The effect of microcystin-LR, an inhibitor of protein phosphatases PP1 and PP2A, was studied on protein synthesis by measuring the incorporation of labelled amino acid into protein in isolated rat hepatocytes. Microcystin-LR inhibited protein synthesis in the first minutes of the incubation period, and half-maximum effect was obtained at about 60 nM. Such an inhibition was also observed in the presence of different protein phosphatase inhibitors, i.e. okadaic acid, calyculin A and microcystin-RR. This effect was observed in whole hepatocytes, in the supernatant of the post-mitochondrial fraction and in the microsomal fraction. It was independent of a substrate supply and of the labelled amino acid used. Furthermore, this inhibition preceded the previously reported glucose-6-phosphatase activation induced by microcystin-LR [Claeyssens, Chédeville and Lavoinne (1993) FEBS Lett. 315, 7-10].
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Research Article| March 15 1995
Microcystin-LR induced an inhibition of protein synthesis in isolated rat hepatocytes
Biochem J (1995) 306 (3): 693–696.
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S Claeyssens, A Francois, A Chedeville, A Lavoinne; Microcystin-LR induced an inhibition of protein synthesis in isolated rat hepatocytes. Biochem J 15 March 1995; 306 (3): 693–696. doi: https://doi.org/10.1042/bj3060693
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