Figure 5.

CKII activity on lipin 1β depends on the reaction time and the amounts of CKII, lipin 1β, and ATP. Lipin 1β was incubated with CKII and [γ-³²P]ATP at 30 °C, and its phosphorylation was monitored by following the incorporation of the radioactive phosphate into the protein. The reaction mixtures were spotted onto nitrocellulose papers, which were washed with 75 mm phosphoric acid and subjected to scintillation counting. The CKII reaction was conducted by varying the amount of CKII (A), the reaction time (B), the amount of lipin 1β (C), and the concentration of ATP (D). A, B, and C, 50 μm ATP; A, C, and D, 15 min; A, B, and D, 0.1 μg of lipin 1β; B, C, and D, 0.2 μg of CKII. The data shown are means ± S.D. (error bars) from triplicate assays.