Structural insights into the recognition of substrates and activators by the OSR1 kinase

Fabrizio Villa, Jürgen Goebel, Fatema H. Rafiqi, Maria Deak, Jacob Thastrup, Dario R. Alessi, D. M F van Aalten

Research output: Contribution to journalArticlepeer-review

Abstract

The oxidative-stress-responsive kinase 1 (OSR1) and the STE20/ SPS1-related proline/alanine-rich kinase (SPAK) are key enzymes in a signalling cascade regulating the activity of Na+/ K+/2Cl- co-transporters (NKCCs) in response to osmotic stress. Both kinases have a conserved carboxy-terminal (CCT) domain, which recognizes a unique peptide (Arg-Phe-Xaa-Val) motif present in OSR1- and SPAK-activating kinases (with-no-lysine kinase 1 (WNK1) and WNK4) as well as its substrates (NKCC1 and NKCC2). Here, we describe the structural basis of this recognition event as shown by the crystal structure of the CCT domain of OSR1 in complex with a peptide containing this motif, derived from WNK4. The CCT domain forms a novel protein fold that interacts with the Arg-Phe-Xaa-Val motif through a surface-exposed groove. An intricate web of interactions is observed between the CCT domain and an Arg-Phe-Xaa-Val motif-containing peptide derived from WNK4. Mutational analysis shows that these interactions are required for the CCT domain to bind to WNK1 and NKCC1. The CCT domain structure also shows how phosphorylation of a Ser/Thr residue preceding the Arg-Phe-Xaa-Val motif results in a steric clash, promoting its dissociation from the CCT domain. These results provide the first molecular insight into the mechanism by which the SPAK and OSR1 kinases specifically recognize their upstream activators and downstream substrates.

Original languageEnglish
Pages (from-to)839-845
Number of pages7
JournalEMBO Reports
Volume8
Issue number9
DOIs
Publication statusPublished - Sep 2007

ASJC Scopus subject areas

  • Cell Biology
  • Genetics

Fingerprint Dive into the research topics of 'Structural insights into the recognition of substrates and activators by the OSR1 kinase'. Together they form a unique fingerprint.

Cite this