Study of OxcT function in Caulobacter crescentus copper tolerance

  • Julia Zakaria

    Student thesis: Master typesMaster in biochemistry and molecular and cell biology, Professional focus

    Abstract

    Despite its essentially at low dose, the excess of copper (Cu) is toxic to all forms of life. In the model alpha-proteobacterium Caulobacter crescentus, a bimodal response to Cu has been previously identified by our lab. The oxcT gene (CCNA_00027), a new actor of Cu tolerance in C. crescentus, was identified in a genetic screen seeking for Cu-sensitive mutants. In addition, a RNAseq experiment shows a Cu-dependent upregulation of oxcT expression. Consistent with these observations, oxcT deletion (ΔoxcT) leads to an increased Cu sensitivity in both rich and poor media. No increased sensitivity to other heavy-metals was observed. Surprinsingly, no significant increase in cellular Cu content could be observed in the ΔoxcT mutant. Measurements of the intracellular Fe content as well as of growth curves in low and high Fe concentration under Cu stress demonstrated a link between Fe homeostasis and the role of OxcT in Cu tolerance. These observations are consistent with the control of oxcT expression by the ferric uptake regulator (Fur). Finally, an OxcT affinity purification assay followed by mass spectrometry highlighted a list of potential OxcT partners. Interaction between OxcT and a selected candidate will be studied in the near future.
    Date of AwardJan 2022
    Original languageEnglish
    Awarding Institution
    • University of Namur
    SupervisorJean-Yves Matroule (Supervisor)

    Keywords

    • copper
    • Caulobacter crescentus
    • 2OG Fe(II) dependent-oxygenase

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