title: A cDNA clone from the sea lamprey Petromyzon marinus coding for a scavenger receptor Cys-rich (SRCR) domain protein.
abstract: Our knowledge of the immune system in the early vertebrates, the Agnatha, and the molecules involved in their immune reactions is fragmentary. By serendipity we discovered a cDNA clone in a library made from gut poly(A)+RNA of the sea lamprey, Petromyzon marinus (Pema), that translates into the SREG (SRCR-EGF, see below) protein which resembles cell-membrane proteins of mammalian immune cells. The putative translated product is a type-I integral membrane glycoprotein which contains two scavenger receptor Cys-rich (SRCR) domains flanking five epidermal growth factor (EGF)-like repeats. The two SRCR domains are closely related to CD6 (expressed on human lymphocytes), WC1 (expressed on mammalian CD4-CD8(-)-gamma delta T cells) and M130 (expressed on human macrophages). The Pema-SREG may therefore be involved in intercellular contacts and cell activation or differentiation in the immune system. It is thus a potential marker that can be used to investigate the lamprey immune system.
authors.affiliation: Max-Planck-Institut für Biologie, Abt. Immungenetik, Tübingen, Germany.
authors.forename: W E
authors.initials: WE
authors.lastname: Mayer
authors.forename: H
authors.initials: H
authors.lastname: Tichy
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015703:Antigens, CD / Q000096:biosynthesis / Q000737:chemistry; D000945:Antigens, Differentiation, T-Lymphocyte / Q000096:biosynthesis / Q000737:chemistry; D001483:Base Sequence; D002462:Cell Membrane / Q000276:immunology; D003001:Cloning, Molecular; D016384:Consensus Sequence; D003545:Cysteine; D018076:DNA, Complementary / Q000378:metabolism; D004815:Epidermal Growth Factor / Q000737:chemistry; D015723:Gene Library; D006801:Humans; D007798:Lampreys / Q000235:genetics*; D008264:Macrophages / Q000276:immunology; D008322:Mammals; D008562:Membrane Glycoproteins / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics; D008565:Membrane Proteins; D008969:Molecular Sequence Data; D010802:Phylogeny; D014176:Protein Biosynthesis; D011971:Receptors, Immunologic / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics*; D018110:Receptors, Lipoprotein; D051116:Receptors, Scavenger; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry; D051122:Scavenger Receptors, Class B; D017386:Sequence Homology, Amino Acid; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; C062279:CD6 antigen; D018076:DNA, Complementary; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D011971:Receptors, Immunologic; D018110:Receptors, Lipoprotein; D051116:Receptors, Scavenger; D011994:Recombinant Proteins; C454739:Scarb1 protein, mouse; D051122:Scavenger Receptors, Class B; D004815:Epidermal Growth Factor; D003545:Cysteine