title: The membrane-type collectin CL-P1 is a scavenger receptor on vascular endothelial cells.
abstract: Collectins are a family of C-type lectins that have collagen-like sequences and carbohydrate recognition domains (CRD). They are involved in host defense through their ability to bind to carbohydrate antigens of microorganisms. The scavenger receptors type A and MARCO are classical type scavenger receptors that have internal collagen-like domains. Here we describe a new scavenger receptor that is a membrane-type collectin from placenta (collectin placenta 1 (CL-P1)), which has a typical collectin collagen-like domain and a CRD. The cDNA has an insert of about 2.2 kilobases coding for a protein containing 742 amino acid residues. The deduced amino acid sequence shows that CL-P1 is a type II membrane protein, has a coiled-coil region, a collagen-like domain, and a CRD. It resembles type A scavenger receptors because the scavenger receptor cysteine-rich domain is replaced by a CRD. Northern analyses, reverse transcription-polymerase chain reaction, and immunohistochemistry show that CL-P1 is expressed in vascular endothelial cells but not in macrophages. By immunoblotting and flow cytometry CL-P1 appears to be a membrane glycoprotein of about 140 kDa in human umbilical vein or arterial endothelial cells, placental membrane extracts, and CL-P1 transfected Chinese hamster ovary cells. We found that CL-P1 can bind and phagocytose not only bacteria (Escherichia coli and Staphylococcus aureus) but also yeast (Saccharomyces cerevisiae). Furthermore, it reacts with oxidized low density lipoprotein (OxLDL) but not with acetylated LDL (AcLDL). These binding activities are inhibited by polyanionic ligands (polyinosinic acid, polyguanylic acid, dextran sulfate) and OxLDL but not by polycationic ligands (polyadenylic acid or polycytidylic acid), LDL, or AcLDL. These results indicate that CL-P1 might play important roles in host defenses that are different from those of soluble collectins in innate immunity.
authors.affiliation: Department of Microbiology, Asahikawa Medical College, Midorigaoka-Higashi, Asahikawa 078-8510, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Ohtani
authors.forename: Y
authors.initials: Y
authors.lastname: Suzuki
authors.forename: S
authors.initials: S
authors.lastname: Eda
authors.forename: T
authors.initials: T
authors.lastname: Kawai
authors.forename: T
authors.initials: T
authors.lastname: Kase
authors.forename: H
authors.initials: H
authors.lastname: Keshi
authors.forename: Y
authors.initials: Y
authors.lastname: Sakai
authors.forename: A
authors.initials: A
authors.lastname: Fukuoh
authors.forename: T
authors.initials: T
authors.lastname: Sakamoto
authors.forename: H
authors.initials: H
authors.lastname: Itabe
authors.forename: T
authors.initials: T
authors.lastname: Suzutani
authors.forename: M
authors.initials: M
authors.lastname: Ogasawara
authors.forename: I
authors.initials: I
authors.lastname: Yoshida
authors.forename: N
authors.initials: N
authors.lastname: Wakamiya
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D016466:CHO Cells; D002462:Cell Membrane / Q000378:metabolism; D003001:Cloning, Molecular; D037222:Collectins; D006224:Cricetinae; D017931:DNA Primers; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism*; D006801:Humans; D037102:Lectins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008565:Membrane Proteins; D008969:Molecular Sequence Data; D011956:Receptors, Cell Surface / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011971:Receptors, Immunologic / Q000378:metabolism*; D018110:Receptors, Lipoprotein; D051116:Receptors, Scavenger; D051117:Scavenger Receptors, Class A; D051122:Scavenger Receptors, Class B; D017386:Sequence Homology, Amino Acid
chemical_list: C422442:COLEC12 protein, human; D037222:Collectins; D017931:DNA Primers; D037102:Lectins; D008565:Membrane Proteins; D011956:Receptors, Cell Surface; D011971:Receptors, Immunologic; D018110:Receptors, Lipoprotein; D051116:Receptors, Scavenger; C454739:Scarb1 protein, mouse; D051117:Scavenger Receptors, Class A; D051122:Scavenger Receptors, Class B