Kinase activity of Lyn.

CD34⁺ cells stimulated with EPO for 4 days were incubated with or without the addition of NU-L_PAN for a further 18 hours. Incubated cells were stimulated with 5 U/mL EPO for 0, 5, and 15 minutes, after which Lyn proteins were immunoprecipitated. Lyn (A) was detected using anti-Lyn antibody. The relative activity of Lyn was calculated from the radioactivity count of [³²P] incorporated into phosphorylated Raytide EL, the tyrosine kinase substrate (B). A result representative of 5 separate experiments is presented.