Structure determination of ASK1 using cryo-EM

D. Košek1, K. Honzejková1,2, V. Obšilová1, T. Obšil1,2

1Department of Structural Biology of Signaling Proteins, Division BIOCEV, Institute of Physiology of the Czech Academy of Sciences, Vestec, Czech Republic

2Department of Physical and Macromolecular Chemistry, Faculty of Science, Charles University, Prague, Czech Republic

dalibor.kosek@fgu.cas.cz

 

ASK1 (apoptosis signal-regulating kinase 1) is a member of the protein family MAP3K which triggers p38 or JNK dependent signaling pathways leading to inflamation or apoptosis [1,2]. ASK1 dysfunction has been implicated in neurodegenerative, cardiovascular and oncogenic diseases  [3,4,5] and, thus, ASK1 represents a prospective drug target. However, key aspects of its activation mechanism remains unclear. To better understand the principle of ASK1 activation, we investigated the structure and oligomeric behavior of N-terminal part of ASK1. Here, we present the structure determination of this N-terminal part of ASK1 using cryo-EM including sample optimization, strategy to manage the preferred orientation of particle, data analysis with local 3D classification and refinement to overcome the heterogeneity of the complex.

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This study was supported by the Czech Science Foundation (Project 19-00121S), the Czech Academy of Sciences (Research Project RVO: 67985823 of the Institute of Physiology).

We acknowledge Cryo-electron microscopy and tomography core facility CEITEC MU of CIISB, Instruct-CZ Centre, supported by MEYS CR (LM2023042) and European Regional Development Fund-Project „UP CIISB“ (No. CZ.02.1.01/0.0/0.0/18_046/0015974).