Restin, belonging to the
melanoma-associated
antigen superfamily, was firstly cloned from the differentiated HL-60 cells when induced by
all-trans retinoic acid (ATRA) in our lab. Our previous results showed that
restin might be correlated to cell cycle arrest. Due to the importance of p53 in the regulation of cell growth and the relationship between p53 and ATRA, we tried to test the relationship between p53 and
restin. Firstly, transfection results showed that p53 was able to upregulate the expression of
restin at the transcriptional level when p53 was transfected into eukaryotic cells. Secondly, the bioinformatics analysis revealed that the upstream sequence (about 2 kb) from the first ATG of the ORF of
restin gene contained a p53 binding site. In order to confirm that p53 was involved in the transcriptional regulation of
restin, we cloned the upstream sequence of
restin and constructed the promoter
luciferase reporter system. From the
luciferase activity, we demonstrated that the promoter of
restin gene could be induced by ATRA. Then, another two
luciferase reporter plasmids driven by the reporter of
restin with no (RPdelta p53-luc) or mutant (mRP-luc) p53 binding site were constructed to see the regulation of
restin by p53. Results showed that the transcriptional upregulation of
restin gene was not due to the putative p53 binding site on the upstream of
restin gene. We proposed that p53 upregulated
restin transcription through an indirect way rather than direct interaction with the cis-activating
element of the
restin promoter.