pubmed:abstractText |
We have expressed the catalytic domain of Chinese hamster HMG-CoA reductase, and 13 point mutations involving the region around the single phosphorylation site for AMP-activated protein kinase. After phosphorylation, these were used to test the specificity of isoforms of protein phosphatase-2A [bovine PP2A(C) (catalytic subunit) and PP2A1 (ABC heterotrimer)] and protein phosphatase-2C (human alpha; mouse alpha, beta1, beta2, beta3, beta4, beta5). PP2A1 had > 50-fold higher activity for HMG-CoA reductase variants than PP2A(C), but their relative selectivity for different variants was similar. Although the specificities of PP2A and PP2C were distinct, no dramatic differences in selectivity were observed between different PP2C isoforms.
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