Non-invasive visualization of the lipid product of class I PI3K in transgenic mouse models.
PI3Ks (phosphoinositide 3-kinases) regulate many critical cellular responses by producing PI(3,4,5)P(3) (phosphatidylinositol 3,4,5-trisphosphate). To facilitate the spatio-temporal characterization of PI(3,4,5)P(3) in living primary cells, we generated a novel strain of transgenic mice [AktPH (Akt pleckstrin homology domain)-GFP (green fluorescent protein) Tg (transgenic) mice] that express a fluorescent bioprobe for PI(3,4,5)P(3)/PI(3,4)P(2) (phosphatidylinositol 3,4-bisphosphate). By crossing AktPH-GFP Tg mice with strains of gene-targeted 'knockout' mice lacking a particular phosphoinositide-metabolizing enzyme, we have been able to evaluate the contribution of each enzyme to PI(3,4,5)P(3) localization in migrating neutrophils. Our results indicate that PI3Kgamma and the PI(3,4,5)P(3) phosphatase SHIP1 [SH2 (Src homology 2)-containing inositol phosphatase-1] are the key regulators of PI(3,4,5)P(3) dynamics during fMet-Leu-Phe (N-formylmethionyl-leucylphenylalanine; 'chemotactic peptide')-stimulated neutrophil migration. Our study has also validated the fluorescent transgenic strategy for studying PI(3,4,5)P(3) metabolism in physiological and pathological situations.
Sasaki
T
T
Department of Pathology and Immunology, Akita University School of Medicine, 1-1-1 Hondo, Akita, Japan. tsasaki@med.akita-u.ac.jp
Sasaki
J
J
Watanabe
K
K
Suzuki
A
A
D000818:Animals; D004789:Enzyme Activation; D049452:Green Fluorescent Proteins / Q000378:metabolism; D007295:Inositol Phosphates / Q000378:metabolism; D051379:Mice; D008822:Mice, Transgenic; D008954:Models, Biological; D051059:PTEN Phosphohydrolase / Q000378:metabolism; D019869:Phosphatidylinositol 3-Kinases / Q000235:genetics* / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism
D007295:Inositol Phosphates; D011993:Recombinant Fusion Proteins; C118500:inositol 3,4,5-trisphosphate; D049452:Green Fluorescent Proteins; D019869:Phosphatidylinositol 3-Kinases; D051059:PTEN Phosphohydrolase