enzymology Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. ...

, a phosphatidylinositol-4,5-bisphosphate 3-kinase () is an

enzyme Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products ...

that catalyzes the

chemical reaction A chemical reaction is a process that leads to the chemical transformation of one set of chemical substances to another. Classically, chemical reactions encompass changes that only involve the positions of electrons in the forming and breaking ...

: :ATP + 1-phosphatidyl-1D-myo-inositol 4,5-bisphosphate

\rightleftharpoons

ADP + 1-phosphatidyl-1D-myo-inositol 3,4,5-trisphosphate Thus, the two substrates of this enzyme are ATP and 1-phosphatidyl-1D-myo-inositol 4,5-bisphosphate, whereas its two products are

ADP Adp or ADP may refer to: Aviation * Aéroports de Paris, airport authority for the Parisian region in France * Aeropuertos del Perú, airport operator for airports in northern Peru * SLAF Anuradhapura, an airport in Sri Lanka * Ampara Airp ...

and 1-phosphatidyl-1D-myo-inositol 3,4,5-trisphosphate. This enzyme belongs to the family of

transferase A transferase is any one of a class of enzymes that catalyse the transfer of specific functional groups (e.g. a methyl or glycosyl group) from one molecule (called the donor) to another (called the acceptor). They are involved in hundreds o ...

s, specifically those transferring phosphorus-containing groups (

phosphotransferase Phosphotransferases are a category of enzymes ( EC number 2.7) that catalyze phosphorylation reactions. The general form of the reactions they catalyze is: :A-P + B \rightleftharpoons B-P + A Where ''P'' is a phosphate group and A and B are the d ...

s) with an alcohol group as acceptor. The systematic name of this enzyme class is ATP:1-phosphatidyl-1D-myo-inositol-4,5-bisphosphate 3-phosphotransferase. This enzyme is also called type I phosphoinositide 3-kinase. This enzyme participates in 29 metabolic pathways: inositol phosphate metabolism, erbb signaling pathway, phosphatidylinositol signaling system, mtor signaling pathway,

apoptosis Apoptosis (from grc, ἀπόπτωσις, apóptōsis, 'falling off') is a form of programmed cell death that occurs in multicellular organisms. Biochemical events lead to characteristic cell changes ( morphology) and death. These changes in ...

, VEGF signaling pathway, focal adhesion, toll-like receptor signaling pathway,

jak-stat signaling pathway The JAK-STAT signaling pathway is a chain of interactions between proteins in a cell, and is involved in processes such as immunity, cell division, cell death, and tumour formation. The pathway communicates information from chemical signals ou ...

, natural killer cell mediated cytotoxicity, t cell receptor signaling pathway, b cell receptor signaling pathway, fc epsilon ri signaling pathway, leukocyte transendothelial migration, regulation of actin cytoskeleton, insulin signaling pathway, progesterone-mediated oocyte maturation, Type II diabetes mellitus,

colorectal cancer Colorectal cancer (CRC), also known as bowel cancer, colon cancer, or rectal cancer, is the development of cancer from the colon or rectum (parts of the large intestine). Signs and symptoms may include blood in the stool, a change in bowel ...

renal cell carcinoma Renal cell carcinoma (RCC) is a kidney cancer that originates in the lining of the proximal convoluted tubule, a part of the very small tubes in the kidney that transport primary urine. RCC is the most common type of kidney cancer in adults, re ...

pancreatic cancer Pancreatic cancer arises when cells in the pancreas, a glandular organ behind the stomach, begin to multiply out of control and form a mass. These cancerous cells have the ability to invade other parts of the body. A number of types of pancr ...

endometrial cancer Endometrial cancer is a cancer that arises from the endometrium (the lining of the uterus or womb). It is the result of the abnormal growth of cells that have the ability to invade or spread to other parts of the body. The first sign is most ...

glioma A glioma is a type of tumor that starts in the glial cells of the brain or the spine. Gliomas comprise about 30 percent of all brain tumors and central nervous system tumours, and 80 percent of all malignant brain tumours. Signs and symptoms ...

prostate cancer Prostate cancer is cancer of the prostate. Prostate cancer is the second most common cancerous tumor worldwide and is the fifth leading cause of cancer-related mortality among men. The prostate is a gland in the male reproductive system that su ...

melanoma Melanoma, also redundantly known as malignant melanoma, is a type of skin cancer that develops from the pigment-producing cells known as melanocytes. Melanomas typically occur in the skin, but may rarely occur in the mouth, intestines, or eye ( ...

, chronic myeloid leukemia,

acute myeloid leukemia Acute myeloid leukemia (AML) is a cancer of the myeloid line of blood cells, characterized by the rapid growth of abnormal cells that build up in the bone marrow and blood and interfere with normal blood cell production. Symptoms may inclu ...

, small cell lung cancer, and non-small cell lung cancer.

Structural studies

As of late 2007, 6 structures have been solved for this class of enzymes, with PDB accession codes , , , , , and .

Examples

Human genes encoding proteins with phosphatidylinositol-4,5-bisphosphate 3-kinase activity include: * PIK3CA *

PIK3CB Phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit beta isoform is an enzyme that in humans is encoded by the ''PIK3CB'' gene. Phosphoinositide 3-kinases (PI3Ks) phosphorylate the 3-prime OH position of the inositol ring of inosito ...

* PIK3CD *

PIK3CG Phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit gamma isoform is an enzyme that in humans is encoded by the ''PIK3CG'' gene. Function This gene encodes a protein that belongs to the pi3/pi4-kinase family of proteins. The gene p ...

References

* EC 2.7.1 Enzymes of known structure {{2.7-enzyme-stub