Fig. 1.
CD33 phosphorylation in myeloid cell lines is induced by phorbol esters.
U937 cells or HL-60 cells were labeled with [32P]-orthophosphate for 1 hour and then treated for 12 minutes with either PMA (18 nM), DMSO (1.5%), or control (0.001% DMSO) for 12 minutes. CD33 immunoprecipitates were isolated using My9, blotted onto nitrocellulose, and detected by fluorography.