Bioinformatic and expression analyses of genes mediating zinc homeostasis in Nostoc punctiforme
Data(s) |
01/02/2009
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Resumo |
Zinc homeostasis was investigated in <i>Nostoc punctiforme</i>. Cell tolerance to Zn<sup>2+</sup> over 14 days showed that ZnCl<sub>2</sub> levels above 22 µM significantly reduced cell viability. After 3 days in 22 µM ZnCl<sub>2</sub>, ca. 12% of the Zn<sup>2+</sup> was in an EDTA-resistant component, suggesting an intracellular localization. Zinquin fluorescence was detected within cells exposed to concentrations up to 37 µM relative to 0 µM treatment. Radiolabeled <sup>65</sup>Zn showed Zn<sup>2+</sup> uptake increased over a 3-day period, while efflux occurred more rapidly within a 3-h time period. Four putative genes involved in Zn2+ uptake and efflux in <i>N. punctiforme</i> were identified: (i) the predicted Co/Zn/Cd cation transporter, putative CDF; (ii) the predicted divalent heavy-metal cation transporter, putative Zip; (iii) the ATPase component and Fe/Zn uptake regulation protein, putative Fur; and (iv) an ABC-type Mn/Zn transport system, putative zinc ZnuC, ZnuABC system component. Quantitative real-time PCR indicated the responsiveness of all four genes to 22 µM ZnCl<sub>2</sub> within 3 h, followed by a reduction to below basal levels after 24 h by putative ZIP, ZnuC, and Fur and a reduction to below basal level after 72 h by putative CDF efflux gene. These results demonstrate differential regulation of zinc transporters over time, indicating a role for them in zinc homeostasis in N. punctiforme.<br /> |
Identificador | |
Idioma(s) |
eng |
Publicador |
American Society for Microbiology |
Relação |
http://dro.deakin.edu.au/eserv/DU:30022586/michalczyk-bioinformaticande-2009.pdf http://dx.doi.org/10.1128/AEM.02481-08 |
Direitos |
2009, American Society for Microbiology |
Tipo |
Journal Article |