scholarly journals Phosphorylation of fibrinogen by casein kinase 2

1986 ◽  
Vol 234 (3) ◽  
pp. 523-526 ◽  
Author(s):  
M D Guasch ◽  
M Plana ◽  
J M Pena ◽  
E Itarte
Keyword(s):  
Glycogen Synthase ◽  
Gradient Centrifugation ◽  
High Mobility ◽  
Casein Kinase ◽  
Casein Kinase 2 ◽  
Serine Phosphorylation ◽  
Polymorphonuclear Leucocytes ◽  
High Mobility Group Protein ◽  
Human Fibrinogen ◽  
Alpha Chain

Casein kinase 2 from rat liver cytosol phosphorylated human fibrinogen in a reaction that was not stimulated by Ca2+ or cyclic AMP, but was markedly inhibited by heparin, and proceeded at a similar rate when either ATP or GTP was used as phosphate donor. Analysis of casein kinase 2 by glycerol-density-gradient centrifugation showed that the activities towards fibrinogen, casein, phosvitin, high-mobility-group protein 14 and glycogen synthase coincided. Maximal incorporation into fibrinogen by casein kinase 2 averaged 1 mol of phosphate/mol of protein substrate, most of it in the alpha-chain, although some phosphorylation of the beta-chain was also detected. Analysis of phosphorylated alpha-chain revealed that most of the phosphate was incorporated on serine. Phosphorylation of human fibrinogen was also performed by casein kinase 2 from human polymorphonuclear leucocytes, lymphocytes and platelets.

scholarly journals Effect of starvation, diabetes and insulin on the casein kinase 2 from rat liver cytosol

1985 ◽  
Vol 225 (2) ◽  
pp. 321-326 ◽  
Author(s):  
C Martos ◽  
M Plana ◽  
M D Guasch ◽  
E Itarte
Keyword(s):  
Rat Liver ◽  
Glycogen Synthase ◽  
Gradient Centrifugation ◽  
Diabetic Rats ◽  
Casein Kinase ◽  
Casein Kinase 2 ◽  
Partial Purification ◽  
Liver Cytosol ◽  
Casein Kinases ◽  
Rat Liver Cytosol

Starvation, diabetes and insulin did not alter the concentration of casein kinases in rat liver cytosol. However, the Km for casein of casein kinase 2 from diabetic rats was about 2-fold lower than that from control animals. Administration of insulin to control rats did not alter this parameter, but increased the Km for casein of casein kinase 2 in diabetic rats. Starvation did not affect the kinetic constants of casein kinases. The effect of diabetes on casein kinase 2 persisted after partial purification of the enzyme by glycerol-density-gradient centrifugation and affected also its activity on other protein substrates such as phosvitin, high-mobility-group protein 14 and glycogen synthase. The results indicate that rat liver cytosol casein kinase 2 is under physiological control.

scholarly journals Cyclic AMP-independent casein/glycogen synthase kinases from pig polymorphonuclear leucocytes

1981 ◽  
Vol 193 (3) ◽  
pp. 829-837 ◽  
Author(s):  
J. Manuel Pena ◽  
Roser Cussó ◽  
Emilio Itarte
Keyword(s):  
Cyclic Amp ◽  
Kinase Inhibitor ◽  
Glycogen Synthase ◽  
Gel Filtration ◽  
Casein Kinase ◽  
Casein Kinase 2 ◽  
Polymorphonuclear Leucocytes ◽  
Rabbit Muscle ◽  
Casein Kinase 1 ◽  
Glycogen Synthase Kinases

