Sequential autophosphorylation steps in the interleukin-1 receptor-associated kinase-1 regulate its availability as an adapter in interleukin-1 signaling
| Autor: | Detlef Neumann, Holger Wesche, Anne-Christin Mackensen, Ping Cao, Christian Kollewe, Shyun Li, Michael U. Martin, Johannes Knop |
|---|---|
| Rok vydání: | 2003 |
| Předmět: |
Threonine
Receptor complex Spectrometry Mass Electrospray Ionization Time Factors Protein Conformation Genetic Vectors Immunoblotting Molecular Sequence Data Biology Transfection Biochemistry Models Biological Mass Spectrometry Cell Line Fluorescence Resonance Energy Transfer Humans Amino Acid Sequence Kinase activity Cloning Molecular Phosphorylation Receptors Immunologic Molecular Biology Death domain Adaptor Proteins Signal Transducing Kinase Autophosphorylation Intracellular Signaling Peptides and Proteins Receptors Interleukin-1 Cell Biology Antigens Differentiation Precipitin Tests Cell biology Protein Structure Tertiary Interleukin-1 Receptor-Associated Kinases Protein kinase domain Myeloid Differentiation Factor 88 Signal transduction Carrier Proteins Dimerization Protein Kinases Interleukin-1 Signal Transduction |
| Zdroj: | The Journal of biological chemistry. 279(7) |
| ISSN: | 0021-9258 |
| Popis: | The interleukin-1 receptor-associated kinase 1 (IRAK-1) is an important adapter in the signaling complex of the Toll/interleukin-1 (IL-1) receptor family. Formation of the signaling IL-1 receptor complex results in the activation and hyperphosphorylation of IRAK-1, which leads to a pronounced shift of its apparent molecular mass in gel electrophoresis. Presently, the individual residues phosphorylated in IRAK-1 and the consequences for IRAK-1 function are unknown. We define sequential phosphorylation steps in IRAK-1, which are, in vitro, autophosphorylation. First, IRAK-1 is phosphorylated at Thr209. By fluorescence energy transfer experiments, we demonstrate that Thr209 phosphorylation results in a conformational change of the kinase domain, permitting further phosphorylations to take place. Substitution of Thr209 by alanine results in a kinase-inactive IRAK-1. Second, Thr387 in the activation loop is phosphorylated, leading to full enzymatic activity. Third, IRAK-1 autophosphorylates several times in the proline-, serine-, and threonine-rich ProST region between the N-terminal death domain and kinase domain. Hyperphosphorylation of this region leads to dissociation of IRAK-1 from the upstream adapters MyD88 and Tollip but leaves its interaction with the downstream adapter TRAF6 unaffected. This identifies IRAK-1 as a novel type of adapter protein, which employs its own kinase activity to introduce negative charges adjacent to the protein interaction domain, which anchors IRAK-1 at the active receptor complex. Thus, IRAK-1 regulates its own availability as an adapter molecule by sequential autophosphorylation. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|