But I've observed that, althought the transfection efficiency is low, the few cells expressing GFP alone (the empty vector) look well and show a intense cytoplasmic fluorescence, but virtuallly any cell is expressing the fusion protein.
When I electroporated the cells, the pattern of expression is the same (OK for empty GFP, none for fusion protein).
An idea is that I'm trying to express a protein that is toxic for the cells (is a kinase domain), but:
a) The level of expression and transfection efficiency of this fusion protein is wonderful in HEK and COS cells (not so good for CHO, with results resembling those of neuroblastoma)
c) When I treated SK-N-SH cells with retinoic acid (to differenciate these proliferating cells into neurons), results didn't changed.
What experiments should I perform to confirm that the fusion protein is toxic or what could be happening in the cells?













