Changes in tyrosine phosphorylation are discernible following stimulation with FK1012 but not rapamycin.

Western blot analysis of whole-cell lysates from Ba/F3 cells coexpressing c-Kit^3FKBP12 and Flt-3^3FRB and stimulated with either FK1012 (left) or rapamycin (right). Lysates from COS cells expressing either fusion (COS c-Kit^3FKBP12 and COS Flt-3^3FRB) have been included for size comparisons. Top panels show antiphosphotyrosine antibody labeling (4G10; Upstate Biotechnology, Lake Placid, NY) at various times in response to either FK1012 (100 nM) or rapamycin (100 nM). Bottom panels show the same blots after being stripped and reprobed with the anti-HA.11 antibody (Berkeley Antibody Company, Berkeley, CA) to show equivalent loading.