title: Proteomic analysis of neuroendocrine peptidergic system disruption using the AtT20 pituitary cell line as a model.
abstract: Environmental pollutants may affect the activities of many cellular enzymes. The effect on the proteome of enzymatic inhibitors can be determined using two-dimensional (2D) gel electrophoresis. In neuroendocrine cells, proprotein convertases 1 and 2 (PC1 and PC2) mediate the proteolytic activation of many precursors to peptide hormones and neuropeptides. Enzymatic activities of these calcium-dependent proteinases are readily regulated by chelating agents and by heavy metals ions found in the environment. Such an inhibition could result in a potentially pathological disruption of the peptidergic system. We are interesting in finding out to what extent specific inhibition of these enzymes could affect the proteome of a neuroendocrine cell. To address this question, we used the mouse pituitary AtT20 cell line as a model. We compared the proteomic pattern of control cells to that of cells overexpressing proSAAS, a PC1-specific inhibitor. The comparison was conducted using two-dimensional (2D) gel electrophoresis, mass spectrometric identification of differing proteins and immunoblotting to confirm their identity. The 2D analysis revealed a number of alterations in the proteome of proSAAS-overexpressing cells. Mass spectrometric analysis of tryptic peptides identified two proteins found in more abundance in these cells as proSAAS and Ephrin type A receptor 2.
authors.affiliation: Ottawa Health Research Institute, University of Ottawa, Faculty of Medicine, Ontario, Canada.
authors.forename: Fumin
authors.initials: F
authors.lastname: Dong
authors.forename: Liming
authors.initials: L
authors.lastname: Ma
authors.forename: Michel
authors.initials: M
authors.lastname: Chrétien
authors.forename: Majambu
authors.initials: M
authors.lastname: Mbikay
mesh_terms: D000818:Animals; D002460:Cell Line; D015180:Electrophoresis, Gel, Two-Dimensional; D015151:Immunoblotting; D051379:Mice; D009419:Nerve Tissue Proteins / Q000378:metabolism; D009479:Neuropeptides; D009490:Neurosecretory Systems / Q000378:metabolism*; D045664:Proprotein Convertase 1 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D045706:Proprotein Convertase 2 / Q000378:metabolism*; D040901:Proteomics / Q000379:methods*
chemical_list: D009419:Nerve Tissue Proteins; D009479:Neuropeptides; C112832:Pcsk1n protein, mouse; D045664:Proprotein Convertase 1; D045706:Proprotein Convertase 2