title: Scavenger receptor CL-P1 mediates endocytosis by associating with AP-2μ2.
abstract: BACKGROUND
  Scavenger receptor CL-P1 (collectin placenta 1) has been found recently as a first membrane-type collectin which is mainly expressed in vascular endothelial cells. CL-P1 can endocytose OxLDL as well as microbes but in general, the endocytosis mechanism of a scavenger receptor is not well elucidated.
  
  
  METHODS
  We screened a placental cDNA library using a yeast two-hybrid system to detect molecules associated with the cytoplasmic domain of CL-P1. We analyzed the binding and endocytosis of several ligands in CL-P1 transfectants and performed the inhibition study using tyrphostin A23 which is a specific inhibitor of tyrosine kinase, especially in μ2-dependent endocytosis and the site-directed mutagenesis in the endocytosis YXXΦ motif in CL-P1 cytoplasmic region. Furthermore, the SiRNA study of clathrin, adaptor AP-2 and dynamin-2 during the endocytosis of OxLDL in CL-P1 transfectant cells was carried out.
  
  
  RESULTS
  We identified μ2 subunit of the AP-2 adaptor complex as a molecule associated with the cytoplasmic region of CL-P1. We demonstrated that AP-2μ2 was essential for CL-P1 mediated endocytosis of OxLDL in CL-P1 transfectant cells and its endocytosis was also mediated by clathrin, dynamin and adaptin complex molecules.
  
  
  CONCLUSIONS
  Tyrosine-based YXXΦ sequences play an important role in CL-P1-mediated OxLDL endocytosis associated with AP-2μ2.
  
  
  CONCLUSIONS
  This might be the first finding of the clear endocytosis mechanism in scavenger receptor CL-P1.
authors.affiliation: Department of Microbiology & Immunochemistry Asahikawa Medical University, 2-1-1-1 Midorigaoka-Higashi, Asahikawa 078-8510, Japan.
authors.forename: SeongJae
authors.initials: S
authors.lastname: Jang
authors.affiliation: Department of Microbiology & Immunochemistry Asahikawa Medical University, 2-1-1-1 Midorigaoka-Higashi, Asahikawa 078-8510, Japan.
authors.forename: Katsuki
authors.initials: K
authors.lastname: Ohtani
authors.affiliation: Department of Microbiology & Immunochemistry Asahikawa Medical University, 2-1-1-1 Midorigaoka-Higashi, Asahikawa 078-8510, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Fukuoh
authors.affiliation: Department of Microbiology & Immunochemistry Asahikawa Medical University, 2-1-1-1 Midorigaoka-Higashi, Asahikawa 078-8510, Japan.
authors.forename: Kenichiro
authors.initials: K
authors.lastname: Mori
authors.affiliation: Department of Microbiology & Immunochemistry Asahikawa Medical University, 2-1-1-1 Midorigaoka-Higashi, Asahikawa 078-8510, Japan.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Yoshizaki
authors.affiliation: Department of Microbiology, School of Human Science and Environment, University of Hyogo, Himeji 670-0092, Japan.
authors.forename: Noritoshi
authors.initials: N
authors.lastname: Kitamoto
authors.affiliation: Department of Microbiology & Immunochemistry Asahikawa Medical University, 2-1-1-1 Midorigaoka-Higashi, Asahikawa 078-8510, Japan.
authors.forename: YounUck
authors.initials: Y
authors.lastname: Kim
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, 2-1-1-1 Midorigaoka-Higashi, Asahikawa 078-8510, Japan. Electronic address: wakamiya@asahikawa-med.ac.jp.
authors.forename: Nobutaka
authors.initials: N
authors.lastname: Wakamiya
keywords: Adaptor complex; Collectin; Endocytosis; Scavenger Receptors; Tyrosine motif