title: Extracellular and transmembrane region of a podocalyxin-like protein 1 fragment identified from colon cancer cell lines.
abstract: Regulated intramembrane proteolysis of membrane proteins has been shown to play an important role in cell differentiation and in the pathogenesis of diseases. The aim of the present study was to identify novel peptides generated by intramembrane proteolysis. The peptides were identified in serum-free cultured (SFC) media from various cell lines by surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF-MS). A 2315-Da peptide found only in medium from SFC colon cancer cell lines was identified and shown to consist of a portion of both the extracellular and transmembrane regions of human podocalyxin-like 1. This protein fragment was not found in lung or pancreatic cancer cell lines by immunoprecipitation-SELDI tests using an antibody specific to this fragment, suggesting that this human podocalyxin-like protein 1 fragment may be unique to colon cancer cell lines.
authors.affiliation: Advanced Life Science Institute Inc., 2-10-23 Maruyamadai, Wako, Saitama 351-0112, Japan.
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Ito
authors.forename: Noboru
authors.initials: N
authors.lastname: Maki
authors.forename: Osamu
authors.initials: O
authors.lastname: Hazeki
authors.forename: Kazuki
authors.initials: K
authors.lastname: Sasaki
authors.forename: Munenori
authors.initials: M
authors.lastname: Nekooki
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D014408:Biomarkers, Tumor / Q000302:isolation & purification*; D045744:Cell Line, Tumor; D003110:Colonic Neoplasms / Q000737:chemistry* / Q000378:metabolism; D016895:Culture Media, Serum-Free / Q000032:analysis; D006801:Humans; D008565:Membrane Proteins / Q000302:isolation & purification* / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D009363:Neoplasm Proteins / Q000302:isolation & purification*; D010449:Peptide Mapping; D017434:Protein Structure, Tertiary; D012795:Sialoglycoproteins / Q000302:isolation & purification* / Q000378:metabolism; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods
chemical_list: D014408:Biomarkers, Tumor; D016895:Culture Media, Serum-Free; D008565:Membrane Proteins; D009363:Neoplasm Proteins; D012795:Sialoglycoproteins; C001643:podocalyxin