title: Small Molecule Inhibitors Targeting Tec Kinase Block Unconventional Secretion of Fibroblast Growth Factor 2.
abstract: Fibroblast growth factor 2 (FGF2) is a potent mitogen promoting both tumor cell survival and tumor-induced angiogenesis. It is secreted by an unconventional secretory mechanism that is based upon direct translocation across the plasma membrane. Key steps of this process are (i) phosphoinositide-dependent membrane recruitment, (ii) FGF2 oligomerization and membrane pore formation, and (iii) extracellular trapping mediated by membrane-proximal heparan sulfate proteoglycans. Efficient secretion of FGF2 is supported by Tec kinase that stimulates membrane pore formation based upon tyrosine phosphorylation of FGF2. Here, we report the biochemical characterization of the direct interaction between FGF2 and Tec kinase as well as the identification of small molecules that inhibit (i) the interaction of FGF2 with Tec, (ii) tyrosine phosphorylation of FGF2 mediated by Tec in vitro and in a cellular context, and (iii) unconventional secretion of FGF2 from cells. We further demonstrate the specificity of these inhibitors for FGF2 because tyrosine phosphorylation of a different substrate of Tec is unaffected in their presence. Building on previous evidence using RNA interference, the identified compounds corroborate the role of Tec kinase in unconventional secretion of FGF2. In addition, they are valuable lead compounds with great potential for drug development aiming at the inhibition of FGF2-dependent tumor growth and metastasis.
authors.affiliation: From the Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, 69120 Heidelberg, Germany.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: La Venuta
authors.affiliation: From the Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, 69120 Heidelberg, Germany.
authors.forename: Sabine
authors.initials: S
authors.lastname: Wegehingel
authors.affiliation: the European Molecular Biology Laboratory (EMBL), Meyerhofstrasse 1, 69117 Heidelberg, Germany, and.
authors.forename: Peter
authors.initials: P
authors.lastname: Sehr
authors.affiliation: From the Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, 69120 Heidelberg, Germany.
authors.forename: Hans-Michael
authors.initials: HM
authors.lastname: Müller
authors.affiliation: From the Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, 69120 Heidelberg, Germany.
authors.forename: Eleni
authors.initials: E
authors.lastname: Dimou
authors.affiliation: From the Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, 69120 Heidelberg, Germany.
authors.forename: Julia P
authors.initials: JP
authors.lastname: Steringer
authors.affiliation: From the Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, 69120 Heidelberg, Germany.
authors.forename: Mareike
authors.initials: M
authors.lastname: Grotwinkel
authors.affiliation: the Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), DKFZ-ZMBH Allianz, Im Neuenheimer Feld 282, 69120 Heidelberg, Germany.
authors.forename: Nikolai
authors.initials: N
authors.lastname: Hentze
authors.affiliation: the Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), DKFZ-ZMBH Allianz, Im Neuenheimer Feld 282, 69120 Heidelberg, Germany.
authors.forename: Matthias P
authors.initials: MP
authors.lastname: Mayer
authors.affiliation: the European Molecular Biology Laboratory (EMBL), Meyerhofstrasse 1, 69117 Heidelberg, Germany, and.
authors.forename: David W
authors.initials: DW
authors.lastname: Will
authors.affiliation: the European Molecular Biology Laboratory (EMBL), Meyerhofstrasse 1, 69117 Heidelberg, Germany, and.
authors.forename: Ulrike
authors.initials: U
authors.lastname: Uhrig
authors.affiliation: the European Molecular Biology Laboratory (EMBL), Meyerhofstrasse 1, 69117 Heidelberg, Germany, and.
authors.forename: Joe D
authors.initials: JD
authors.lastname: Lewis
authors.affiliation: From the Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, 69120 Heidelberg, Germany, walter.nickel@bzh.uni-heidelberg.de.
authors.forename: Walter
authors.initials: W
authors.lastname: Nickel
mesh_terms: D000818:Animals; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D016222:Fibroblast Growth Factor 2 / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D010766:Phosphorylation / Q000187:drug effects; D047428:Protein Kinase Inhibitors / Q000737:chemistry / Q000494:pharmacology*; D055503:Protein Multimerization / Q000502:physiology*; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism*; D034622:RNA Interference
chemical_list: D047428:Protein Kinase Inhibitors; D016222:Fibroblast Growth Factor 2; C089848:Tec protein-tyrosine kinase; D011505:Protein-Tyrosine Kinases
keywords: FGF2; Tec kinase; fibroblast growth factor (FGF); phosphoinositide; protein phosphorylation; protein secretion; protein translocation; protein translocation across membranes; unconventional protein secretion