Figure 2.

RNA stimulation of C1 hnRNP protein phosphorylation does not require prior micrococcal nuclease treatment of the nuclear extract. C1 hnRNP protein was incubated with [γ-³²P]ATP as in Fig. 1, except that the HeLa nuclear extract was not pretreated with micrococcal nuclease. Lanes: 1, control (no other additions); 2, 1 μM okadaic acid; and 3, 150 μg/ml nuclear extract RNA (no okadaic acid).