An endosymbiont positively modulates ornithine decarboxylase in host trypanosomatids.
Some trypanosomatids, such as Crithidia deanei, are endosymbiont-containing species. Aposymbiotic strains are obtained after antibiotic treatment, revealing interesting aspects of this symbiotic association. Ornithine decarboxylase (ODC) promotes polyamine biosynthesis and contributes to cell proliferation. Here, we show that ODC activity is higher in endosymbiont-bearing trypanosomatids than in aposymbiotic cells, but isolated endosymbionts did not display this enzyme activity. Intriguingly, expressed levels of ODC were similar in both strains, suggesting that ODC is positively modulated in endosymbiont-bearing cells. When the aposymbiotic strain was grown in conditioned medium, obtained after cultivation of the endosymbiont-bearing strain, cellular proliferation as well as ODC activity and localization were similar to that observed in the endosymbiont-containing trypanosomatids. Furthermore, dialyzed-heated medium and trypsin treatment reduced ODC activity of the aposymbiont strain. Taken together, these data indicate that the endosymbiont can enhance the protozoan ODC activity by providing factors of protein nature, which increase the host polyamine metabolism.
Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, 21941-590 Rio de Janeiro, RJ, Brazil.
Mariana Lins
ML
Frossard
Sergio Henrique
SH
Seabra
Renato Augusto
RA
DaMatta
Wanderley
W
de Souza
Fernando Garcia
FG
de Mello
Maria Cristina
MC
Machado Motta
D000818:Animals; D018407:Bacterial Physiological Phenomena; D001426:Bacterial Proteins / Q000378:metabolism*; D003421:Crithidia / Q000145:classification / Q000201:enzymology* / Q000382:microbiology*; D004789:Enzyme Activation; D009955:Ornithine Decarboxylase / Q000378:metabolism*; D013045:Species Specificity; D013559:Symbiosis / Q000502:physiology*
D001426:Bacterial Proteins; D009955:Ornithine Decarboxylase