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Insulin-like Growth Factor 2 Receptor
Insulin-like growth factor 2 receptor (IGF2R), also called the cation-independent mannose-6-phosphate receptor (CI-MPR) is a protein that in humans is encoded by the ''IGF2R'' gene. IGF2R is a multifunctional protein receptor that binds insulin-like growth factor 2 (IGF2) at the cell surface and mannose-6-phosphate (M6P)-tagged proteins in the ''trans''- Golgi network. Structure The structure of the IGF2R is a type I transmembrane protein (that is, it has a single transmembrane domain with its C-terminus on the cytoplasmic side of lipid membranes) with a large extracellular/lumenal domain and a relatively short cytoplasmic tail. The extracellular domain consists of a small region homologous to the collagen-binding domain of fibronectin and of fifteen repeats of approximately 147 amino acid residues. Each of these repeats is homologous to the 157-residue extracytoplasmic domain of the mannose 6-phosphate receptor. Binding to IGF2 is mediated through one of the repeats, while tw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, responding to stimuli, providing structure to cells and organisms, and transporting molecules from one location to another. Proteins differ from one another primarily in their sequence of amino acids, which is dictated by the nucleotide sequence of their genes, and which usually results in protein folding into a specific 3D structure that determines its activity. A linear chain of amino acid residues is called a polypeptide. A protein contains at least one long polypeptide. Short polypeptides, containing less than 20–30 residues, are rarely considered to be proteins and are commonly called peptides. The individual amino acid residues are bonded together by peptide bonds and adjacent amino acid residues. The sequence of amino acid residue ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acid Hydrolase
An acid hydrolase is an enzyme that works best at acidic pHs. It is commonly located in lysosomes, which are acidic on the inside. Acid hydrolases may be nucleases, proteases, glycosidases, lipases, phosphatases, sulfatases and phospholipases and make up the approximately 50 degradative enzymes of the lysosome that break apart biological matter. types of Acid Hydrolase: -Nucleases (P1 from Penicillium citrinum, used in the food industry for taste enhancement or present in Gouda cheese) -Lipase: for example lysosomal acid lipase. -Proteases -Glycosidases See also *Antimicrobial peptides *Cathelicidin *Hydrolase Hydrolase is a class of enzyme that commonly perform as biochemical catalysts that use water to break a chemical bond, which typically results in dividing a larger molecule into smaller molecules. Some common examples of hydrolase enzymes are este ... References EC 3.1.1 {{3.1-enzyme-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mannose 6-phosphate Receptor
The mannose 6-phosphate receptors (MPRs) are transmembrane glycoproteins that target enzymes to lysosomes in vertebrates. Mannose 6-phosphate receptors bind newly synthesized lysosomal hydrolases in the trans-Golgi network (TGN) and deliver them to pre-lysosomal compartments. There are two different MPRs, one of ~300kDa and a smaller, dimeric receptor of ~46kDa. The larger receptor is known as the cation-independent mannose 6-phosphate receptor ( CI-MPR), while the smaller receptor ( CD-MPR) requires divalent cations to efficiently recognize lysosomal hydrolases. While divalent cations are not essential for ligand binding by the human CD-MPR, the nomenclature has been retained. Both of these receptors bind terminal mannose 6-phosphate with similar affinity (CI-MPR = 7 μM, CD-MPR = 8 μM) and have similar signals in their cytoplasmic domains for intracellular trafficking. History Elizabeth Neufeld was studying patients who had multiple inclusion bodies present in their ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IGF-1 Receptor
The insulin-like growth factor 1 (IGF-1) receptor is a protein found on the surface of human cells. It is a transmembrane receptor that is activated by a hormone called insulin-like growth factor 1 (IGF-1) and by a related hormone called IGF-2. It belongs to the large class of tyrosine kinase receptors. This receptor mediates the effects of IGF-1, which is a polypeptide protein hormone similar in molecular structure to insulin. IGF-1 plays an important role in growth and continues to have anabolic effects in adults – meaning that it can induce hypertrophy of skeletal muscle and other target tissues. Mice lacking the IGF-1 receptor die late in development, and show a dramatic reduction in body mass. This testifies to the strong growth-promoting effect of this receptor. Structure Two alpha subunits and two beta subunits make up the IGF-1 receptor. Both the α and β subunits are synthesized from a single mRNA precursor. The precursor is then glycosylated, proteolytically cle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 immunophenotyping of cells. In terms of physiology, CD molecules can act in numerous ways, often acting as receptors or ligands important to the cell. A signal cascade is usually initiated, altering the behavior of the cell (see cell signaling). Some CD proteins do not play a role in cell signaling, but have other functions, such as cell adhesion. CD for humans is numbered up to 371 (). Nomenclature The CD nomenclature was proposed and established in the 1st International Workshop and Conference on Human Leukocyte Differentiation Antigens (HLDA), which was held in Paris in 1982. This system was intended for the classification of the many monoclonal antibodies (mAbs) generated by different laboratories around the world against epitopes on the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
M6PRBP1
