CK2 phosphorylates AP-2α and increases its transcriptional activity

( Kai Qun Ren ),( Shuang Lin Xiang ),( Fang Li He ),( Wen Feng Zhang ),( Xiao Feng Ding ),( Yan Yang Wu ),( Li Ping Yang ),( Jian Lin Zhou ),( Xiang Gao ),( Jian Zhang ) 생화학분자생물학회(구 한국생화학분자생물학회) 2011 BMB Reports Vol.44 No.7

Transcription factor AP-2α involves in the process of mammalian embryonic development and tumorigenesis. Many studies have shown that AP-2α functions in association with other interacting proteins. In a two-hybrid screening, the regulatory subunit β of protein casein kinase 2 (CK2β) was identified as an interacting protein of AP-2α; we confirmed this interaction using in-vitro GST pull-down and in-vivo co-immunoprecipitation assays; in an endogenous co-immunoprecipitation experiment, we further found the catalytic subunit α of protein casein kinase 2 (CK2α) also exists in the complex. Phosphorylation analysis revealed that AP-2α was phosphorylated by CK2 kinase majorly at the site of Ser429, and such phosphorylation could be blocked by CK2 specific inhibitor 4,5,6,7-tetrabromobenzotriazole (TBB) in a dose-dependent manner. Luciferase assays demonstrated that both CK2α and CK2β enhanced the transcription activity of AP-2α; moreover, CK2β increased the stability of AP-2α. Our data suggest a novel cellular function of CK-2 as a transcriptional co-activator of AP-2α.

CK2-dependent phosphorylation positively regulates stress-induced activation of Msn2 in Saccharomyces cerevisiae

Cho, B.R.,Hahn, J.S. Elsevier Science 2017 Biochimica et biophysica acta. Gene regulatory mec Vol.1860 No.6

CK2 is a highly conserved Ser/Thr protein kinase involved in a large number of cellular processes. Here, we demonstrate that CK2-dependent phosphorylation positively regulates Msn2/4, the general stress response transcriptional activators in Saccharomyces cerevisiae, in response to various types of environmental stress conditions. CK2 overexpression elicits hyperactivation of Msn2/4, whereas deletion of one of the CK2 catalytic subunits, especially CKA2, leads to reduced transcriptional activity of Msn2/4 in response to glucose starvation, H<SUB>2</SUB>O<SUB>2,</SUB> and lactic acid. The CKA2 deletion mutant also shows increased stress sensitivity. CK2 phosphorylates Ser194 and Ser638 in Msn2 and replacement of Ser638 with alanine leads to reduced Msn2 activity upon stress and reduced tolerance to H<SUB>2</SUB>O<SUB>2</SUB> and lactic acid. CKA2 deletion mutant shows shorter nuclear retention time of Msn2 upon lactic acid stress, suggesting that CK2 might regulate nuclear localization of Msn2. However, Msn2<SUP>S194A, S638A</SUP> mutant shows normal nuclear import and export patterns upon stress, suggesting that CK2 might positively regulate the general stress response not only by direct phosphorylation of Msn2/4, but also by regulating cellular translocation machinery.

Estrogen Induces CK2α Activation via Generation of Reactive Oxygen Species

정수연,임선영 대한의생명과학회 2019 Biomedical Science Letters Vol.25 No.1

The protein kinase CK2α (formerly Casein Kinase II) is implicated in tumorigenesis and transformation. However, the mechanisms of CK2α activation in breast cancer have yet to be elucidated. This study investigated the mechanisms of CK2α activation in estrogen signaling. Estrogen increased reactive oxygen species (ROS) production, CK2α activity, and protein expression in estrogen receptor positive (ER+) MCF-7 human breast cancer cells, which were inhibited by the antioxidant N-acetyl-L-cysteine. H2O2 enhanced CK2α activity and protein expression. Human epidermal growth factor (EGF) increased ROS production, CK2α activity and protein expression in EGF receptor 2 (HER2)-overexpressing MCF-7 (MCF-7 HER2) cells, but not in MCF-7 cells. Estrogen induced the phosphorylation of p38 mitogen-activated protein kinase (MAPK). The p38 inhibitor, SB202190, blocked estrogen-induced increases in ROS production, CK2α activity and CK2α protein expression. The data suggest that ROS/p38 MAPK is the key inducer of CK2α activation in response to estrogen or EGF.

