What is kinase?
What is kinase? In short, kinases are enzymes that catalyze the transfer of phosphate groups to specific substrates by high-energy donor molecules. In biochemistry, a kinase is an enzyme that catalyzes the transfer of phosphate groups from high-energy, phosphoric acid donor molecules to specific substrates. This process is called phosphorylation, where the substrate acquires a phosphate group, and the high-energy ATP molecule provides the phosphate group. This transesterification produces phosphorylated substrate and ADP. Conversely, when a phosphorylated substrate provides a phosphate group and ADP, it is called dephosphorylation to obtain a phosphate group (a high-energy molecule that produces a dephosphorylated substrate and ATP). During glycolysis, phosphorylation and dephosphorylation occur four times.
Kinases are roughly divided into: CK1, AGC, CAMK, CMGC, GYC, TK, TKL, STE, Atypical, etc. At present, the common kinase products in the industry are roughly divided into four categories: protein kinase, fat kinase, fructose kinase and mutant kinase.
Lipid kinase is one of the most promising new potential drug targets. Lipid kinase phosphorylates lipids in cells on the plasma membrane as well as on organelle membranes. The addition of phosphate groups can change the reactivity and positioning of lipids and can be used for signal transmission.
Phosphatidylinositol kinase phosphorylates phosphatidylinositol substances, such as phosphatidylinositol 3,4-bisphosphate, phosphatidylinositol 3,4,5-triphosphate (PIP3) and phosphatidylinositol Alcohol 3-phosphate (PI3P). Kinases include phosphoinositide 3-kinase (PI3K), phosphatidylinositol-4-phosphate 3-kinase and phosphatidylinositol-4,5-bisphosphate 3-kinase. The phosphorylation status of phosphatidylinositol plays a major role in cell signaling, such as in the insulin signaling pathway, and also in endocytosis, exocytosis, and other trafficking events. Mutations in these kinases, such as PI3K, can cause cancer or insulin resistance. PI3K is divided into three categories with different structures and functions. Class I enzymes have been extensively studied and have become promising drug targets in cancer and immune diseases. PI3K is a family of enzymes involved in cell functions (such as cell growth, proliferation, differentiation, movement, survival, and intracellular trafficking), and these enzymes are involved in cancer. Many of these functions are related to the ability of class I PI 3-kinases in the PI3K / AKT / mTOR pathway to activate protein kinase B.
Sphingosine kinase (SK) is a relatively common kinase in lipid kinase, which catalyzes the conversion of sphingosine to sphingosine-1-phosphate (S1P). The activated sphingosine kinase migrates from the cytosol to the plasma membrane, where it transfers gamma phosphate from ATP or GTP to sphingosine. S1P receptors are GPCR receptors, so S1P has the ability to regulate G protein signaling. The generated signals can activate intracellular effectors such as ERK, Rho GTPase, Rac GTPase, PLC, and AKT / PI3K. It can also play a role in target molecules in cells. S1P has been shown to directly inhibit the histone deacetylase activity of HDAC. In contrast, dephosphorylated sphingosine can promote apoptosis, so understanding the regulation of SK is crucial because it plays an important role in determining cell fate. Studies have shown that SKs can promote cancer cell proliferation because they can promote cell proliferation, and in certain types of cancer, SK1 is present in higher concentrations.