scholarly journals Pyruvate Kinase M Links Glucose Availability to Protein Synthesis

2019 ◽  
Author(s):  
Nevraj S. Kejiou ◽  
Lena Ilan ◽  
Stefan Aigner ◽  
Enching Luo ◽  
Ines Rabano ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Protein Synthesis ◽  
Pyruvate Kinase ◽  
Cell Cycle Regulation ◽  
Protein Translation ◽  
Glycolytic Enzyme ◽  
Metabolic State ◽  
Elongation Step ◽  
Cycle Regulation ◽  
Glucose Availability

AbstractHow human cells coordinate various metabolic processes, such as glycolysis and protein translation, remains unclear. One key insight is that various metabolic enzymes have been found to associate with mRNAs, however whether these enzymes regulate mRNA biology in response to changes in cellular metabolic state remains unknown. Here we report that the glycolytic enzyme, pyruvate kinase M (PKM), inhibits the translation of 7% of the transcriptome in response to elevated levels of glucose and pyruvate. Our data suggest that in the presence of glucose and pyruvate, PKM associates with ribosomes that are synthesizing stretches of polyacidic nascent polypeptides and stalls the elongation step of translation. PKM-regulated mRNAs encode proteins required for the cell cycle and may explain previous results linking PKM to cell cycle regulation. Our study uncovers an unappreciated link between glycolysis and the ribosome that likely coordinates the intake of glycolytic metabolites with the regulation of protein synthesis and the cell cycle.

scholarly journals Cyclophosphamide Inhibits PI3K/AKT/mTOR Signaling Pathway in Mice Kidneys

Proceedings ◽  
2018 ◽  
Vol 2 (25) ◽  
pp. 1587 ◽  
Author(s):  
Gulsah Albayrak ◽  
Pinar Kilicarslan Sonmez ◽  
Damla Akogullari ◽  
Elgin Turkoz Uluer
Keyword(s):  
Cell Cycle ◽  
Protein Synthesis ◽  
Signaling Pathway ◽  
Cell Cycle Regulation ◽  
Kidney Tissue ◽  
Mtor Signaling ◽  
Mtor Signaling Pathway ◽  
Cellular Functions ◽  
Cycle Regulation ◽  
Experimental Group

Cyclophosphamide (CTX), also known as cytophosphane among other, is a medication used as chemotherapy and to suppress the immune system. The PI3K/AKT/mTOR pathway is involved in the regulation of diverse cellular functions, including cell growth, protein synthesis, cell cycle regulation, glucose metabolism, and motility. In our study eight weeks old C57BL/6 female mice were divided into 3 groups as control (C), sham (S) and experimental group. The experimental group has been established with CTX treatment. No treatment was applied to the C group. The S group were given an equal amount of saline. CTX was administered intraperitoneally one every 2 days for 3 weeks; the first dose was 70 mg/kg, the ongoing doses were 30 mg/kg. At the end of 3 weeks mice were sacrificed and kidneys were taken for investigation. In order to show the effect of cyclophosphamide in kidney tissue, the tissues were stained via indirect immunohistochemistry with PI3K, AKT and mTOR primary antibodies. In our study, PI3K, AKT and mTOR expression levels were found to be significantly decreased in CTX-mediated mechanisms indicating that the mechanisms of CTX might involve in the inhibition of PI3K/AKT/mTOR signaling pathway.

scholarly journals Genetic variants and cognitive functions in patients with brain tumors

2019 ◽  
Vol 21 (10) ◽  
pp. 1297-1309 ◽  
Author(s):  
Denise D Correa ◽  
Jaya Satagopan ◽  
Axel Martin ◽  
Erica Braun ◽  
Maria Kryza-Lacombe ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cell Cycle ◽  
Dna Repair ◽  
Brain Tumor ◽  
Brain Tumors ◽  
Cell Cycle Regulation ◽  
Cognitive Outcome ◽  
Cholesterol Transport ◽  
Tumor Patients ◽  
Cycle Regulation

