Csde1 is required for proliferation and differentiation of I/11 erythroblasts. (A) Protein levels of Csde1 in I/11 erythroblasts 3 days after transduction with Sc shRNA lentivirus and 2 distinct shRNA lentiviruses complementary to Csde1. (B) Cumulative cell numbers of I/11 erythroblast cultures after transduction with control shRNA (▴) and shRNA against Csde1 (A ▩ and B ■). Numbers are calculated from 3 independent experiments. (C) I/11 erythroblasts were transduced with lentiviral shRNA as indicated. Cells were cultured for 3 days in proliferation conditions (top panels), followed by 4 days in differentiation conditions (bottom panels) before being harvested for cytospins and stained for hemoglobin (brown color) and histological dyes. Bars represent 25 μm. (D) Western blots containing lysates from parental MEL-birA cells and cells expressing bio-tagged Csde1 were stained for Csde1 (red). The tagged band runs above the endogenous protein (left image) and was stained with fluorophore-conjugated streptavidin, indicating biotinylation (yellow-green band, right image). (E) The enrichment of Apaf-1, Bag1, and Csde1 in RNA isolated from Csde1 pull-downs with streptavidin beads from MEL cells expressing biotagged-Csde11 compared with pull-downs from parental MEL cells (set at 1; n = 4). (F) Real-time PCR on total RNA used as input in RNA-IP (n = 4).