title: CacyBP/SIP phosphatase activity in neuroblastoma NB2a and colon cancer HCT116 cells.
abstract: Recently, we have reported that CacyBP/SIP could be a novel phosphatase for ERK1/2 kinase. In this work, we analyzed the CacyBP/SIP phosphatase activity toward ERK1/2 in 2 cell lines of different origin. We showed that overexpression of CacyBP/SIP in NB2a cells resulted in a lower level of phosphorylated ERK1/2 (P-ERK1/2) in the nuclear fraction while such overexpression in HCT116 cells had no effect on the level of P-ERK1/2. Moreover, we found that overexpression of CacyBP/SIP resulted in higher phosphatase activity in the nuclear fraction obtained from NB2a cells when compared with HCT116 cells. Using 2-D electrophoresis we showed that the pattern of spots representing CacyBP/SIP differed in these 2 cell lines and was probably due to a different phosphorylation state of this protein. We also established that after overexpression of CacyBP/SIP in NB2a cells, the amount of nuclear β-catenin was low, while it remained high in HCT116 cells. Since NB2a cells have differentiation potential and HCT116 cells do not, our data suggest that different activity of CacyBP/SIP in these 2 cell lines might affect the ERK1/2 pathway in the differentiation or proliferation processes.
authors.affiliation: Nencki Institute of Experimental Biology, 3 Pasteur Street, 02-093 Warsaw, Poland.
authors.forename: Ewa
authors.initials: E
authors.lastname: Kilanczyk
authors.forename: Urszula
authors.initials: U
authors.lastname: Wasik
authors.forename: Anna
authors.initials: A
authors.lastname: Filipek
mesh_terms: D000818:Animals; D002135:Calcium-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D003110:Colonic Neoplasms / Q000201:enzymology*; D006801:Humans; D051379:Mice; D019950:Mitogen-Activated Protein Kinase 1 / Q000235:genetics / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000235:genetics / Q000378:metabolism; D009447:Neuroblastoma / Q000201:enzymology*
chemical_list: C491778:CACYBP protein, human; D002135:Calcium-Binding Proteins; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3