Constitutive tyrosine phosphorylation of the inhibitory paired Ig-like receptor PIR-B
AUTOR(ES)
Ho, Le Hong
FONTE
The National Academy of Sciences
RESUMO
PIR-A and PIR-B are activating and inhibitory Ig-like receptors on murine B lymphocytes, dendritic cells, and myeloid-lineage cells. The inhibitory function of PIR-B is mediated via its cytoplasmic immunoreceptor tyrosine-based inhibitory motifs, whereas PIR-A pairs with the Fc receptor common γ chain to form an activating receptor complex. In these studies, we observed constitutive tyrosine phosphorylation of PIR-B molecules on macrophages and B lymphocytes, irrespective of the cell activation status. Splenocyte PIR-B molecules were constitutively associated with the SHP-1 protein tyrosine phosphatase and Lyn protein tyrosine kinase. In Lyn-deficient mice, PIR-B tyrosine phosphorylation was greatly reduced. Unexpectedly, tyrosine phosphorylation of PIR-B was not observed in most myeloid and B cell lines but could be induced by ligation of the PIR molecules. Finally, the phosphorylation status of PIR-B was significantly reduced in MHC class I-deficient mice, although not in mice deficient in TAP1 or MHC class II expression. These findings suggest a physiological inhibitory role for PIR-B that is regulated by endogenous MHC class I-like ligands.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=24777Documentos Relacionados
- The paired Ig-like receptor PIR-B is an inhibitory receptor that recruits the protein-tyrosine phosphatase SHP-1
- Inhibition of IgE-mediated mast cell activation by the paired Ig-like receptor PIR-B
- Paternal monoallelic expression of the paired immunoglobulin-like receptors PIR-A and PIR-B
- Paired Ig-like receptor homologs in birds and mammals share a common ancestor with mammalian Fc receptors
- Ig-like domains: Evolution from simple interaction molecules to sophisticated antigen recognition