The Localization Of Hsp3104 Protein In Schizosaccharomyces Pombe And Its Function Related To Oxidative Stress

Hsp3104 in Schizosaccharomyces pombe belongs to DJ-1/Thi J/Pfp I superfamily,which is mainly composed of low specific proteins in almost all prokaryotes and eukaryotes.DJ-1 in human is the most famous member of DJ-1 superfamily.It plays an important role in protecting human from cancer,cardiovascular disease and neurodegenerative disease.In Schizosaccharomyces pombe,trz2 encodes t RNase Z~L,which is involved in the processing of mitochondrial t RNAs 3'terminal.Knockout of Dnm1 in trz2overexpressing strain can save the cell from death.After analyzing the transcriptome data of trz2 overexpressing strains,we found that the transcription levels of genes related to oxidative stress were increased,including hsp3104.We speculate that hsp3104 has the function of resisting oxidative stress,but there are few studies on the gene function before.Therefore,we studied the function of hsp3104.First,we analyzed the protein sequence of hsp3104 and found that it has mitochondrial localization sequence.Western blot analysis showed that it is located in mitochondria.After that,we analyzed the effect of hsp3104 deletion on cell growth by spot assay,and found that hsp3104 deletion leads to heat stress,oxidative stress and cell growth and death in stationary phase.We found that the level of reactive oxygen species(ROS)increased in hsp3104 deletion strains.There are two ways to resist oxidative stress in vivo:high-level oxidative stress mediated by Sty1 and low-level oxidative stress mediated by Pap1.Gpx1 and Atf1 belong to Sty1 mediated pathway.We found that the expression of Gpx1 and Atf1 protein had no change compared with the wild type.Interestingly,we found that the localization of Pap1,a transcription factor in response to low-level oxidative stress,was transferred from the cytoplasm to the nucleus in the hsp3104 deletion strain,which indicated that?hsp3104 causes low-level oxidative stress pathway in the stationary phase of cells and activates Pap1pathway rather than Sty1 mediated high-level oxidative stress pathway.Oxidative stress is closely related to mitochondrial function.In order to explore the functional relationship between hsp3104 and mitochondria,we observed the mitochondrial morphology of?hsp3104 and found that it is similar to the wild type.By detecting the mitochondrial protein expression of?hsp3104,we found that the deletion of hsp3104 affectes the expression of Cox2 in the log phase of cell growth.However,the deletion of hsp3104 at the stationary phase leads to the increase of mitochondrial protein expression.We speculated that the ROS level of cells at the stationary phase was increased due to the lack of nutrition,and hsp3104 may have the function of scavenging ROS,so that the wild-type cells can grow normally;A part of ROS in hsp3104 deletion strains could not be cleared,which led to low level of oxidative stress.Mitochondria may increase its mass and induce fusion to induce compensatory reaction conducive to cell survival,which leads to the increase of the expression of mitochondrial genome protein.This project provides new ideas for understanding the pathogenesis of diseases related to DJ-1 superfamily proteins and mitochondria,and for finding new strategies for disease prevention and treatment.