title: A novel pair of immunoglobulin-like receptors expressed by B cells and myeloid cells.
abstract: An Fcalpha receptor probe of human origin was used to identify novel members of the Ig gene superfamily in mice. Paired Ig-like receptors, named PIR-A and PIR-B, are predicted from sequence analysis of the cDNAs isolated from a mouse splenic library. Both type I transmembrane proteins possess similar ectodomains with six Ig-like loops, but have different transmembrane and cytoplasmic regions. The predicted PIR-A protein has a short cytoplasmic tail and a charged Arg residue in the transmembrane region that, by analogy with the FcalphaR relative, suggests the potential for association with an additional transmembrane protein to form a signal transducing unit. In contrast, the PIR-B protein has an uncharged transmembrane region and a long cytoplasmic tail containing four potential immunoreceptor tyrosine-based inhibitory motifs. These features are shared by the related killer inhibitory receptors. PIR-A proteins appear to be highly variable, in that predicted peptide sequences differ for seven randomly selected PIR-A clones, whereas PIR-B cDNA clones are invariant. Southern blot analysis with PIR-B and PIR-A-specific probes suggests only one PIR-B gene and multiple PIR-A genes. The PIR-A and PIR-B genes are expressed in B lymphocytes and myeloid lineage cells, wherein both are expressed simultaneously. The characteristics of the highly-conserved PIR-A and PIR-B genes and their coordinate cellular expression suggest a potential regulatory role in humoral, inflammatory, and allergic responses.
authors.affiliation: Department of Pathology, Division of Developmental and Clinical Immunology, University of Alabama, Birmingham, AL 35294-3300, USA.
authors.forename: H
authors.initials: H
authors.lastname: Kubagawa
authors.forename: P D
authors.initials: PD
authors.lastname: Burrows
authors.forename: M D
authors.initials: MD
authors.lastname: Cooper
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology*; D002874:Chromosome Mapping; D002888:Chromosomes, Human, Pair 19; D004247:DNA / Q000378:metabolism; D018076:DNA, Complementary; D015870:Gene Expression; D015723:Gene Library; D005819:Genetic Markers; D014644:Genetic Variation; D006412:Hematopoietic Stem Cells / Q000276:immunology*; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D005810:Multigene Family; D009928:Organ Specificity; D016133:Polymerase Chain Reaction; D011971:Receptors, Immunologic / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D013154:Spleen / Q000276:immunology
chemical_list: D018076:DNA, Complementary; D005819:Genetic Markers; C105948:Pira1 protein, mouse; C491379:Pira2 protein, mouse; C491378:Pira3 protein, mouse; C491377:Pira4 protein, mouse; C491376:Pira5 protein, mouse; C491375:Pira6 protein, mouse; C491374:Pira7 protein, mouse; C105949:Pirb protein, mouse; D011971:Receptors, Immunologic; D004247:DNA