KinaseIn biochemistry, a kinase (ˈkaɪneɪs,ˈkɪneɪs,-eɪz) is an enzyme that catalyzes the transfer of phosphate groups from high-energy, phosphate-donating molecules to specific substrates. This process is known as phosphorylation, where the high-energy ATP molecule donates a phosphate group to the substrate molecule. This transesterification produces a phosphorylated substrate and ADP. Conversely, it is referred to as dephosphorylation when the phosphorylated substrate donates a phosphate group and ADP gains a phosphate group (producing a dephosphorylated substrate and the high energy molecule of ATP).
Protein kinase AIn cell biology, protein kinase A (PKA) is a family of serine-threonine kinase whose activity is dependent on cellular levels of cyclic AMP (cAMP). PKA is also known as cAMP-dependent protein kinase (). PKA has several functions in the cell, including regulation of glycogen, sugar, and lipid metabolism. It should not be confused with 5'-AMP-activated protein kinase (AMP-activated protein kinase). Protein kinase A, more precisely known as adenosine 3',5'-monophosphate (cyclic AMP)-dependent protein kinase, abbreviated to PKA, was discovered by chemists Edmond H.
Serine/threonine-specific protein kinaseA serine/threonine protein kinase () is a kinase enzyme, in particular a protein kinase, that phosphorylates the OH group of the amino-acid residues serine or threonine, which have similar side chains. At least 350 of the 500+ human protein kinases are serine/threonine kinases (STK). In enzymology, the term serine/threonine protein kinase describes a class of enzymes in the family of transferases, that transfer phosphates to the oxygen atom of a serine or threonine side chain in proteins.
Protein kinaseA protein kinase is a kinase which selectively modifies other proteins by covalently adding phosphates to them (phosphorylation) as opposed to kinases which modify lipids, carbohydrates, or other molecules. Phosphorylation usually results in a functional change of the target protein (substrate) by changing enzyme activity, cellular location, or association with other proteins. The human genome contains about 500 protein kinase genes and they constitute about 2% of all human genes. There are two main types of protein kinase.
Mitogen-activated protein kinaseA mitogen-activated protein kinase (MAPK or MAP kinase) is a type of protein kinase that is specific to the amino acids serine and threonine (i.e., a serine/threonine-specific protein kinase). MAPKs are involved in directing cellular responses to a diverse array of stimuli, such as mitogens, osmotic stress, heat shock and proinflammatory cytokines. They regulate cell functions including proliferation, gene expression, differentiation, mitosis, cell survival, and apoptosis.
Tyrosine kinaseA tyrosine kinase is an enzyme that can transfer a phosphate group from ATP to the tyrosine residues of specific proteins inside a cell. It functions as an "on" or "off" switch in many cellular functions. Tyrosine kinases belong to a larger class of enzymes known as protein kinases which also attach phosphates to other amino acids such as serine and threonine. Phosphorylation of proteins by kinases is an important mechanism for communicating signals within a cell (signal transduction) and regulating cellular activity, such as cell division.
Receptor tyrosine kinaseReceptor tyrosine kinases (RTKs) are the high-affinity cell surface receptors for many polypeptide growth factors, cytokines, and hormones. Of the 90 unique tyrosine kinase genes identified in the human genome, 58 encode receptor tyrosine kinase proteins. Receptor tyrosine kinases have been shown not only to be key regulators of normal cellular processes but also to have a critical role in the development and progression of many types of cancer.
PhosphorylationIn biochemistry, phosphorylation is the attachment of a phosphate group to a molecule or an ion. This process and its inverse, dephosphorylation, are common in biology. Protein phosphorylation often activates (or deactivates) many enzymes. Phosphorylation is essential to the processes of both anaerobic and aerobic respiration, which involve the production of adenosine triphosphate (ATP), the "high-energy" exchange medium in the cell.
Latent tuberculosisLatent tuberculosis (LTB), also called latent tuberculosis infection (LTBI) is when a person is infected with Mycobacterium tuberculosis, but does not have active tuberculosis (TB). Active tuberculosis can be contagious while latent tuberculosis is not, and it is therefore not possible to get TB from someone with latent tuberculosis. The main risk is that approximately 10% of these people (5% in the first two years after infection and 0.1% per year thereafter) will go on to develop active tuberculosis.
Immunosuppressive drugImmunosuppressive drugs, also known as immunosuppressive agents, immunosuppressants and antirejection medications, are drugs that inhibit or prevent the activity of the immune system. Immunosuppressive drugs can be classified into five groups: glucocorticoids cytostatics antibodies drugs acting on immunophilins other drugs Glucocorticoid In pharmacologic (supraphysiologic) doses, glucocorticoids, such as prednisone, dexamethasone, and hydrocortisone are used to suppress various allergic, inflammatory, and autoimmune disorders.
