| 1. |
- Filipiak, Kamila, et al.
(författare)
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Human Protein Kinase CK2 Phosphorylates Matrix Metalloproteinase 2 and Inhibits its Activity
- 2014
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Ingår i: ChemBioChem. - : Wiley. - 1439-4227 .- 1439-7633. ; 15:13, s. 1873-1876
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Tidskriftsartikel (refereegranskat)abstract
- Matrix metalloproteinase 2 (MMP-2) is involved in cancer development and is overexpressed in a variety of malignant tumors. MMP-2 activity is controlled mainly by transcription, proteolytic activation, and inhibition by endogenous inhibitors. It had previously been demonstrated that MMP-2 activity is also regulated by phosphorylation at several sites by protein kinase C. Here we demonstrate, by means of bioinformatics and biochemical and cellular assays, that protein kinase CK2 also acts as a modulator of MMP-2 activity. CK2 down-regulates MMP-2 in vitro, and inhibition of CK2 in human fibrosarcoma cells results in up-regulation of MMP-2. The discovery of the crosstalk between MMP-2 and CK2 opens the possibility of new combined anticancer therapies.
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| 2. |
- Fraczyk, Tomasz, et al.
(författare)
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Phosphorylation of thymidylate synthase from various sources by human protein kinase CK2 and its catalytic subunits
- 2010
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Ingår i: Bioorganic chemistry (Print). - : Elsevier BV. - 0045-2068. ; 38:3, s. 124-131
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Tidskriftsartikel (refereegranskat)abstract
- Thymidylate synthase (TS) was found to be a substrate for both catalytic subunits of human CK2, with phosphorylation by CK2alpha and CK2alpha' characterized by similar K(m) values, 4.6microM and 4.2microM, respectively, but different efficiencies, the apparent turnover number with CK2alpha being 10-fold higher. With both catalytic subunits, phosphorylation of human TS, like calmodulin and BID, was strongly inhibited in the presence of the regulatory subunit CK2beta, the holoenzyme being activated by polylysine. Phosphorylation of recombinant human, rat, mouse and Trichinella spiralis TSs proteins was compared, with the human enzyme being apparently a much better substrate than the others. Following hydrolysis and TLC, phosphoserine was detected in human and rat, and phosphotyrosine in T. spiralis, TS, used as substrates for CK2alpha. MALDI-TOF MS analysis led to identification of phosphorylated Ser(124) in human TS, within a sequence LGFS(124)TREEGD, atypical for a CK2 substrate recognition site. The phosphorylation site is located in a region considered important for the catalytic mechanism or regulation of human TS, corresponding to the loop 107-128. Following phosphorylation by CK2alpha, resulting in incorporation of 0.4mol of phosphate per mol of dimeric TS, human TS exhibits unaltered K(m) values for dUMP and N(5,10)-methylenetetrahydrofolate, but a 50% lower turnover number, pointing to a strong influence of Ser(124) phosphorylation on its catalytic efficiency.
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| 3. |
- Kubinski, Konrad, et al.
(författare)
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Yeast Elf1 factor is phosphorylated and interacts with protein kinase CK2
- 2006
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Ingår i: Journal of Biochemistry and Molecular Biology. - 1225-8687 .- 0219-1024. ; 39:3, s. 311-318
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Tidskriftsartikel (refereegranskat)abstract
- One of the biggest group of proteins influenced by protein kinase CK2 is formed by factors engaged in gene expression. Here we have reported recently identified yeast transcription elongation factor Elf1 as a new substrate for both monomeric and tetrameric forms of CK2. Elf1 serves as a substrate for both the recombinant CK2alpha' (K(m) 0.38 microM) and holoenzyme (K(m) 0.13 microM). By MALDI-MS we identified the two serine residues at positions 95 and 117 as the most probable in vitro phosphorylation sites. Coimmunoprecypitation experiments show that Elf1 interacts with catalytic (alpha and alpha') as well as regulatory (beta and beta') subunits of CK2. These data may help to elucidate the role of protein kinase CK2 and Elf1 in the regulation of transcription elongation.
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| 4. |
- Masłyk, Maciej, et al.
