Unknown,Transcriptomics,Genomics,Proteomics

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The hierarchy of transition metal homeostasis: Iron controls manganese accumulation in a unicellular cyanobacterium.

ABSTRACT: Iron and manganese are part of a small group of transition metals required for photosynthetic electron transport. Here, we present evidence for a functional link between iron and manganese homeostasis. In the unicellular cyanobacterium, Synechocystis sp. PCC 6803 Fe and Mn deprivation resulted in distinct modifications of the function of the photosynthetic apparatus. For example, iron limitation modifies the rate of QA re-oxidation in photosystem II, a complex that contains more Mn than Fe. The intracellular elemental quotas of Fe and Mn are also linked. Fe limitation reduces the intracellular Mn quota. Mn limitation did not exert a reciprocal effect on Fe quotas. Microarray analysis comparing Mn and Fe limitation revealed a stark difference in the extent of the transcriptional response to the two limiting conditions, reflective of the physiological data. The effects of Fe limitation on the transcriptional network are widespread while the effects on Mn limitation are highly specific. Our analysis also revealed an overlap in the transcriptional response of specific Fe and Mn transporters. This overlap provides a framework for explaining Fe limitation induced changes in Mn quotas. Fe transporters can serve as a low affinity Mn transport system. Under iron limitation the specificity of the Fe transport system changes, making it a less efficient Mn transport system. We monitored the gene expression of Synechocystis PCC6083 at standard conditions and after 2 days of iron limitation (0Fe), manganese limitation (0Mn) and combined iron and manganese limitation (0Fe0Mn). Each timepoint and condition was sampled in triplicates. Due to strong deviations in one of the three repeats for the 0Mn and 0Fe0Mn conditions, the corresponding replicates were excluded from further analysis.

ORGANISM(S): Synechocystis sp. PCC 6803

SUBMITTER: Jens Georg

PROVIDER: E-GEOD-48416 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

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The hierarchy of transition metal homeostasis: Iron controls manganese accumulation in a unicellular cyanobacterium.

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