Gbetagammas and the Ras binding domain of p110gamma are both important regulators of PI(3)Kgamma signalling in neutrophils.
Through their ability to regulate production of the key lipid messenger PtdIns(3,4,5)P(3), the class I phosphatidylinositol-3-OH kinases (PI(3)Ks) support many critical cell responses. They, in turn, can be regulated by cell-surface receptors through signals acting on either their adaptor subunits (for example, through phosphotyrosine or Gbetagammas) or their catalytic subunits (for example, through GTP-Ras). The relative significance of these controlling inputs is undefined in vivo. Here, we have studied the roles of Gbetagammas, the adaptor p101, Ras and the Ras binding domain (RBD) in the control of the class I PI(3)K, PI(3)Kgamma, in mouse neutrophils. Loss of p101 leads to major reductions in the accumulation of PtdIns(3,4,5)P(3), activation of protein kinase B (PKB) and in migration towards G-protein activating ligands in vitro, and to an aseptically inflamed peritoneum in vivo. Loss of sensitivity of PI(3)Kgamma to Ras unexpectedly caused similar reductions, but additionally caused a substantial loss in production of reactive oxygen species (ROS). We conclude that Gbetagammas, p101 and the Ras-RBD interaction all have important roles in the regulation of PI(3)Kgamma in vivo and that they can simultaneously, but differentially, control distinct PI(3)Kgamma effectors.
Suire
Sabine
S
The Babraham Institute, Babraham, Cambs CB22 3AT, UK.
Condliffe
Alison M
AM
Ferguson
G John
GJ
Ellson
Chris D
CD
Guillou
Hervé
H
Davidson
Keith
K
Welch
Heidi
H
Coadwell
John
J
Turner
Martin
M
Chilvers
Edwin R
ER
Hawkins
Phillip T
PT
Stephens
Len
L
D000818:Animals; D001665:Binding Sites; D015153:Blotting, Western / Q000379:methods; D002465:Cell Movement / Q000187:drug effects; D058534:Class I Phosphatidylinositol 3-Kinases; D015936:Complement C5a / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005260:Female; D044387:GTP-Binding Protein beta Subunits / Q000737:chemistry / Q000378:metabolism*; D044388:GTP-Binding Protein gamma Subunits / Q000737:chemistry / Q000378:metabolism*; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008815:Mice, Inbred Strains; D018345:Mice, Knockout; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D009504:Neutrophils / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D019869:Phosphatidylinositol 3-Kinases / Q000235:genetics / Q000378:metabolism*; D018129:Phosphatidylinositol Phosphates / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D012694:Serine / Q000378:metabolism; D015398:Signal Transduction; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D018631:ras Proteins / Q000378:metabolism*
D044387:GTP-Binding Protein beta Subunits; D044388:GTP-Binding Protein gamma Subunits; D007527:Isoenzymes; D018129:Phosphatidylinositol Phosphates; D017382:Reactive Oxygen Species; C060974:phosphatidylinositol 3,4,5-triphosphate; D012694:Serine; D009240:N-Formylmethionine Leucyl-Phenylalanine; D015936:Complement C5a; D019869:Phosphatidylinositol 3-Kinases; C509622:1-phosphatidylinositol 3-kinase p110 subunit, mouse; D058534:Class I Phosphatidylinositol 3-Kinases; D051057:Proto-Oncogene Proteins c-akt; D018631:ras Proteins; D013755:Tetradecanoylphorbol Acetate