Fe65-PTB2 Dimerization Mimics Fe65-APP Interaction.Feilen, L.P., Haubrich, K., Strecker, P., Probst, S., Eggert, S., Stier, G., Sinning, I., Konietzko, U., Kins, S., Simon, B., Wild, K.
(2017) Front Mol Neurosci 10: 140-140
- PubMed: 28553201
- DOI: 10.3389/fnmol.2017.00140
- PubMed Abstract:
Physiological function and pathology of the Alzheimer's disease causing amyloid precursor protein (APP) are correlated with its cytosolic adaptor Fe65 encompassing a WW and two phosphotyrosine-binding domains (PTBs). The C-terminal Fe65-PTB2 binds a ...
Physiological function and pathology of the Alzheimer's disease causing amyloid precursor protein (APP) are correlated with its cytosolic adaptor Fe65 encompassing a WW and two phosphotyrosine-binding domains (PTBs). The C-terminal Fe65-PTB2 binds a large portion of the APP intracellular domain (AICD) including the GYENPTY internalization sequence fingerprint. AICD binding to Fe65-PTB2 opens an intra-molecular interaction causing a structural change and altering Fe65 activity. Here we show that in the absence of the AICD, Fe65-PTB2 forms a homodimer in solution and determine its crystal structure at 2.6 Å resolution. Dimerization involves the unwinding of a C-terminal α-helix that mimics binding of the AICD internalization sequence, thus shielding the hydrophobic binding pocket. Specific dimer formation is validated by nuclear magnetic resonance (NMR) techniques and cell-based analyses reveal that Fe65-PTB2 together with the WW domain are necessary and sufficient for dimerization. Together, our data demonstrate that Fe65 dimerizes via its APP interaction site, suggesting that besides intra- also intermolecular interactions between Fe65 molecules contribute to homeostatic regulation of APP mediated signaling.
Heidelberg University Biochemistry Center (BZH), University of HeidelbergHeidelberg, Germany.,European Molecular Biology Laboratory (EMBL), Structural and Computational BiologyHeidelberg, Germany.,Institute for Regenerative Medicine (IREM), University of ZurichZurich, Switzerland.,Division of Human Biology and Human Genetics, University of KaiserslauternKaiserslautern, Germany.