The src homology 2-containing inositol phosphatase (SHIP) is the gatekeeper of mast cell degranulation.

Thapsigargin-induced degranulation of mast cells is dependent on transient activation of phosphatidylinositol-3 kinase.

Thapsigargin, which elevates cytosolic calcium levels by inhibiting the sarcoplasmic/endoplasmic reticulum calcium-dependent ATPase, was tested for its ability to degranulate bone marrow-derived mast cells (BMMCs) from src homology 2-containing inositol phosphatase +/+ (SHIP+/+) and SHIP-/- mice. As was found previously with steel factor, thapsigargin stimulated far more degranulation in SHIP-/...

SH2 domain-containing inositol polyphosphate 5'-phosphatase is the main mediator of the inhibitory action of the mast cell function-associated antigen.

The mast cell function-associated Ag (MAFA) is a type II membrane glycoprotein originally found on the plasma membrane of rat mucosal-type mast cells (RBL-2H3 line). A C-type lectin domain and an immunoreceptor tyrosine-based inhibitory motif (ITIM) are located in the extracellular and intracellular domains of MAFA, respectively. MAFA clustering has previously been shown to suppress the secreto...

The effect of phosphatases SHP-1 and SHIP-1 on signaling by the ITIM- and ITAM-containing Fc receptors Fc RIIB and Fc RIIA

Inositol and tyrosine phosphatases have been implicated in inhibitory signaling by an Fc receptor for immunoglobulin G, Fc RIIB, in B cells, mast cells, and monocytes. Here, we propose a role for the Src homology 2 (SH2)-containing tyrosine phosphatase-1 (SHP-1) in Fc RIIB-mediated inhibition of Fc R signaling. Coexpression of SHP-1 enhances Fc RIIB-mediated inhibition of Fc RIIA phagocytosis i...

Effects of Src Homology Domain 2 (SH2)-Containing Inositol Phosphatase (SHIP), SH2-Containing Phosphotyrosine Phosphatase (SHP)-1, and SHP-2 SH2 Decoy Proteins on FcgRIIB1-Effector Interactions and Inhibitory Functions

A Regulatory Role for Src Homology 2 Domain–Containing Inositol 5′-Phosphatase (Ship) in Phagocytosis Mediated by Fcγ Receptors and Complement Receptor 3 (αMβ2; Cd11b/Cd18)

The Src homology 2 domain-containing inositol 5'-phosphatase (SHIP) is recruited to immunoreceptor tyrosine-based inhibition motif (ITIM)-containing proteins, thereby suppressing phosphatidylinositol 3-kinase (PI 3-kinase)-dependent pathways. The role of SHIP in phagocytosis, a PI 3-kinase-dependent pathway, is unknown. Overexpression of SHIP in macrophages led to an inhibition of phagocytosis ...