scholarly journals Casein Kinase II-Type Protein Kinase from Pea Cytoplasm and Its Inactivation by Alkaline Phosphatase in Vitro

1993 ◽  
Vol 103 (3) ◽  
pp. 955-962 ◽  
Author(s):  
S. Zhang ◽  
C. D. Jin ◽  
S. J. Roux
Keyword(s):  
Alkaline Phosphatase ◽  
Protein Kinase ◽  
Casein Kinase Ii ◽  
Casein Kinase ◽  
Type Protein

scholarly journals DNA repair protein O6-alkylguanine-DNA alkyltransferase is phosphorylated by two distinct and novel protein kinases in human brain tumour cells

2000 ◽  
Vol 351 (2) ◽  
pp. 393-402 ◽  
Author(s):  
Srinivas R. S. MULLAPUDI ◽  
Francis ALI-OSMAN ◽  
Jiang SHOU ◽  
Kalkunte S. SRIVENUGOPAL
Keyword(s):  
Dna Repair ◽  
Protein Kinase ◽  
Tyrosine Kinase ◽  
Protein Kinases ◽  
Casein Kinase Ii ◽  
Casein Kinase ◽  
Biochemical Modulation ◽  
Cell Extracts ◽  
Dna Alkyltransferase

We showed recently that human O6-alkylguanine-DNA alkyltransferase (AGT), an important target for improving cancer chemotherapy, is a phosphoprotein and that phosphorylation inhibits its activity [Srivenugopal, Mullapudi, Shou, Hazra and Ali-Osman (2000) Cancer Res. 60, 282–287]. In the present study we characterized the cellular kinases that phosphorylate AGT in the human medulloblastoma cell line HBT228. Crude cell extracts used Mg2+ more efficiently than Mn2+ for phosphorylating human recombinant AGT (rAGT) protein. Both [γ-32P]ATP and [γ-32P]GTP served as phosphate donors, with the former being twice as efficient. Specific components known to activate protein kinase A, protein kinase C and calmodulin-dependent kinases did not stimulate the phosphorylation of rAGT. Phosphoaminoacid analysis after reaction in vitro with ATP or GTP showed that AGT was modified at the same amino acids (serine, threonine and tyrosine) as in intact HBT228 cells. Although some of these properties pointed to casein kinase II as a candidate enzyme, known inhibitors and activators of casein kinase II did not affect rAGT phosphorylation. Fractionation of the cell extracts on poly(Glu/Tyr)-Sepharose resulted in the adsorption of an AGT kinase that modified the tyrosine residues and the exclusion of a fraction that phosphorylated AGT on serine and threonine residues. In-gel kinase assays after SDS/PAGE and non-denaturing PAGE revealed the presence of two AGT kinases of 75 and 130kDa in HBT228 cells. The partly purified tyrosine kinase, identified as the 130kDa enzyme by the same assays, was strongly inhibited by tyrphostin 25 but not by genestein. The tyrosine kinase used ATP or GTP to phosphorylate the AGT protein; this reaction inhibited the DNA repair activity of AGT. Evidence that the kinases might physically associate with AGT in cells was also provided. These results demonstrate that two novel cellular protein kinases, a tyrosine kinase and a serine/threonine kinase, both capable of using GTP as a donor, phosphorylate the AGT protein and affect its function. The new kinases might serve as potential targets for strengthening the biochemical modulation of AGT in human tumours.

scholarly journals A casein kinase II-related activity is involved in phosphorylation of microtubule-associated protein MAP-1B during neuroblastoma cell differentiation.

1988 ◽  
Vol 106 (6) ◽  
pp. 2057-2065 ◽  
Author(s):  
J Díaz-Nido ◽  
L Serrano ◽  
E Méndez ◽  
J Avila
Keyword(s):  
Protein Kinase ◽  
Neuroblastoma Cells ◽  
Casein Kinase Ii ◽  
Casein Kinase ◽  
Related Activity ◽  
Dependent Protein Kinase ◽  
Protein Map ◽  
Dependent Protein

