title: Scavenger receptor CL-P1 mainly utilizes a collagen-like domain to uptake microbes and modified LDL.
abstract: BACKGROUND
  Collectins are considered to play a role in host defense via complement activation and opsonization, and are composed of a collagen-like domain and a carbohydrate recognition domain (CRD). Collectin placenta 1 (CL-P1) showed scavenger receptor activity as functions in vitro, and has three candidate domains: a coiled-coil domain, a collagen-like domain and CRD.
  
  
  METHODS
  We constructed seven types of CL-P1 deletion mutants to determine the site of each ligand binding domain, and observed whether the specific binding to sugar ligand, microbes, or oxidized LDL decreases or not in cells with CL-P1 deletion mutants and CL-P1 containing mutations of amino acid, respectively.
  
  
  RESULTS
  CL-P1 mainly interacted with ligands of microbes through the collagen-like domain and it binds a sugar ligand through the CRD. Additionally it could bind oxidized low density lipoprotein (OxLDL) due to the coiled-coil domain as well as the collagen-like domain. This binding study using mutants at three positively charged sites in the collagen-like domain reveals that the site of R496 K499 K502 plays the most important role in ligand binding functions for microbes and OxLDL.
  
  
  CONCLUSIONS
  CL-P1 has three unique functional domains: the collagen-like domain mainly acts against most negatively charged ligands, and the CRD specifically does against sugar substances, while the coiled-coil domain additionally acts on modified LDL.
  
  
  CONCLUSIONS
  We considered that the binding activity for various ligands due to the association of a coiled-coil domain, a collagen-like domain and/or a CRD in CL-P1, might play a role in physiological functions in the animal body.
authors.affiliation: Department of Microbiology & Immunochemistry, Asahikawa Medical University, Asahikawa 078-8510, Japan.
authors.forename: Kenichiro
authors.initials: K
authors.lastname: Mori
authors.affiliation: Department of Microbiology & Immunochemistry, Asahikawa Medical University, Asahikawa 078-8510, Japan.
authors.forename: Katsuki
authors.initials: K
authors.lastname: Ohtani
authors.affiliation: Department of Microbiology & Immunochemistry, Asahikawa Medical University, Asahikawa 078-8510, Japan.
authors.forename: SeongJae
authors.initials: S
authors.lastname: Jang
authors.affiliation: Department of Microbiology & Immunochemistry, Asahikawa Medical University, Asahikawa 078-8510, Japan; Department of Biomedical Sciences, University of Sun Moon, Asan City 336-708, Republic of Korea.
authors.forename: YounUck
authors.initials: Y
authors.lastname: Kim
authors.affiliation: Department of Microbiology & Immunochemistry, Asahikawa Medical University, Asahikawa 078-8510, Japan.
authors.forename: Insu
authors.initials: I
authors.lastname: Hwang
authors.affiliation: Department of Microbiology & Immunochemistry, Asahikawa Medical University, Asahikawa 078-8510, Japan.
authors.forename: Nitai
authors.initials: N
authors.lastname: Roy
authors.affiliation: Department of Microbiology & Immunochemistry, Asahikawa Medical University, Asahikawa 078-8510, Japan.
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Matsuda
authors.affiliation: Department of Bioresources, Research Center for Zoonosis Control, Hokkaido University, Sapporo 001-0020, Japan.
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Suzuki
authors.affiliation: Department of Microbiology & Immunochemistry, Asahikawa Medical University, Asahikawa 078-8510, Japan. Electronic address: wakamiya@asahikawa-med.ac.jp.
authors.forename: Nobutaka
authors.initials: N
authors.lastname: Wakamiya
keywords: Collagen; Collectin; Endocytosis; OxLDL; Phagocytosis; Scavenger receptor