1. Two cyclic AMP-independent casein/glycogen synthase kinases were purified from pig polymorphonuclear leucocytes by chromatography on phosphocellulose followed by affinity chromatography on casein–Sepharose 4B or gel filtration on Bio-Gel A-1.5m. When the affinity step was used, the specific activities were 86 and 43units/mg of protein for casein kinase 1 and 2, respectively, whereas these values were 94 and 90units/mg of protein when the gel-filtration step was used. 2. These kinases differ as follows: (a) the molecular weight of casein kinase 1 (38000) is very much lower than that of casein kinase 2 (185000); (b) the Km for casein (0.46mg/ml) and Ka for Mg2+ (0.3mm) of casein kinase 1 are lower than those of casein kinase 2 (0.90mg/ml and 1.7mm respectively); (c) KCl stimulates the phosphorylation of casein by casein kinase 1, whereas it inhibits phosvitin phosphorylation by this enzyme; on the contrary, the effect of KCl on casein kinase 2 is very similar with either casein or phosvitin as substrate; (d) although both kinases phosphorylate rabbit muscle glycogen synthase I, the ratio of glycogen synthase to casein phosphorylation by casein kinase 1 is about 4-fold greater than that by casein kinase 2. Furthermore, 32P incorporation into glycogen synthase promoted by casein kinase 1 (3.6mol of 32P/mol of 85000-dalton subunit) is twice that observed with casein kinase 2 (1.8mol of 32P/mol of 85000-dalton subunit). Such a phosphorylation results in a decrease in the glucose 6-phosphate-independence ratio of glycogen synthase to 10–15 with casein kinase 1 and to 35–45 with casein kinase 2. 3. The activity of both kinases is neither stimulated by cyclic AMP, Ca2+ and calmodulin nor inhibited by cyclic AMP-dependent protein kinase inhibitor protein. 4. No phosphorylation kinase activity was observed with casein kinase 1 and 2 at either pH6.8 or 8.2 in the presence of Ca2+. 5. Activities of both kinases on casein and glycogen synthase decreased in parallel when incubated at 50°C.

Phosphorylation of the high-mobility-group-like protein P1 by casein kinase-2

1989 ◽  
Vol 184 (3) ◽  
pp. 529-534 ◽  
Author(s):  
Gunhild M. MAELANDSMO ◽  
Anne C. OSTVOLD ◽  
Soren G. LALAND
Keyword(s):  
High Mobility ◽  
Casein Kinase ◽  
Casein Kinase 2 ◽  
High Mobility Group

scholarly journals Casein kinase 2-dependent serine phosphorylation of MuSK regulates acetylcholine receptor aggregation at the neuromuscular junction

2006 ◽  
Vol 20 (13) ◽  
pp. 1800-1816 ◽  
Author(s):  
Tatiana Cheusova ◽  
Muhammad Amir Khan ◽  
Steffen Wolfgang Schubert ◽  
Anne-Claude Gavin ◽  
Thierry Buchou ◽  
...  
Keyword(s):  
Neuromuscular Junction ◽  
Acetylcholine Receptor ◽  
Casein Kinase ◽  
Casein Kinase 2 ◽  
Serine Phosphorylation ◽  
Receptor Aggregation

scholarly journals Obesity-Linked Phosphorylation of SIRT1 by Casein Kinase 2 Inhibits Its Nuclear Localization and Promotes Fatty Liver

2017 ◽  
Vol 37 (15) ◽  
Author(s):  
Sung E. Choi ◽  
Sanghoon Kwon ◽  
Sunmi Seok ◽  
Zhen Xiao ◽  
Kwan-Woo Lee ◽  
...  
Keyword(s):  
Fatty Liver ◽  
Nuclear Localization ◽  
Liver Steatosis ◽  
Phosphorylation Site ◽  
Casein Kinase ◽  
Casein Kinase 2 ◽  
Serine Phosphorylation ◽  
Acid Oxidation ◽  
Specific Expression ◽  
Nonalcoholic Fatty Liver

ABSTRACT Sirtuin1 (SIRT1) deacetylase delays and improves many obesity-related diseases, including nonalcoholic fatty liver disease (NAFLD) and diabetes, and has received great attention as a drug target. SIRT1 function is aberrantly low in obesity, so understanding the underlying mechanisms is important for drug development. Here, we show that obesity-linked phosphorylation of SIRT1 inhibits its function and promotes pathological symptoms of NAFLD. In proteomic analysis, Ser-164 was identified as a major serine phosphorylation site in SIRT1 in obese, but not lean, mice, and this phosphorylation was catalyzed by casein kinase 2 (CK2), the levels of which were dramatically elevated in obesity. Mechanistically, phosphorylation of SIRT1 at Ser-164 substantially inhibited its nuclear localization and modestly affected its deacetylase activity. Adenovirus-mediated liver-specific expression of SIRT1 or a phosphor-defective S164A-SIRT1 mutant promoted fatty acid oxidation and ameliorated liver steatosis and glucose intolerance in diet-induced obese mice, but these beneficial effects were not observed in mice expressing a phosphor-mimic S164D-SIRT1 mutant. Remarkably, phosphorylated S164-SIRT1 and CK2 levels were also highly elevated in liver samples of NAFLD patients and correlated with disease severity. Thus, inhibition of phosphorylation of SIRT1 by CK2 may serve as a new therapeutic approach for treatment of NAFLD and other obesity-related diseases.

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