title: PI3K class IB pathway in neutrophils.
abstract: Activation of G(i)-coupled receptors in neutrophils stimulates class IB phosphoinositide 3-kinase (PI3K) (also known as PI3Kgamma) through the combined actions of Gbetagamma subunits and the small guanosine triphosphatase (GTPase) Ras, resulting in the production of phosphatidylinositol 3,4,5-trisphosphate [PI(3,4,5)P3] and phosphatidylinositol 3,4-bisphosphate [PI(3,4)P2] in the plasma membrane. In most cases, the effectors of this pathway possess a pleckstrin homology (PH) domain that mediates the interaction with and regulation by these two lipid messengers. These direct effectors sit within a complex regulatory network that includes several other signaling pathways and that is responsible for the control of important neutrophil functions, including adhesion, chemotaxis, secretion, and the "respiratory burst" [activation of the nicotinamide adenosine diphosphate (NADPH) oxidase]. Although the molecular details that link the direct effectors of class IB PI3K to these complex cell responses are still largely unknown, these responses involve complex regulation of small GTPases of the Rac, Rho, and Arf families.
authors.affiliation: Bioinformatics Group, The Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK.
authors.forename: Simon
authors.initials: S
authors.lastname: Andrews
authors.forename: Len R
authors.initials: LR
authors.lastname: Stephens
authors.forename: Phillip T
authors.initials: PT
authors.lastname: Hawkins
mesh_terms: D020727:ADP-Ribosylation Factors / Q000378:metabolism; D000818:Animals; D058544:Class Ib Phosphatidylinositol 3-Kinase; D006801:Humans; D007527:Isoenzymes / Q000378:metabolism; D009504:Neutrophils / Q000201:enzymology / Q000378:metabolism*; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D018129:Phosphatidylinositol Phosphates / Q000378:metabolism; D010766:Phosphorylation; D043562:Receptors, G-Protein-Coupled / Q000378:metabolism*; D015398:Signal Transduction; D020744:rac GTP-Binding Proteins / Q000378:metabolism; D018631:ras Proteins / Q000378:metabolism; D020741:rho GTP-Binding Proteins / Q000378:metabolism
chemical_list: D007527:Isoenzymes; D018129:Phosphatidylinositol Phosphates; D043562:Receptors, G-Protein-Coupled; C060974:phosphatidylinositol 3,4,5-triphosphate; C060980:phosphatidylinositol 3,4-diphosphate; D019869:Phosphatidylinositol 3-Kinases; D058544:Class Ib Phosphatidylinositol 3-Kinase; C546760:PIK3CG protein, human; D020727:ADP-Ribosylation Factors; D020744:rac GTP-Binding Proteins; D018631:ras Proteins; D020741:rho GTP-Binding Proteins