title: [Identification and characterization of LAPTM4B encoded by a human hepatocellular carcinoma-associated novel gene].
abstract: OBJECTIVE
  To identify and characterize the novel proteins encoded by a HCC-associated novel gene, LAPTM4B (lysosomeassociated protein transmembrane 4 beta).
  
  
  METHODS
  The novel proteins was identified by Western blot, immunohistochemistry and 2D electrophoresis; the molecular interactions were studied by co-immunoprecipitation.
  
  
  RESULTS
  LAPTM4B encoded two isoforms of proteins with molecular weight 35 x 10(3) and 24 x 10(3) and pI 9.07 and 4.65, respectively. The expression levels of LAPTM4B proteins in HCC tissues and cell lines were upregulated and related to differentiation, and most dramatically raised for 35 x 10(3) one. It was demonstrated that LAPTM4B--integrin alpha 6 and LAPTM4B--EGFR signaling complexes were formed when BEL-7402 cells were seeded on laminin substrate.
  
  
  CONCLUSIONS
  The LAPTM4B-35 protein is overexpressed in human HCC tissues and cell lines and may involve in signal transduction triggered by extracellular matrix via interaction with integrin alpha 6 and EGFR on cell surface.
authors.affiliation: Department of Cell Biology and Genetics, Peking University School of Basic Medical Sciences, Beijing 100083, China.
authors.forename: Xinrong
authors.initials: X
authors.lastname: Liu
authors.forename: Rouli
authors.initials: R
authors.lastname: Zhou
authors.forename: Qingyun
authors.initials: Q
authors.lastname: Zhang
authors.forename: Ye
authors.initials: Y
authors.lastname: Zhang
authors.forename: Genze
authors.initials: G
authors.lastname: Shao
authors.forename: Yueying
authors.initials: Y
authors.lastname: Jin
authors.forename: Sha
authors.initials: S
authors.lastname: Zhang
authors.forename: Ming
authors.initials: M
authors.lastname: Lin
authors.forename: Jing'an
authors.initials: J
authors.lastname: Rui
authors.forename: Daxiong
authors.initials: D
authors.lastname: Ye
mesh_terms: D006528:Carcinoma, Hepatocellular / Q000235:genetics*; D006801:Humans; D007150:Immunohistochemistry; D008113:Liver Neoplasms / Q000235:genetics*; D008565:Membrane Proteins / Q000235:genetics*; D015513:Oncogene Proteins / Q000235:genetics*; D015398:Signal Transduction; D015854:Up-Regulation
chemical_list: C477083:LAPTM4B protein, human; D008565:Membrane Proteins; D015513:Oncogene Proteins