IκB kinase-induced interaction of TPL-2 kinase with 14-3-3 is essential for Toll-like receptor activation of ERK-1 and -2 MAP kinases
Research output: Contribution to journal › Article
Colleges, School and Institutes
- Divisions of Immune Cell Biology.
- Division of Physical Biochemistry, National Institute of Medical Research, London, U.K.
- Protein Purification Facility (PPF), Cancer Research UK, London Research Institute, London WC2A 3PX, United Kingdom.
- Divisions of Immune Cell Biology, firstname.lastname@example.org.
The MEK-1/2 kinase TPL-2 is critical for Toll-like receptor activation of the ERK-1/2 MAP kinase pathway during inflammatory responses, but it can transform cells following C-terminal truncation. IκB kinase (IKK) complex phosphorylation of the TPL-2 C terminus regulates full-length TPL-2 activation of ERK-1/2 by a mechanism that has remained obscure. Here, we show that TPL-2 Ser-400 phosphorylation by IKK and TPL-2 Ser-443 autophosphorylation cooperated to trigger TPL-2 association with 14-3-3. Recruitment of 14-3-3 to the phosphorylated C terminus stimulated TPL-2 MEK-1 kinase activity, which was essential for TPL-2 activation of ERK-1/2. The binding of 14-3-3 to TPL-2 was also indispensible for lipopolysaccharide-induced production of tumor necrosis factor by macrophages, which is regulated by TPL-2 independently of ERK-1/2 activation. Our data identify a key step in the activation of TPL-2 signaling and provide a mechanistic insight into how C-terminal deletion triggers the oncogenic potential of TPL-2 by rendering its kinase activity independent of 14-3-3 binding.
|Journal||Proceedings of the National Academy of Sciences of the United States of America|
|Publication status||Published - 10 Jun 2014|
- 14-3-3 Proteins/genetics, Animals, Cells, Cultured, Enzyme Activation, HEK293 Cells, Humans, I-kappa B Kinase/metabolism, Immunoblotting, Lipopolysaccharides/pharmacology, MAP Kinase Kinase Kinases/genetics, MAP Kinase Signaling System, Macrophages/drug effects, Mice, Mice, Inbred C57BL, Mice, Knockout, Mitogen-Activated Protein Kinase 1/metabolism, Mitogen-Activated Protein Kinase 3/metabolism, NF-kappa B p50 Subunit/genetics, Phosphorylation, Protein Binding, Proto-Oncogene Proteins/genetics, Serine/genetics, Toll-Like Receptors/metabolism, Tumor Necrosis Factor-alpha/metabolism