PI4KB Antibody / Phosphatidylinositol 4-kinase beta

Phosphatidylinositol 4-kinase beta is an enzyme that in humans is encoded by the PI4KB gene. Inositol phospholipids have an important role in intracellular signaling in response to hormones, growth factors and neurotransmitters. Phosphatidylinositol 4-kinase phosphorylates phosphatidylinositol (PI) to phosphatidylinositol-4-phosphate (PIP) . In a second step, PIP is further phosphorylated to phosphatidylinositol-4,5-bisphosphate (PIP2), and PIP2 is subsequently hydrolyzed by phospholipase C, producing the two intracellular second messengers, inositol 1,4,5-triphosphate (IP3) and diacylglycerol (DAG) . PI4K230, PI4K92 and PI4K55 are three PI4 kinase isoforms that have been characterized and classified according to their molecular weights of 230, 92 and 55 kD. Previously, PI4 kinases were classified into type II and III enzymes. All isoforms are located on distinct membranes and cellular compartments suggesting various tasks. PI4K230 is located at the endoplasmatic reticulum and outer membranes of mitochondria, PI4K92 at the Golgi apparatus and endoplasmatic reticulum, and PI4K55 at the plasma membrane and endosomes. PI4K230 is predominantly expressed in brain and moderately sensitive to wortmannin as well as specifically and irreversibly inhibited by cyclitol derivatives.