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Signal Regulatory Protein
A Signal-regulatory protein (SIRP) is one of a family of transmembrane glycoproteins involved in immunological signalling, expressed mainly by myeloid cells. Members include : * Signal-regulatory protein alpha, ligand= CD47 * SIRPB1 * SIRPB2 * SIRPD * SIRPG Signal-regulatory protein gamma is a protein that in humans is encoded by the ''SIRPG'' gene. SIRPG has also recently been designated CD172G (cluster of differentiation 172G). The protein encoded by this gene is a member of the signal-regulatory ..., ligand=CD47 References Single-pass transmembrane proteins {{membrane-protein-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transmembrane Protein
A transmembrane protein (TP) is a type of integral membrane protein that spans the entirety of the cell membrane. Many transmembrane proteins function as gateways to permit the transport of specific substances across the membrane. They frequently undergo significant conformational changes to move a substance through the membrane. They are usually highly hydrophobic and aggregate and precipitate in water. They require detergents or nonpolar solvents for extraction, although some of them (beta-barrels) can be also extracted using denaturing agents. The peptide sequence that spans the membrane, or the transmembrane segment, is largely hydrophobic and can be visualized using the hydropathy plot. Depending on the number of transmembrane segments, transmembrane proteins can be classified as single-span (or bitopic) or multi-span (polytopic). Some other integral membrane proteins are called monotopic, meaning that they are also permanently attached to the membrane, but do not pass ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glycoprotein
Glycoproteins are proteins which contain oligosaccharide chains covalently attached to amino acid side-chains. The carbohydrate is attached to the protein in a cotranslational or posttranslational modification. This process is known as glycosylation. Secreted extracellular proteins are often glycosylated. In proteins that have segments extending extracellularly, the extracellular segments are also often glycosylated. Glycoproteins are also often important integral membrane proteins, where they play a role in cell–cell interactions. It is important to distinguish endoplasmic reticulum-based glycosylation of the secretory system from reversible cytosolic-nuclear glycosylation. Glycoproteins of the cytosol and nucleus can be modified through the reversible addition of a single GlcNAc residue that is considered reciprocal to phosphorylation and the functions of these are likely to be an additional regulatory mechanism that controls phosphorylation-based signalling. In contrast, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Myeloid Cell
A myelocyte is a young cell of the granulocytic series, occurring normally in bone marrow (can be found in circulating blood when caused by certain diseases). Structure When stained with the usual dyes, the cytoplasm is distinctly basophilic and relatively more abundant than in myeloblasts or promyelocytes, even though myelocytes are smaller cells. Numerous cytoplasmic granules are present in the more mature forms of myelocytes. Neutrophilic and eosinophilic granules are peroxidase-positive, while basophilic granules are not. The nuclear chromatin is coarser than that observed in a promyelocyte, but it is relatively faintly stained and lacks a well-defined membrane. The nucleus is fairly regular in contour (not indented), and seems to be 'buried' beneath the numerous cytoplasmic granules. (If the nucleus were indented, it would likely be a metamyelocyte.) Measurement There is an internationally agreed method of counting blasts, with results from M1 upwards. Development ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Signal-regulatory Protein Alpha
Signal regulatory protein α (SIRPα) is a regulatory membrane glycoprotein from SIRP family expressed mainly by myeloid cells and also by stem cells or neurons. SIRPα acts as inhibitory receptor and interacts with a broadly expressed transmembrane protein CD47 also called the "don't eat me" signal. This interaction negatively controls effector function of innate immune cells such as host cell phagocytosis. SIRPα diffuses laterally on the macrophage membrane and accumulates at a phagocytic synapse to bind CD47 and signal 'self', which inhibits the cytoskeleton-intensive process of phagocytosis by the macrophage. This is analogous to the self signals provided by MHC class I molecules to NK cells via Ig-like or Ly49 receptors. NB. Protein shown to the right is CD47 not SIRP α. Structure The cytoplasmic region of SIRPα is highly conserved between rats, mice and humans. Cytoplasmic region contains a number of tyrosine residues, which likely act as ITIMs. Upon CD47 ligation, SIRP ... [...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 environmental chemi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CD47
CD47 (Cluster of Differentiation 47) also known as integrin associated protein (IAP) is a transmembrane protein that in humans is encoded by the CD47 gene. CD47 belongs to the immunoglobulin superfamily and partners with membrane integrins and also binds the ligands thrombospondin-1 ( TSP-1) and signal-regulatory protein alpha ( SIRPα). CD-47 acts as a ''don't eat me'' signal to macrophages of the immune system which has made it a potential therapeutic target in some cancers, and more recently, for the treatment of pulmonary fibrosis. CD47 is involved in a range of cellular processes, including apoptosis, proliferation, adhesion, and migration. Furthermore, it plays a key role in immune and angiogenic responses. CD47 is ubiquitously expressed in human cells and has been found to be overexpressed in many different tumor cells. Expression in equine cutaneous tumors has been reported as well. Structure CD47 is a 50 kDa membrane receptor that has extracellular N-termina ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SIRPB1
Signal-regulatory protein beta-1 is a protein that in humans is encoded by the ''SIRPB1'' gene. SIRPB1 has also recently been designated CD172B (cluster of differentiation 172B). The protein encoded by this gene is a member of the signal-regulatory-protein (SIRP) family, and also belongs to the immunoglobulin superfamily. SIRP family members are receptor-type transmembrane glycoproteins known to be involved in the negative regulation of receptor tyrosine kinase-coupled signaling processes. This protein was found to interact with TYROBP/DAP12, a protein bearing immunoreceptor tyrosine-based activation motifs. This protein was also reported to participate in the recruitment of tyrosine kinase SYK. Alternatively spliced transcript variants have been found for this gene. Interactions SIRPB1 has been shown to interact with 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 trans ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SIRPG
Signal-regulatory protein gamma is a protein that in humans is encoded by the ''SIRPG'' gene. SIRPG has also recently been designated CD172G (cluster of differentiation 172G). The protein encoded by this gene is a member of the signal-regulatory protein (SIRP) family, and also belongs to the immunoglobulin superfamily The immunoglobulin superfamily (IgSF) is a large protein superfamily of cell surface and soluble proteins that are involved in the recognition, binding, or adhesion processes of cells. Molecules are categorized as members of this superfamily .... SIRP family members are receptor-type transmembrane glycoproteins known to be involved in the negative regulation of receptor tyrosine kinase-coupled signaling processes. Alternatively spliced transcript variants encoding different isoforms have been described. References Further reading * * * * * * * External links PDBe-KBprovides an overview of all the structure information available in the PDB for Human Si ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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