title: CopR of Sulfolobus solfataricus represents a novel class of archaeal-specific copper-responsive activators of transcription.
abstract: In trace amounts, copper is essential for the function of key enzymes in prokaryotes and eukaryotes. Organisms have developed sophisticated mechanisms to control the cytosolic level of the metal, manage its toxicity and survive in copper-rich environments. Here we show that the Sulfolobus CopR represents a novel class of copper-responsive regulators, unique to the archaeal domain. Furthermore, by disruption of the ORF Sso2652 (copR) of the Sulfolobus solfataricus genome, we demonstrate that the gene encodes a transcriptional activator of the copper-transporting ATPase CopA gene and co-transcribed copT, encoding a putative copper-binding protein. Disruption resulted in a loss of copper tolerance in two copR-knockout mutants, while metals such as zinc, cadmium and chromium did not affect their growth. Copper sensitivity in the mutant was linked to insufficient levels of expression of CopA and CopT. The findings were further supported by time-course inductively coupled plasma optical emission spectrometry measurements, whereby continued accumulation of copper in the S. solfataricus mutant was observed. In contrast, copper accumulation in the wild-type stabilized after reaching approximately 6 pg (µg total protein)(-1). Complementation of the disrupted mutant with a wild-type copy of the copR gene restored the wild-type phenotype with respect to the physiological and transcriptional response to copper. These observations, taken together, lead us to propose that CopR is an activator of copT and copA transcription, and the member of a novel class of copper-responsive regulators.
authors.affiliation: Department of Biochemistry and Microbiology, Rutgers, The State University of New Jersey, New Brunswick, NJ, USA.
authors.forename: Aramis
authors.initials: A
authors.lastname: Villafane
authors.affiliation: Department of Biochemistry and Microbiology, Rutgers, The State University of New Jersey, New Brunswick, NJ, USA.
authors.forename: Yekaterina
authors.initials: Y
authors.lastname: Voskoboynik
authors.affiliation: Department of Biochemistry and Microbiology, Rutgers, The State University of New Jersey, New Brunswick, NJ, USA.
authors.forename: Ilona
authors.initials: I
authors.lastname: Ruhl
authors.affiliation: Department of Biochemistry and Microbiology, Rutgers, The State University of New Jersey, New Brunswick, NJ, USA.
authors.forename: David
authors.initials: D
authors.lastname: Sannino
authors.affiliation: Beadle Center for Genetics, University of Nebraska at Lincoln, Lincoln, NE, USA.
authors.forename: Yukari
authors.initials: Y
authors.lastname: Maezato
authors.affiliation: Beadle Center for Genetics, University of Nebraska at Lincoln, Lincoln, NE, USA.
authors.forename: Paul
authors.initials: P
authors.lastname: Blum
authors.affiliation: Department of Biochemistry and Microbiology, Rutgers, The State University of New Jersey, New Brunswick, NJ, USA.
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Bini
mesh_terms: D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism; D019843:Archaeal Proteins / Q000235:genetics / Q000378:metabolism*; D027682:Cation Transport Proteins / Q000235:genetics / Q000378:metabolism; D003300:Copper / Q000378:metabolism*; D000073840:Copper-Transporting ATPases; D019848:Gene Expression Regulation, Archaeal; D010802:Phylogeny; D048229:Sulfolobus solfataricus / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic
chemical_list: D019843:Archaeal Proteins; D027682:Cation Transport Proteins; D015534:Trans-Activators; D003300:Copper; D000251:Adenosine Triphosphatases; D000073840:Copper-Transporting ATPases