Inhibition of casein kinase 2 enhances the death ligand- and natural kiler cell-induced hepatocellular carcinoma cell death

Kim, H.-R.,Kim, K.,Lee, K.-H.,Kim, S. J.,Kim, J. Blackwell Publishing Ltd 2008 Clinical and experimental immunology Vol.152 No.2

<P>Summary</P><P>Recent studies have shown that the inhibition of casein kinase 2 (CK2) sensitizes many cancer cells to Fas ligand- and tumour necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis. However, it has not been demonstrated directly whether CK2 inhibition can also enhance the cytotoxicity of natural killer (NK) cells, which actually use the death ligands to kill cancer cells <I>in vivo</I>. To address whether NK cell-mediated cancer cell death is affected by the inhibition of CK2, we first checked whether the death ligand-induced apoptosis of hepatocellular carcinoma cells (HCCs) and HeLa were affected by CK2 inhibition. We then investigated the effect of CK2 inhibition on NK cytotoxicity against HCCs and HeLa cells and its mechanistic features. Inhibition of CK2 by emodin increased the apoptotic cell death of HepG2, Hep3B and HeLa when the cancer cell lines were treated with a soluble form of recombinant TRAIL or an agonistic antibody of Fas. This phenomenon appeared to be correlated with the expression level of death receptors on the cancer cell surface. More interestingly, the inhibition of CK2 also greatly increased the NK cell-mediated cancer cell killing. The NK cytotoxicity against the cancer cells increased about twofold when the target cells were pretreated with a specific CK2 inhibitor, emodin or 4,5,6,7-tetrabromobenzotriazole. Furthermore, the increase of the NK cytotoxicity against cancer cells by CK2 inhibition was granule-independent and mediated possibly by the death ligands on the NK cell surface. This suggests that CK2 inhibitors could be used to enhance the cytotoxicity of NK cells and consequently increase host tumour immunity.</P>

Inactivation of the FoxO3a transcription factor is associated with the production of reactive oxygen species during protein kinase CK2 downregulation-mediated senescence in human colon cancer and breast cancer cells

Park, Seong-Yeol,Bae, Young-Seuk Elsevier 2016 Biochemical and biophysical research communication Vol.478 No.1

<P><B>Abstract</B></P> <P>We previously showed that protein kinase CK2 downregulation mediates senescence through the reactive oxygen species (ROS)–p53–p21<SUP>Cip1/WAF1</SUP> pathway in various human cells. In the present study, we investigated whether the FoxO3a transcription factor is associated with ROS production during CK2 downregulation-induced senescence in human colon cancer HCT116 and breast cancer MCF-7 cells. FoxO3a overexpression suppressed ROS production and p53 stabilization induced by a CK2α knockdown. CK2α downregulation induced nuclear export of FoxO3a through stimulation of AKT-mediated phosphorylation of FoxO3a and decreased transcription of its target genes (Cu/ZnSOD, MnSOD, and catalase). In contrast, CK2α overexpression inhibited AKT-mediated FoxO3a phosphorylation. This resulted in nuclear accumulation of FoxO3a, and elevated expression of its target genes. Therefore, these data indicate for the first time that CK2 downregulation stimulates ROS generation by inhibiting FoxO3a during premature senescence in human colon and breast cancer cells.</P> <P><B>Highlights</B></P> <P> <UL> <LI> FoxO3a overexpression inhibited ROS production mediated by CK2α knockdown. </LI> <LI> CK2α downregulation induced nuclear export of FoxO3a via AKT activation. </LI> <LI> CK2α downregulation reduced transcription of FoxO3a target genes including SOD. </LI> <LI> CK2α upregulation elevated nuclear import and target gene expression of FoxO3a. </LI> <LI> This study indicates that CK2 can modulate the intracellular ROS level via FoxO3a. </LI> </UL> </P>