A neuroblastoma protein related to the brain microtubule-associated protein, MAP-1B, as determined by immunoprecipitation and coassembly with brain microtubules, becomes phosphorylated when N2A mouse neuroblastoma cells are induced to generate microtubule-containing neurites. To characterize the protein kinases that may be involved in this in vivo phosphorylation of MAP-1B, we have studied its in vitro phosphorylation. In brain microtubule protein, MAP-1B appears to be phosphorylated in vitro by an endogenous casein kinase II-like activity which also phosphorylates the related protein MAP-1A but scarcely phosphorylates MAP-2. A similar kinase activity has been detected in cell-free extracts of differentiating N2A cells. Using brain MAP preparations devoid of endogenous kinase activities and different purified protein kinases, we have found that MAP-1B is barely phosphorylated by cAMP-dependent protein kinase, Ca/calmodulin-dependent protein kinase, or Ca/phospholipid-dependent protein kinase whereas MAP-1B is one of the preferred substrates, together with MAP-1A, for casein kinase II. Brain MAP-1B phosphorylated in vitro by casein kinase II efficiently coassembles with microtubule proteins in the same way as in vivo phosphorylated MAP-1B from neuroblastoma cells. Furthermore, the phosphopeptide patterns of brain MAP-1B phosphorylated in vitro by either purified casein kinase II or an extract obtained from differentiating neuroblastoma cells are identical to each other and similar to that of in vivo phosphorylated neuroblastoma MAP-1B. Thus, we suggest that the observed phosphorylation of a protein identified as MAP-1B during neurite outgrowth is mainly due to the activation of a casein kinase II-related activity in differentiating neuroblastoma cells. This kinase activity, previously implicated in beta-tubulin phosphorylation (Serrano, L., J. Díaz-Nido, F. Wandosell, and J. Avila, 1987. J. Cell Biol. 105: 1731-1739), may consequently have an important role in posttranslational modifications of microtubule proteins required for neuronal differentiation.

scholarly journals Casein kinase I-like protein kinases encoded by YCK1 and YCK2 are required for yeast morphogenesis.

1993 ◽  
Vol 13 (5) ◽  
pp. 2870-2881 ◽  
Author(s):  
L C Robinson ◽  
M M Menold ◽  
S Garrett ◽  
M R Culbertson
Keyword(s):  
Protein Kinase ◽  
Eukaryotic Cell ◽  
Casein Kinase ◽  
Temperature Sensitive ◽  
Protein Kinase Activity ◽  
Restrictive Temperature ◽  
Loss Of Function ◽  
Casein Kinase I ◽  
Yeast Saccharomyces Cerevisiae

Casein kinase I is an acidotropic protein kinase class that is widely distributed among eukaryotic cell types. In the yeast Saccharomyces cerevisiae, the casein kinase I isoform encoded by the gene pair YCK1 and YCK2 is a 60- to 62-kDa membrane-associated form. The Yck proteins perform functions essential for growth and division; either alone supports growth, but loss of function of both is lethal. We report here that casein kinase I-like activity is associated with a soluble Yck2-beta-galactosidase fusion protein in vitro and that thermolabile protein kinase activity is exhibited by a protein encoded by fusion of a temperature-sensitive yck2 allele with lacZ. Cells carrying the yck2-2ts allele arrest at restrictive temperature with multiple, elongated buds containing multiple nuclei. This phenotype suggests that the essential functions of the Yck proteins include roles in bud morphogenesis, possibly in control of cell growth polarity, and in cytokinesis or cell separation. Further, a genetic relationship between the yck2ts allele and deletion of CDC55 indicates that the function of Yck phosphorylation may be related to that of protein phosphatase 2A activity.

scholarly journals Phosphorylation of IkappaBalpha in the C-terminal PEST domain by casein kinase II affects intrinsic protein stability.

1996 ◽  
Vol 16 (4) ◽  
pp. 1401-1409 ◽  
Author(s):  
R Lin ◽  
P Beauparlant ◽  
C Makris ◽  
S Meloche ◽  
J Hiscott
Keyword(s):  
Triple Point ◽  
Cell Activation ◽  
Kinase Activity ◽  
Casein Kinase Ii ◽  
Casein Kinase ◽  
Kinase Assay ◽  
Intrinsic Stability ◽  
Nf Kappab ◽  
Constitutive Phosphorylation

