Signal transductionSignal transduction is the process by which a chemical or physical signal is transmitted through a cell as a series of molecular events. Most commonly, protein phosphorylation is catalyzed by protein kinases, ultimately resulting in a cellular response. Proteins responsible for detecting stimuli are generally termed receptors, although in some cases the term sensor is used. The changes elicited by ligand binding (or signal sensing) in a receptor give rise to a biochemical cascade, which is a chain of biochemical events known as a signaling pathway.
SteroidA steroid (named after the steroid cholesterol which was first described in gall stones from Ancient Greek chole- 'bile' and stereos 'solid') is a biologically active organic compound with four rings arranged in a specific molecular configuration. Steroids have two principal biological functions: as important components of cell membranes that alter membrane fluidity; and as signaling molecules. Hundreds of steroids are found in plants, animals and fungi.
Anaphase-promoting complexAnaphase-promoting complex (also called the cyclosome or APC/C) is an E3 ubiquitin ligase that marks target cell cycle proteins for degradation by the 26S proteasome. The APC/C is a large complex of 11–13 subunit proteins, including a cullin (Apc2) and RING (Apc11) subunit much like SCF. Other parts of the APC/C have unknown functions but are highly conserved. It was the discovery of the APC/C (and SCF) and their key role in eukaryotic cell-cycle regulation that established the importance of ubiquitin-mediated proteolysis in cell biology.
Cell adhesionCell adhesion is the process by which cells interact and attach to neighbouring cells through specialised molecules of the cell surface. This process can occur either through direct contact between cell surfaces such as cell junctions or indirect interaction, where cells attach to surrounding extracellular matrix, a gel-like structure containing molecules released by cells into spaces between them. Cells adhesion occurs from the interactions between cell-adhesion molecules (CAMs), transmembrane proteins located on the cell surface.
Cell adhesion moleculeCell adhesion molecules (CAMs) are a subset of cell surface proteins that are involved in the binding of cells with other cells or with the extracellular matrix (ECM), in a process called cell adhesion. In essence, CAMs help cells stick to each other and to their surroundings. CAMs are crucial components in maintaining tissue structure and function. In fully developed animals, these molecules play an integral role in generating force and movement and consequently ensuring that organs are able to execute their functions normally.
CalmodulinCalmodulin (CaM) (an abbreviation for calcium-modulated protein) is a multifunctional intermediate calcium-binding messenger protein expressed in all eukaryotic cells. It is an intracellular target of the secondary messenger Ca2+, and the binding of Ca2+ is required for the activation of calmodulin. Once bound to Ca2+, calmodulin acts as part of a calcium signal transduction pathway by modifying its interactions with various target proteins such as kinases or phosphatases.
TioguanineTioguanine, also known as thioguanine or 6-thioguanine (6-TG) is a medication used to treat acute myeloid leukemia (AML), acute lymphocytic leukemia (ALL), and chronic myeloid leukemia (CML). Long-term use is not recommended. It is given by mouth. Common side effects include bone marrow suppression, liver problems and inflammation of the mouth. It is recommended that liver enzymes be checked weekly when on the medication. People with a genetic deficiency in thiopurine S-methyltransferase are at higher risk of side effects.
GibberellinGibberellins (GAs) are plant hormones that regulate various developmental processes, including stem elongation, germination, dormancy, flowering, flower development, and leaf and fruit senescence. GAs are one of the longest-known classes of plant hormone. It is thought that the selective breeding (albeit unconscious) of crop strains that were deficient in GA synthesis was one of the key drivers of the "green revolution" in the 1960s, a revolution that is credited to have saved over a billion lives worldwide.
MercaptopurineMercaptopurine (6-MP), sold under the brand name Purinethol among others, is a medication used for cancer and autoimmune diseases. Specifically it is used to treat acute lymphocytic leukemia (ALL), acute promyelocytic leukemia (APL), Crohn's disease, and ulcerative colitis. For acute lymphocytic leukemia it is generally used with methotrexate. It is taken by mouth. Common side effects include bone marrow suppression, liver toxicity, vomiting, and loss of appetite.
EstrogenEstrogen or oestrogen (see spelling differences) is a category of sex hormone responsible for the development and regulation of the female reproductive system and secondary sex characteristics. There are three major endogenous estrogens that have estrogenic hormonal activity: estrone (E1), estradiol (E2), and estriol (E3). Estradiol, an estrane, is the most potent and prevalent. Another estrogen called estetrol (E4) is produced only during pregnancy. Estrogens are synthesized in all vertebrates and some insects.
