Quantitative Proteomics Reveals Dynamic Interaction of c-Jun N-terminal Kinase (JNK) with RNA Transport Granule Proteins Splicing Factor Proline- and Glutamine-rich (Sfpq) and Non-POU Domain-containing Octamer-binding Protein (Nono) during Neuronal Differentiation

Abstract

The c-Jun N-terminal kinase (JNK) is an important mediator of physiological and pathophysiological processes in the central nervous system. Importantly, JNK not only is involved in neuronal cell death, but also plays a significant role in neuronal differentiation and regeneration. For example, nerve growth factor induces JNK-dependent neuronal differentiation in several model systems. The mechanism by which JNK mediates neuronal differentiation is not well understood. Here, we employed a proteomic strategy to better characterize the function of JNK during neuronal differentiation. We used SILAC-based quantitative proteomics to identify proteins that interact with JNK in PC12 cells in a nerve growth factor-dependent manner. Intriguingly, we found that JNK interacted with neuronal transport granule proteins such as Sfpq and Nono upon NGF treatment. We validated the specificity of these interactions by showing that they were disrupted by a specific peptide inhibitor that blocks the interaction of JNK with its substrates.

Antimicrobial defence and persistent infection in insects revisited

“…In total, 20 ml of denaturation buffer were added to 10 ml of protein samples and used for in-solution protein digestion as described previously [27]. Briefly, proteins, solubilized in denaturation buffer, were reduced with 10 mM DTT for 30 min, followed by alkylation with 55 mM iodoacetamide for 20 min, and overnight digestion with 1 mg lysyl endopeptidase (LysC) (catalogue number 125-05061, Wako, Japan), resuspended in 50 mM ammonium bicarbonate (ABC).…”

PSF: nuclear busy‐body or nuclear facilitator?

“…However, while Cdk2 does phosphorylate PSF in cells and in vitro , a version of PSF containing T687 as the only putative Cdk2 site is not a substrate for phosphorylation by this kinase . Two additional serine/threonine kinases, protein kinase C α (PKCa) and the c‐Jun N‐terminal kinase (JNK), have been shown to associate with PSF, although it remains to be determined if PSF is a substrate for the activity of these kinases, and if so, which residues are phosphorylated …”

Structural Study on Apoptosis of Chronic Eosinophilic Leukemia Cells by Interaction of S100A8 with Splicing Factor, Proline and Glutamine-Rich

“…These results indicated that SFPQ functions in the cytosol as well as the nucleus. Western blot analyses showed that NONO and SFPQ were colocalized in the cytosolic and nuclear fractions, but more amount was shown in the nucleus than in the cytosol (Sury et al, 2015). The evaluation of proximity ligation assay signals with NONO antibody, SFPQ antibody, and 4',6-diamidino-2-phenylendole (DAPI) nuclear counterstaining also revealed that NONO-SFPQ colocalization was mainly found in the nucleus.…”

“…Therefore, they suggested that the coiled coil interaction and polymerization domains of SFPQ are necessary for the localization in paraspeckles (Lee et al, 2015). The coiled coil structure was visualized using negative stain electron microscopy (Lee et al, 2015), and the location was investigated using confocal microscopy (Sury et al, 2015). SFPQ was accumulated in the dark nucleolar caps.…”

“…In addition, SFPQ was found in the cytosol when PC12 cells were differentiated using the neuronal growth factor (NGF). Sury et al (2015) showed that SFPQ has a significant role in neuronal differentiation with interaction with c-Jun N-terminal kinase (JNK) in the cytosol. The result can prove that SFPQ also has the function in cytosol as well as in nucleus.…”