Nucleotide sequence and expression of a Drosophila metallothionein.
A Drosophila melanogaster cDNA clone was isolated based on its more intense hybridization to RNA sequences from copper-fed larvae than from control larval RNA. This clone showed strong hybridization to mouse metallothionein I cDNA at reduced stringency. Its nucleotide sequence includes an open reading segment which codes for a 40-amino acid protein; this protein is identified as metallothionein based on its similarity to the amino-terminal portion of mammalian and crab metalloproteins. The 10 cysteine residues present occur in five pairs of near vicinal cysteines (Cys-X-Cys). This cDNA sequence hybridized to a 400-nucleotide polyadenylated RNA whose presence in the cells of the alimentary canal of larvae was stimulated by ingestion of cadmium or copper; in other tissues this RNA was present at much lower levels. Mercury, silver, and zinc induced metallothionein to a lesser extent. The level of metallothionein RNA increased very soon after the initiation of metal treatment and reached a maximum after approximately 36 h.
Lastowski-Perry
D
D
Otto
E
E
Maroni
G
G
D000818:Animals; D001483:Base Sequence; D002104:Cadmium / Q000494:pharmacology; D003300:Copper / Q000494:pharmacology; D004247:DNA; D004331:Drosophila melanogaster / Q000235:genetics* / Q000254:growth & development; D007814:Larva / Q000187:drug effects / Q000378:metabolism; D008668:Metallothionein / Q000235:genetics*; D009693:Nucleic Acid Hybridization; D012313:RNA / Q000096:biosynthesis
D002104:Cadmium; D012313:RNA; D003300:Copper; D004247:DNA; D008668:Metallothionein