Plk3 phosphorylates topoisomerase IIα at Thr1342, a site that is not recognized by Plk1

2008 ◽  
Vol 411 (1) ◽  
pp. 27-32 ◽  
Author(s):  
Masato Iida ◽  
Masao Matsuda ◽  
Hideya Komatani
Keyword(s):  
Cell Cycle ◽  
Kinase Assay ◽  
Cell Cycle Distribution ◽  
Physical Interaction ◽  
Topoisomerase Iiα ◽  
In Vitro Kinase Assay ◽  
A Site ◽  
Cycle Regulation

The Plk (polo-like kinase) family is involved in cell-cycle machinery. Despite the possible overlapping involvement of Plk1 and Plk3 in cell-cycle distribution, the precise role of each Plk might be different. To investigate mechanisms that may differentiate their physiological roles, we compared the substrate specificities of Plk1 and Plk3 using synthetic peptides. Among these substrate peptides, topoisomerase IIα EKT1342DDE-containing synthetic peptide was strongly phosphorylated by Plk3 but not by Plk1. By modulating the topoisomerase IIα peptide, we identified residues at positions +1, +2 and +4 as determinants of differential substrate recognition between Plk1 and Plk3. Acidic residues at positions +2 and +4 appear to be a positive determinant for Plk3 but not Plk1. Variation at position +1 appears to be tolerated by Plk3, while a hydrophobic residue at +1 is critical for Plk1 activity. The direct phosphorylation of Thr1342 of topoisomerase IIα by Plk3 was demonstrated with an in vitro kinase assay, and overexpression of Plk3 induced the phosphorylation of Thr1342 in cellular topoisomerase IIα. Furthermore, the physical interaction between Plk3 and topoisomerase IIα was also demonstrated in cells in addition to phosphorylation. These data suggest that topoisomerase IIα is a novel physiological substrate for Plk3 and that Plk1 and Plk3 play different roles in cell-cycle regulation.

scholarly journals CircNFIX promotes progression of glioma through regulating miR-378e/RPN2 axis

2019 ◽  
Vol 38 (1) ◽  
Author(s):  
Chenyu Ding ◽  
Zanyi Wu ◽  
Honghai You ◽  
Hongliang Ge ◽  
Shufa Zheng ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Xenograft Model ◽  
Circular Rna ◽  
Luciferase Reporter ◽  
Migration And Invasion ◽  
Cell Cycle Distribution ◽  
Glioma Progression

Abstract Background Circular RNA nuclear factor I X (circNFIX) has been reported to play an important role in glioma progression. However, the mechanism by which circNFIX participates in glioma progression remains poorly understood. Methods GERIA online were used to analyze the abnormally expressed genes in glioma tissues. The expression levels of circNFIX, microRNA (miR)-378e and Ribophorin-II (RPN2) were measured by quantitative real-time polymerase chain reaction or western blot. Cell cycle distribution, apoptosis, glycolysis, migration and invasion were determined by flow cytometry, special kit and trans-well assays, respectively. The target association between miR-378e and circNFIX or RPN2 was confirmed by luciferase reporter assay, RNA immunoprecipitation and pull-down. Xenograft model was established to investigate the role of circNFIX in vivo. Results The expression of circNFIX was enhanced in glioma tissues and cells compared with matched controls and high expression of circNFIX indicated poor outcomes of patients. Knockdown of circNFIX led to arrest of cell cycle, inhibition of glycolysis, migration and invasion and promotion of apoptosis in glioma cells. circNFIX was a sponge of miR-378e. miR-378e overexpression suppressed cell cycle process, glycolysis, migration and invasion but promoted apoptosis. miR-378e silence abated the suppressive role of circNFIX knockdown in glioma progression. RPN2 as a target of miR-378e was positively regulated via circNFIX by competitively sponging miR-378e. Silencing circNFIX decreased glioma xenograft tumor growth by regulating miR-378e/RPN2 axis. Conclusion Knockdown of circNFIX inhibits progression of glioma in vitro and in vivo by increasing miR-378e and decreasing RPN2, providing a novel mechanism for understanding the pathogenesis of glioma.

scholarly journals Comparative analysis of two murine CDC25B isoforms

2017 ◽  
Vol 69 (1) ◽  
pp. 35-44
Author(s):  
Min Kang ◽  
Aera Bang ◽  
Ok Choi ◽  
Seung Han
Keyword(s):  
Cell Cycle ◽  
Binding Capacity ◽  
Kinase Assay ◽  
Rt Pcr ◽  
Cdc2 Kinase ◽  
Nitrophenyl Phosphate ◽  
Mouse Tissues ◽  
Almost All ◽  
Cycle Regulation