AbstractBackgroundPatients with brain tumors treated with radiotherapy (RT) and chemotherapy (CT) often experience cognitive dysfunction. We reported that single nucleotide polymorphisms (SNPs) in the APOE, COMT, and BDNF genes may influence cognition in brain tumor patients. In this study, we assessed whether genes associated with late-onset Alzheimer’s disease (LOAD), inflammation, cholesterol transport, dopamine and myelin regulation, and DNA repair may influence cognitive outcome in this population.MethodsOne hundred and fifty brain tumor patients treated with RT ± CT or CT alone completed a neurocognitive assessment and provided a blood sample for genotyping. We genotyped genes/SNPs in these pathways: (i) LOAD risk/inflammation/cholesterol transport, (ii) dopamine regulation, (iii) myelin regulation, (iv) DNA repair, (v) blood–brain barrier disruption, (vi) cell cycle regulation, and (vii) response to oxidative stress. White matter (WM) abnormalities were rated on brain MRIs.ResultsMultivariable linear regression analysis with Bayesian shrinkage estimation of SNP effects, adjusting for relevant demographic, disease, and treatment variables, indicated strong associations (posterior association summary [PAS] ≥ 0.95) among tests of attention, executive functions, and memory and 33 SNPs in genes involved in: LOAD/inflammation/cholesterol transport (eg, PDE7A, IL-6), dopamine regulation (eg, DRD1, COMT), myelin repair (eg, TCF4), DNA repair (eg, RAD51), cell cycle regulation (eg, SESN1), and response to oxidative stress (eg, GSTP1). The SNPs were not significantly associated with WM abnormalities.ConclusionThis novel study suggests that polymorphisms in genes involved in aging and inflammation, dopamine, myelin and cell cycle regulation, and DNA repair and response to oxidative stress may be associated with cognitive outcome in patients with brain tumors.

scholarly journals Phosphorylation of RCC1 on Serine 11 Facilitates G1/S Transition in HPV E7-Expressing Cells

Biomolecules ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 995
Author(s):  
Xiaoyan Hou ◽  
Lijun Qiao ◽  
Ruijuan Liu ◽  
Xuechao Han ◽  
Weifang Zhang
Keyword(s):  
Cell Cycle ◽  
Cervical Cancer ◽  
Cell Cycle Regulation ◽  
Cell Cycle Progression ◽  
Mtor Pathway ◽  
Cycle Progression ◽  
Post Translational Modifications ◽  
Hpv E7 ◽  
Cycle Regulation

Persistent infection of high-risk human papillomavirus (HR-HPV) plays a causal role in cervical cancer. Regulator of chromosome condensation 1 (RCC1) is a critical cell cycle regulator, which undergoes a few post-translational modifications including phosphorylation. Here, we showed that serine 11 (S11) of RCC1 was phosphorylated in HPV E7-expressing cells. However, S11 phosphorylation was not up-regulated by CDK1 in E7-expressing cells; instead, the PI3K/AKT/mTOR pathway promoted S11 phosphorylation. Knockdown of AKT or inhibition of the PI3K/AKT/mTOR pathway down-regulated phosphorylation of RCC1 S11. Furthermore, S11 phosphorylation occurred throughout the cell cycle, and reached its peak during the mitosis phase. Our previous data proved that RCC1 was necessary for the G1/S cell cycle progression, and in the present study we showed that the RCC1 mutant, in which S11 was mutated to alanine (S11A) to mimic non-phosphorylation status, lost the ability to facilitate G1/S transition in E7-expressing cells. Moreover, RCC1 S11 was phosphorylated by the PI3K/AKT/mTOR pathway in HPV-positive cervical cancer SiHa and HeLa cells. We conclude that S11 of RCC1 is phosphorylated by the PI3K/AKT/mTOR pathway and phosphorylation of RCC1 S11 facilitates the abrogation of G1 checkpoint in HPV E7-expressing cells. In short, our study explores a new role of RCC1 S11 phosphorylation in cell cycle regulation.

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