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Non-catalytic Tyrosine-phosphorylated Receptors
Non-catalytic tyrosine-phosphorylated receptors (NTRs), also called immunoreceptors or Src-family kinase-dependent receptors, are a group of cell surface receptors expressed by White blood cell, leukocytes that are important for cell migration and the recognition of abnormal cells or structures and the initiation of an immune response. These transmembrane receptors are not grouped into the NTR family based on sequence homology, but because they share a conserved Cell signaling#signaling pathways, signaling pathway utilizing the same signaling motifs. A signaling cascade is initiated when the receptors bind their respective ligand resulting in cell activation. For that tyrosine residues in the cytoplasmic tail of the receptors have to be phosphorylated, hence the receptors are referred to as tyrosine-phosphorylated receptors. They are called non-catalytic receptors, as the receptors have no intrinsic tyrosine kinase activity and cannot phosphorylate their own tyrosine residues. Phosph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell Surface Receptors
Cell surface receptors (membrane receptors, transmembrane receptors) are receptor (biochemistry), receptors that are embedded in the cell membrane, plasma membrane of cell (biology), cells. They act in cell signaling by receiving (binding to) extracellular matrix, extracellular molecules. They are specialized integral membrane proteins that allow communication between the cell and the extracellular, 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 (biochemistry)#Receptor/ligand binding affinity, ligand binding affects a biochemical cascade, 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Actin
Actin is a family of globular multi-functional proteins that form microfilaments in the cytoskeleton, and the thin filaments in muscle fibrils. It is found in essentially all eukaryotic cells, where it may be present at a concentration of over 100 μM; its mass is roughly 42 kDa, with a diameter of 4 to 7 nm. An actin protein is the monomeric subunit of two types of filaments in cells: microfilaments, one of the three major components of the cytoskeleton, and thin filaments, part of the contractile apparatus in muscle cells. It can be present as either a free monomer called G-actin (globular) or as part of a linear polymer microfilament called F-actin (filamentous), both of which are essential for such important cellular functions as the mobility and contraction of cells during cell division. Actin participates in many important cellular processes, including muscle contraction, cell motility, cell division and cytokinesis, vesicle and organelle mov ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
KIR2DS1
Killer cell immunoglobulin-like receptor, two domains, short cytoplasmic tail, 1 is a protein that in humans is encoded by the KIR2DS1 gene In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei .... Function Killer cell immunoglobulin-like receptors (KIRs) are transmembrane glycoproteins expressed by natural killer cells and subsets of T cells. The KIR genes are polymorphic and highly homologous and they are found in a cluster on chromosome 19q13.4 within the 1 Mb leukocyte receptor complex (LRC). The gene content of the KIR gene cluster varies among haplotypes, although several 'framework' genes are found in all haplotypes ( KIR3DL3, KIR3DP1, KIR3DL4, KIR3DL2). The KIR proteins are classified by the number of extracellular immunoglobulin domains (2D or 3D) and by whether they ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
KIR3DL2
Killer cell immunoglobulin-like receptor 3DL2 is a protein that in humans is encoded by the ''KIR3DL2'' gene. Structure Killer cell immunoglobulin-like receptors (KIRs) are transmembrane glycoproteins expressed on natural killer (NK) cells and subsets of T cells. KIR proteins are classified based on the number of extracellular immunoglobulin (Ig) domains—either two (2D) or three (3D)—and the length of their cytoplasmic tails: long (L) or short (S). KIR3DL2 is a member of the 3DL family, containing three Ig-like domains and a long cytoplasmic tail. The long tail includes one or more immune tyrosine-based inhibitory motifs (ITIMs), which mediate inhibitory signaling upon ligand engagement. In contrast, KIRs with short cytoplasmic tails lack ITIMs and instead signal through association with TYRO protein tyrosine kinase binding protein, resulting in activating signals. The KIR genes are polymorphic and highly homologous, clustered on chromosome 19q13.4 within the 1 Mb leuk ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
KIR2DL1
Killer cell immunoglobulin-like receptor 2DL1 is a protein that in humans is encoded by the ''KIR2DL1'' gene In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei .... Function Killer-cell immunoglobulin-like receptors (KIRs) are transmembrane glycoproteins expressed by natural killer cells and subsets of T cells. The KIR genes are polymorphic and highly homologous and they are found in a cluster on chromosome 19q13.4 within the 1 Mb leukocyte receptor complex (LRC). The gene content of the KIR gene cluster varies among haplotypes, although several "framework" genes are found in all haplotypes (KIR3DL3, KIR3DP1, KIR2DL4, KIR3DL2). The KIR proteins are classified by the number of extracellular immunoglobulin domains (2D or 3D) and by whether they have a long (L) or short (S) cytoplasm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Killer-cell Immunoglobulin-like Receptors
