Zebrafish △ 113p53 is an N-terminal truncated p53 isoform which functions to antagonize p53 mediated apoptotic activity and △ 113p53 is a p53-resposne gene.Interestingly △ 113p53 does not act on p53 in a dominant-negative manner,but interferes with the p53 function by differentially modulating p53-target gene expression to protect cells from apoptosis.Previous studies showed that over-expressed △113p53 and p53 proteins formed a complex.However,it is not known whether endogenous p53 and △113p53 proteins also interact with each other and if this interaction is required for △113p53 to inhibit the apoptotic activity of the full-length p53.