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Study of the role of two ferritins in Caulobacter crescentus iron metabolism and their regulation.

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Author(s):
Mirian Molnar Rodrigues
Total Authors: 1
Document type: Master's Dissertation
Press: São Paulo.
Institution: Universidade de São Paulo (USP). Instituto de Ciências Biomédicas (ICB/SDI)
Defense date:
Examining board members:
Marilis do Valle Marques; Elizabeth Angelica Leme Martins; Aline Maria da Silva
Advisor: Marilis do Valle Marques
Abstract

Bacteria utilize intracellular iron storage proteins (ferritins) that allow access to the metal when it is present in low amount. In this study the role of ferritins Bfr and Dps was studied by analyzing the phenotype of mutant strains, and their regulation was studied using the lacZ reporter gene, in <font face=\"Symbol\">b-galactosidase activity assays. The results showed increased expression of bfr in iron excess, and that this gene is positively regulated by Fur. dps expression was increased under iron deficiency and in the stationary phase. Expression assays in the mutant strains <font face=\"Symbol\">DoxyR, <font face=\"Symbol\">DsRNA1 and <font face=\"Symbol\">DsRNA2 showed differences in expression levels compared to wild type. ECF sigma factor SigJ is important for maximum levels of bfr expression and SigT for maximal dps expression. The coding regions of bfr, dps or both have been deleted. The results showed that the <font face=\"Symbol\">Ddps and double mutant strains showed increased susceptibility to H2O2, and <font face=\"Symbol\">Dbfr showed a similar pattern to the NA1000 strain. The iron concentration determination showed that both ferritins play equivalent roles in intracellular iron storage. (AU)