|
Cathepsin W
Cathepsin W is a protein that in humans is encoded by the ''CTSW'' gene. The protein encoded by this gene, a member of the peptidase C1 family of cysteine cathepsins, is a cysteine protease cathepsin that may have a specific function in the mechanism or regulation of T-cell cytolytic activity. The encoded protein is found associated with the cell membrane inside the endoplasmic reticulum of natural killer and cytotoxic T-cells. Expression of this gene is up-regulated by interleukin-2. References Further reading * * * * * * * * * * External links * The MEROPS online database for peptidases and their inhibitorsC01.037 Proteases EC 3.4.22 Cathepsins {{gene-11-stub ... [...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] |
Gene
In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a basic unit of heredity and 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: protein-coding genes and noncoding genes. During gene expression, the DNA is first copied into RNA. The RNA can be directly functional or be the intermediate template for a protein that performs a function. The transmission of genes to an organism's offspring is the basis of the inheritance of phenotypic traits. These genes make up different DNA sequences called genotypes. Genotypes along with environmental and developmental factors determine what the phenotypes will be. Most biological traits are under the influence of polygenes (many different genes) as well as gen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cysteine Cathepsin
Papain-like proteases (or papain-like (cysteine) peptidases; abbreviated PLP or PLCP) are a large protein family of cysteine protease enzymes that share protein structure, structural and catalytic mechanism, enzymatic properties with the group's namesake member, papain. They are found in all domains of life. In animals, the group is often known as cysteine cathepsins or, in older literature, lysosomal peptidases. In the MEROPS protease enzyme classification system, papain-like proteases form Clan CA. Papain-like proteases share a common catalytic dyad active site featuring a cysteine amino acid residue that acts as a nucleophile. The human genome encodes eleven cysteine cathepsins which have a broad range of physiological functions. In some parasites papain-like proteases have roles in host (biology), host invasion, such as cruzipain from ''Trypanosoma cruzi''. In plants, they are involved in host defense and in development. Studies of papain-like proteases from prokaryotes have la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cysteine Protease
Cysteine proteases, also known as thiol proteases, are hydrolase enzymes that degrade proteins. These proteases share a common catalytic mechanism that involves a nucleophilic cysteine thiol in a catalytic triad or dyad. Discovered by Gopal Chunder Roy in 1873, the first cysteine protease to be isolated and characterized was papain, obtained from ''Carica papaya''. Cysteine proteases are commonly encountered in fruits including the papaya, pineapple, fig and kiwifruit. The proportion of protease tends to be higher when the fruit is unripe. In fact, the latex of dozens of different plant families are known to contain cysteine proteases. Cysteine proteases are used as an ingredient in meat tenderizers. Classification The MEROPS protease classification system counts 14 superfamilies plus several currently unassigned families (as of 2013) each containing many families. Each superfamily uses the catalytic triad or dyad in a different protein fold and so represent convergent evolutio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cathepsin
Cathepsins (Ancient Greek ''kata-'' "down" and ''hepsein'' "boil"; abbreviated CTS) are proteases ( enzymes that degrade proteins) found in all animals as well as other organisms. There are approximately a dozen members of this family, which are distinguished by their structure, catalytic mechanism, and which proteins they cleave. Most of the members become activated at the low pH found in lysosomes. Thus, the activity of this family lies almost entirely within those organelles. There are, however, exceptions such as cathepsin K, which works extracellularly after secretion by osteoclasts in bone resorption. Cathepsins have a vital role in mammalian cellular turnover. Classification * Cathepsin A (serine protease) * Cathepsin B (cysteine protease) * Cathepsin C (cysteine protease) * Cathepsin D (aspartyl protease) * Cathepsin E (aspartyl protease) * Cathepsin F (cysteine proteinase) * Cathepsin G (serine protease) * Cathepsin H (cysteine protease) * Cathepsin K (cysteine protea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
T-cell
A T cell is a type of lymphocyte. T cells are one of the important white blood cells of the immune system and play a central role in the adaptive immune response. T cells can be distinguished from other lymphocytes by the presence of a T-cell receptor (TCR) on their cell surface. T cells are born from hematopoietic stem cells, found in the bone marrow. Developing T cells then migrate to the thymus gland to develop (or mature). T cells derive their name from the thymus. After migration to the thymus, the precursor cells mature into several distinct types of T cells. T cell differentiation also continues after they have left the thymus. Groups of specific, differentiated T cell subtypes have a variety of important functions in controlling and shaping the immune response. One of these functions is immune-mediated cell death, and it is carried out by two major subtypes: CD8+ "killer" and CD4+ "helper" T cells. (These are named for the presence of the cell surface proteins CD8 or C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell Membrane
