title: Structural requirements for cub domain containing protein 1 (CDCP1) and Src dependent cell transformation.
abstract: Cub domain containing protein 1 (CDCP1) is strongly expressed in tumors derived from lung, colon, ovary, or kidney. It is a membrane protein that is phosphorylated and then bound by Src family kinases. Although expression and phosphorylation of CDCP1 have been investigated in many tumor cell lines, the CDCP1 features responsible for transformation have not been fully evaluated. This is in part due to the lack of an experimental system in which cellular transformation depends on expression of exogenous CDCP1 and Src. Here we use retrovirus mediated co-overexpression of c-Src and CDCP1 to induce focus formation of NIH3T3 cells. Employing different mutants of CDCP1 we show that for a full transformation capacity, the intact amino- and carboxy-termini of CDCP1 are essential. Mutation of any of the core intracellular tyrosine residues (Y734, Y743, or Y762) abolished transformation, and mutation of a palmitoylation motif (C689,690G) strongly reduced it. Src kinase binding to CDCP1 was not required since Src with a defective SH2 domain generated even more CDCP1 dependent foci whereas Src myristoylation was necessary. Taken together, the focus formation assay allowed us to define structural requirements of CDCP1/Src dependent transformation and to characterize the interaction of CDCP1 and Src.
authors.affiliation: Pharma Research and Early Development, Roche Diagnostics GmbH, Penzberg, Germany.
authors.forename: Gwendlyn
authors.initials: G
authors.lastname: Kollmorgen
authors.forename: Birgit
authors.initials: B
authors.lastname: Bossenmaier
authors.forename: Gerhard
authors.initials: G
authors.lastname: Niederfellner
authors.forename: Hans-Ulrich
authors.initials: HU
authors.lastname: Häring
authors.forename: Reiner
authors.initials: R
authors.lastname: Lammers
mesh_terms: D000818:Animals; D015703:Antigens, CD / Q000235:genetics / Q000378:metabolism*; D000951:Antigens, Neoplasm; D015815:Cell Adhesion Molecules / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D002471:Cell Transformation, Neoplastic / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D054878:Lipoylation; D051379:Mice; D009154:Mutation; D041681:NIH 3T3 Cells; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D019061:src-Family Kinases / Q000235:genetics / Q000378:metabolism*
chemical_list: D015703:Antigens, CD; D000951:Antigens, Neoplasm; C432044:CDCP1 protein, human; D015815:Cell Adhesion Molecules; D009363:Neoplasm Proteins; D019061:src-Family Kinases