stress response protein Gls24 is induced by copper and interacts with the CopZ copper chaperone of Enterococcus hirae

• Published in: FEMS microbiology letters Vol. 302; no. 1; pp. 69 - 75
• Main Authors: Stoyanov, Jivko V, Mancini, Stefano, Lu, Zen Huat, Mourlane, Frédéric, Poulsen, Kristian R, Wimmer, Reinhard, Solioz, Marc
• Format: Journal Article
• Language: English
• Published: Oxford, UK Oxford, UK : Blackwell Publishing Ltd 2010; Blackwell Publishing Ltd; Wiley-Blackwell; Oxford University Press
• Subjects: Adaptation, Physiological; Bacterial Proteins - metabolism; Bacteriology; Biological and medical sciences; Circular dichroism; Copper; Copper - metabolism; copper chaperone; copper homeostasis; Deoxyribonucleic acid; Dichroism; DNA; Enterococcus - genetics; Enterococcus - metabolism; Enterococcus hirae; Fundamental and applied biological sciences. Psychology; Gene expression; Gene Expression Regulation, Bacterial; Heat-Shock Proteins - biosynthesis; Heat-Shock Proteins - genetics; Homeostasis; Hybrid systems; Microbiology; Miscellaneous; Molecular Chaperones - metabolism; Molecular Sequence Data; Operon; Proteins; Stress response; stress response protein; Stress, Physiological; Surface plasmon resonance; Trans-Activators - metabolism; Transcriptional Activation; Two-Hybrid System Techniques; Yeast; yeast two-hybrid system; Yeasts; yeast two-hybrid system; copper chaperone; stress response protein; surface plasmon resonance; copper homeostasis; Lactic acid bacteria; Yeast; Chaperone; Homeostasis; Protein; Stress; Heavy metal; Streptococcaceae; Enterococcus hirae; Bacteria; Micrococcales; Copper
• ISSN: 0378-1097; 1574-6968
• DOI: 10.1111/j.1574-6968.2009.01833.x

Intracellular copper routing in Enterococcus hirae is accomplished by the CopZ copper chaperone. Under copper stress, CopZ donates Cu⁺ to the CopY repressor, thereby releasing its bound zinc and abolishing repressor-DNA interaction. This in turn induces the expression of the cop operon, which encodes CopY and CopZ, in addition to two copper ATPases, CopA and CopB. To gain further insight into the function of CopZ, the yeast two-hybrid system was used to screen for proteins interacting with the copper chaperone. This led to the identification of Gls24, a member of a family of stress response proteins. Gls24 is part of an operon containing eight genes. The operon was induced by a range of stress conditions, but most notably by copper. Gls24 was overexpressed and purified, and was shown by surface plasmon resonance analysis to also interact with CopZ in vitro. Circular dichroism measurements revealed that Gls24 is partially unstructured. The current findings establish a novel link between Gls24 and copper homeostasis.