Regulation Of P73 On The Sirtuin Family Of Transcription And Protein Expression

Sirtuins or Sir2 (silent information regulator 2)-related enzymes have been defined as a family of nicotinamide-adenine dinucleotide(NAD+-dependent histone deacetylase, which may link the metabolic rate of cells to aging and oxidative stress. Numerous studies confirm that Sirtuins has played an important role in gene silencing, DNA damage and repair, mitosis regulation and anti-apoptosis.p73,a member of the p53 family of transcription factors, which is very familiar with tumor suppressor P53.Including the regulation of downstream target genes, apoptosis, cell cycle arrest and so on. Meanwhile the p73 deficient mouse is so different, it doesn't form spontaneous tumors, but it has some developmental defects. It suggests that p73 may play a role in the development of nervous and immune systems.There are some isoforms, we focus on p73α,p73β.In this paper, to analyze the effection of p73 at the transcriptional level of Sirtuin family members, we use the dual luciferase reporter system.We construct a serie of fragments of Sirtuin family and fused to a luciferase reporter gene,which is expressed in 293T cells.We found that p73α,β, two major isoforms of p73,could activate the promoter of Sirtuins.To further prove this conclution, through the reverse transcriptase PCR(RT-PCR), we cloned the sequence of human Sirtuins.We found p73α,βactivate Sirtuins'transcription, upregulate the mRNA level.Not as we expected, through the western blot,we found that p73α,βcouldn't upregulate the protein expression in 293T cells.As the endogenous expression of p73 is too low to detect, I construct the fusion plasmid of pGEX-4T1-P73a, purified in vitro, get the homemade p73 antibody. At the same time, I made three RNAi plasmid of p73,to detect whether inhibition of endogenouse p73 could effect the transcription and translation of Sirtuins. This article provides some clues for the research about the relation of p73 and Sirtuins.