The NF-kappaB/Rel transcription factors participate in the activation of immune system regulatory genes and viral early genes including the human immunodeficiency virus type 1 long terminal repeat. NF-kappaB/Rel proteins are coupled to inhibitory molecules, collectively termed IkappaB, which are responsible for cytoplasmic retention of NF-kappaB. Cell activation leads to the phosphorylation and degradation of IkappaBalpha, permitting NG-kappaB/Rel translocation to the nucleus and target gene activation. To further characterize the signaling events that contribute to IkappaBalpha phosphorylation, a kinase activity was isolated from Jurkat T cells that specifically interacted with IkappaBalpha in an affinity chromatography step and phosphorylated IkappaBalpha with high specificity in vitro. By using an in-gel kinase assay with recombinant IkappaBalpha as substrate, two forms of the kinase (43 and 38 kDa) were identified. Biochemical criteria and immunological cross-reactivity identified the kinase activity as the alpha catalytic subunit of casein kinase II (CKII). Deletion mutants of IkappaBalpha delta1 to delta4) localized phosphorylation to the C-terminal PEST domain of IkappaBalpha. Point mutation of residues T-291, S-283, and T-299 dramatically reduced phosphorylation of IkappaBalpha by the kinase in vitro. NIH-3T3 cells that stably expressed wild-type IkappaBalpha (wtIkappaB), double-point-mutated IkappaBalpha (T291A, S283A), or triple-point-mutated IkappaBalpha (T291A, S283A, T299A) under the control of the tetracycline-responsive promoter were generated. Constitutive phosphorylation of the triple point mutant was eliminated in vivo, although tumor necrosis factor-inducible IkappaBalpha degradation was unaffected. In cell lines and in transiently transfected cells, mutation of the CKII sites in IkappaBalpha resulted in a protein with increased intrinsic stability. Together with results demonstrating a role for N-terminal sites in inducer-mediated phosphorylation and degradation of IkappaBalpha, these studies indicate that CKII sites in the C-terminal PEST domain are important for constitutive phosphorylation and intrinsic stability of IkappaBalpha.

scholarly journals Varicella-Zoster Virus Fc Receptor Component gI Is Phosphorylated on Its Endodomain by a Cyclin-Dependent Kinase

1999 ◽  
Vol 73 (2) ◽  
pp. 1320-1330 ◽  
Author(s):  
Ming Ye ◽  
Karen M. Duus ◽  
Junmin Peng ◽  
David H. Price ◽  
Charles Grose
Keyword(s):  
Fusion Protein ◽  
Varicella Zoster Virus ◽  
Phosphorylation Site ◽  
Cytoplasmic Tail ◽  
Casein Kinase Ii ◽  
Fc Receptor ◽  
Casein Kinase ◽  
Cyclin Dependent Kinase ◽  
Varicella Zoster

Varicella-zoster virus (VZV) glycoprotein gI is a type 1 transmembrane glycoprotein which is one component of the heterodimeric gE:gI Fc receptor complex. Like VZV gE, VZV gI was phosphorylated in both VZV-infected cells and gI-transfected cells. Preliminary studies demonstrated that a serine 343-proline 344 sequence located within the gI cytoplasmic tail was the most likely phosphorylation site. To determine which protein kinase catalyzed the gI phosphorylation event, we constructed a fusion protein, consisting of glutathione-S-transferase (GST) and the gI cytoplasmic tail, called GST-gI-wt. When this fusion protein was used as a substrate for gI phosphorylation in vitro, the results demonstrated that GST-gI-wt fusion protein was phosphorylated by a representative cyclin-dependent kinase (CDK) called P-TEFb, a homologue of CDK1 (cdc2). When serine 343 within the serine-proline phosphorylation site was replaced with an alanine residue, the level of phosphorylation of the gI fusion protein was greatly reduced. Subsequent experiments with individually immunoprecipitated mammalian CDKs revealed that the VZV gI fusion protein was phosphorylated best by CDK1, to a lesser degree by CDK2, and not at all by CDK6. Transient-transfection assays carried out in the presence of the specific CDK inhibitor roscovitine strongly supported the prior results by demonstrating a marked decrease in gI phosphorylation while gI protein expression was unaffected. Finally, the possibility that VZV gI contained a CDK phosphorylation site in its endodomain was of further interest because its partner, gE, contains a casein kinase II phosphorylation site in its endodomain; prior studies have established that CDK1 can phosphorylate casein kinase II.

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