title: Tumor promoter PMA enhances kindlin-2 and decreases vimentin recruitment into cell adhesion sites.
abstract: Phorbol diester PMA (phorbol 12-myristate 13-acetate) is a well-known promoter of tumor progression. PMA also regulates cell adhesion by several mechanisms including conformational activation of integrins and integrin clustering. Here, PMA was shown to induce lamellipodia formation and reorganization of the adhesion sites as well as actin and vimentin filaments independently of integrin preactivation. To further analyze the mechanism of PMA action, the protein composition in the α1β1 integrin/collagen IV adhesion sites was analyzed by mass spectrometry and proteomics. In four independent experiments we observed the reduced recruitment of vimentin in relation to integrin α1 subunit. This was in full agreement with the fact that we also detected the retraction of vimentin from cell adhesions by confocal microscopy. Furthermore, the accumulation of kindlin-2 into cell adhesions was significantly increased after PMA treatment. Kindlin-2 siRNA inhibited cell spreading as well as the formation of actin fibrils and cell adhesions, but did not prevent the effect of PMA on lamellipodia formation. Thus, kindlin-2 recruitment was considered to be a consequence rather than the primary cause for the loss of connection between vimentin and the adhesion sites.
authors.affiliation: Department of Biochemistry, University of Turku, Turku, Finland; MediCity Research Laboratory, University of Turku, Turku, Finland.
authors.forename: Maria
authors.initials: M
authors.lastname: Salmela
authors.affiliation: Department of Biochemistry, University of Turku, Turku, Finland.
authors.forename: Pekka
authors.initials: P
authors.lastname: Rappu
authors.affiliation: Department of Biochemistry, University of Turku, Turku, Finland; MediCity Research Laboratory, University of Turku, Turku, Finland.
authors.forename: Johanna
authors.initials: J
authors.lastname: Lilja
authors.affiliation: Department of Biochemistry, University of Turku, Turku, Finland; MediCity Research Laboratory, University of Turku, Turku, Finland.
authors.forename: Henri
authors.initials: H
authors.lastname: Niskanen
authors.affiliation: Department of Biochemistry, University of Turku, Turku, Finland; MediCity Research Laboratory, University of Turku, Turku, Finland.
authors.forename: Elina
authors.initials: E
authors.lastname: Taipalus
authors.affiliation: Department of Biochemistry, University of Turku, Turku, Finland; MediCity Research Laboratory, University of Turku, Turku, Finland.
authors.forename: Johanna
authors.initials: J
authors.lastname: Jokinen
authors.affiliation: Department of Biochemistry, University of Turku, Turku, Finland; MediCity Research Laboratory, University of Turku, Turku, Finland. Electronic address: jyrki.heino@utu.fi.
authors.forename: Jyrki
authors.initials: J
authors.lastname: Heino
mesh_terms: D000818:Animals; D063646:Carcinogenesis / Q000187:drug effects; D002448:Cell Adhesion / Q000187:drug effects*; D002460:Cell Line; D006224:Cricetinae; D003599:Cytoskeleton / Q000187:drug effects / Q000378:metabolism; D039222:Integrin alpha1beta1 / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism*; D009363:Neoplasm Proteins / Q000378:metabolism*; D021381:Protein Transport / Q000187:drug effects; D011554:Pseudopodia / Q000187:drug effects / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*; D014746:Vimentin / Q000378:metabolism*
chemical_list: C477322:FERMT3 protein, human; D039222:Integrin alpha1beta1; D008565:Membrane Proteins; D009363:Neoplasm Proteins; D014746:Vimentin; D013755:Tetradecanoylphorbol Acetate
keywords: Cell adhesion; Integrin; Kindlin; PMA; Vimentin