Phosphorylation of Xenopus transcription factor IIIA by an oocyte protein kinase CK2

2002 ◽  
Vol 362 (2) ◽  
pp. 375-382 ◽  
Author(s):  
Cara J. WESTMARK ◽  
Romi GHOSE ◽  
Paul W. HUBER

Transcription factor IIIA (TFIIIA), isolated from the cytoplasmic 7S ribonucleoprotein complex of Xenopus oocytes, is phosphorylated when incubated with [γ-32P]ATP. This modification is due to a trace kinase activity that remains associated with the factor through several steps of purification. The kinase can use either ATP or GTP, and will phosphorylate casein and phosvitin to the exclusion of TFIIIA. The kinase is reactive with a ten-amino-acid peptide that is a specific substrate for protein kinase CK2 (CK2; formerly casein kinase II). In addition, inhibition of phosphorylation by heparin and stimulation by spermidine indicate that the activity can be ascribed to CK2. Phospho amino acid analysis established that serine is the sole phosphoryl acceptor in TFIIIA. There are four consensus sites for CK2 in TFIIIA; all contain serine residues at the putative site of phosphorylation. TFIIIA immunoprecipitated from oocytes, which were incubated with [32P]orthophosphate, is also phosphorylated exclusively on serine residues. Only the cyanogen bromide fragment, which was derived from the N-terminal end of TFIIIA, is labelled in vivo. A recognition sequence for CK2, located at Ser16 in the β-turn of the first zinc-finger domain, is the only protein kinase consensus sequence present in this peptide. Assays in vitro with site-specific mutants of TFIIIA established that Ser16 is the preferred site of phosphorylation, with some secondary modification at Ser314.

2003 ◽  
Vol 84 (2) ◽  
pp. 497-505 ◽  
Author(s):  
Yasuhiko Matsushita ◽  
Mayumi Ohshima ◽  
Kuniaki Yoshioka ◽  
Masamichi Nishiguchi ◽  
Hiroshi Nyunoya

2008 ◽  
Vol 312 (1-2) ◽  
pp. 61-69 ◽  
Author(s):  
Maciej Masłyk ◽  
Elżbieta Kochanowicz ◽  
Rafał Zieliński ◽  
Konrad Kubiński ◽  
Ulf Hellman ◽  
...  

2017 ◽  
Vol 72 (11-12) ◽  
pp. 459-465 ◽  
Author(s):  
Beatriz E. Boscán ◽  
Graciela L. Uzcanga ◽  
Maritza Calabokis ◽  
Rocío Camargo ◽  
Frank Aponte ◽  
...  

AbstractA polypeptide band with an apparent molecular weight of 55,000 was phosphorylated in vitro in whole-cell lysates ofTrypanosoma equiperdum. This band corresponds to tubulin as demonstrated by immunoprecipitation of the phosphorylated polypeptide fromT. equiperdumextracts when anti-α and anti-β tubulin monoclonal antibodies were employed. A parasite protein kinase CK2 was in charge of modifying tubulin given that common mammalian CK2 inhibitors such as emodin and GTP, hindered the phosphorylation of tubulin and exogenously added casein. Interestingly, a divalent cation-dependent translocation of theT. equiperdumtubulin and the CK2 responsible for its phosphorylation was noticed, suggesting a direct interaction between these two proteins. Additionally, this fraction of tubulin and its kinase coeluted using separations based on parameters as different as charge (DEAE-Sepharose anion-exchange chromatography) and size (Sephacryl S-300 gel filtration chromatography). Analyses by non-denaturing polyacrylamide gel electrophoresis and immunoblot of the purified and radioactively labeled fraction containing both tubulin and the CK2 enzyme, established the phosphorylation of a single band that was recognized by anti-CK2 α-subunit and anti-tubulin antibodies. All these findings revealed a physical association between a pool of tubulin and a CK2 inT. equiperdum.