Mannose-6-phosphate receptor binding protein 1 (M6PRBP1) is a protein which in humans is encoded by the ''M6PRBP1'' gene. Its gene product, as well as the gene itself, is commonly known as TIP47. Function Mannose 6-phosphate receptors (MPRs) deliver lysosomal hydrolase from the Golgi to endosomes and then return to the Golgi complex. The protein encoded by this gene interacts with the cytoplasmic domains of both cation-independent and cation-dependent MPRs, and is required for endosome-to-Golgi transport. This protein also binds directly to the GTPase RAB9 (RAB9A), a member of the RAS oncogene family. The interaction with RAB9 has been shown to increase the affinity of this protein for its cargo. The mannose-6-phosphate receptor-binding properties of TIP47 are disputed, despite the designation of M6PRBP1 as TIP47's gene symbol. TIP47 protein is most commonly described in the scientific literature as a coat protein for lipid droplets. TIP47 belongs to the peripilin protein ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Retromer
Retromer is a complex of proteins that has been shown to be important in recycling transmembrane receptors from endosomes to the Golgi apparatus, ''trans''-Golgi network (TGN). Background Retromer is a heteropentameric complex, which in humans is composed of a less defined membrane-associated sorting nexin dimer (SNX1, SNX2, SNX5, SNX6), and a vacuolar protein sorting (Vps) trimer containing VPS26A, Vps26, VPS29, Vps29, VPS35, Vps35. Although the SNX dimer is required for the recruitment of retromer to the endosomal membrane, the cargo binding function of this complex is contributed by the core trimer through the binding of Vps35 subunit to various cargo molecules including cation-dependent mannose-6-phosphate receptor, M6PR GPR177, wntless and sortilin 1, sortilin. Early study on sorting of acid hydrolases such as carboxypeptidase Y (CPY) in S. cerevisiae mutants has led to the identification of retromer in mediating the retrograde trafficking of the pro-CPY receptor (SORCS1, Vp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endosome
Endosomes are a collection of intracellular sorting organelles in eukaryotic cells. They are parts of endocytic membrane transport pathway originating from the trans Golgi network. Molecules or ligands internalized from the plasma membrane can follow this pathway all the way to lysosomes for degradation or can be recycled back to the cell membrane in the endocytic cycle. Molecules are also transported to endosomes from the trans Golgi network and either continue to lysosomes or recycle back to the Golgi apparatus. Endosomes can be classified as early, sorting, or late depending on their stage post internalization. Endosomes represent a major sorting compartment of the endomembrane system in cells. Function Endosomes provide an environment for material to be sorted before it reaches the degradative lysosome. For example, low-density lipoprotein (LDL) is taken into the cell by binding to the LDL receptor at the cell surface. Upon reaching early endosomes, the LDL dissociates ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GGA1
ADP-ribosylation factor-binding protein GGA1 is a protein that in humans is encoded by the ''GGA1'' gene. This gene encodes a member of the Golgi-localized, gamma adaptin ear-containing, ARF-binding (GGA) protein family. Members of this family are ubiquitous coat proteins that regulate the trafficking of proteins between the trans-Golgi network and the lysosome. These proteins share an amino-terminal VHS domain which mediates sorting of the mannose 6-phosphate receptors at the trans-Golgi network. They also contain a carboxy-terminal region with homology to the ear domain of gamma-adaptins. Multiple alternatively spliced transcript variants encoding different isoforms have been found for this gene. Interactions GGA1 has been shown to interact with Sortilin 1, BACE2, RABEP1 and ARF3 ADP-ribosylation factor 3 is a protein that in humans is encoded by the ''ARF3'' gene. Function ADP-ribosylation factor 3 (ARF3) is a member of the human ARF gene family. These genes encode smal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lumen (anatomy)
In biology, a lumen (plural lumina) is the inside space of a tubular structure, such as an artery or intestine. It comes . It can refer to: *The interior of a vessel, such as the central space in an artery, vein or capillary through which blood flows. *The interior of the gastrointestinal tract *The pathways of the bronchi in the lungs *The interior of renal tubules and urinary collecting ducts *The pathways of the female genital tract, starting with a single pathway of the vagina, splitting up in two lumina in the uterus, both of which continue through the Fallopian tubes In cell biology, a lumen is a membrane-defined space that is found inside several organelles, cellular components, or structures: *thylakoid, endoplasmic reticulum, Golgi apparatus, lysosome, mitochondrion, or microtubule Transluminal procedures ''Transluminal procedures'' are procedures occurring through lumina, including: *Natural orifice transluminal endoscopic surgery in the lumina of, for example, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endocytosis
Endocytosis is a cellular process in which substances are brought into the cell. The material to be internalized is surrounded by an area of cell membrane, which then buds off inside the cell to form a vesicle containing the ingested material. Endocytosis includes pinocytosis (cell drinking) and phagocytosis (cell eating). It is a form of active transport. History The term was proposed by De Duve in 1963. Phagocytosis was discovered by Élie Metchnikoff in 1882. Pathways Endocytosis pathways can be subdivided into four categories: namely, receptor-mediated endocytosis (also known as clathrin-mediated endocytosis), caveolae, pinocytosis, and phagocytosis Phagocytosis () is the process by which a cell uses its plasma membrane to engulf a large particle (≥ 0.5 μm), giving rise to an internal compartment called the phagosome. It is one type of endocytosis. A cell that performs phagocytosis is .... *Clathrin-mediated endocytosis is mediated by the production of smal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