CK2 downregulation induces senescence-associated heterochromatic foci formation through activating SUV39h1 and inactivating G9a

Park, Jeong-Woo,Kim, Jin Joo,Bae, Young-Seuk Elsevier 2018 Biochemical and biophysical research communication Vol.505 No.1

<P><B>Abstract</B></P> <P>Cellular senescence is an irreversible form of cell cycle arrest and senescent cells have a unique gene expression profile that is frequently accompanied by senescence-associated heterochromatic foci (SAHF). Here, we present evidence that CK2 downregulation induces trimethylation of histone H3 Lys 9 (H3K9me3), selective binding of HP1γ to H3K9me3, formation of SAHF, and reduction of cyclin D1 expression in HCT116 and MCF-7 cells. CK2 downregulation-mediated H3K9me3 is associated with induction of H3K9 trimethylase SUV39h1 as well as reduction of H3K9 dimethylase G9a and GLP in cells. In addition, Pharmacological inhibition of SUV39h1 and G9a overexpression significantly attenuated induction of senescence-associated β-galactosidase (SA-β-gal) activity, H3K9me3 and SAHF formation in CK2-downregulated cells. Moreover, CK2 downregulation induced H3K9me3 in nematodes. Taken together, these results demonstrate that CK2 downregulation leads to H3K9me3 and SAHF formation by increasing SUV39h1 and decreasing G9a.</P> <P><B>Highlights</B></P> <P> <UL> <LI> CK2 downregulation induces histone H3K9me3 in human cells and nematodes. </LI> <LI> CK2 downregulation results in induction of SUV39h1 and reduction of G9a and GLP. </LI> <LI> SUV39h1 inhibition or G9a upregulation suppress CK2 knockdown-mediated SAHF formation. </LI> <LI> Therefore, this study suggests that CK2 downregulation induces SAHF formation. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Investigation of metabolic perturbation in CK2α-overexpressed colon cancer cells by carbon isotope using GC/MS

이준민,임대균,오민규 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.1

CK2α is a serine/threonine kinase that is constitutively active in multiple cancer cells. Using colon cancer cell lines such as HT29 and SW620, CK2α induced epithelial mesenchymal transition and the transitioned cells became more proliferative. We assumed that CK2α could affect cancer cell growth by modulating energy metabolism. Therefore, we examined the reprogrammed metabolic fluxes of CK2α on glucose metabolism via isotope labeled substrates and could successfully determine the relative amount and mass isotopomer distribution(MID) of metabolites using GC/MS. The results showed that continuous activation of CK2α facilitates the Warburg effect and anaplerotic pathway. Besides, results also showed CK2α overexpression affected glutamine uptake metabolism, varying amount and MID of TCA intermediates. This study suggests that because oncogenes regulate important metabolic enzymes and metabolism signaling pathways, CK2α is an excellent metabolic target for cancer therapy.

Downregulation of JMJD2a and LSD1 is involved in CK2 inhibition-mediated cellular senescence through the p53-SUV39h1 pathway

