Ubiquitin ligaseA ubiquitin ligase (also called an E3 ubiquitin ligase) is a protein that recruits an E2 ubiquitin-conjugating enzyme that has been loaded with ubiquitin, recognizes a protein substrate, and assists or directly catalyzes the transfer of ubiquitin from the E2 to the protein substrate. In simple and more general terms, the ligase enables movement of ubiquitin from a ubiquitin carrier to another thing (the substrate) by some mechanism. The ubiquitin, once it reaches its destination, ends up being attached by an isopeptide bond to a lysine residue, which is part of the target protein.
Catenin beta-1Catenin beta-1, also known as beta-catenin (β-catenin), is a protein that in humans is encoded by the CTNNB1 gene. Beta-catenin is a dual function protein, involved in regulation and coordination of cell–cell adhesion and gene transcription. In humans, the CTNNB1 protein is encoded by the CTNNB1 gene. In Drosophila, the homologous protein is called armadillo. β-catenin is a subunit of the cadherin protein complex and acts as an intracellular signal transducer in the Wnt signaling pathway.
Biochemical cascadeA biochemical cascade, also known as a signaling cascade or signaling pathway, is a series of chemical reactions that occur within a biological cell when initiated by a stimulus. This stimulus, known as a first messenger, acts on a receptor that is transduced to the cell interior through second messengers which amplify the signal and transfer it to effector molecules, causing the cell to respond to the initial stimulus. Most biochemical cascades are series of events, in which one event triggers the next, in a linear fashion.
Linker (computing)In computing, a linker or link editor is a computer system program that takes one or more s (generated by a compiler or an assembler) and combines them into a single executable file, library file, or another "object" file. A simpler version that writes its output directly to memory is called the loader, though loading is typically considered a separate process. Computer programs typically are composed of several parts or modules; these parts/modules do not need to be contained within a single , and in such cases refer to each other by means of symbols as addresses into other modules, which are mapped into memory addresses when linked for execution.
Dynamic-link libraryDynamic-link library (DLL) is Microsoft's implementation of the shared library concept in the Microsoft Windows and OS/2 operating systems. These libraries usually have the DLL, OCX (for libraries containing ActiveX controls), or DRV (for legacy system drivers). The file formats for DLLs are the same as for Windows EXE files – that is, Portable Executable (PE) for 32-bit and 64-bit Windows, and New Executable (NE) for 16-bit Windows. As with EXEs, DLLs can contain code, data, and resources, in any combination.
Functional selectivityFunctional selectivity (or “agonist trafficking”, “biased agonism”, “biased signaling”, "ligand bias" and “differential engagement”) is the ligand-dependent selectivity for certain signal transduction pathways relative to a reference ligand (often the endogenous hormone or peptide) at the same receptor. Functional selectivity can be present when a receptor has several possible signal transduction pathways. To which degree each pathway is activated thus depends on which ligand binds to the receptor.
Spindle apparatusIn cell biology, the spindle apparatus is the cytoskeletal structure of eukaryotic cells that forms during cell division to separate sister chromatids between daughter cells. It is referred to as the mitotic spindle during mitosis, a process that produces genetically identical daughter cells, or the meiotic spindle during meiosis, a process that produces gametes with half the number of chromosomes of the parent cell. Besides chromosomes, the spindle apparatus is composed of hundreds of proteins.
Organometallic chemistryOrganometallic chemistry is the study of organometallic compounds, chemical compounds containing at least one chemical bond between a carbon atom of an organic molecule and a metal, including alkali, alkaline earth, and transition metals, and sometimes broadened to include metalloids like boron, silicon, and selenium, as well. Aside from bonds to organyl fragments or molecules, bonds to 'inorganic' carbon, like carbon monoxide (metal carbonyls), cyanide, or carbide, are generally considered to be organometallic as well.
Chirality (chemistry)In chemistry, a molecule or ion is called chiral (ˈkaɪrəl) if it cannot be superposed on its by any combination of rotations, translations, and some conformational changes. This geometric property is called chirality (kaɪˈrælɪti). The terms are derived from Ancient Greek χείρ (cheir) 'hand'; which is the canonical example of an object with this property. A chiral molecule or ion exists in two stereoisomers that are mirror images of each other, called enantiomers; they are often distinguished as either "right-handed" or "left-handed" by their absolute configuration or some other criterion.
Allosteric regulationIn biochemistry, allosteric regulation (or allosteric control) is the regulation of an enzyme by binding an effector molecule at a site other than the enzyme's active site. The site to which the effector binds is termed the allosteric site or regulatory site. Allosteric sites allow effectors to bind to the protein, often resulting in a conformational change and/or a change in protein dynamics. Effectors that enhance the protein's activity are referred to as allosteric activators, whereas those that decrease the protein's activity are called allosteric inhibitors.
