ABSTRACT
We studied the effect of the Mycobacterium tuberculosis prokaryotic ubiquitin-like protein-proteasome system on mono-resistant to rifampin resistance to M.tuberculosis.A resazurin-based assay was employed to evaluate minimum inhibitory concentration (MIC) and comparative research on mono-resistant to rifampin MTB with Pup,Dop,PafA,Mpa genes expression and deletion of the difference.Above testing strains,respectively,carbonyl cyanide chlorobenzene hydrazone (CCCP),reserpine (RP),verapamil (VP)and chlorpromazine (CPZ) were tested.We compared and analyzed the change of rifampicin MICs on the various strains.Compared with rifampin resistant MTB,overexpression of Pup,Dop,PafA and Mpa genes were able to make monorifampicin of M.tuberculosis to enhance resistance to rifampin.Deletion of Pup gene,Mpa gene,Dop gene,PafA gene significantly decreased the resistance to rifampicin alone MTB,and the P value was ＜0.05.Results indicated that 4 kinds of efflux pump inhibitors can reduce the degree of rifampin MIC in different strains.Through the factorial analysis,there were some interactions between MTB and PPS efflux pump inhibitors,and the P value was ＜0.05.MTB PPS has influence on mono-rifampin resistance to MTB and it may regulate the efflux pathway related protein to influence its resistance.
ABSTRACT
Objective To study the effects of prokaryotic ubiquitin-like protein ( Pup)-proteasome system on the growth of Mycobacterium strains.Methods The genes encoding Pup ( pup gene) and protea-someβsubunit ( prcB gene) were respectively knocked out from Mycobacterium smegmatis ( M.sm) strains by homologous recombination.The growth and viability of the wild-type and mutant strains of M.sm were an-alyzed under normal culture condition and under hypoxia as well as anaerobic conditions.Results The pup and prcB genes were completely and precisely knocked out from M.sm strains and the mutant strains were named △SM-Pup and△SM-prcB, respectively.The△SM-Pup strains grew faster than the wild type ( WT) and△SM-prcB strains.No significantly differences in the growth of M.sm were found between the WT and△SM-prcB strains.Conclusion The Pup-proteasome system was involved in the growth of M.sm, espe-cially the pup gene.There was difference between pup and prcB genes in regulating the growth of M.sm.The functions and influences of Pup-proteasome system still need further investigation.
ABSTRACT
Objective:To explore the regulation of prokaryotic ubiquitin-like protein ( Pup )-proteasome system on the persistence of Mycobacterium tuberculosis by inducing Mycobacterium tuberculosis to being persistence state under hypoxia conditions and then analyzing the difference on the expression levels of Pup,Dop,PafA and Mpa gene at various time and different conditions. Methods:The total mRNA of the international standard virulent strains of Mycobacterium tuberculosis(H37Rv),which were cultured under hypoxia and aerobic conditions, were extracted from each group at various time and purity of the mRNA were identified.The expression of Pup,Dop,PafA and Mpa genes of M.tuberculosis strains in each group were quantified by SYBR Green I qRT-PCR,which aimed at finding the difference among the expression of Pup,Dop,PafA and Mpa genes at various time and different conditions.Results:The expression levels of Pup, Dop, PafA and Mpa genes in Mycobacterium tuberculosis under hypoxia conditions were measured at various times.The expression levels of Pup,Dop,PafA and Mpa genes:compared with the 0 d,the expression of the Pup gene was up-regulated 1.66,2.43 and 2.76-fold at 4 d,7 d,10 d respectively(P<0.05);the expression of the Dop gene was up-regulated 1.38, 1.91,2.54 and 3.28-fold at 2 d,4 d,7 d,10 d respectively(P<0.05);the expression of the PafA gene was up-regulated 1.22,1.75, 2.37 and 2.67-fold at 2 d,4 d,7 d,10 d respectively( P<0.05);the expression of the Mpa gene was up-regulated 1.66,2.21 and 2.63-fold at 4 d,7 d,10 d respectively(P<0.05).Take the aerobic conditions as control,under hypoxic conditions with the same culture time,the expression of the Pup gene was up-regulated 1.85,2.81 and 2.93-fold in 4 d,7 d,10 d respectively(P<0.05);the ex-pression of the Dop gene was up-regulated 1.20,1.76,2.01 and 3.01-fold in 2 d,4 d,7 d,10 d,respectively( P<0.05);the expression of the PafA gene was up-regulated 1.22,1.57,2.29 and 2.29-fold in 2 d,4 d,7 d,10 d,respectively(P<0.05);the expression of the Mpa gene was up-regulated 1.16,1.58,2.16 and 2.69-fold in 2 d,4 d,7 d,10 d,respectively(P<0.05).Conclusion:Under hypoxic conditions,there were significant differences on the expressions of Pup, Dop, PafA and Mpa genes at various times;what′s more, significant differences on the expressions of Pup,Dop,PafA and Mpa genes exist between hypoxic and aerobic conditions at the same time,Prokaryotic ubiquitin-like protein( Pup)-proteasome system plays a regulatory role on M.tuberculosis′s persistence.
