دورية
Mechanism of Inhibition of Protein Phosphatase 1 by DARPP-32: Studies with Recombinant DARPP-32 and Synthetic Peptides
| العنوان: | Mechanism of Inhibition of Protein Phosphatase 1 by DARPP-32: Studies with Recombinant DARPP-32 and Synthetic Peptides |
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| المؤلفون: | Desdouits, F., Cheetham, J.J., Huang, H.B., Kwon, Y.G., Silva, E.F.D.E., Denefle, P., Ehrlich, M.E., Nairn, A.C., Greengard, P., Girault, J.A. |
| المصدر: | Biochemical and Biophysical Research Communications; January 1995, Vol. 206 Issue: 2 p652-658, 7p |
| مستخلص: | The mechanism of inhibition of protein phosphatase-1 catalytic subunit (PP-1c) by recombinant DARPP-32 and synthetic peptides was studied. DARPP-32 was expressed in Escherichia colias a non-fusion protein using a pEt-3a plasmid, purified to homogeneity and shown to have physicochemical properties similar to those of the protein purified from bovine brain. Recombinant DARPP-32 phosphorylated on threonine-34 by cAMP-dependent protein kinase inhibited PP-1c with an IC50≍ 0.5 nM, comparable to that obtained with bovine DARPP-32. Non-phosphorylated DARPP-32, and mutated forms in which threonine-34 was replaced by an alanine or a glutamic acid, inhibited PP-1c with an IC50≍ 1 μM. Surface plasmon resonance analysis showed binding of PP-1c to nonphospho- and phospho-DARPP-32-(8-38) synthetic peptides with apparent Kdvalues of 1.2 and 0.3 μM,respectively, supporting the existence of an interaction between non-phosphorylated DARPP-32 and PP-1c that is increased by phosphorylation of DARPP-32 at threonine-34. These results suggest a model in which DARPP-32 interacts with PP-1c by at least two low affinity sites, the combination of which is responsible for the high affinity (nM) inhibition. |
| قاعدة البيانات: | Supplemental Index |
Full Text Finder | تدمد: | 0006291X 10902104 |
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| DOI: | 10.1006/bbrc.1995.1092 |