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Phosphorylation is crucial in regulating various biological processes. However, comprehensive phosphoproteomic profiling in the termination of liver regeneration (LR) is still missing. Here, we used Tandem Mass Tag (TMT) labeling coupled with phosphopeptide enrichment and two-dimensional (2D) liquid chromatography-mass spectrometry (LC-MS)/MS analysis to establish a global phosphoproteomic map in the liver of mice at day 5 after partial hepatectomy (PH). Altogether, 9731 phosphosites from 3443 proteins were identified and 7802 phosphosites from 2980 proteins were quantified. Motif analysis of the identified phosphosites revealed a diverse array of consensus sequences, suggesting that multiple kinase families including ERK/MAPK, PKA/PKC, CaMK-II, CKII, and CDK may be involved in the termination of LR. Functional clustering analysis of proteins with dysregulated phosphosites showed that they mainly participate in metabolic pathways, DNA replication, and tight junction. More importantly, the deletion of PP2Acα in the liver remarkably changes the overall phosphorylation profile, indicating its critical role in regulating the termination of LR. Finally, several differentially phosphorylated sites were validated by co-immunoprecipitation and Western blot. Taken together, our data unravel the first comprehensive phosphoproteomic map in the termination of LR in mice, which greatly expands our knowledge in the complicated regulation of this process and provides new directions for the treatment of liver cancer using liver resection.

There are no known approved pharmacotherapies for non‐alcoholic fatty liver disease (NAFLD) in the clinical setting. Although studies have provided substantial evidence that geranylgeranyl diphosphate synthase (GGPPS) is a potential therapeutic target for the treatment of NAFLD corresponding drug screening is rare. A GGPPS‐targeted inhibitor is identified using a structure‐based virtual small molecule screening method. The interaction of 4‐AZ and GGPPS is detected by microscale thermophoresis. 4‐AZ degradation of GGPPS by the ubiquitin‐proteasome pathway is detected by western blotting. The anti‐steatotic effect of 4‐AZ in vivo is detected by CT. Lipid‐related gene detection is detected by real‐time PCR both in primary hepatocytes and mice. The compound inhibits the accumulation of lipids in primary hepatocytes and decreases lipogenic gene expression through GGPPS. Pharmacological studies show that 4‐AZ can attenuate hepatic steatosis and improve liver injury in high‐fat diet‐induced mice. This data provides a novel application of 4‐AZ NAFLD therapy, proving that the inhibition of GGPPS is a novel strategy for the treatment of NAFLD. [ABSTRACT FROM AUTHOR]

Endophytes in woody plants are much less understood. Pantoea strain FBS135 is an endophytic bacterium isolated from Pinus massoniana with the ability to promote pine growth significantly. In this study, we demonstrated that FBS135 has the astonishing ability of low nitrogen tolerance but no ability of nitrogen fixation. To exactly determine the phylogenetic status of FBS135, we sequenced the whole genomes of P. eucalypti LMG 24197T and P. vagans 24199T, type strains of two Pantoea species, which are evolutionarily closest to FBS135. P. eucalypti LMG 24197T contained a single chromosome of 4,035,995 bp (C+G, 54.6%) plus three circular plasmids while LMG 24199T comprises a single circular chromosome of 4,050,173 bp (C+G, 55.6%) and two circular plasmids. With the genomic information, FBS135 was finally identified as a P. eucalypti strain, although it showed some different physiological traits from the two type strains. Comparative genomic analyses were performed for the three strains, revealing their common molecular basis associated with plant lifecycle as well as the differences in their gene arrangements relating to nitrogen utilization. [ABSTRACT FROM AUTHOR]