A 32 kDa protein?whose phosphorylation correlates with oncogenic Ras-induced cell cycle arrest in activatedXenopus egg extracts?is identified as ribosomal protein S6

2004 ◽  
Vol 201 (2) ◽  
pp. 305-319 ◽  
Author(s):  
Jerry Pinghwa Pian ◽  
Tun-Lan Huang ◽  
Pei-Chi Tsai ◽  
Jian-Peng Shi ◽  
Hong Cu ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Ribosomal Protein ◽  
Cell Cycle Arrest ◽  
Oncogenic Ras ◽  
Cycle Arrest ◽  
Ribosomal Protein S6 ◽  
Egg Extracts

scholarly journals Characterization of p96h2bk: immunoreaction with an anti-Erk(extracellular-signal-regulated kinase) peptide antibody and activity in Xenopus oocytes and eggs

1998 ◽  
Vol 335 (1) ◽  
pp. 43-50
Author(s):  
Dong-Hua CHEN ◽  
Chin-Tin CHEN ◽  
Yong ZHANG ◽  
Mei-Ann LIU ◽  
Roberto CAMPOS-GONZALEZ ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Arrest ◽  
Xenopus Oocytes ◽  
Protein Kinase Activity ◽  
Cell Stage ◽  
Extracellular Signal Regulated Kinase ◽  
Oncogenic Ras ◽  
Cycle Arrest ◽  
Extracellular Signal ◽  
M Phase

We have shown previously that oncogenic Ras induces cell cycle arrest in activated Xenopus egg extracts [Pan, Chen and Lin (1994) J. Biol. Chem. 269, 5968–5975]. The cell cycle arrest correlates with the stimulation of a protein kinase activity that phosphorylates histone H2b in vitro (designated p96h2bk) [Chen and Pan (1994) J. Biol. Chem. 269, 28034–28043]. We report here that p96h2bk is likely to be p96ram, a protein of approx. 96 kDa that immunoreacts with a monoclonal antibody (Mk-1) raised against a synthetic peptide derived from a sequence highly conserved in Erk1/Erk2 (where Erk is extracellular-signal-regulated kinase). This is supported by two lines of evidence. First, activation/inactivation of p96h2bk correlates with upward/downward bandshifts of p96ram in polyacrylamide gels. Secondly, both p96h2bk and p96ram can be immunoprecipitated by antibody Mk-1. We also studied the activity of p96h2bk/p96ram in Xenopus oocytes and eggs. p96h2bk/p96ram was inactive in stage 6 oocytes, was active in unfertilized eggs, and became inactive again in eggs after fertilization. Since stage 6 oocytes are at G2-phase of the cell cycle, unfertilized eggs arrest at M-phase and eggs exit M-phase arrest after fertilization, the results thus indicate that p96h2bk/p96ram activity is cell cycle dependent. Moreover, microinjection of oncogenic Ras into fertilized eggs at the one-cell stage arrests the embryos at the two-cell stage, and this induced arrest is correlated with an inappropriate activation of p96h2bk/p96ram. The data are consistent with the concept that inappropriate activation of p96h2bk/p96ram plays a role in the cell cycle arrest induced by oncogenic Ras.

scholarly journals Oncogenic ras and p53 Cooperate To Induce Cellular Senescence

2002 ◽  
Vol 22 (10) ◽  
pp. 3497-3508 ◽  
Author(s):  
Gerardo Ferbeyre ◽  
Elisa de Stanchina ◽  
Athena W. Lin ◽  
Emmanuelle Querido ◽  
Mila E. McCurrach ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Map Kinase ◽  
Cell Cycle Arrest ◽  
Cellular Senescence ◽  
Null Mouse ◽  
P53 Expression ◽  
Oncogenic Ras ◽  
Cycle Arrest ◽  
Murine Fibroblasts ◽  
Mitogen Activated Protein