ABSTRACT
Proteasome pathway is another major pathway of protein degradation in addition to lysosome in eukaryotic cell ,which involved a number of physiological functions regulation in cell .Prokaryotic ubiquitin-like protein was found in My-cobacterium tuberculosis in 2008 .With the effect of co-factor Dop ,PafA and Mpa ,Pup can mark a variety of protein ubiquitina-tion followed by importing them into proteasomal degradation .The target protein of Pup-proteasome system like FabD ,PanB , Ino1 ,Icl ,SodA ,and MtrA are involved with metabolism ,signal transduction pathways ,virulence factors ,pathogenicity and the persistence of bacteria in the host cell .Proteasome inhibitor make the function of proteasome restricted and the accumula-tion of Pup’s labeled substrate result in changes in the expression of gene indirectly ,which impacted the ability of resistance to outside pressure and the pathogenicity of Mycobacterium tuberculosis . The finding Pup-proteasome system reveals a novel mechanism of protein degradation in prokaryotes ,which is expected to become a new target of treatment of anti-TB drugs . Here ,we summarize the progress on the Pup-proteasome system in Mycobacterium tuberculosis .
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Objective:To study the correlation different drug-resistant mycobacterium tuberculosis clinical isolates of prokaryotic ubiquitin-like protein ( Pup )-proteasome of Pup, Dop, PafA, Mpa gene expression level and mycobacterium tuberculosis Pup-proteasome system with Xinjiang region widely popular drug-resistant mycobacterium tuberculosis in clinical isolates resistance.Methods:Total RNA of Mtb was extracted from cultured Mtb during the logarithmic phase in drug-susceptible strains in Xinjiang region,the clinical strains drug sensitive to INH,RFP,SM and EB respectively,and multidrug-resistant(MDR) strains.And then the purity of total RNA was identified.The expressing of Pup-proteasome relevant gene( Pup,Dop,Mpa,PafA) were quantified using SYBR GreenⅠqRT-PCR which aimed at finding the correlation between Mtb Pup-proteasome system and drug resistance of Mtb clinical isolates widespread in Xingjiang region by analyzing the expression of Pup, Dop, PafA, Mpa gene among different isolates.Results:Compared with the drug-senstive clinical isolates, mRNA expression level of Pup, Mpa gene was down-regulated in resistant M.tuberculosis clinical isolates INH ( INH-MTB) ,RFP ( RFP-MTB) ,SM ( SM-MTB) and EB ( EB-MTB) ,mRNA expression levels of genes in Dop and PafA was higher in resistant M.tuberculosis clinical isolates,the difference was statistically significant(P<0.05).Compared with MDR strain, the expression of Pup, Dop, Mpa gene were up-regulated different in the resistant M.tuberculosis clinical isolates isolates ,the expression of PafA gene was down-regulated different,the difference was statistically significant( P<0.05).Conclusion:The differentially expressed gene of Pup、Dop、PafA、Mpa gene in sensitive strains,INH-MTB,RFP-MTB,SM-MTB,EB-MTB and MDR strains.The Mycobacterium tuberculosis Pup-proteasome system.Therefore,the Pup-proteasome system have association with the drug resistance of Mtb strains widespread in Xinjiang region.