Fig. 8

Functional activity of caspase-X. a A schematic diagram of constructs. FLAG/CaspX and FLAG/CaspXΔN are FLAG-tagged molecules consisting of intact or truncated caspase-X. b Cytotoxicity assays of human HeLa cells expressing caspase-X and its truncated forms. Plasmid constructs encoding FLAG/CaspX or FLAG/CaspXΔN and the pCAG-mCherry plasmid were co-transfected into HeLa cells in the presence or absence of baculovirus p35, which is a pan-caspase inhibitor. After 2 days of growth, cultures were washed to remove floating cells, and then fixed; viability was determined by monitoring mCherry-positive cells. Both phase-contrast and red fluorescence images were captured for each field under the microscope. Scale bars represent 100 μm. c A summary of cytotoxicity assays on caspase-X. After cultivation, transfected cells were harvested and lysed in the lysis buffer for the preparation of cell extracts. Fluorescence absorbance of mCherry in each cell extract was measured and viability of transfected cells was indicated by fluorescent intensity. The number in parentheses indicates the ratio of the plasmid mixture. Data are presented as the means and standard deviations of samples counted from four independent experiments (i.e. biological replicates), and are expressed relative to the empty vector (Vector 1 + Vector 2 + mCherry) value. An asterisk indicates p < 0.05 (Student’s t-test)