Metal interaction and regulation of Tetrahymena pigmentosa metallothionein genes.
The patterns of expression of two metallothionein (MT) genes, MT-1 and MT-2, previously identified as Cd-MT and Cu-MT, were analysed in Tetrahymena pigmentosa in response to metal inducers cadmium, copper and zinc and to a mixture of copper and cadmium at appropriate concentrations. Co-treatment induces synergistic accumulation of both metals and higher expression of MT-mRNAs in the first few hours. mRNA levels were observed not to completely correlate with MT-protein levels, suggesting that post-transcriptional regulation may be involved in MT induction. MT-1 is induced to higher levels than MT-2. Zinc does not induce any MT expression. The lowest level of mRNA was observed for MT-2, induced only by copper. Cadmium is a powerful inducer of the MT-1 gene, although a very low transcription rate by copper occurs in the first hour.
Boldrin
Francesco
F
Department of Biology, University of Padova, Italy.
Santovito
Gianfranco
G
Irato
Paola
P
Piccinni
Ester
E
D000818:Animals; D015152:Blotting, Northern; D002104:Cadmium / Q000378:metabolism; D003300:Copper / Q000378:metabolism; D005786:Gene Expression Regulation; D017125:Genes, Protozoan; D008668:Metallothionein / Q000096:biosynthesis / Q000235:genetics*; D008670:Metals / Q000494:pharmacology*; D013768:Tetrahymena / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D013997:Time Factors
D008670:Metals; D002104:Cadmium; D003300:Copper; D008668:Metallothionein