays a role in both pro- and anti-inflammatory responses depending on the state of IgA bound. Inside-out signaling primes FcαRI in order for it to bind its ligand, while outside-in signaling caused by ligand binding depends on FcαRI association with the Fc receptor gamma chain (FcR γ-chain). Though FcαRI is part of the Fc receptor immunoglobulin superfamily, the protein's primary structure is similar to receptors in the leukocyte receptor cluster (LRC), and the ''FCAR'' gene appears amidst LRC genes on chromosome 19. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TYROBP
TYRO protein tyrosine kinase-binding protein is an adapter protein that in humans is encoded by the ''TYROBP'' gene. Function This gene encodes a transmembrane signaling polypeptide which contains an immunoreceptor tyrosine-based activation motif (ITAM) in its cytoplasmic domain. The encoded protein may associate with the killer cell immunoglobulin-like receptor (KIR) family of membrane glycoproteins and may act as an activating signal transduction element. This protein may bind zeta-chain associated protein kinase 70 kDa (ZAP-70) and spleen tyrosine kinase (SYK) and play a role in signal transduction, bone modeling, brain myelination, and inflammation. Mutations within this gene have been associated with polycystic lipomembranous osteodysplasia with sclerosing leukoencephalopathy (PLOSL), also known as Nasu-Hakola disease. Its putative receptor, triggering receptor expressed on myeloid cells 2 (TREM2), also causes PLOSL. Two alternative transcript variants encoding distin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
T-cell Surface Glycoprotein CD3 Epsilon Chain
CD3e molecule, epsilon also known as CD3E is a polypeptide which in humans is encoded by the ''CD3E'' gene which resides on chromosome 11. Function The protein encoded by this gene is the CD3-epsilon polypeptide, which together with CD3-gamma, - delta and -zeta, and the T-cell receptor alpha/beta and gamma/delta heterodimers, forms the T cell receptor- CD3 complex. This complex plays an important role in coupling antigen recognition to several intracellular signal-transduction pathways. The genes encoding the epsilon, gamma and delta polypeptides are located in the same cluster on chromosome 11. The epsilon polypeptide plays an essential role in T-cell development. Clinical significance Defects in this gene cause severe immunodeficiency. This gene has also been linked to a susceptibility to type I diabetes in women. Interactions T-cell surface glycoprotein CD3 epsilon chain has been shown to interact with TOP2B, CD3EAP and NCK2. See also * CD3 (immunology) * Cluster ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CD3D
T-cell surface glycoprotein CD3 delta chain is a protein that in humans is encoded by the ''CD3D'' gene. Interactions CD3D has been shown to interact with CD8A. See also * CD3 (immunology) * Cluster of differentiation The cluster of differentiation (also known as cluster of designation or classification determinant and often abbreviated as CD) is a protocol used for the identification and investigation of cell surface molecules providing targets for immunophen ... References Further reading * * * * * * * * * * * * * * * * * * * External links * * PDBe-KBprovides an overview of all the structure information available in the PDB for Human T-cell surface glycoprotein CD3 delta chain (CD3D) Clusters of differentiation {{membrane-protein-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CD3G
T-cell surface glycoprotein CD3 gamma chain is a protein that in humans is encoded by the ''CD3G'' gene. T cell antigen receptor (TCR) is associated on the T cell surface with a complex of protein called CD3. CD3G (gamma chain) is one of the four peptides (gamma, delta, epsilon and zeta) that form CD3. Defects in CD3G are associated with T cell immunodeficiency. See also * CD3 (immunology) * Cluster of differentiation The cluster of differentiation (also known as cluster of designation or classification determinant and often abbreviated as CD) is a protocol used for the identification and investigation of cell surface molecules providing targets for immunophen ... References Further reading * * * * * * * * * * * * * * * * * * * * External links * * Clusters of differentiation {{membrane-protein-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
INPP5D
Src homology 2 (SH2) domain containing inositol polyphosphate 5-phosphatase 1 (SHIP1) is an enzyme with phosphatase activity. SHIP1 is structured by multiple domain and is encoded by the ''INPP5D'' gene in humans. SHIP1 is expressed predominantly by hematopoietic cells but also, for example, by osteoblasts and endothelial cells. This phosphatase is important for the regulation of cellular activation. Not only catalytic but also adaptor activities of this protein are involved in this process. Its movement from the cytosol to the cytoplasmic membrane, where predominantly performs its function, is mediated by tyrosine phosphorylation of the intracellular chains of cell surface receptors that SHIP1 binds. Insufficient regulation of SHIP1 leads to different pathologies. Structure and regulation of activity SHIP1 is a 145 kDa large protein and member of the inositol polyphosphate-5-phosphatase (INPP5) family. Alternate transcriptional splice variants, encoding different isoforms, ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PTPN11
Tyrosine-protein phosphatase non-receptor type 11 (PTPN11) also known as protein-tyrosine phosphatase 1D (PTP-1D), Src homology region 2 domain-containing phosphatase-2 (SHP-2), or protein-tyrosine phosphatase 2C (PTP-2C) is an enzyme that in humans is encoded by the ''PTPN11'' gene. PTPN11 is a protein tyrosine phosphatase (PTP) Shp2. PTPN11 is a member of the protein tyrosine phosphatase (PTP) family. PTPs are known to be signaling molecules that regulate a variety of cellular processes including cell growth, differentiation, mitotic cycle, and oncogenic transformation. This PTP contains two tandem Src homology-2 domains, which function as phospho-tyrosine binding domains and mediate the interaction of this PTP with its substrates. This PTP is widely expressed in most tissues and plays a regulatory role in various cell signaling events that are important for a diversity of cell functions, such as mitogenic activation, metabolic control, transcription regulation, and cell migrati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PTPN6
Tyrosine-protein phosphatase non-receptor type 6, also known as Src homology region 2 domain-containing phosphatase-1 (SHP-1), is an enzyme that in humans is encoded by the ''PTPN6'' gene. Function The protein encoded by this gene is a member of the protein tyrosine phosphatase (PTP) family. PTPs are known to be signaling molecules that regulate a variety of cellular processes including cell growth, differentiation, mitotic cycle, and oncogenic transformation. N-terminal part of this PTP contains two tandem Src homolog ( SH2) domains, which act as protein phospho-tyrosine binding domains, and mediate the interaction of this PTP with its substrates. This PTP is expressed primarily in hematopoietic cells, and functions as an important regulator of multiple signaling pathways in hematopoietic cells. This PTP has been shown to interact with, and dephosphorylate a wide spectrum of phospho-proteins involved in hematopoietic cell signaling, (e.g., the LYN-CD22- SHP-1 pathway). Multiple ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Immunoreceptor Tyrosine-based Inhibitory Motif
An immunoreceptor tyrosine-based inhibitory motif (ITIM), is a conserved sequence of amino acids that is found intracellularly in the cytoplasmic domains of many inhibitory receptors of the non-catalytic tyrosine-phosphorylated receptor family found on immune cells. These immune cells include T cells, B cells, NK cells, dendritic cells, macrophages and mast cells. ITIMs have similar structures of S/I/V/LxYxxI/V/L, where x is any amino acid, Y is a tyrosine residue that can be phosphorylated, S is the amino acide Serine, I is the amino acid Isoleucine, and V is the amino acid Valine. ITIMs recruit SH2 domain-containing phosphatases, which inhibit cellular activation. ITIM-containing receptors often serve to target Immunoreceptor tyrosine-based activation motif(ITAM)-containing receptors, resulting in an innate inhibition mechanism within cells. ITIM bearing receptors have important role in regulation of immune system allowing negative regulation at different levels of the immune re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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