UBE1C is upregulated and promotes neddylation of p53 in lung cancer.

NEDDylation is a type of protein post-translational modification that has high similarity to ubiquitination. UBE1C encodes NEDDylation E1 enzyme, locates at chromatin region 3p14.1 and shows high gene dosage amplification frequency in both Asian and Caucasian lung cancer patients. However, its NEDDylation substrates and roles in tumorigenesis remain elucidated. In this study, we aim to investigate the oncogenic role of UBE1C and its involvement in how NEDDylation regulates p53 in lung cancer. We found that UBE1C mRNA overexpression and DNA amplification in most of the lung cell lines and cancer patients. Patients with UBE1C overexpression showed poor prognosis. Moreover, we demonstrated that overexpression of UBE1C and NEDD8, a NEDDylation moiety, resulted in the p53 NEDDylation with inhibition of p53 acetylation at K373 residue. Importantly, UBE1C-mediated NEDDylation downregulated the transcriptional activity of p53 by inhibiting p53 ability to target promoter regions of its downstream transcription targets, consequently inhibiting the promoter activities and the expression of mRNA and protein of the p53 downstream genes including p21 and PTEN. In addition, UBE1C and NEDD8 overexpression promoted migration, invasion, and proliferation of lung cancer cells. Our findings suggest that UBE1C acts as an oncogene with prognostic potential and highlight a potential role of UBE1C-mediated NEDDylation in downregulation of p53 transcriptional activity in lung cancer.

Lysosomal cystine mobilization shapes the response of TORC1 and tissue growth to fasting.

Adaptation to nutrient scarcity involves an orchestrated response of metabolic and signaling pathways to maintain homeostasis. We find that in the fat body of fasting Drosophila, lysosomal export of cystine coordinates remobilization of internal nutrient stores with reactivation of the growth regulator target of rapamycin complex 1 (TORC1). Mechanistically, cystine was reduced to cysteine and metabolized to acetyl-coenzyme A (acetyl-CoA) by promoting CoA metabolism. In turn, acetyl-CoA retained carbons from alternative amino acids in the form of tricarboxylic acid cycle intermediates and restricted the availability of building blocks required for growth. This process limited TORC1 reactivation to maintain autophagy and allowed animals to cope with starvation periods. We propose that cysteine metabolism mediates a communication between lysosomes and mitochondria, highlighting how changes in diet divert the fate of an amino acid into a growth suppressive program.

Illuminating a Dark Kinase: Structure-Guided Design, Synthesis, and Evaluation of a Potent Nek1 Inhibitor and Its Effects on the Embryonic Zebrafish Pronephros.

NIMA-related kinase 1 (Nek1) has lately garnered attention for its widespread function in ciliogenesis, apoptosis, and the DNA-damage response. Despite its involvement in various diseases and its potential as a cancer drug target, no directed medicinal chemistry efforts toward inhibitors against this dark kinase are published. Here, we report the structure-guided design of a potent small-molecule Nek1 inhibitor, starting from a scaffold identified by kinase cross-screening analysis. Seven lead compounds were identified in silico and evaluated for their inhibitory activity. The top compound, 10f, was further profiled for efficacy, toxicity, and bioavailability in a zebrafish polycystic kidney disease model. Administration of 10f caused the expansion of fluorescence-labeled proximal convoluted tubules, supporting our hypothesis that Nek1-inhibition causes cystic kidneys in zebrafish embryos. Compound 10f displayed insignificant inhibition in 48 of 50 kinases in a selectivity test panel. The findings provide a powerful tool to further elucidate the function and pharmacology of this neglected kinase.

Design, synthesis and biological evaluation of novel aminopyrazole- and 7-azaindole-based Nek1 inhibitors and their effects on zebrafish kidney development.

NIMA-related protein kinase Nek1 is crucially involved in cell cycle regulation, DNA repair and microtubule regulation and dysfunctions of Nek1 play key roles in amyotrophic lateral sclerosis (ALS), polycystic kidney disease (PKD) and several types of radiotherapy resistant cancer. Targeting of Nek1 could reveal a new class of radiosensitizing substances and provide useful tools to better understand the aforementioned diseases. In this report we explore substituted aminopyrazoles and 7-azaindoles as potent inhibitors for the Nek1 kinase domain and examine their effect on kidney organogenesis in Danio rerio.