Opposite patterns of expression of SRSF5 mature mRNA and protein during late erythroid differentiation.

A. Steady-state mRNA analysis. Cells were cultured in the absence (−) or presence (+) of DMSO for 4 days to trigger erythroid differentiation. SRSF5 and SRSF3 mRNAs were amplified using specific appropriate forward and reverse primers (see text). Mk: size markers.B. Real-time RT-PCR analysis of SRSF5 and SRSF3 mRNAs. Steady-state mRNA levels were normalized with respect to actin mRNA, used as internal control. Cells were cultured in the absence (untreated) or presence (DMSO) of DMSO for 4 days. Note that cell induction to erythroid differentiation led to a more than threefold increase of steady-state levels of SRSF5 mRNA, when compared with uninduced cells, whereas SRSF3 mRNA remained roughly unchanged. C. Immunoblot analysis of SRSF5 expression in MEL cells. Cells were left untreated (−), or treated (+) with 1.8% DMSO for 4 days. SRSF5 was revealed using either mAb104, an antibody that immunoreacts with all the prototypical SR proteins (left panel), or pAb-SRSF5, a specific anti-SRSF5 antibody (right panel). MEL cell induction using DMSO resulted in a decrease of SRSF5 protein signal.Actin and Grb2 were used as controls.