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ADAM12
Disintegrin and metalloproteinase domain-containing protein 12 (previously Meltrin) is an enzyme that in humans is encoded by the ''ADAM12'' gene. ADAM12 has two splice variants: ADAM12-L, the long form, has a transmembrane region and ADAM12-S, a shorter variant, is soluble and lacks the transmembrane and cytoplasmic domains. Function This gene encodes a member of the ADAM (a disintegrin and metalloprotease) protein family. Members of this family are membrane-anchored proteins structurally related to snake venom disintegrins, and have been implicated in a variety of biological processes involving cell-cell and cell-matrix interactions, including fertilization, muscle development, and neurogenesis. This gene has two alternatively spliced transcripts: a shorter secreted form and a longer membrane-bound form. The shorter form is found to stimulate myogenesis. Clinical Significance ADAM 12, a metalloprotease that binds insulin growth factor binding protein-3 (IGFBP-3), appear ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Actinin, Alpha 2
Alpha-actinin-2 is a protein which in humans is encoded by the ''ACTN2'' gene. This gene encodes an alpha-actinin isoform that is expressed in both skeletal and cardiac muscles and functions to anchor myofibrillar actin thin filaments and titin to Z-discs. Structure Alpha-actinin-2 is a 103.8 kDa protein composed of 894 amino acids. Each molecule is rod-shaped (35 nm in length) and it homodimerizes in an anti-parallel fashion. Each monomer has an N-terminal actin-binding region composed of two calponin homology domains, two C-terminal EF hand domains, and four tandem spectrin-like repeats form the rod domain in the central region of the molecule. The high-resolution crystal structure of human alpha-actinin 2 at 3.5 Å was recently resolved. Alpha actinins belong to the spectrin gene superfamily which represents a diverse group of actin-binding cytoskeletal proteins, including spectrin, dystrophin, utrophin and fimbrin. Skeletal, cardiac, and smooth muscle isoforms are loca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
A Disintegrin And Metalloprotease
ADAMs (short for a disintegrin and metalloproteinase) are a family of single-pass transmembrane and secreted metalloendopeptidases. All ADAMs are characterized by a particular protein domain, domain organization featuring a pro-domain, a metalloprotease, a disintegrin, a cysteine-rich, an epidermal-growth factor like and a transmembrane domain, as well as a C-terminal cytoplasmic tail. Nonetheless, not all human ADAMs have a functional protease domain, which indicates that their biological function mainly depends on protein–protein interactions. Those ADAMs which are active proteases are classified as sheddases because they cut off or shed extracellular portions of transmembrane proteins. For example, ADAM10 can cut off part of the HER2 receptor, thereby activating it. ADAM genes are found in animals, choanoflagellates, fungi and some groups of green algae. Most green algae and all land plants probably had ADAM proteins but lost them. ADAMs are categorized under the enzyme gro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metalloprotease
A metalloproteinase, or metalloprotease, is any protease enzyme whose catalytic mechanism involves a metal. An example is ADAM12 which plays a significant role in the fusion of muscle cells during embryo development, in a process known as myogenesis. Most metalloproteases require zinc, but some use cobalt. The metal ion is coordinated to the protein via three ligands. The ligands coordinating the metal ion can vary with histidine, glutamate, aspartate, lysine, and arginine. The fourth coordination position is taken up by a labile water molecule. Treatment with chelating agents such as EDTA leads to complete inactivation. EDTA is a metal chelator that removes zinc, which is essential for activity. They are also inhibited by the chelator orthophenanthroline. Classification There are two subgroups of metalloproteinases: * Exopeptidases, metalloexopeptidases ( EC number: 3.4.17). * Endopeptidases, metalloendopeptidases (3.4.24). Well known metalloendopeptidases include ADAM prot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PIK3R1
Phosphatidylinositol 3-kinase regulatory subunit alpha is an enzyme that in humans is encoded by the ''PIK3R1'' gene. Function Phosphatidylinositol 3-kinase phosphorylates the inositol ring of phosphatidylinositol at the 3-prime position. The enzyme comprises a 110 kD catalytic subunit and a regulatory subunit of either 85, 55, or 50 kD. The ''Pik3r1'' gene locus encodes the 85 kD regulatory subunit, as well as 55 and 50 kD regulatory subunits. It used to be thought that alternative splicing of this gene resulted in three transcript variants encoding different isoforms. In fact, it has since been shown that the 55 and 50kD subunits have their own promotors within the gene locus ''Pik3r1''. Phosphatidylinositol 3-kinase plays an important role in the metabolic actions of insulin, and a mutation in this gene has been associated with insulin resistance. Suppression specifically of the 85kD subunit in early murine embryoid body development results in a transient cell-cell adhe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IGFBP3
Insulin-like growth factor-binding protein 3, also known as IGFBP-3, is a protein that in humans is encoded by the ''IGFBP3'' gene. IGFBP-3 is one of six insulin-like growth factor-binding protein, IGF binding proteins (IGFBP1, IGFBP-1 to IGFBP6, IGFBP-6) that have highly conserved structures and bind the insulin-like growth factors IGF-1 and IGF-2 with high affinity. IGFBP7, IGFBP-7, sometimes included in this family, shares neither the conserved structural features nor the high IGF affinity. Instead, IGFBP7, IGFBP-7 binds IGF1R, which blocks IGF-1 and IGF-2 binding, resulting in apoptosis. Function IGFBP-3 was first isolated, characterized, and quantitated in human plasma, in 1986. It has well-documented functions in the circulation, in the extracellular environment, and inside cells. It is the main IGF transport protein in the bloodstream, where it carries the growth factors predominantly in stable complexes that contain the binding protein, either IGF-1 or IGF-2, and a third ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enzyme
