Etoposide Induced Protein 2.4 (EI24)

EI24 has higher expression in p53-expressing cells than in control cells and is an immediate-early induction target of p53-mediated apoptosis. The protein encoded by this gene contains six putative transmembrane domains and may suppress cell growth by inducing apoptotic cell death through the caspase 9 and mitochondrial pathways. This gene is located on human chromosome 11q24, a region frequently altered in cancers. Alternative splicing results in two transcript variants encoding different isoforms.Western blot analysis indicated that ei24 expression is approximately 500-fold higher in dead cells than in healthy cells. Phase contrast and fluorescence microscopy showed that cells expressing Ei24 but not those coexpressing the apoptosis suppressor BCL2L1  displayed the typical morphologic features of apoptosis.