title: SHIP2 is recruited to the cell membrane upon macrophage colony-stimulating factor (M-CSF) stimulation and regulates M-CSF-induced signaling.
abstract: The Src homology 2-containing inositol phosphatase SHIP1 functions in hemopoietic cells to limit activation events mediated by PI3K products, including Akt activation and cell survival. In contrast to the limited cellular expression of SHIP1, the related isoform SHIP2, is widely expressed in both parenchymal and hemopoietic cells. The goal of this study was to determine how SHIP2 functions to regulate M-CSF signaling. We report that 1) SHIP2 was tyrosine-phosphorylated in M-CSF-stimulated human alveolar macrophages, human THP-1 cells, murine macrophages, and the murine macrophage cell line RAW264; 2) SHIP2 associated with the M-CSF receptor after M-CSF stimulation; and 3) SHIP2 associated with the actin-binding protein filamin and localization to the cell membrane, requiring the proline-rich domain, but not on the Src homology 2 domain of SHIP2. Analyzing the function of SHIP2 in M-CSF-stimulated cells by expressing either wild-type SHIP2 or an Src homology 2 domain mutant of SHIP2 reduced Akt activation in response to M-CSF stimulation. In contrast, the expression of a catalytically deficient mutant of SHIP2 or the proline-rich domain of SHIP2 enhanced Akt activation. Similarly, the expression of wild-type SHIP2 inhibited NF-kappaB-mediated gene transcription. Finally, fetal liver-derived macrophages from SHIP2 gene knockout mice enhanced activation of Akt in response to M-CSF treatment. These data suggest a novel regulatory role for SHIP2 in M-CSF-stimulated myeloid cells.
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, and The Dorothy M. Davis Heart and Lung Research Institute, Ohio State University, Columbus, OH 43210, USA.
authors.forename: Yijie
authors.initials: Y
authors.lastname: Wang
authors.forename: Rosemary J
authors.initials: RJ
authors.lastname: Keogh
authors.forename: Melissa G
authors.initials: MG
authors.lastname: Hunter
authors.forename: Christina A
authors.initials: CA
authors.lastname: Mitchell
authors.forename: Randall S
authors.initials: RS
authors.lastname: Frey
authors.forename: Kamran
authors.initials: K
authors.lastname: Javaid
authors.forename: Asrar B
authors.initials: AB
authors.lastname: Malik
authors.forename: Stéphane
authors.initials: S
authors.lastname: Schurmans
authors.forename: Susheela
authors.initials: S
authors.lastname: Tridandapani
authors.forename: Clay B
authors.initials: CB
authors.lastname: Marsh
mesh_terms: D000818:Animals; D002460:Cell Line; D002462:Cell Membrane / Q000276:immunology / Q000378:metabolism; D002478:Cells, Cultured; D003285:Contractile Proteins / Q000378:metabolism; D015536:Down-Regulation; D064448:Filamins; D006801:Humans; D016173:Macrophage Colony-Stimulating Factor / Q000378:metabolism / Q000502:physiology*; D008264:Macrophages / Q000276:immunology / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008840:Microfilament Proteins / Q000378:metabolism; D009000:Monocytes / Q000276:immunology / Q000378:metabolism; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000235:genetics; D041681:NIH 3T3 Cells; D000072183:Phosphatidylinositol-3,4,5-Trisphosphate 5-Phosphatases; D010744:Phosphoric Monoester Hydrolases / Q000172:deficiency / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D010766:Phosphorylation; D011392:Proline / Q000378:metabolism; D011485:Protein Binding; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D017434:Protein Structure, Tertiary / Q000502:physiology; D021381:Protein Transport / Q000276:immunology; D011518:Proto-Oncogene Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt; D016186:Receptor, Macrophage Colony-Stimulating Factor / Q000378:metabolism; D015398:Signal Transduction / Q000276:immunology; D014443:Tyrosine / Q000378:metabolism; D018909:src Homology Domains / Q000502:physiology
chemical_list: D003285:Contractile Proteins; D064448:Filamins; D008840:Microfilament Proteins; D016328:NF-kappa B; D011518:Proto-Oncogene Proteins; D014443:Tyrosine; D016173:Macrophage Colony-Stimulating Factor; D011392:Proline; D016186:Receptor, Macrophage Colony-Stimulating Factor; C494918:AKT1 protein, human; D017346:Protein Serine-Threonine Kinases; D051057:Proto-Oncogene Proteins c-akt; D010744:Phosphoric Monoester Hydrolases; C098706:INPPL1 protein, human; D000072183:Phosphatidylinositol-3,4,5-Trisphosphate 5-Phosphatases