An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different molecules known as product (chemistry), products. Almost all metabolism, metabolic processes in the cell (biology), cell need enzyme catalysis in order to occur at rates fast enough to sustain life. Metabolic pathways depend upon enzymes to catalyze individual steps. The study of enzymes is called ''enzymology'' and the field of pseudoenzyme, pseudoenzyme analysis recognizes that during evolution, some enzymes have lost the ability to carry out biological catalysis, which is often reflected in their amino acid sequences and unusual 'pseudocatalytic' properties. Enzymes are known to catalyze more than 5,000 biochemical reaction types. Other biocatalysts include Ribozyme, catalytic RNA molecules, also called ribozymes. They are sometimes descr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epithelium
Epithelium or epithelial tissue is a thin, continuous, protective layer of cells with little extracellular matrix. An example is the epidermis, the outermost layer of the skin. Epithelial ( mesothelial) tissues line the outer surfaces of many internal organs, the corresponding inner surfaces of body cavities, and the inner surfaces of blood vessels. Epithelial tissue is one of the four basic types of animal tissue, along with connective tissue, muscle tissue and nervous tissue. These tissues also lack blood or lymph supply. The tissue is supplied by nerves. There are three principal shapes of epithelial cell: squamous (scaly), columnar, and cuboidal. These can be arranged in a singular layer of cells as simple epithelium, either simple squamous, simple columnar, or simple cuboidal, or in layers of two or more cells deep as stratified (layered), or ''compound'', either squamous, columnar or cuboidal. In some tissues, a layer of columnar cells may appear to be stratified d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proteases
A protease (also called a peptidase, proteinase, or proteolytic enzyme) is an enzyme that catalyzes proteolysis, breaking down proteins into smaller polypeptides or single amino acids, and spurring the formation of new protein products. They do this by cleaving the peptide bonds within proteins by hydrolysis, a reaction where water breaks bonds. Proteases are involved in numerous biological pathways, including digestion of ingested proteins, protein catabolism (breakdown of old proteins), and cell signaling. In the absence of functional accelerants, proteolysis would be very slow, taking hundreds of years. Proteases can be found in all forms of life and viruses. They have independently evolved multiple times, and different classes of protease can perform the same reaction by completely different catalytic mechanisms. Classification Based on catalytic residue Proteases can be classified into seven broad groups: * Serine proteases - using a serine alcohol * Cysteine prot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atlas Of Genetics And Cytogenetics In Oncology And Haematology
The Atlas of Genetics and Cytogenetics in Oncology and Haematology, created in 1997 by Jean-Loup Huret (with bioinformatics by Philippe Dessen) is a collection of resources on genes, chromosomes anomalies, leukemias, solid tumours, and cancer-prone diseases. The project is accessible through Internet and is made of encyclopedic-style files, as well as traditional overviews, links towards websites and databases devoted to cancer and/or genetics, case reports in haematology. It also encompasses teaching items in various languages. Starting first from cytogenetics in the nineteens, the Atlas now combines different types of knowledge in a single web site: genes and their function, cell biology (ex: Apoptosis), pathological data, diseases and their clinical implications, cytogenetics, but also medical genetics, with hereditary disorders associated with an increased risk of cancer. This gives a wider and more global view of cancer genetics, while these data are usually dispersed. I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MEROPS
MEROPS is an online database for peptidases (also known as proteases, proteinases and proteolytic enzymes) and their inhibitors. The classification scheme for peptidases was published by Rawlings & Barrett in 1993, and that for protein inhibitors by Rawlings ''et al.'' in 2004.Rawlings, N.D., Tolle, D.P. & Barrett, A.J. (2004) "Evolutionary families of peptidase inhibitors." ''Biochem J'' 378, 705-716. The most recent version, MEROPS 12.5, was released in September 2023. Overview The classification is based on similarities at the tertiary and primary structural levels. Comparisons are restricted to that part of the sequence directly involved in the reaction, which in the case of a peptidase must include the active site, and for a protein inhibitor the reactive site. The classification is hierarchical: sequences are assembled into families, and families are assembled into clans. Each peptidase, family, and clan has a unique identifier. Classification Family The families of pe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TNF-alpha
Tumor necrosis factor (TNF), formerly known as TNF-α, is a chemical messenger produced by the immune system that induces inflammation. TNF is produced primarily by activated macrophages, and induces inflammation by binding to its receptors on other cells. It is a member of the tumor necrosis factor superfamily, a family of transmembrane proteins that are cytokines, chemical messengers of the immune system. Excessive production of TNF plays a critical role in several inflammatory diseases, and TNF-blocking drugs are often employed to treat these diseases. TNF is produced primarily by macrophages but is also produced in several other cell types, such as T cells, B cells, dendritic cells, and mast cells. It is produced rapidly in response to pathogens, cytokines, and environmental stressors. TNF is initially produced as a type II transmembrane protein (tmTNF), which is then cleaved by TNF alpha converting enzyme (TACE) into a soluble form (sTNF) and secreted from the cell. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