Killer-cell immunoglobulin-like receptors (KIRs), are a family of type I Transmembrane protein, transmembrane glycoproteins expressed on the Cell membrane, plasma membrane of Natural killer cell, natural killer (NK) cells and a minority of T cells. In humans, they are encoded in the leukocyte receptor complex (LRC) on chromosome 19q13.4; the KIR region is approximately 150 kilobases and contains 14 loci, including 7 protein-coding genes (some duplicated) and 2 pseudogenes. They regulate the killing function of these cells by interacting with MHC class I, major histocompatibility (MHC) class I molecules, which are expressed on all nucleated cell types. KIR receptors can distinguish between MHC I allelic variants, which allows them to detect virus, virally infected cells or Malignant transformation, transformed cells. KIRs are paired receptors, meaning some have activating and others have inhibitory functions; most KIRs are inhibitory: their recognition of MHC molecules suppresses t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FCRL1
Fc receptor-like protein 1 is a protein that in humans is encoded by the ''FCRL1'' gene In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei .... References Further reading * * * * * Fc receptors {{gene-1-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fc Receptor-like Molecule
Fc receptor-like molecules (FCRLs) are a class of proteins that resemble Fc receptors. They have been characterized in a number of species, including humans and mice. A subset of FCRLs are preferentially expressed by B lymphocytes. Unlike the classical Fc receptors, there is no strong evidence that suggests that FCRLs bind to the Fc portion of antibodies. Their function is unknown. It has been indicated that FCRLs may be a unique marker for immune cells in the brain called microglia, compared to other CNS cells and peripheral immune cells. Members * FCRL1 * FCRL2 * FCRL3 * FCRL4 * FCRL5 * FCRL6 * FCRLA. FCRLA associates with IgM, IgG and IgA. * FCRLB See also * Fc receptor In immunology, an Fc receptor is a protein found on the surface of certain cells – including, among others, B lymphocytes, follicular dendritic cells, natural killer cells, macrophages, neutrophils, eosinophils, basophils, human platele ... References Further reading * * * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CD32
CD32 (cluster of differentiation 32), also known as FcγRII or FCGR2, is a surface receptor glycoprotein belonging to the Ig gene superfamily. CD32 can be found on the surface of a variety of immune cells. CD32 has a low-affinity for the Fc region of IgG antibodies in monomeric form, but high affinity for IgG immune complexes. CD32 has two major functions: cellular response regulation, and the uptake of immune complexes. Cellular responses regulated by CD32 include phagocytosis, cytokine stimulation, and endocytic transport. Dysregulated CD32 is associated with different forms of autoimmunity, including systemic lupus erythematosus. In humans, there are three major CD32 subtypes: CD32A, CD32B, and CD32C. While CD32A and CD32C are involved in activating cellular responses, CD32B is inhibitory. Structure and signaling CD32 is a type I transmembrane protein with a helical transmembrane region. Whereas the extracellular region consists of three immunoglobulin domains (roughly ... [...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 (CD64C) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antibody
An antibody (Ab) or immunoglobulin (Ig) is a large, Y-shaped protein belonging to the immunoglobulin superfamily which is used by the immune system to identify and neutralize antigens such as pathogenic bacteria, bacteria and viruses, including those that cause disease. Each individual antibody recognizes one or more specific antigens, and antigens of virtually any size and chemical composition can be recognized. Antigen literally means "antibody generator", as it is the presence of an antigen that drives the formation of an antigen-specific antibody. Each of the branching chains comprising the "Y" of an antibody contains a paratope that specifically binds to one particular epitope on an antigen, allowing the two molecules to bind together with precision. Using this mechanism, antibodies can effectively "tag" the antigen (or a microbe or an infected cell bearing such an antigen) for attack by cells of the immune system, or can neutralize it directly (for example, by blocking a p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fragment Crystallizable Region
The fragment crystallizable region (Fc region) is the tail region of an antibody that interacts with cell surface receptors called Fc receptors and some proteins of the complement system. This region allows antibodies to activate the immune system, for example, through binding to Fc receptors. In IgG, IgA and IgD antibody isotypes, the Fc region is composed of two identical protein fragments, derived from the second and third constant domains of the antibody's two heavy chains; IgM and IgE Fc regions contain three heavy chain constant domains (CH domains 2–4) in each polypeptide chain. The Fc regions of IgGs bear a highly conserved N-glycosylation site. Glycosylation of the Fc fragment is essential for Fc receptor-mediated activity. The N-glycans attached to this site are predominantly core- fucosylated diantennary structures of the complex type. In addition, small amounts of these N-glycans also bear bisecting GlcNAc and α-2,6 linked sialic acid residues. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
