Rac2 is activated in response to fMLP in neutrophils from healthy volunteers and MDS patients.

Neutrophils were stimulated with 0.1 μM fMLP for the indicated time. Stimulation was stopped by the addition of 3 × lysis buffer. Activated Rac2 was precipitated using GST-PAKcrib protein precoupled to glutathione-Sepharose beads. Proteins were separated by 15% SDS-PAGE and membranes were probed with Rac antibodies, followed by enhanced chemiluminescence. Rac activation was investigated in neutrophils from 8 MDS patients and 8 healthy controls. (A) Two representative blots from healthy subjects. (B) Three representative blots from MDS patients. Equal amounts of glutathione-Sepharose beads were loaded in all samples, as determined by Ponceau S staining of the membranes (not shown).