title: Proteomic analysis of nuclear proteins from proliferative and differentiated human colonic intestinal epithelial cells.
abstract: Self-renewing tissues such as the intestine contain progenitor proliferating cells which subsequently differentiate. Cell proliferation and differentiation involve gene regulation processes which take place in the nucleus. A human intestinal epithelial cell line model (Caco2/TC7) which reproduces these dynamic processes has been used to perform proteomic studies on nuclear proteins. Nuclei from Caco2/TC7 cells at proliferative and differentiated stages were purified by subcellular fractionation. After two-dimensional gel electrophoresis separation and ruthenium staining, 400 protein spots were detected by image analysis. Eighty-five spots corresponding to 60 different proteins were identified by matrix-assisted laser desorption/ionization mass spectrometry in nuclei from proliferative cells. Comparison of nuclear proteomes from proliferative or differentiated cells by differential display resulted in the identification of differentially expressed proteins such as nucleolin, hnRNP A2/B1 and hnRNP A1. By using Western blot analysis, we found that the expression and number of specific isoforms of these nuclear proteins decreased in differentiated cells. Immunocytochemistry experiments also showed that in proliferative cells nucleolin was distributed in nucleoli-like bodies. In contrast, hnRNPs A2/B1 and A1 were dispersed throughout the nucleus. This study of the nuclear proteome from intestinal epithelial cells represents the first step towards the establishment of a protein database which will be a valuable resource in future studies on the differential expression of nuclear proteins in response to physiological, pharmacological and pathological modulations.
authors.affiliation: INSERM U381, Strasbourg, France.
authors.forename: Natacha
authors.initials: N
authors.lastname: Turck
authors.forename: Sophie
authors.initials: S
authors.lastname: Richert
authors.forename: Patrick
authors.initials: P
authors.lastname: Gendry
authors.forename: Jeanne
authors.initials: J
authors.lastname: Stutzmann
authors.forename: Michèle
authors.initials: M
authors.lastname: Kedinger
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Leize
authors.forename: Patricia
authors.initials: P
authors.lastname: Simon-Assmann
authors.forename: Alain
authors.initials: A
authors.lastname: Van Dorsselaer
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Launay
mesh_terms: D018938:Caco-2 Cells; D002455:Cell Division / Q000502:physiology; D002467:Cell Nucleus / Q000737:chemistry* / Q000502:physiology; D003106:Colon / Q000737:chemistry* / Q000166:cytology / Q000502:physiology; D003110:Colonic Neoplasms / Q000737:chemistry; D015180:Electrophoresis, Gel, Two-Dimensional; D004848:Epithelium / Q000737:chemistry / Q000502:physiology; D006801:Humans; D007150:Immunohistochemistry; D020543:Proteome / Q000737:chemistry* / Q000502:physiology; D016622:Silver Staining; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D020543:Proteome