MilliporeSigma
  • JNK-mediated phosphorylation of DLK suppresses its ubiquitination to promote neuronal apoptosis.

JNK-mediated phosphorylation of DLK suppresses its ubiquitination to promote neuronal apoptosis.

The Journal of cell biology (2013-08-28)
Sarah Huntwork-Rodriguez, Bei Wang, Trent Watkins, Arundhati Sengupta Ghosh, Christine D Pozniak, Daisy Bustos, Kim Newton, Donald S Kirkpatrick, Joseph W Lewcock
ABSTRACT

Neurons are highly polarized cells that often project axons a considerable distance. To respond to axonal damage, neurons must transmit a retrograde signal to the nucleus to enable a transcriptional stress response. Here we describe a mechanism by which this signal is propagated through injury-induced stabilization of dual leucine zipper-bearing kinase (DLK/MAP3K12). After neuronal insult, specific sites throughout the length of DLK underwent phosphorylation by c-Jun N-terminal kinases (JNKs), which have been shown to be downstream targets of DLK pathway activity. These phosphorylation events resulted in increased DLK abundance via reduction of DLK ubiquitination, which was mediated by the E3 ubiquitin ligase PHR1 and the de-ubiquitinating enzyme USP9X. Abundance of DLK in turn controlled the levels of downstream JNK signaling and apoptosis. Through this feedback mechanism, the ubiquitin-proteasome system is able to provide an additional layer of regulation of retrograde stress signaling to generate a global cellular response to localized external insults.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
Anti-Ubiquitinylated proteins Antibody, clone FK2, clone FK2, Upstate®, from mouse
Sigma-Aldrich
MISSION® esiRNA, targeting human MAPK10