ADAM15 protein amplifies focal adhesion kinase phosphorylation under genotoxic stress conditions

J Biol Chem. 2012 Jun 15;287(25):21214-23. doi: 10.1074/jbc.M112.347120. Epub 2012 Apr 27.

Abstract

ADAM15, a disintegrin and metalloproteinase, is capable of counteracting genotoxic stress-induced apoptosis by the suppression of caspase-3 activation. A cell line expressing the membrane-bound ADAM15 without its cytoplasmic tail, however, lost this anti-apoptotic property, suggesting a crucial role of the intracellular domain as a scaffold for recruitment of survival signal-transducing kinases. Accordingly, an enhanced phosphorylation of FAK at Tyr-397, Tyr-576, and Tyr-861 was detected upon genotoxic stress by camptothecin in ADAM15-transfected T/C28a4 cells, but not in transfectants expressing an ADAM15 mutant without the cytoplasmic tail. Accordingly, a specific binding of the cytoplasmic ADAM15 domain to the C terminus of FAK could be shown by mammalian two-hybrid, pulldown, and far Western studies. In cells expressing full-length ADAM15, a concomitant activation of Src at Tyr-416 was detected upon camptothecin exposure. Cells transfected with a chimeric construct consisting of the extracellular IL-2 receptor α-chain and the cytoplasmic ADAM15 domain were IL-2-stimulated to prove that the ADAM15 tail can transduce a percepted extracellular signal to enhance FAK and Src phosphorylation. Our studies further demonstrate Src binding to FAK but not a direct Src interaction with ADAM15, suggesting FAK as a critical intracellular adaptor for ADAM15-dependent enhancement of FAK/Src activation. Moreover, the apoptosis induction elicited by specific inhibitors (PP2, FAK 14 inhibitor) of FAK/Src signaling was significantly reduced by ADAM15 expression. The newly uncovered counter-regulatory response to genotoxic stress in a chondrocytic survival pathway is potentially also relevant to apoptosis resistance in neoplastic growth.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • ADAM Proteins / genetics
  • ADAM Proteins / metabolism*
  • Caspase 3 / genetics
  • Caspase 3 / metabolism
  • Cell Line
  • Chondrocytes / enzymology*
  • DNA Damage*
  • Enzyme Activation / genetics
  • Enzyme Inhibitors / pharmacology
  • Focal Adhesion Kinase 1 / genetics
  • Focal Adhesion Kinase 1 / metabolism*
  • Humans
  • Interleukin-2 / genetics
  • Interleukin-2 / metabolism
  • Interleukin-2 Receptor alpha Subunit / genetics
  • Interleukin-2 Receptor alpha Subunit / metabolism
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism*
  • Phosphorylation
  • Protein Structure, Tertiary
  • Signal Transduction*
  • src-Family Kinases / antagonists & inhibitors
  • src-Family Kinases / genetics
  • src-Family Kinases / metabolism

Substances

  • Enzyme Inhibitors
  • IL2 protein, human
  • IL2RA protein, human
  • Interleukin-2
  • Interleukin-2 Receptor alpha Subunit
  • Membrane Proteins
  • Focal Adhesion Kinase 1
  • PTK2 protein, human
  • src-Family Kinases
  • CASP3 protein, human
  • Caspase 3
  • ADAM Proteins
  • ADAM15 protein, human