Lipid molecules induce p38α activation via a novel molecular switch.

Journal Article (Journal Article)

p38α mitogen-activated protein kinase (MAPK) is generally activated by dual phosphorylation but has also been shown to exhibit alternative activation modes. One of these modes included a direct interaction with phosphatidylinositol ether lipid analogues (PIA) inducing p38α autoactivation and apoptosis. Perifosine, an Akt inhibitor in phase II clinical trials, also showed p38α activation properties similarly to those of PIAs. The crystal structures of p38α in complex with PIA23, PIA24 and perifosine provide insights into this unique activation mode. The activating molecules bind a unique hydrophobic binding site in the kinase C'-lobe formed in part by the MAPK insert region. In addition, there are conformational changes in the short αEF/αF loop region that acts as an activation switch, inducing autophosphorylation. Structural and biochemical characterization of the αEF/αF loop identified Trp197 as a key residue in the lipid binding and in p38α catalytic activity. The lipid binding site also accommodates hydrophobic inhibitor molecules and, thus, can serve as a novel p38α-target for specific activation or inhibition, with novel therapeutic implications.

Full Text

Duke Authors

Cited Authors

  • Tzarum, N; Eisenberg-Domovich, Y; Gills, JJ; Dennis, PA; Livnah, O

Published Date

  • December 14, 2012

Published In

Volume / Issue

  • 424 / 5

Start / End Page

  • 339 - 353

PubMed ID

  • 23079240

Electronic International Standard Serial Number (EISSN)

  • 1089-8638

Digital Object Identifier (DOI)

  • 10.1016/j.jmb.2012.10.007

Language

  • eng

Conference Location

  • Netherlands