Detection of Lis1 Gene Frame Shift Mutation in Human Hepatocarcinoma

GST fusion protein expression system combined with protein truncation test(PTT) protocol was used to detect gene frame shift mutation. The RT-PCR products of Lis1 genes from hepatocarcinoma samples were respectively cloned into a GST fusion protein expression vector pGEX-1, then expressed in E.coli. The results showed a truncated 33 kD fusion protein in SDS-PAGE, although the full-translated product of Lis1 gene should be of 71 kD. Sequencing revealed insertion of an A residue, causing the premature termination of translation, between the 163th and 164th nucleotide of Lis1 gene. This improved PTT assay was proved to be a fast and effective way in detecting gene frame shift mutation.