Disease relevance of Lilrb4

• Mouse mammary tumor virus-producing cultures of mouse mammary tumor cells synthesize a viral-related polypeptide of molecular weight of 73,000 (gp 73) which is rapidly labeled during a short pulse but disappears during the chase concomitantly with the appearance of label in the virion glycoproteins gp 49 and gp 37.5/33 [1].

High impact information on Lilrb4

• Murine gp49, a 49-kDa type I transmembrane glycoprotein, is a member of the Ig-like receptors expressed on the surface of cells involved in natural immunity such as mast cells, NK cells, and macrophages [2].
• Importantly, gp49 is not expressed on spleen- and liver-derived lymphocytes, including NK cells, but its expression is induced in vitro on NK cells following IL-2 stimulation, or in vivo by infection with murine CMV [3].
• gp49 is a Mr 49,000 glycoprotein expressed on the surface of mouse bone marrow-derived mast cells, which are progenitors for the major in vivo mast cell subclasses, typified by intestinal mucosal mast cells and serosal mast cells [4].
• The amino-terminal amino acid sequence of gp49 was determined after isolation of the solubilized membrane protein by affinity chromatography with the B23.1 anti-gp49 monoclonal antibody [4].
• The predicted extracellular domain of gp49 contains two regions of 48 and 51 amino acids, each flanked by cysteine residues [4].

Chemical compound and disease context of Lilrb4

• The anti-mouse mammary tumor virus serum precipitated the major virion glycoproteins gp49 and gp37.5/33.5 and a viral-related nonvirion glycoprotein of 76,000 daltons [5].

Biological context of Lilrb4

• Cholera toxin did not elicit phosphorylation of gp49 [6].
• The substantial sequence identity of the introns of the gp49A and gp49B genes is comparable to that of the exons, establishing the gene pair as the most homologous of the gp49-related family and suggesting that the gp49A and gp49B genes arose by duplication with relatively little subsequent mutation [7].
• Members of the gp49-related family of mouse and human immunoglobulin (Ig) superfamily receptors have significant amino acid sequence homology in their C2-type, Ig-like domains and include the killer cell Ig-like receptors (KIRs) for major histocompatibility complex class I molecules [7].

Anatomical context of Lilrb4

• Thus, gp49, a membrane glycoprotein preferentially expressed by the progenitor mast cell population, is a new member of the immunoglobulin superfamily [4].
• These data suggest that gp49, a plasma membrane glycoprotein preferentially expressed by mouse BMMC, may be either directly or indirectly phosphorylated via protein kinase C during mast cell activation-secretion [6].

Associations of Lilrb4 with chemical compounds

• Treatment of the immunoprecipitated 42,000 and 49,000 Mr forms with endoglycosidase F reduced the Mr of both to 37,000, as did intrinsic radiolabeling of BMMC in the presence of tunicamycin, indicating that both the 42,000 Mr precursor form and the 49,000 Mr cell surface molecule (gp49) contained N-linked carbohydrate [6].
• Activation of [32P]orthophosphate-labeled BMMC by sensitization with mouse monoclonal IgE anti-TNP and challenge with TNP-BSA or by exposure to the calcium ionophore A23187 elicited the rapid phosphorylation of gp49 but not of its precursor forms, as did treatment of the cells with PMA [6].

Analytical, diagnostic and therapeutic context of Lilrb4

• Molecular cloning of gp49, a cell-surface antigen that is preferentially expressed by mouse mast cell progenitors and is a new member of the immunoglobulin superfamily [4].

References