karolina.honzejkova@seznam.cz
Apoptosis signal-regulating kinase 1 (ASK1), a member of mitogen-activated protein kinase kinase kinase (MAPKKK) family, is a serine/threonine kinase, which is a fundamental component of the MAP kinase signal transduction pathway [1]. Its dysregulation is associated with the pathogenesis of neurodegenerative, tumor, cardiovascular and other diseases [2, 3, 4]. The balance between up- and down-regulation is maintained through oligomerization and protein-protein interactions, however the molecular mechanism is largely unclear [5]. The main aim of this study is to describe the oligomeric behavior of three different N-terminal constructs of ASK1 and its interaction with thioredoxin (TRX). We performed SV-AUC, SAXS, XL-MS, rigid-body modelling and protein-protein docking for either ASK1 variants alone or in complex with TRX. Altogether, experiments performed up to now have shown, that all N-terminal constructs of ASK1 are at least partially capable of forming a dimer in solution. The concentration-dependent dimerization is driven by the kinase domain, however according to SV-AUC and XL-MS it appears that the central regulatory region might be also involved. The role of TRX in the process of ASK1 dimerization is still unclear, neither AUC nor SAXS analysis of ASK1:TRX complexes were able to provide satisfying results, therefore further experiments have been planned to determine its role.
This work was supported by the Czech Science Foundation (Project 19-00121S).