Biomaterial Database

Phosphatidylinositol 3'-kinase is associated with a serine kinase that is activated by okadaic acid. 1998

K A Cengel, and J P Godbout, and G G Freund

Department of Pathology, University of Illinois at Urbana-Champaign 61801, USA.

Okadaic acid (OA) is a potent inhibitor of PP1 and PP2A serine/threonine phosphatases and an inhibitor of phosphatidylinositol 3'-kinase (PI 3-kinase) recruitment/ activation. Here we report that PI 3-kinase associates with a serine kinase activated by OA. Whole cell phosphorylation studies showed that PI 3-kinase associates with a wortmannin insensitive 76 kDa serine phosphoprotein (pp76) distinct from the p85 subunit of PI 3-kinase. Serine kinase assays demonstrated that pp76 phosphorylation was dependent upon a wortmannin insensitive serine kinase contained within PI 3-kinase/pp76 complexes and that this kinase had different cation requirements than PI 3-kinase serine kinase. Treatment of whole cells with OA lead to a wortmannin-independent 7.6-fold increase in pp76 serine phosphorylation and to a 7-fold rise in pp76 kinase activity. Together, these findings indicate that pp76 is a PI 3-kinase associated phosphoprotein and suggest that pp76 may be a novel PI 3-kinase associated serine kinase that is activated by OA.

UI	MeSH Term	Description	Entries
D009101	Multiple Myeloma	A malignancy of mature PLASMA CELLS engaging in monoclonal immunoglobulin production. It is characterized by hyperglobulinemia, excess Bence-Jones proteins (free monoclonal IMMUNOGLOBULIN LIGHT CHAINS) in the urine, skeletal destruction, bone pain, and fractures. Other features include ANEMIA; HYPERCALCEMIA; and RENAL INSUFFICIENCY.	Myeloma, Plasma-Cell,Kahler Disease,Myeloma, Multiple,Myeloma-Multiple,Myelomatosis,Plasma Cell Myeloma,Cell Myeloma, Plasma,Cell Myelomas, Plasma,Disease, Kahler,Multiple Myelomas,Myeloma Multiple,Myeloma, Plasma Cell,Myeloma-Multiples,Myelomas, Multiple,Myelomas, Plasma Cell,Myelomas, Plasma-Cell,Myelomatoses,Plasma Cell Myelomas,Plasma-Cell Myeloma,Plasma-Cell Myelomas
D010750	Phosphoproteins		Phosphoprotein
D010766	Phosphorylation	The introduction of a phosphoryl group into a compound through the formation of an ester bond between the compound and a phosphorus moiety.	Phosphorylations
D010768	Phosphoserine	The phosphoric acid ester of serine.	Serine Phosphate,Phosphorylserine,Seryl Phosphate,Phosphate, Serine,Phosphate, Seryl
D011233	Precipitin Tests	Serologic tests in which a positive reaction manifested by visible CHEMICAL PRECIPITATION occurs when a soluble ANTIGEN reacts with its precipitins, i.e., ANTIBODIES that can form a precipitate.	Precipitin Test,Test, Precipitin,Tests, Precipitin
D004791	Enzyme Inhibitors	Compounds or agents that combine with an enzyme in such a manner as to prevent the normal substrate-enzyme combination and the catalytic reaction.	Enzyme Inhibitor,Inhibitor, Enzyme,Inhibitors, Enzyme
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000077191	Wortmannin	An androstadiene metabolite produced by the fungi PENICILLIUM funiculosum that inhibits PHOSPHATIDYLINOSITOL-3-KINASES and alloantigen-specific activation of T-LYMPHOCYTES in human tumor cell lines. It is widely used in CELL BIOLOGY research and has broad therapeutic potential.	MS 54,MS-54,MS54
D000730	Androstadienes	Derivatives of the steroid androstane having two double bonds at any site in any of the rings.
D014407	Tumor Cells, Cultured	Cells grown in vitro from neoplastic tissue. If they can be established as a TUMOR CELL LINE, they can be propagated in cell culture indefinitely.	Cultured Tumor Cells,Neoplastic Cells, Cultured,Cultured Neoplastic Cells,Cell, Cultured Neoplastic,Cell, Cultured Tumor,Cells, Cultured Neoplastic,Cells, Cultured Tumor,Cultured Neoplastic Cell,Cultured Tumor Cell,Neoplastic Cell, Cultured,Tumor Cell, Cultured