Insulin stimulation of nucleoside triphosphatase activity in isolated nuclear envelopes

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Science  28 May 1982:
Vol. 216, Issue 4549, pp. 1005-1007
DOI: 10.1126/science.6281885


The activity of nucleoside triphosphatase, an enzyme that regulates nuclear messenger RNA transport, was measured in highly purified nuclear envelopes isolated from rat liver. Addition of picomolar concentrations of insulin to freshly prepared nuclear envelopes directly increased the enzyme activity. The major effect of insulin on this enzyme was to increase the maximum velocity of its activity; no significant effects were seen on the affinity constant. These studies raise the possibility, therefore, that the nuclear envelope is a site where insulin regulates nuclear functions.