The cell membrane (also known as the plasma membrane (PM) or cytoplasmic membrane, and historically referred to as the plasmalemma) is a biological membrane that separates and protects the interior of all cells from the outside environment (the extracellular space). The cell membrane consists of a lipid bilayer, made up of two layers of phospholipids with cholesterols (a lipid component) interspersed between them, maintaining appropriate membrane fluidity at various temperatures. The membrane also contains membrane proteins, including integral proteins that span the membrane and serve as membrane transporters, and peripheral proteins that loosely attach to the outer (peripheral) side of the cell membrane, acting as enzymes to facilitate interaction with the cell's environment. Glycolipids embedded in the outer lipid layer serve a similar purpose. The cell membrane controls the movement of substances in and out of cells and organelles, being selectively permeable to ions a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endoplasmic Reticulum
The endoplasmic reticulum (ER) is, in essence, the transportation system of the eukaryotic cell, and has many other important functions such as protein folding. It is a type of organelle made up of two subunits – rough endoplasmic reticulum (RER), and smooth endoplasmic reticulum (SER). The endoplasmic reticulum is found in most eukaryotic cells and forms an interconnected network of flattened, membrane-enclosed sacs known as cisternae (in the RER), and tubular structures in the SER. The membranes of the ER are continuous with the outer nuclear membrane. The endoplasmic reticulum is not found in red blood cells, or spermatozoa. The two types of ER share many of the same proteins and engage in certain common activities such as the synthesis of certain lipids and cholesterol. Different types of cells contain different ratios of the two types of ER depending on the activities of the cell. RER is found mainly toward the nucleus of cell and SER towards the cell membrane or plasma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Natural Killer
Natural killer cells, also known as NK cells or large granular lymphocytes (LGL), are a type of cytotoxic lymphocyte critical to the innate immune system that belong to the rapidly expanding family of known innate lymphoid cells (ILC) and represent 5–20% of all circulating lymphocytes in humans. The role of NK cells is analogous to that of cytotoxic T cells in the vertebrate adaptive immune response. NK cells provide rapid responses to virus-infected cell and other intracellular pathogens acting at around 3 days after infection, and respond to tumor formation. Typically, immune cells detect the major histocompatibility complex (MHC) presented on infected cell surfaces, triggering cytokine release, causing the death of the infected cell by lysis or apoptosis. NK cells are unique, however, as they have the ability to recognize and kill stressed cells in the absence of antibodies and MHC, allowing for a much faster immune reaction. They were named "natural killers" because of the n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytotoxic T-cell
A cytotoxic T cell (also known as TC, cytotoxic T lymphocyte, CTL, T-killer cell, cytolytic T cell, CD8+ T-cell or killer T cell) is a T lymphocyte (a type of white blood cell) that kills cancer cells, cells that are infected by intracellular pathogens (such as viruses or bacteria), or cells that are damaged in other ways. Most cytotoxic T cells express T-cell receptors (TCRs) that can recognize a specific antigen. An antigen is a molecule capable of stimulating an immune response and is often produced by cancer cells, viruses, bacteria or intracellular signals. Antigens inside a cell are bound to class I MHC molecules, and brought to the surface of the cell by the class I MHC molecule, where they can be recognized by the T cell. If the TCR is specific for that antigen, it binds to the complex of the class I MHC molecule and the antigen, and the T cell destroys the cell. In order for the TCR to bind to the class I MHC molecule, the former must be accompanied by a glycoprotein ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interleukin-2
Interleukin-2 (IL-2) is an interleukin, a type of cytokine signaling molecule in the immune system. It is a 15.5–16 kDa protein that regulates the activities of white blood cells (leukocytes, often lymphocytes) that are responsible for immunity. IL-2 is part of the body's natural response to microbial infection, and in discriminating between foreign ("non-self") and "self". IL-2 mediates its effects by binding to IL-2 receptors, which are expressed by lymphocytes. The major sources of IL-2 are activated CD4+ T cells and activated CD8+ T cells. IL-2 receptor IL-2 is a member of a cytokine family, each member of which has a four alpha helix bundle; the family also includes IL-4, IL-7, IL-9, IL-15 and IL-21. IL-2 signals through the IL-2 receptor, a complex consisting of three chains, termed alpha (CD25), beta (CD122) and gamma ( CD132). The gamma chain is shared by all family members. The IL-2 receptor (IL-2R) α subunit binds IL-2 with low affinity (Kd~ 10â ... [...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 12.3, was released in September 2020. 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] |
