Bovine prion protein as a modulator of protein kinase CK2.
On the basis of far-Western blot and plasmon resonance (BIAcore) experiments, we show here that recombinant bovine prion protein (bPrP) (25-242) strongly interacts with the catalytic alpha/alpha' subunits of protein kinase CK2 (also termed 'casein kinase 2'). This association leads to increased phosphotransferase activity of CK2alpha, tested on calmodulin or specific peptides as substrate. We also show that bPrP counteracts the inhibition of calmodulin phosphorylation promoted by the regulatory beta subunits of CK2. A truncated form of bPrP encompassing the C-terminal domain (residues 105-242) interacts with CK2 but does not affect its catalytic activity. The opposite is found with the N-terminal fragment of bPrP (residues 25-116), although the stimulation of catalysis is less efficient than with full-size bPrP. These results disclose the potential of the PrP to modulate the activity of CK2, a pleiotropic protein kinase that is particularly abundant in the brain.
Meggio
F
F
Dipartimento di Chimica Biologica, Università di Padova, Viale G. Colombo 3, 35121 Padova, Italy.
Negro
A
A
Sarno
S
S
Ruzzene
M
M
Bertoli
A
A
Sorgato
M C
MC
Pinna
L A
LA
D000818:Animals; D015153:Blotting, Western; D002147:Calmodulin / Q000378:metabolism; D047390:Casein Kinase II; D020134:Catalytic Domain; D002417:Cattle; D004305:Dose-Response Relationship, Drug; D004926:Escherichia coli / Q000378:metabolism; D006801:Humans; D010455:Peptides / Q000378:metabolism; D010766:Phosphorylation; D011328:Prions / Q000737:chemistry* / Q000378:metabolism; D011485:Protein Binding; D020033:Protein Isoforms; D017346:Protein Serine-Threonine Kinases / Q000737:chemistry* / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D020349:Surface Plasmon Resonance; D013696:Temperature; D013997:Time Factors
D002147:Calmodulin; D010455:Peptides; D011328:Prions; D020033:Protein Isoforms; D011994:Recombinant Proteins; D047390:Casein Kinase II; D017346:Protein Serine-Threonine Kinases