The HIV-1 nef protein interferes with phosphatidylinositol 3-kinase activation 1.
nef is a human immunodeficiency virus (HIV) gene encoding a 27-kDa myristoylated protein with structural features of a signal transducing molecule, but whose functions are largely unknown. We studied the interactions of Nef with the signal transduction pathways triggered by the platelet-derived growth factor (PDGF) receptor. The association of phosphatidylinositol (PI) 3-kinase with the activated receptor was severely impaired by nef expression. Conversely, PDGF-induced receptor tyrosine phosphorylation, binding to phospholipase C-gamma and to Ras-GAP were not modified. Microtubule-associated protein kinase activation and intracellular calcium influx in response to PDGF were either unaffected or only slightly enhanced. Nef significantly reduced the proliferative response to the growth factor, while the chemotactic response was unchanged. These data show that Nef affects selectively the PI 3-kinase signaling pathway and suggest that this interference results in some of the HIV adverse effects on host cell functions.
Graziani
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Institute for Cancer Research and Treatment (IRCC), University of Torino Medical School, 10126 Torino, Italy.
Galimi
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Medico
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Cottone
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Gramaglia
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D
Boccaccio
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Comoglio
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D016475:3T3 Cells; D000818:Animals; D000077214:Becaplermin; D015220:Calcium Channels / Q000378:metabolism; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism; D002455:Cell Division; D004789:Enzyme Activation; D005786:Gene Expression Regulation; D015693:Gene Products, nef / Q000235:genetics / Q000502:physiology*; D015754:Genes, nef; D015497:HIV-1 / Q000378:metabolism*; D051379:Mice; D019869:Phosphatidylinositol 3-Kinases; D010766:Phosphorylation; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000037:antagonists & inhibitors / Q000378:metabolism*; D010982:Platelet-Derived Growth Factor / Q000037:antagonists & inhibitors / Q000494:pharmacology; D020574:Proto-Oncogene Proteins c-sis; D017479:Receptors, Platelet-Derived Growth Factor / Q000378:metabolism; D015398:Signal Transduction; D054311:nef Gene Products, Human Immunodeficiency Virus
D015220:Calcium Channels; D015693:Gene Products, nef; D010982:Platelet-Derived Growth Factor; D020574:Proto-Oncogene Proteins c-sis; D054311:nef Gene Products, Human Immunodeficiency Virus; D000077214:Becaplermin; D019869:Phosphatidylinositol 3-Kinases; D017853:Phosphotransferases (Alcohol Group Acceptor); D017479:Receptors, Platelet-Derived Growth Factor; D017871:Calcium-Calmodulin-Dependent Protein Kinases