Meggio F, Negro A, Sarno S, Ruzzene M, Bertoli A, Sorgato M C, Pinna L A
Dipartimento di Chimica Biologica, Università di Padova, Viale G. Colombo 3, 35121 Padova, Italy.
Biochem J. 2000 Nov 15;352 Pt 1(Pt 1):191-6.
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.
基于远缘杂交印迹法和表面等离子体共振（BIAcore）实验，我们在此表明重组牛朊蛋白（bPrP）（25 - 242）与蛋白激酶CK2（也称为“酪蛋白激酶2”）的催化α/α'亚基强烈相互作用。这种结合导致以钙调蛋白或特定肽为底物时，CK2α的磷酸转移酶活性增加。我们还表明，bPrP可对抗CK2调节性β亚基对钙调蛋白磷酸化的抑制作用。包含C末端结构域（第105 - 242位氨基酸残基）的bPrP截短形式与CK2相互作用，但不影响其催化活性。bPrP的N末端片段（第25 - 116位氨基酸残基）则相反，尽管其对催化作用的刺激效率低于全长bPrP。这些结果揭示了朊蛋白调节CK2活性的潜力，CK2是一种在大脑中特别丰富的多效性蛋白激酶。
