Daxx functions as a scaffold of a protein assembly constituted by GLUT4, JNK1 and KIF5B
✍ Scribed by Vasiliki S. Lalioti; Silvia Vergarajauregui; Yo Tsuchiya; Sonia Hernandez-Tiedra; Ignacio V. Sandoval
- Book ID
- 102883180
- Publisher
- John Wiley and Sons
- Year
- 2009
- Tongue
- English
- Weight
- 623 KB
- Volume
- 218
- Category
- Article
- ISSN
- 0021-9541
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✦ Synopsis
Abstract
We have previously reported the physical interaction between Daxx, the adaptor protein that mediates activation of the Jun amino‐terminal kinase (JNK), and GLUT4, the insulin‐dependent glucose transporter, interaction that involves their C‐domains. Co‐immunoprecipitation and two‐hybrid‐based protein–protein interaction studies show now that Daxx and GLUT4 interact with JNK1 through D‐sites in their NH~2~‐(aa 1‐501) and large endofacial loop, respectively. Serum deprivation strongly enhances the association of JNK1 with Daxx and dissociates the kinase from GLUT4. SP600125, a potent JNK1 inhibitor, reduces the JNK1 activity associated with GLUT4 and the phosphorylation of two minor GLUT4 species in serum‐starved 3T3‐L1 adipocytes. In addition, Daxx interacts with kinesin KIF5B through the 6xTPR domain of the kinesin light chain, a domain engaged in the grab hold of protein cargo by kinesin motors that codistribute with JNK. Depletion of Daxx in 3T3‐L1 adipocytes provokes the partial translocation of the GLUT4 retained in the GLUT4 storage compartment to endosomes. J. Cell. Physiol. 218: 416–426, 2009. © 2008 Wiley‐Liss, Inc.