title: Induction of expression of a 14-3-3 gene in response to copper exposure in the marine alga, Fucus vesiculosus.
abstract: The macro-alga Fucus vesiculosus has a broad global and estuarine distribution and exhibits exceptional resistance to toxic metals, the molecular basis of which is poorly understood. To address this issue a cDNA library was constructed from an environmental isolate of F. vesiculosus growing in an area with chronic copper pollution. Characterisation of this library led to the identification of a cDNA encoding a protein known to be synthesised in response to toxicity, a full length 14-3-3 exhibiting a 71% identity to human/mouse epsilon isoform, 70-71% identity to yeast BMH1/2 and 95 and 71% identity to the Ectocarpus siliculosus 14-3-3 isoforms 1 and 2 respectively. Preliminary characterisation of the expression profile of the 14-3-3 indicated concentration- and time-dependent inductions on acute exposure of F. vesiculosus of copper (3-30 μg/l). Higher concentrations of copper (≥150 μg/l) did not elicit significant induction of the 14-3-3 gene compared with the control even though levels of both intracellular copper and the expression of a cytosolic metal chaperone, metallothionein, continued to rise. Analysis of gene expression within environmental isolates demonstrated up-regulation of the 14-3-3 gene associated with the known copper pollution gradient. Here we report for the first time, identification of a gene encoding a putative 14-3-3 protein in a multicellular alga and provide preliminary evidence to link the induction of this 14-3-3 gene to copper exposure in this alga. Interestingly, the threshold exposure profile may be associated with a decrease in the organism's ability to control copper influx so that it perceives copper as a toxic response.
authors: School of Biosciences, Cardiff University, Cardiff CF10 3AX, Wales, UK.
authors: Jennifer R
authors: JR
authors: Owen
authors: Ceri A
authors: CA
authors: Morris
authors: Beate
authors: B
authors: Nicolaus
authors: John L
authors: JL
authors: Harwood
authors: Peter
authors: P
authors: Kille
mesh_terms: D048948:14-3-3 Proteins / Q000235:genetics* / Q000378:metabolism; D000595:Amino Acid Sequence; D003300:Copper / Q000633:toxicity*; D018076:DNA, Complementary / Q000235:genetics / Q000378:metabolism; D004784:Environmental Monitoring; D044645:Fucus / Q000187:drug effects* / Q000235:genetics* / Q000378:metabolism; D015723:Gene Library; D008969:Molecular Sequence Data; D017422:Sequence Analysis, DNA; D015854:Up-Regulation
chemical_list: D048948:14-3-3 Proteins; D018076:DNA, Complementary; D003300:Copper