(författare)
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Yeast surviving factor Svf1 as a new interacting partner, regulator and in vitro substrate of protein kinase CK2
- 2008
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Ingår i: Molecular and Cellular Biochemistry. - : Springer Science and Business Media LLC. - 0300-8177 .- 1573-4919. ; 312:1-2, s. 61-69
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Tidskriftsartikel (refereegranskat)abstract
- Since Svf1 is phosphoprotein, we investigated whether it was a substrate for protein kinase CK2. According to the amino acid sequence Svf1 harbours 20 putative CK2 phosphorylation sites. Here, we have reported cloning, overexpression, purification and characterization of yeast Svf1 as a substrate for three forms of yeast CK2. Svf1 serves as a substrate for both the recombinant CK2alpha (K (m) 0.35 muM) and CK2alpha' (K (m) 0.18 muM) as well as CK2 holoenzyme (K (m) 1.1 muM). Different K (m) values argue that CK2beta(beta') subunit has an inhibitory effect on the activity of both CK2alpha and CK2alpha' towards surviving factor Svf1. Reconstitution of alpha'(2)betabeta' isoform of CK2 holoenzyme shows that beta/beta' subunits have regulatory effect depending on the kind of CK2 catalytic subunit. This effect was not observed in the case of alpha(2)betabeta' isoform, which may be due to interaction between Svf1 and regulatory CK2beta subunit (shown by co-immunoprecipitation experiments). Interactions between CK2 subunits and Svf1 protein may have influence on ATP as well as ATP-competitive inhibitors (TBBt and TBBz) binding. CK2 phosphorylates up to six serine residues in highly acidic peptide K(199)EVIPESDEEESSADEDDNEDEDEESGDSEEESGSEEESDSEEVEITYED(248) of the Svf1 protein in vitro. Presented data may help to elucidate the role of protein kinase CK2 and Svf1 in the regulation of cell survival pathways.
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| 5. |
- Zielin„ski, Rafal, et al.
(författare)
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Fip1 - an essential component of the Saccharomyces cerevisiae polyadenylation machinery is phosophorylated by protein kinase CK2
- 2006
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Ingår i: Molecular and Cellular Biochemistry. - : Springer Science and Business Media LLC. - 0300-8177 .- 1573-4919. ; 286:1-2, s. 191-197
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Tidskriftsartikel (refereegranskat)abstract
- Since Fip1 is phosphoprotein we investigated whether it is a substrate for protein kinase CK2. According to the amino acid sequence Fip1 harbours twenty putative CK2 phosphorylation sites. Here we have report characterization of Fip1 as a substrate for both forms of CK2. Fip1 serves as a substrate for both the recombinant CK2α ′ (K m 1.28 μM) and holoenzyme (K m 1.4 μM) but not for CK1. By MALDI-MS we identified the two serine residues at positions 73 and 77 as the possible in vitro phosphorylation sites. These data may help to elucidate the role of Fip1 in the mRNA 3'-OH polyadenylation process and the involvement of CK2 mediated phosphorylation in regulation of interactions and activity members of cleavage/polyadenylation factor (CPF) complex.
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| 6. |
- Zielinski, Rafał, et al.
(författare)
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Inhibition of yeast ribosomal stalk phosphorylation by Cu-Zn superoxide dismutase
- 2002
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Ingår i: Biochemical and Biophysical Research Communications - BBRC. - 0006-291X .- 1090-2104. ; 296:5, s. 1310-1316
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Tidskriftsartikel (refereegranskat)abstract
- Reversible phosphorylation of acidic ribosomal proteins of Saccharomyces cerevisiae is an important mechanism, regulating the number of active ribosomes. The key role in regulation of this process is played by specific, second messenger-independent protein kinases. A new protein-inhibitor regulating activity of PK60S kinase has been purified from yeast extracts and characterised. Peptide mass fingerprinting (PMF) and amino-acid sequence analysis by Post Source Decay (PSD) have identified the inhibitor as a Cu-Zn superoxide dismutase (SOD). Inhibition by SOD is competitive with respect to protein substrates-P proteins and 80S ribosome-with K(i) values of 3.7 microM for P2A protein and 0.6 microM for 80S ribosomes. A close correlation was found between the state of phosphorylation of P proteins in diauxic shift and logarithmic growth yeast cells and activity of SOD. The possible mechanism of regulation of PK60S activity, and participation of SOD protein in regulation of 80S-ribosome activity in stress conditions, is discussed.
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