Figure 2.

Nuclei from Murine erythroleukaemia cells (MEL) were isolated and incubated in the presence of ³²Pγ-ATP for 5 minutes. The lipids were extracted and separated by thin layer chromatography. The control lane is nuclei from control murine erthroleukaemia (MEL) cells, while the treated lane shows nuclei isolated after differentiation of MEL cells into erythroblasts. Labelled PtdOH suggests that a nuclear DAG kinase has access to a pool of DAG, labelled PtdIns4P suggests that a nuclear PI-4-Kinase accesses a pool of PtdIns and labelled PtdIns(4,5)P₂ suggests that a nuclear PIPK can access a pool of PtdIns4P. Note the increase in the labelling of nuclear PtdIns(4,5)P₂. The right panel explains how label from ³²Pγ-ATP is incorporated into the various lipids and defines substrates and enzymes.