2002 ◽  
Vol 364 (1) ◽  
pp. 41-47 ◽  
Author(s):  
Maria RUZZENE ◽  
Daniele PENZO ◽  
Lorenzo A. PINNA

Incubation of Jurkat cells with 4,5,6,7-tetrabromobenzotriazole (TBB), a specific inhibitor of protein kinase CK2, induces dose-and time-dependent apoptosis as judged by several criteria. TBB-promoted apoptosis is preceded by inhibition of Ser/Thr phosphorylation of haematopoietic lineage cell-specific protein 1 (HS1) and is accompanied by caspase-dependent fragmentation of the same protein. Both effects are also observable if apoptosis is promoted by anti-Fas antibodies and by etoposide. Moreover, in vitro experiments show that HS1, once phosphorylated by CK2, becomes refractory to cleavage by caspase-3. These findings, in conjunction with similar data in the literature concerning two other CK2 protein substrates, Bid and Max, suggest that CK2 may play a general anti-apoptotic role through the generation of phosphorylated sites conferring resistance to caspase cleavage.


2001 ◽  
Vol 82 (11) ◽  
pp. 2767-2776 ◽  
Author(s):  
Chaysavanh Manichanh ◽  
Camille Olivier-Aubron ◽  
Jean-Pierre Lagarde ◽  
Jean-Thierry Aubin ◽  
Phillipe Bossi ◽  
...  

After serial passage in the presence of increasing concentrations of ganciclovir (GCV) in vitro, a human herpesvirus-6 (HHV-6) mutant exhibiting a decreased sensitivity to the drug was isolated. Analysis of drug susceptibility showed that the IC50 of this mutant was 24-, 52- and 3-fold higher than that of the wild-type (wt) IC50 in the case of GCV, cidofovir and foscarnet, respectively. Genotypic analysis showed two single nucleotide changes as compared to the wild-type: an A→G substitution of the U69 protein kinase (PK) gene resulted in an M318V amino acid substitution and the other change, located in the C-terminal part of the U38 gene, resulted in an A961V amino acid substitution within the DNA polymerase. The M318V change was located within the consensus sequence DISPMN of the putative catalytic domain VI of the PK. This change was homologous to the M460V and M460I changes that had been reported previously within the consensus sequence DITPMN of the human cytomegalovirus (HCMV) UL97 PK and associated with the resistance of HCMV to GCV. The M318V change was also detected by PCR in HHV-6-infected PBMCs from an AIDS patient who had been treated with GCV for a long period of time and exhibited a clinically GCV-resistant HCMV infection. These findings provide strong circumstantial evidence that the M318V change of the PK gene is associated with resistance to GCV and raise the question of cross resistance to this drug among different betaherpesviruses.


2019 ◽  
Vol 20 (23) ◽  
pp. 5951 ◽  
Author(s):  
Antonella Lettieri ◽  
Christian Borgo ◽  
Luca Zanieri ◽  
Claudio D’Amore ◽  
Roberto Oleari ◽  
...  

Protein kinase CK2 (CK2) is a highly conserved and ubiquitous kinase is involved in crucial biological processes, including proliferation, migration, and differentiation. CK2 holoenzyme is a tetramer composed by two catalytically active (α/α’) and two regulatory (β) subunits and exerts its function on a broad range of targets. In the brain, it regulates different steps of neurodevelopment, such as neural differentiation, neuritogenesis, and synaptic plasticity. Interestingly, CK2 mutations have been recently linked to neurodevelopmental disorders; however, the functional requirements of the individual CK2 subunits in neurodevelopment have not been yet investigated. Here, we disclose the role of CK2 on the migration and adhesion properties of GN11 cells, an established model of mouse immortalized neurons, by different in vitro experimental approaches. Specifically, the cellular requirement of this kinase has been assessed pharmacologically and genetically by exploiting CK2 inhibitors and by generating subunit-specific CK2 knockout GN11 cells (with a CRISPR/Cas9-based approach). We show that CK2α’ subunit has a primary role in increasing cell adhesion and reducing migration properties of GN11 cells by activating the Akt-GSK3β axis, whereas CK2α subunit is dispensable. Further, the knockout of the CK2β regulatory subunits counteracts cell migration, inducing dramatic alterations in the cytoskeleton not observed in CK2α’ knockout cells. Collectively taken, our data support the view that the individual subunits of CK2 play different roles in cell migration and adhesion properties of GN11 cells, supporting independent roles of the different subunits in these processes.


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