Analysis of binding interfaces of the human scaffold protein AXIN1 by peptide microarrays

0501855 - BFÚ 2019 RIV US eng J - Journal Article
Harnoš, J. - Ryneš, Jan - Viskova, P. - Foldynova-Trantirkova, S. - Bajard-Esner, L. - Trantírek, L. - Bryja, Vítězslav
Analysis of binding interfaces of the human scaffold protein AXIN1 by peptide microarrays.
Journal of Biological Chemistry. Roč. 293, č. 42 (2018), s. 16337-16347. ISSN 0021-9258. E-ISSN 1083-351X
R&D Projects: GA ČR GA17-12075S; GA MŠMT EF15_003/0000477
Institutional support: RVO:68081707
Keywords : casein kinase-i * beta-catenin * structural basis * transcriptional regulation
OECD category: Biochemistry and molecular biology
Impact factor: 4.106, year: 2018

Intrinsically disordered regions (IDRs) are protein regions that lack persistent secondary or tertiary structure under native conditions. IDRs represent >40% of the eukaryotic proteome and play a crucial role in protein-protein interactions. The classical approach for identification of these interaction interfaces is based on mutagenesis combined with biochemical techniques such as coimmunoprecipitation or yeast two-hybrid screening. This approach either provides information of low resolution (large deletions) or very laboriously tries to precisely define the binding epitope via single amino acid substitutions. Here, we report the use of a peptide microarray based on the human scaffold protein AXIN1 for high-throughput andresolution mapping of binding sites for several AXIN1 interaction partners in vitro. For each of the AXIN1-binding partners tested, i.e. casein kinase 1 E (CK1E), c-Myc, peptidyl-prolyl cis/trans isomerase, NIMA-interacting 1 (Pin1), and p53, we found at least three different epitopes, predominantly in the central IDR of AXIN1. We functionally validated the specific AXIN1-CK1E interaction identified here with epitope-mimicking peptides and with AXIN1 variants having deletions of short binding epitopes. On the basis of these results, we propose a model in which AXIN1 competes with dishevelled (DVL) for CK1E and regulates CK1E-induced phosphorylation of DVL and activation of Wnt/-catenin signaling.
Permanent Link: http://hdl.handle.net/11104/0293830