ABSTRACT Oncogenic activation of the mitogen-activated protein (MAP) kinase cascade in murine fibroblasts initiates a senescence-like cell cycle arrest that depends on the ARF/p53 tumor suppressor pathway. To investigate whether p53 is sufficient to induce senescence, we introduced a conditional murine p53 allele (p53val135 ) into p53-null mouse embryonic fibroblasts and examined cell proliferation and senescence in cells expressing p53, oncogenic Ras, or both gene products. Conditional p53 activation efficiently induced a reversible cell cycle arrest but was unable to induce features of senescence. In contrast, coexpression of oncogenic ras or activated mek1 with p53 enhanced both p53 levels and activity relative to that observed for p53 alone and produced an irreversible cell cycle arrest that displayed features of cellular senescence. p19ARF was required for this effect, since p53 −/− ARF −/− double-null cells were unable to undergo senescence following coexpression of oncogenic Ras and p53. Although the levels of exogenous p53 achieved in ARF-null cells were relatively low, the stabilizing effects of p19ARF on p53 could not explain the cooperation between oncogenic Ras and p53 in promoting senescence. Hence, enforced p53 expression without oncogenic ras in p53 −/− mdm2 −/− double-null cells produced extremely high p53 levels but did not induce senescence. Taken together, our results indicate that oncogenic activation of the MAP kinase pathway in murine fibroblasts converts p53 into a senescence inducer through both quantitative and qualitative mechanisms.

The Ribosomal Protein RPLP0 Mediates PLAAT4-induced Cell Cycle Arrest and Cell Apoptosis

2019 ◽  
Vol 77 (3) ◽  
pp. 253-260 ◽  
Author(s):  
Chun-Hua Wang ◽  
Lu-Kai Wang ◽  
Chang-Chieh Wu ◽  
Mao-Liang Chen ◽  
Ming-Cheng Lee ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Ribosomal Protein ◽  
Cell Cycle Arrest ◽  
Cell Apoptosis ◽  
Cycle Arrest

Nucleolar Stress and p53 Mediated Erythroid Failure in Diamond Blackfan Anemia

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 42-42
Author(s):  
Colin Sieff ◽  
Harvey F. Lodish
Keyword(s):  
Cell Cycle ◽  
Ribosomal Protein ◽  
Cell Cycle Arrest ◽  
Ribosomal Rna ◽  
Mammalian Cells ◽  
Pcr Analysis ◽  
Erythroid Cells ◽  
Cycle Arrest ◽  
Nucleolar Stress ◽  
Primary Mouse

Abstract The discovery that several ribosomal protein genes can be mutated in DBA suggests that ribosomal protein gene mutations may account for many or all cases of DBA, and focuses attention on the ribosome. While experiments in yeast and mammalian cells show that RPS19 depletion or mutation leads to a block in ribosomal RNA biosynthesis, this result does not explain why erythropoiesis is so severely affected in DBA. We hypothesize that during fetal development immature erythroid cells proliferate more rapidly than other lineages and therefore require very high ribosome synthetic rates to generate sufficient capacity for translation of erythroid specific transcripts that must take place before these unique cells enucleate. To test this kinetic hypothesis we measured RNA biogenesis in primary mouse fetal liver cells and reported previously that during the first 24 hours cell number increases 3–4 fold while, remarkably, there is a 6-fold increase in RNA content during the same period, suggesting that the cells accumulate an excess of ribosomal RNA (80% of measured RNA) during early erythropoiesis. Retrovirus infected siRNA RPS19 knockdown cells show reduced proliferation of FACS sorted GFP positive cells at 48 hours. Although the cell yield is reduced, the differentiation pattern of the surviving GFP positive cells is similar to that of the controls. While quantitative RT-PCR analysis shows that RPS19 mRNA is rapidly depleted, Western analysis during this time course does not show a deficiency of RPS19 protein. This suggests strongly that the proliferative defect is not due to insufficiency of RPS19 protein, and is more likely due nucleolar stress induced by the block in ribosome biogenesis. Molecular consequences could lead to redistribution of cell cycle proteins normally resident in the nucleolus with consequent p53 mediated cell cycle arrest and or apoptosis. To test this hypothesis we used a culture system that allows expansion without differentiation of immature cells in SCF, EPO, IGF-1 and dexamethasone. Under these conditions proliferation of siRNA expressing precursors is reduced with an increased proportion arrested in G0/G1 in the knockdown cells. Furthermore, p53 is increased in the knockdown cells. Taken together, these data suggest that RPS19 insufficient cells undergo a nucleolar stress response and erythroid cells proliferate poorly because of p53 mediated cell cycle arrest and apoptosis.