CDC25B phosphatase plays a pivotal role in the cell cycle process by dephosphorylating and activating the CDC2 kinase of maturation-promoting factor (MPF). In mice, two transcripts of Cdc25B are generated by the alternative splicing of one gene. We compared the properties of these two forms of CDC25B. When the expression pattern of Cdc25B was examined using RT-PCR, both forms were detected in almost all mouse tissues tested. The expression of two forms of the CDC25B protein in various mouse tissues was confirmed using Western blotting with generated isoform specific antibodies. CDC25B1 tends to accumulate more in the cytosol than CDC25B2 does, and they have different binding capacity for 14-3-3 proteins. CDC25B1 was more effective in dephosphorylating in vitro substrate para-nitrophenyl phosphate and showed higher activity in the modified histone H1 kinase assay than CDC25B2. These results suggest that the two forms of CDC25B play different roles in cell cycle regulation.

scholarly journals Direct physical interaction of active Ras with mSIN1 regulates mTORC2 signaling

BMC Cancer ◽  
2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Mehraj-U-Din Lone ◽  
Javed Miyan ◽  
Mohammad Asif ◽  
Showkat A. Malik ◽  
Parul Dubey ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Molecular Mechanisms ◽  
Protein Localization ◽  
Energy Levels ◽  
Kinase Assay ◽  
Proximity Ligation Assay ◽  
Migration And Invasion ◽  
Physical Interaction

Abstract Background The mechanistic (or mammalian) target of rapamycin (mTOR), a Ser/Thr kinase, associates with different subunits forming two functionally distinct complexes, mTORC1 and mTORC2, regulating a diverse set of cellular functions in response to growth factors, cellular energy levels, and nutrients. The mechanisms regulating mTORC1 activity are well characterized; regulation of mTORC2 activity, however, remains obscure. While studies conducted in Dictyostelium suggest a possible role of Ras protein as a potential upstream regulator of mTORC2, definitive studies delineating the underlying molecular mechanisms, particularly in mammalian cells, are still lacking. Methods Protein levels were measured by Western blotting and kinase activity of mTORC2 was analyzed by in vitro kinase assay. In situ Proximity ligation assay (PLA) and co-immunoprecipitation assay was performed to detect protein-protein interaction. Protein localization was investigated by immunofluorescence and subcellular fractionation while cellular function of mTORC2 was assessed by assaying extent of cell migration and invasion. Results Here, we present experimental evidence in support of the role of Ras activation as an upstream regulatory switch governing mTORC2 signaling in mammalian cancer cells. We report that active Ras through its interaction with mSIN1 accounts for mTORC2 activation, while disruption of this interaction by genetic means or via peptide-based competitive hindrance, impedes mTORC2 signaling. Conclusions Our study defines the regulatory role played by Ras during mTORC2 signaling in mammalian cells and highlights the importance of Ras-mSIN1 interaction in the assembly of functionally intact mTORC2.

Biological Role of CDK 11 and 12 in Cell Cycle and its Function in Tumorigenesis

2020 ◽  
Author(s):  
Shamim Mushtaq
Keyword(s):  
Breast Cancer ◽  
Cell Cycle ◽  
Web Of Science ◽  
The Body ◽  
Main Role ◽  
Hallmarks Of Cancer ◽  
Cyclin Dependent Kinases ◽  
Tumor Studies ◽  
Cycle Regulation

Uninhibited proliferation and abnormal cell cycle regulation are the hallmarks of cancer. The main role of cyclin dependent kinases is to regulate the cell cycle and cell proliferation. These protein kinases are frequently down regulated or up regulated in various cancers. Two CDK family members, CDK 11 and 12, have contradicting views about their roles in different cancers. For example, one study suggests that the CDK 11 isoforms, p58, inhibits growth of breast cancer whereas, the CDK 11 isoform, p110, is highly expressed in breast tumor. Studies regarding CDK 12 show variation of opinion towards different parts of the body, however there is a consensus that upregulation of cdk12 increases the risk of breast cancer. Hence, CDK 11 and CDK 12 need to be analyzed to confirm their mechanism and their role regarding therapeutics, prognostic value, and ethnicity in cancer. This article gives an outline on both CDKs of information known up to date from Medline, PubMed, Google Scholar and Web of Science search engines, which were explored and thirty relevant researches were finalized.

Deregulation of cell cycle and related microRNA expression induced by vinyl chloride monomer in hepatocytes of rats

2021 ◽  
pp. 074823372110155
Author(s):  
Weizhe Pan ◽  
Shengnan Yu ◽  
Jin Jia ◽  
Junyang Hu ◽  
Liang Jie ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Vinyl Chloride ◽  
Male Rats ◽  
Cell Cycle Distribution ◽  
Vinyl Chloride Monomer ◽  
Dynamic Changes ◽  
Cell Cycle Deregulation ◽  
Change Dynamic ◽  
Related Proteins

