Proteomic analysis of the tetraspanin web using LC-ESI-MS/MS and MALDI-FTICR-MS.
Tetraspanins are integral membrane proteins involved in a variety of physiological and pathological processes. In cancer, clinical and experimental studies have reported a link between tetraspanin expression levels and metastasis. Tetraspanins play a role as organizers of a molecular network of interactions, the "tetraspanin web". Here, we have performed a proteomic characterization of the tetraspanin web using a model of human colon cancer consisting of two cell lines derived from primary tumor and metastasis from the same patient. The tetraspanin complexes were isolated after immunoaffinity purification and the proteins were identified by MS using LC-ESI-MS/MS and MALDI-FTICR. The high resolution and mass accuracy of FTICR MS allowed reliable identification using mass finger printing with only two peptides. Thus, it could be used to resolve the composition of complex peptide mixtures from membrane proteins. Different types of membrane proteins were identified, including adhesion molecules (integrins, Lu/B-CAM, GA733 proteins), receptors and signaling molecules (BAI2, PKC, G proteins), proteases (ADAM10, TADG15), and membrane fusion proteins (syntaxins) as well as poorly characterized proteins (CDCP1, HEM-1, CTL1, and CTL2). Some components were differentially detected in the tetraspanin web of the two cell lines. These differences may be relevant for tumor progression and metastasis.
André
Magali
M
INSERM U602, Institut André Lwoff, Université Paris XI, Hôpital Paul Brousse, Villejuif Cedex, France.
Le Caer
Jean-Pierre
JP
Greco
Céline
C
Planchon
Sébastien
S
El Nemer
Wassim
W
Boucheix
Claude
C
Rubinstein
Eric
E
Chamot-Rooke
Julia
J
Le Naour
François
F
D000595:Amino Acid Sequence; D000911:Antibodies, Monoclonal / Q000378:metabolism; D003110:Colonic Neoplasms / Q000737:chemistry; D006801:Humans; D013058:Mass Spectrometry / Q000379:methods*; D008565:Membrane Proteins / Q000737:chemistry* / Q000378:metabolism; D008969:Molecular Sequence Data; D009362:Neoplasm Metastasis; D009363:Neoplasm Proteins / Q000032:analysis; D010449:Peptide Mapping / Q000379:methods; D010455:Peptides / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D020543:Proteome / Q000032:analysis*; D040901:Proteomics / Q000379:methods*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D014407:Tumor Cells, Cultured
D000911:Antibodies, Monoclonal; D008565:Membrane Proteins; D009363:Neoplasm Proteins; D010455:Peptides; D020543:Proteome