scholarly journals Phosphorylation of Cdc25C by pp90Rsk Contributes to a G2 Cell Cycle Arrest in Xenopus Cycling Egg Extracts

Cell Cycle ◽  
2004 ◽  
Vol 4 (1) ◽  
pp. 148-154 ◽  
Author(s):  
Justin Chun ◽  
Andrew S-S Chau ◽  
Ferdinand G. Maingat ◽  
Stuart D. Edmonds ◽  
Hanne L. Ostergaard ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Arrest ◽  
Cycle Arrest ◽  
Egg Extracts ◽  
G2 Cell Cycle Arrest

scholarly journals Loss of RPS27a expression regulates cell cycle, apoptosis, and proliferation via the RPS27a-RPL11-MDM2-p53 pathway in lung adenocarcinoma cells

2021 ◽  
Author(s):  
Hongyan Li ◽  
Hong Zhang ◽  
Guomin Huang ◽  
Zhitong Bing ◽  
Hongtao Luo ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Lung Adenocarcinoma ◽  
Ribosomal Protein ◽  
Cell Cycle Arrest ◽  
Complex Structure ◽  
Protein Docking ◽  
Stable Complex ◽  
P53 Expression ◽  
Cycle Arrest ◽  
Tcga Dataset

Abstract Background Some ribosomal proteins (RPs) might regulate the MDM2–p53 loop by binding to RPL5 or RPL11. This study aimed to explore whether ribosomal protein S27a (RPS27a) interacted with the ribosomal protein L11 (RPL11) to regulate p53 in lung adenocarcinoma (LUAD) cells. Methods RPL11-interacting proteins were identified using a proteomics approach. Co-immunoprecipitation (co-IP), docking analysis, GST-fusion and in vitro ubiquitination assay were used to analyze the interaction of RPS27a and RPL11. Cell cycle, apoptosis, cell invasion, cell viability and colony-formation assay were analyzed by knocking down RPS27a. The RPS27a mRNA expression in LUAD was analyzed based on the TCGA dataset and the RPS27a expression was detected by immunohistochemistry in LUAD samples. At last, the RPS27a and p53 expression were analyzed by immunohistochemistry in xenograft tumors by blocking RPS27a. Results The ablation of RPS27a inhibits murine double minute 2 (MDM2)-mediated p53 ubiquitination, induced G1/S cell cycle arrest and apoptosis, and inhibited the proliferation of LUAD cells. Also, it induced p53-dependent cell cycle arrest and RPL11-dependent p53 activation. The protein–protein docking results revealed that RPS27a and RPL11 formed a stable complex structure. The GST-fusion protein–protein association assay demonstrated that RPS27a bound to RPL11. The overexpressed RPS27a in LUAD was found to be correlated with a poorer prognosis based on the TCGA dataset. RPS27a expression was high in patients with LUAD. Blocking RPS27a increased p53, thus, suppressing cell proliferation and A549 xenograft growth in nude mice. Conclusions This study was novel in reporting that RPs bound to RPL11 to regulate the MDM2-p53 feedback loop, revealing that RPS27a plays an important function in LUAD growth. Hence, RPS27a might provide a diagnostic marker or therapeutic target for patients with LUAD.

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