Figure 1.

A, Microsomal membranes prepared from G. sulphuraria at different times during the culture period were incubated for 10 min with [γ-³²P]ATP. Lipids were extracted under acidic conditions and separated by TLC in a basic solvent. Characteristic patterns of lipid phosphorylation are evident. After 5 to 7 d in culture, PA decreased and PIP₂ increased. The autoradiograph is from a representative experiment. The experiment was repeated four times with similar results. B, The in vitro phosphorylation products from the experiment shown in A were quantified with a Bioscan scanner. Vertical bars indicate the duplicate range. Counts at the origin were not included in the quantification.