Fig. 1. Phosphorylation of chicken erythroid ankyrin in vivo and in vitro. Ankyrin immunoprecipitates were prepared from the detergent-soluble (S) and -insoluble (I) fractions from erythroid cells labeled with ³²P-orthophosphate for 4 hours (lanes 1-4) or from unlabeled cells (lanes 5-8). Some of the cells used for these analyses were incubated in the presence of 100 nM calyculin A for 4 hours prior to detergent lysis (lanes 3, 4, 7, and 8). Immunoprecipitates from unlabeled cells were incubated in kinase buffer containing [-³²P]-ATP for 30 minutes at 37°C prior to gel analysis (lanes 5-8). Immune complexes were resolved on a 6% SDS polyacrylamide gel. Individual ankyrin isoforms were visualized by staining with GelCode Blue, and ³²P-labeled species were detected by autoradiography. Lane 8^* is a five-fold longer exposure of lane 8. The migrations of the 225 kDa, 220 kDa and 205 kDa ankyrin isoforms are indicated to the left of the figure. The migration of the hyperphosphorylated 225 kDa (225^*) and 205 kDa (205^*) isoforms are indicated to the right of the figure.

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