RRC ID 72361
Author Henshall TL, Jones KL, Wilkinson R, Jackson DE.
Title Src homology 2 domain-containing protein-tyrosine phosphatases, SHP-1 and SHP-2, are required for platelet endothelial cell adhesion molecule-1/CD31-mediated inhibitory signaling.
Journal J Immunol
Abstract Platelet endothelial cell adhesion molecule-1 (PECAM-1/CD31) is a newly assigned member of the Ig immunoreceptor tyrosine-based inhibitory motif superfamily, and its functional role is suggested to be an inhibitory receptor that modulates immunoreceptor tyrosine-based activation motif-dependent signaling cascades. To test whether PECAM-1 is capable of delivering inhibitory signals in B cells and the functional requirement of protein-tyrosine phosphatases (PTPs) for this inhibitory signaling, we generated chimeric Fc gamma RIIB1-PECAM-1 receptors containing the extracellular and transmembrane portions of murine Fc gamma RIIB1 and the cytoplasmic domain of human PECAM-1. These chimeric receptors were stably expressed in chicken DT40 B cells either as wild-type or mutant cells deficient in SHP-1(-/-), SHP-2(-/-), SHIP(-/-), or SHP-1/2(-/-) and then assessed for their ability to inhibit B cell Ag receptor (BCR) signaling. Coligation of wild-type Fc gamma RIIB1-PECAM-1 with BCR resulted in inhibition of intracellular calcium release, suggesting that the cytoplasmic domain of PECAM-1 is capable of delivering an inhibitory signal that blocks BCR-mediated activation. This PECAM-1-mediated inhibitory signaling correlated with tyrosine phosphorylation of the Fc gamma RIIB1-PECAM-1 chimera, recruitment of SHP-1 and SHP-2 PTPs by the phosphorylated chimera, and attenuation of calcium mobilization responses. Mutational analysis of the two tyrosine residues, 663 and 686, constituting the immunoreceptor tyrosine-based inhibitory motifs in PECAM-1 revealed that both tyrosine residues play a crucial role in the inhibitory signal. Functional analysis of various PTP-deficient DT40 B cell lines stably expressing wild-type chimeric Fc gamma RIIB1-PECAM-1 receptor indicated that cytoplasmic Src homology 2-domain-containing phosphatases, SHP-1 and SHP-2, were both necessary and sufficient to deliver inhibitory negative regulation upon coligation of BCR complex with inhibitory receptor.
Volume 166(5)
Pages 3098-106
Published 2001-3-1
DOI 10.4049/jimmunol.166.5.3098
PMID 11207261
MeSH Amino Acid Motifs / genetics Amino Acid Motifs / immunology Animals B-Lymphocytes / enzymology* B-Lymphocytes / immunology* B-Lymphocytes / metabolism Cell Line Chickens Consensus Sequence / genetics Consensus Sequence / immunology Cytoplasm / immunology Down-Regulation / genetics Down-Regulation / immunology* Humans Intracellular Signaling Peptides and Proteins Lymphocyte Activation / genetics Mice Platelet Endothelial Cell Adhesion Molecule-1 / genetics Platelet Endothelial Cell Adhesion Molecule-1 / physiology* Protein Structure, Tertiary / genetics Protein Tyrosine Phosphatase, Non-Receptor Type 11 Protein Tyrosine Phosphatase, Non-Receptor Type 6 Protein Tyrosine Phosphatases / deficiency Protein Tyrosine Phosphatases / genetics Protein Tyrosine Phosphatases / physiology* Receptors, IgG / genetics Recombinant Fusion Proteins / immunology Recombinant Fusion Proteins / pharmacology SH2 Domain-Containing Protein Tyrosine Phosphatases Signal Transduction / genetics Signal Transduction / immunology* Tyrosine / genetics Tyrosine / physiology src Homology Domains / genetics src Homology Domains / immunology*
IF 4.886
Human and Animal Cells SHP1^(-) DT40(RCB1466) SHP1^(-)/SHP2^(-) DT40(RCB1501) SHP2^(-) DT40(RCB1502) SHIP^(-) DT40(RCB1465)