Role of the inositol phosphatase SHIP in negative regulation of the immune system by the receptor Fc(gamma)RIIB.
Immune complexes are potent activators of inflammatory cells, triggering effector responses through the crosslinking of Fc receptors (FcRs) such as Fc(epsilon)RI or Fc(gamma)RIII. On B cells and mast cells, immune complexes are also negative regulators of activation triggered by antigen and Fc receptors, a consequence of coligation of the B-cell antigen receptor or Fc(epsilon)RI, respectively, and the inhibitory receptor Fc(gamma)RIIB. Here we show that inhibitory signalling by Fc(gamma)RIIB does not require the SH2-domain-containing protein tyrosine phosphatase, SHP-1, in mast cells and results in the recruitment of the SH2-domain-containing inositol polyphosphate 5-phosphatase, SHIP, to the tyrosine-phosphorylated 13-amino-acid inhibitory motif of Fc(gamma)RIIB in both B cells and mast cells. SHIP, by hydrolysing the 5-phosphate of phosphatidylinositol(3,4,5)P3 and inositol(1,3,4,5)P4, suggests a mechanism by which Fc(gamma)RIIB can inhibit calcium influx and downstream responses triggered by immune receptors.
Ono
M
M
Molecular Biology Program, Memorial Sloan-Kettering Cancer Center, New York 10021, USA.
Bolland
S
S
Tempst
P
P
Ravetch
J V
JV
D000595:Amino Acid Sequence; D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology*; D002118:Calcium / Q000378:metabolism; D015550:Cell Degranulation; D002460:Cell Line; D047908:Intracellular Signaling Peptides and Proteins; D008407:Mast Cells / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D010455:Peptides / Q000276:immunology; D000072183:Phosphatidylinositol-3,4,5-Trisphosphate 5-Phosphatases; D010744:Phosphoric Monoester Hydrolases / Q000502:physiology*; D010766:Phosphorylation; D054592:Protein Tyrosine Phosphatase, Non-Receptor Type 11; D053824:Protein Tyrosine Phosphatase, Non-Receptor Type 6; D017027:Protein Tyrosine Phosphatases / Q000502:physiology; D017452:Receptors, IgG / Q000502:physiology*; D054593:SH2 Domain-Containing Protein Tyrosine Phosphatases; D015398:Signal Transduction; D018909:src Homology Domains / Q000502:physiology
D047908:Intracellular Signaling Peptides and Proteins; D010455:Peptides; D017452:Receptors, IgG; D010744:Phosphoric Monoester Hydrolases; C516724:PTPN11 protein, human; C509249:PTPN6 protein, human; D054592:Protein Tyrosine Phosphatase, Non-Receptor Type 11; D053824:Protein Tyrosine Phosphatase, Non-Receptor Type 6; D017027:Protein Tyrosine Phosphatases; C516725:Ptpn11 protein, mouse; C509248:Ptpn6 protein, mouse; D054593:SH2 Domain-Containing Protein Tyrosine Phosphatases; C098706:INPPL1 protein, human; D000072183:Phosphatidylinositol-3,4,5-Trisphosphate 5-Phosphatases; D002118:Calcium