Biology subjects

Denault, J.-B.

Publications and source records attributed to Denault, J.-B..

3 recordsLinked to original sources

bioRxiv2024

Non-canonical altPIDD1 protein: unveiling the true major translational output of the PIDD1 gene

Proteogenomics has enabled the detection of novel proteins encoded in non-canonical or alternative open reading frames (altORFs) in genes already coding a reference protein. Reanalysis of proteomic and ribo-seq data revealed that the p53-induced death domain-containing protein (or PIDD1) gene encodes a second 171 amino acid protein, altPIDD1, in addition to the known 910 amino acid-long PIDD1 protein. The two ORFs overlap almost completely, and the translation initiation site of altPIDD1 is located upstream of PIDD1. AltPIDD1 has more translational and protein level evidence than PIDD1 across various cell lines and tissues. In HEK293 cells, the altPIDD1 to PIDD1 ratio is 40 to 1, as measured with isotope-labeled (heavy) peptides and targeted proteomics. AltPIDD1 localizes to cytoskeletal structures labeled with phalloidin, including stress fibres, lamellipodia and filopodia, interacts with cytoskeletal proteins and is cleaved during apoptosis. Unlike most non-canonical proteins, altPIDD1 is not evolutionarily young but emerged in placental mammals. Overall, we identify PIDD1 as a dual-coding gene, with altPIDD1, not the annotated protein, being the primary product of translation. Summary blurbThis research uncovers PIDD1 as a dual-coding gene, revealing a previously unknown protein, altPIDD1, as the primary product with higher expression and cytoskeletal interactions.

biochemistry↗

bioRxiv2024

Spatiotemporal regulation of the hepatocyte growth factor receptor MET activity by sorting nexins 1 and 2 in HCT116 colorectal cancer cells

Cumulative research findings support the idea that endocytic trafficking is crucial in regulating receptor signaling and associated diseases. Specifically, strong evidence points to the involvement of sorting nexins (SNXs), particularly SNX1 and SNX2, in the signaling and trafficking of the receptor tyrosine kinase (RTK) MET in colorectal cancer (CRC). Activation of hepatocyte growth factor (HGF) receptor MET is a key driver of CRC progression. In this study, we utilized human HCT116 CRC cells with SNX1 and SNX2 genes knocked out to demonstrate that their absence leads to a delay in MET entering early endosomes. This delay results in increased phosphorylation of both MET and AKT upon HGF stimulation, while ERK1/2 (extracellular signal-regulated kinases 1 and 2) phosphorylation remains unaffected. Despite these changes, HGF-induced cell proliferation, scattering, and migration remain similar between the parental and the SNX1/2 knockout cells. However, in the absence of SNX1 and SNX2, these cells exhibit increased resistance to TRAIL-induced apoptosis. This research underscores the intricate relationship between intracellular trafficking, receptor signaling, and cellular responses and demonstrates for the first time that the modulation of MET trafficking by SNX1 and SNX2 is critical for receptor signaling that may exacerbate the disease.

cancer biology↗

bioRxiv2022

Apelin Stimulation of the Perivascular MuSC Niche Enhances Endogenous Repair in Muscular Dystrophy

Impaired skeletal muscle stem cell (MuSC) function has long been suspected to contribute to the pathogenesis of muscular dystrophy (MD). Here we describe that defects in the endothelial cell (EC) compartment of the perivascular stem cell niche in three different types of MD are associated with inefficient mobilization of MuSCs following tissue damage. Using chemoinformatic analysis, we identified the 13 amino acid form of the peptidic hormone apelin (AP-13) as a candidate for systemic stimulation of skeletal muscle ECs. In dystrophic mice, administration of AP-13 generates a pro-myogenic EC-rich niche that supports MuSC function and markedly improves tissue regeneration, muscle strength, and physical performance. Moreover, we demonstrate that EC specific knockout of the AP-13 receptor leads to regenerative defects that phenocopy major pathological features of MD. Altogether, we provide in vivo proof-of-concept that enhancing endogenous repair by targeting the perivascular niche is a viable therapeutic avenue for MD and characterize AP-13 as a novel drug candidate for systemic treatment of stem cell dysfunction.

cell biology↗