AbstractJournal URL: http://www.eie.gr/iopc-costb22/index.htm

Athanassopoulos, C.M.

Filippou, P.S.

Garnelis, T.

Kyriakidis, D.A.

Lioliou, E.E.

Panagiotidis, C.A.

Papaioannou, D.

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3rd COST B22 ANNUAL CONGRESS: POSTERS 97  
P13 
 
EFFECT OF POLYAMINES AND SYNTHETIC POLYAMINE-
ANALOGUES ON THE EXPRESSION OF THE E. coli ato OPERON 
AND ITS REGULATORY GENES 
 
P.S. Filippou1*, E.E. Lioliou1,3, C.A. Panagiotidis2, C.M. Athanassopoulos4, 
T. Garnelis4, D. Papaioannou4 and D.A. Kyriakidis1,5 
 
1. Laboratory of Biochemistry, Department of Chemistry and 
2. Department of Pharmaceutical Sciences, Aristotle University of Thessaloniki, 
Thessaloniki, 54124, Greece 
3. Laboratory of Prokaryotic Molecular Genetics, Smurfit Institute of Genetics, Trinity 
College, Dublin, Ireland 
4. Laboratory of Synthetic Organic Chemistry, Depar ment of Chemistry, University of 
Patras, 26500 Patras, Greece 
t
 
t  
 
 
 
5. The National Hellenic Research Foundation 48, Vas. Constantinou Ave 11635, 
Athens, Greece  
 
                                                
In bacteria, the biosynthesis of polyamines is modulated both at the level of 
transcription as well as post-translationally. In E. coli, a non-competitive protein 
inhibitor was identified, named Antizyme (Az), which is the gene product of atoC. The 
cloning and sequencing of the E. coli antizyme gene revealed that Az also have a 
second function as a transcriptional regulator AtoC, belonging to the two-component 
system family and Az was identical as the gene product of atoC. AtoC, is a positive 
transcriptional regulator of the atoDAEB operon genes, encoding enzymes involved in 
short chain fatty acid metabolism. The antizyme is referred to as AtoC/Az, to indicate 
its dual function as both a transcriptional and post-translational regulator. The role of 
polyamines at the transcriptional level of atoS and atoC genes as well as that of
atoDAEB(a o) operon is studied. Polyamine-mediated induction was measured in atoSC
positive or negative E. coli backgrounds by using β-galactosidase reporter constructs 
carrying the appropriate promoters (i.e patoDAEB, patoS, patoC). In addition, a 
selection of synthetic polyamine analogues have been tested for their effectiveness in 
inducing the expression of atoC/Az, whose product is a key protein in feedback 
inhibition of putrescine biosynthesis as well as the  transcriptional regulator of the ato
operon. The effects of these compounds were also measured on the ato operon 
expression. The polyamine analogues were tested for their effect on the growth of E.
coli strain MA255 (ODC-, ADC-) which lack polyamines and grow only when exogenous 
polyamines are present. Polyamines, which have been reported to induce AtoC in E.
coli, act at the transcriptional level, since activation of the transcription of AtoC/Az in 
three isogenic Ε. coli strains was observed. In addition, some of the polyamine 
analogues tested to activate the transcription of the atoC gene and the atoDAEB 
operon promoter.  
    


Effect of polyamines and synthetic polyamine-analogues on the expression of the E. coli ato operon and its regulatory genes

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