title: Genomic and functional characterization of the diverse immunoglobulin domain-containing protein (DICP) family.
abstract: A heretofore-unrecognized multigene family encoding diverse immunoglobulin (Ig) domain-containing proteins (DICPs) was identified in the zebrafish genome. Twenty-nine distinct loci mapping to three chromosomal regions encode receptor-type structures possessing two classes of Ig ectodomains (D1 and D2). The sequence and number of Ig domains, transmembrane regions and signaling motifs vary between DICPs. Interindividual polymorphism and alternative RNA processing contribute to DICP diversity. Molecular models indicate that most D1 domains are of the variable (V) type; D2 domains are Ig-like. Sequence differences between D1 domains are concentrated in hypervariable regions on the front sheet strands of the Ig fold. Recombinant DICP Ig domains bind lipids, a property shared by mammalian CD300 and TREM family members. These findings suggest that novel multigene families encoding diversified immune receptors have arisen in different vertebrate lineages and affect parallel patterns of ligand recognition that potentially impact species-specific advantages.
authors.affiliation: Department of Pediatrics, University of South Florida College of Medicine, USF/ACH Children's Research Institute, 140 7th Avenue South, St. Petersburg, FL 33701, USA.
authors.forename: Robert N
authors.initials: RN
authors.lastname: Haire
authors.forename: John P
authors.initials: JP
authors.lastname: Cannon
authors.forename: Marci L
authors.initials: ML
authors.lastname: O'Driscoll
authors.forename: David A
authors.initials: DA
authors.lastname: Ostrov
authors.forename: M Gail
authors.initials: MG
authors.lastname: Mueller
authors.forename: Poem M
authors.initials: PM
authors.lastname: Turner
authors.forename: Ronda T
authors.initials: RT
authors.lastname: Litman
authors.forename: Gary W
authors.initials: GW
authors.lastname: Litman
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Yoder
mesh_terms: D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites / Q000235:genetics; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D014644:Genetic Variation; D023281:Genomics / Q000379:methods*; D007136:Immunoglobulins / Q000737:chemistry / Q000235:genetics; D008958:Models, Molecular; D008969:Molecular Sequence Data; D005810:Multigene Family / Q000235:genetics*; D010743:Phospholipids / Q000737:chemistry / Q000378:metabolism; D010802:Phylogeny; D011485:Protein Binding; D020033:Protein Isoforms / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017434:Protein Structure, Tertiary; D011971:Receptors, Immunologic / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D015027:Zebrafish / Q000235:genetics*; D029961:Zebrafish Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism
chemical_list: C574864:DICP1.1 protein, zebrafish; C574865:DICP2.1 protein, zebrafish; C574866:DICP3.1 protein, zebrafish; D018076:DNA, Complementary; D007136:Immunoglobulins; D010743:Phospholipids; D020033:Protein Isoforms; D011971:Receptors, Immunologic; D029961:Zebrafish Proteins