Vinyl chloride (VC) is a confirmed human carcinogen associated with hepatocellular carcinoma and angiosarcoma. However, the role of microRNAs (miRNAs) in liver cell cycle changes under VC exposure remains unclear, which prevents research on the mechanism of VC-induced carcinogenesis. In this study, male rats were injected intraperitoneally with VC (0, 5, 25, and 125 mg/kg body weight) for 6, 8, and 12 weeks. Cell cycle analysis of liver cells, miRNA-222, miRNA-199a, miRNA-195, and miRNA-125b expression in the liver and serum, and target protein expression were performed at different time points. The results showed a higher percentage of hepatocytes in the G1/G0 and S phases at the end of 6 and 12 weeks of VC exposure, respectively. MiRNA-222 expression decreased initially and then increased, whereas miRNA-199a, miRNA-195, and miRNA-125b expression increased initially and then decreased, which corresponded with changes in cell cycle distribution and related target proteins expression (p27, cyclinA, cyclinD1, and CDK6). The corresponding expression levels of miRNAs in serum did not change. Dynamic changes in miR-222, miR-199a, miR-195, and miR-125b induced by VC can lead to cell cycle deregulation by affecting cell cycle-related proteins, and these miRNAs can serve as early biomarkers for malignant transformation caused by VC.

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.

The Arabidopsis leaf as a model system for investigating the role of cell cycle regulation in organ growth

2005 ◽  
Vol 119 (1) ◽  
pp. 43-50 ◽  
Author(s):  
Gerrit T. S. Beemster ◽  
Steven Vercruysse ◽  
Lieven De Veylder ◽  
Martin Kuiper ◽  
Dirk Inzé
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Regulation ◽  
Model System ◽  
Organ Growth ◽  
Cycle Regulation

scholarly journals Ionic Dissolution Products of NovaBone® Promote Osteoblastic Proliferation via Influences on the Cell Cycle

2009 ◽  
Vol 37 (3) ◽  
pp. 737-745 ◽  
Author(s):  
Z Qiu ◽  
H Yang ◽  
J Wu ◽  
L Wei ◽  
J Li
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Regulation ◽  
Cultured Cells ◽  
Bone Morphogenic Protein ◽  
Mg63 Cells ◽  
Silicon Ions ◽  
Cycle Regulation ◽  
Bone Morphogenic Protein 2 ◽  
Cells Cultured

This study investigated the effects of the ionic dissolution products of NovaBone® on osteoblastic proliferation and cell cycle regulation. MG63 osteoblast-like cells were cultured in NovaBone®-conditioned Dulbecco's Modified Eagle's Medium (DMEM) or control DMEM for 10 days. The concentration of silicon ions was significantly higher in NovaBone®-conditioned DMEM than control DMEM. MG63 cells cultured in NovaBone®-conditioned DMEM exhibited greater proliferation on days 1 and 4 than control cells. There were increased proportions of Novabone®-conditioned DMEM-cultured cells in the S and G2/M phases, and decreased proportions in the G0/G1 phase on days 1 and 4 versus control cells, while no differences were observed on days 7 and 10 between the two groups. Bone morphogenic protein 2 production increased in both groups, but was significantly higher for the NovaBone®-conditioned DMEM-cultured cells on day 10 compared with the controls. In conclusion, the NovaBone® ionic dissolution products, particularly the silicon ions, promoted proliferation of MG63 osteoblast-like cells in vitro via influences on the cell cycle.

The Potential Oncogenic and MLN4924-Resistant Effects of CSN5 on Cervical Cancer Cells

2021 ◽  
Author(s):  
Huilin Zhang ◽  
Ping He ◽  
Qing Zhou ◽  
Yan Lu ◽  
Bingjian Lu
Keyword(s):  
Cell Cycle ◽  
Cervical Cancer ◽  
Cell Proliferation ◽  
Cancer Cells ◽  
Cancer Cell ◽  
Cervical Cancer Cell ◽  
Cervical Cancers ◽  
Cervical Cancer Cells

Abstract BackgroundsCSN5, a member of Cop9 signalosome, is essential for protein neddylation. It has been supposed to serve as an oncogene in some cancers. However, the role of CSN5 has not been investigated in cervical cancer yet.MethodsData from TCGA cohorts and GEO dataset was analyzed to examine the expression profile of CSN5 in cervical cancers. The role of CSN5 on cervical cancer cell proliferation was investigated in cervical cancer cell lines, Siha and Hela, through CSN5 knockdown via CRISPR-CAS9. Western blot was used to detect the effect of CSN5 knockdown and overexpression. CCK8, clone formation assay and cell cycle assay were also employed. Besides, the role CSN5 knockdown in vivo was evaluated by xenograft tumor model. Moreover, MLN4924 was applied in Siha and Hela with CSN5 overexpression.ResultsWe found that downregulation of CSN5 in Siha and Hela cells inhibited cell proliferation in vitro and in vivo, and the inhibitory effects were largely rescued by CSN5 overexpression. Moreover, deletion of CSN5 caused cell cycle arrest rather than inducing apoptosis. Importantly, CSN5 overexpression confers resistance to the anti-cancer effects of MLN4924 (pevonedistat) in cervical cancer cells.ConclusionsOur findings demonstrated that CSN5 functions as an oncogene in cervical cancers and may serve as a potential indicator for predicting the effects of MLN4924 treatment in the future.

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