Local destabilization, rigid body, and fuzzy docking facilitate the phosphorylation of the transcription factor Ets-1 by the mitogen-activated protein kinase ERK2

Proc Natl Acad Sci U S A. 2017 Aug 1;114(31):E6287-E6296. doi: 10.1073/pnas.1702973114. Epub 2017 Jul 17.


Mitogen-activated protein (MAP) kinase substrates are believed to require consensus docking motifs (D-site, F-site) to engage and facilitate efficient site-specific phosphorylation at specific serine/threonine-proline sequences by their cognate kinases. In contrast to other MAP kinase substrates, the transcription factor Ets-1 has no canonical docking motifs, yet it is efficiently phosphorylated by the MAP kinase ERK2 at a consensus threonine site (T38). Using NMR methodology, we demonstrate that this phosphorylation is enabled by a unique bipartite mode of ERK2 engagement by Ets-1 and involves two suboptimal noncanonical docking interactions instead of a single canonical docking motif. The N terminus of Ets-1 interacts with a part of the ERK2 D-recruitment site that normally accommodates the hydrophobic sidechains of a canonical D-site, retaining a significant degree of disorder in its ERK2-bound state. In contrast, the C-terminal region of Ets-1, including its Pointed (PNT) domain, engages in a largely rigid body interaction with a section of the ERK2 F-recruitment site through a binding mode that deviates significantly from that of a canonical F-site. This latter interaction is notable for the destabilization of a flexible helix that bridges the phospho-acceptor site to the rigid PNT domain. These two spatially distinct, individually weak docking interactions facilitate the highly specific recognition of ERK2 by Ets-1, and enable the optimal localization of its dynamic phospho-acceptor T38 at the kinase active site to enable efficient phosphorylation.

Keywords: MAP kinase; proximity-mediated catalysis; solution NMR; transcription factor.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apoptosis Regulatory Proteins
  • Binding Sites / physiology
  • Catalysis
  • Humans
  • MAP Kinase Signaling System / physiology
  • Mitogen-Activated Protein Kinase 1 / antagonists & inhibitors
  • Mitogen-Activated Protein Kinase 1 / genetics
  • Mitogen-Activated Protein Kinase 1 / metabolism*
  • Nuclear Magnetic Resonance, Biomolecular / methods
  • Phosphoproteins / chemistry
  • Phosphorylation / physiology*
  • Protein Binding / physiology
  • Protein Conformation
  • Proto-Oncogene Protein c-ets-1 / genetics
  • Proto-Oncogene Protein c-ets-1 / metabolism*


  • Apoptosis Regulatory Proteins
  • Ets1 protein, mouse
  • Pea15 protein, mouse
  • Phosphoproteins
  • Proto-Oncogene Protein c-ets-1
  • Mitogen-Activated Protein Kinase 1