Expression of furin in differentiating megakaryocytic cells.

Megakaryoblastic Dami cells were cultured with 100 nM PMA for various time periods as indicated. (A) Kinetics of fur mRNA accumulation. Total mRNA (5 μg/lane) was probed with rat riboprobe specific for furin or 18S. The autoradiogram and the densitometry ratio of furin/18S (control set at 1) is represented. (B) Western blot analysis of GATA-1 and FOG-1 in differentiated Dami cells. Cell lysates were separated on 10% sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE) gels and transferred to nitrocellulose membranes. Immunoblotting of GATA-1 and FOG-1 were performed using GATA-1(1/500) or FOG-1 (1/1000)–specific antibodies. Equal loading was confirmed using an antibody against actin (1/200). (C) Fur expression in megakaryocytic cells. Total mRNA was extracted from unstimulated murine and human hematopoietic cell lines and from HL-60 and K562 cells cultured with 100 nM PMA for 3 days; mRNA was probed with rat riboprobe specific for furin or 18S.