Jeong-Woo Park,Young-Seuk Bae 생화학분자생물학회 2022 BMB Reports Vol.55 No.2

Lysine methylation is one of the most important histone modificationsthat modulate chromatin structure. In the present study,the roles of the histone lysine demethylases JMJD2a and LSD1in CK2 downregulation-mediated senescence were investigated. The ectopic expression of JMJD2a and LSD1 suppressed the inductionof senescence-associated β-galactosidase activity andheterochromatin foci formation as well as the reduction of colony-forming and cell migration ability mediated by CK2 knockdown. CK2 downregulation inhibited JMJD2a and LSD1 expressionby activating the mammalian target of rapamycin (mTOR)-ribosomal p70 S6 kinase (p70S6K) pathway. In addition, the downregulationof JMJD2a and LSD1 was involved in activating thep53-p21Cip1/WAF1-SUV39h1-trimethylation of the histone H3 Lys9(H3K9me3) pathway in CK2-downregulated cells. Further, CK2downregulation-mediated JMJD2a and LSD1 reduction was foundto stimulate the dimethylation of Lys370 on p53 (p53K370me2)and nuclear import of SUV39h1. Therefore, this study indicatedthat CK2 downregulation reduces JMJD2a and LSD1 expressionby activating mTOR, resulting in H3K9me3 induction by increasingthe p53K370me2-dependent nuclear import of SUV39h1. These results suggest that CK2 is a potential therapeutic targetfor age-related diseases.

Protein kinase CK2 activates Nrf2 via autophagic degradation of Keap1 and activation of AMPK in human cancer cells

Da Eun Jang,송준빈,Jeong-Woo Park,윤수현,Young-Seuk Bae 생화학분자생물학회 2020 BMB Reports Vol.53 No.5

Protein kinase CK2 downregulation induces premature senescence in various human cell types via activation of the reactive oxygen species (ROS)–p53–p21Cip1/WAF1 pathway. The transcription factor “nuclear factor erythroid 2-related factor 2” (Nrf2) plays an important role in maintaining intracellular redox homeostasis. In this study, Nrf2 overexpression attenuated CK2 downregulation– induced ROS production and senescence markers including SA--gal staining and activation of p53–p21Cip1/WAF1 in human breast (MCF-7) and colon (HCT116) cancer cells. CK2 downregulation reduced the transcription of Nrf2 target genes, such as glutathione S-transferase, glutathione peroxidase 2, and glutathione reductase 1. Furthermore, CK2 downregulation destabilized Nrf2 protein via inhibiting autophagic degradation of Kelch-like ECHassociated protein 1 (Keap1). Finally, CK2 downregulation decreased the nuclear import of Nrf2 by deactivating AMP-activated protein kinase (AMPK). Collectively, our data suggest that both Keap1 stabilization and AMPK inactivation are associated with decreased activity of Nrf2 in CK2 downregulation–induced cellular senescence.

Protein Kinase CK2 Is Upregulated by Calorie Restriction and Induces Autophagy

Jeong-Woo Park,Jihyeon Jeong,Young-Seuk Bae 한국분자세포생물학회 2022 Molecules and cells Vol.45 No.3

Calorie restriction (CR) and the activation of autophagy extend healthspan by delaying the onset of age-associated diseases in most living organisms. Because protein kinase CK2 (CK2) downregulation induces cellular senescence and nematode aging, we investigated CK2’s role in CR and autophagy. This study indicated that CR upregulated CK2’s expression, thereby causing SIRT1 and AMP-activated protein kinase (AMPK) activation. CK2α overexpression, including antisense inhibitors of miR-186, miR-216b, miR-337-3p, and miR-760, stimulated autophagy initiation and nucleation markers (increase in ATG5, ATG7, LC3BII, beclin-1, and Ulk1, and decrease in SQSTM1/p62). The SIRT1 deacetylase, AKT, mammalian target of rapamycin (mTOR), AMPK, and forkhead homeobox type O (FoxO) 3a were involved in CK2-mediated autophagy. The treatment with the AKT inhibitor triciribine, the AMPK activator AICAR, or the SIRT1 activator resveratrol rescued a reduction in the expression of lgg-1 (the Caenorhabditis elegans ortholog of LC3B), bec-1 (the C. elegans ortholog of beclin-1), and unc-51 (the C. elegans ortholog of Ulk1), mediated by kin-10 (the C. elegans ortholog of CK2β) knockdown in nematodes. Thus, this study indicated that CK2 acted as a positive regulator in CR and autophagy, thereby suggesting that these four miRs’ antisense inhibitors can be used as CR mimetics or autophagy inducers.