Copolymers of glutamic acid and tyrosine are potent inhibitors of oocyte casein kinase II

Téllez, Rowena; Gatica, Marta; Allende, Catherine C.; Allende, Jorge E.

doi:10.1016/0014-5793(90)80897-r

Cited by 15 publications

(14 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Indeed, the presence of poly(Glu,Tyr) can increase the efficiency of renaturation and/or stimulate the activity of Ser/Thr kinases, such as PK210 and PK40. On the other hand, as observed in the present study for PK94 and PK38, and in agreement with other reports [16,17], poly(Glu,Tyr) may also inhibit some Ser/Thr kinases. As seen for PK210, PK60 and PK52, and as previously reported [8,9], the relatively high stability of pThr residues in hot alkaline conditions also indicate that phosphoamino acid analysis should be performed on hydrolysates from protein kinases detected by renaturation in the presence of poly(Glu,Tyr).…”

Section: Resultssupporting

confidence: 94%

Identification of cytosolic protein tyrosine kinases of human prostate by renaturation after SDS/PAGE

Durocher

Chapdelaine

Chevalier

1992

Biochemical Journal

View full text Add to dashboard Cite

The identification of protein tyrosine kinases (PTKs) was successfully achieved by renaturation in gels after SDS/PAGE. To this effect, samples were mixed with a PTK substrate, namely the polydispersed co-polymer of glutamic acid and tyrosine [poly(Glu,Tyr), Mr from 30000 to 94000], and were simultaneously submitted to electrophoresis. Following guanidine hydrochloride denaturation, renaturation and phosphorylation with [y-32P]ATP, kinase activity was detected by autoradiography. When applied to cytosol from human hyperplastic prostate, eleven protein kinases were detected, among which one major (Mr 50000) and two minor proteins (Mr 40000 and 38000) were identified as PTKs by the presence of phosphotyrosine. Incubation of the gel in hot alkali after glutaraldehyde cross-linking almost completely eliminated the detection of non-PTK enzymes. On the other hand, in the absence of poly(Glu,Tyr), no PTK activity was detected. Partial purification of cytosolic PTKs indicates that the native Mr of the major phosphotransferase was 44000, as estimated by gel filtration following ammonium sulphate precipitation and anion-exchange chromatography. Upon renaturation after electrophoresis, this fraction showed only one major band active on poly(Glu,Tyr) which was associated with the polypeptide of Mr 50000. This enzyme was also identified following two-dimensional electrophoresis and renaturation in the presence of poly(Glu,Tyr), allowing the determination of a pl in the range 7.5-7.8. Thus PTKs can be easily renatured following electrophoresis and rapidly identified on the basis of their Mr and pl in both crude or partially purified preparations. With the crucial role played by PTKs in the activation of cell function and carcinogenesis, this procedure could be useful in the identification of such enzymes and in distinguishing them from their substrates in gels.

show abstract

Section: Resultssupporting

confidence: 94%

Identification of cytosolic protein tyrosine kinases of human prostate by renaturation after SDS/PAGE

Durocher

Chapdelaine

Chevalier

1992

Biochemical Journal

View full text Add to dashboard Cite

show abstract

“…Active HsCK2␣ is present in erythrocytes (53); this raises the question of selectivity of antimalarial inhibitors based on PfCK2␣ inhibition. We demonstrated that a small molecule inhibitor, Rottlerin, has a much lower IC 50 for PfCK2␣ than for HsCK2␣. Although we have identified in Rottlerin a compound that can distinguish between the human and plasmodial CK2␣ enzymes, it is unlikely to represent a suitable starting point for antimalarial drug discovery, since Rottlerin has multiple targets (41) and is too weak and nonspecific an inhibitor even to be used in cellular assays (5).…”

Section: Discussionmentioning

confidence: 91%

“…One hypothesis for the function of this extension is the downregulation of the alpha subunit. Polyglutamate is a potent CK2 inhibitor (50), and the N-terminal extension of PfCK2␤2 is rich in polyglutamate and polyaspartate. This beta subunit also possesses an insertion of extra acidic residues (including a stretch of 11 consecutive aspartates) (Fig.…”

Section: Discussionmentioning

confidence: 99%

Functional Analysis of Protein Kinase CK2 of the Human Malaria Parasite Plasmodium falciparum

et al. 2009

View full text Add to dashboard Cite

Protein kinase CK2 (casein kinase 2) is a eukaryotic serine/threonine protein kinase with multiple substrates and roles in diverse cellular processes, including differentiation, proliferation, and translation. The mammalian holoenzyme consists of two catalytic alpha or alpha subunits and two regulatory beta subunits. We report the identification and characterization of a Plasmodium falciparum CK2␣ orthologue, PfCK2␣, and two PfCK2␤ orthologues, PfCK2␤1 and PfCK2␤2. Recombinant PfCK2␣ possesses protein kinase activity, exhibits similar substrate and cosubstrate preferences to those of CK2␣ subunits from other organisms, and interacts with both of the PfCK2␤ subunits in vitro. Gene disruption experiments show that the presence of PfCK2␣ is crucial to asexual blood stage parasites and thereby validate the enzyme as a possible drug target. PfCK2␣ is amenable to inhibitor screening, and we report differential susceptibility between the human and P. falciparum CK2␣ enzymes to a small molecule inhibitor. Taken together, our data identify PfCK2␣ as a potential target for antimalarial chemotherapeutic intervention.

show abstract

“…The finding that CKII can use Mn2' and Co*+ is particularly interesting because it indicates that this enzyme is similar to tyrosine protein kinases that are known to be able to use these two divalent ions [20,21]. Previously, work from Pinna's laboratory and from our own [22,23] had demonstrated that CKII is able to recognize the presence of tyrosyl residues within acidic peptides. Recently a novel group of ambivalent protein kinases that can phosphorylate both serine/threonine and tyrosine residues have been described [24].…”

Section: Discussionmentioning

confidence: 96%

Effect of metal ions on the activity of cascein kinase II from Xenopus laevis

et al. 1993

Self Cite

View full text Add to dashboard Cite

CaSein kinase II purified from the nuclei of Xenopus laevis oocytes as well as the recombinant α and β subunits of the X. laevis CKII, produced in E. coli from the cloned cDNA genes, were tested with different divalent metal ions. The enzyme from both sources was active with either Mg2+, Mn2+, or Co2+. Optimal concentrations were 7–10 mM for Mg2+, 0.5–0.7 mM for Mn2+ and 1–2 mM for Co2+. In the presence of Mn2+ or Co2+ the enzyme used GTP more efficiently than ATP as a phosphate donor while the reverse was true in the presence ofMg2+. The apparent K m values for both nucleotide triphosphates were greatly decreased in the presence of Mn2+ as compared with Mg2+. Addition of Zn2+ (above 150 μM) to an assay containing the optimal Mg2+ ion concentration caused strong inhibition of both holoenzyme and α subunit. Inhibition of the holoenzyme by 400 μM Ni2+ could be reversed by high concentrations of Mg2+ but no reversal of this inhibition was observed with the α subunit.

show abstract

Copolymers of glutamic acid and tyrosine are potent inhibitors of oocyte casein kinase II

Cited by 15 publications

References 21 publications

Identification of cytosolic protein tyrosine kinases of human prostate by renaturation after SDS/PAGE

Identification of cytosolic protein tyrosine kinases of human prostate by renaturation after SDS/PAGE

Functional Analysis of Protein Kinase CK2 of the Human Malaria Parasite Plasmodium falciparum

Effect of metal ions on the activity of cascein kinase II from Xenopus laevis

Contact Info

Product

Resources

About