title: Cloning, characterization, and expression of cadmium-induced metallothionein-2 gene from earthworm Pheretima aspergillum (E. Perrier).
abstract: Metallothioneins (MTs) are ubiquitous metal-binding, cysteine-rich proteins, associated with metal accumulation and thus providing protection against toxic heavy metals such as cadmium (Cd). To investigate the mechanisms of enrichment of Cd in the earthworm Pheretima aspergillum, we isolated and cloned metallothionein-2 (MT-2) cDNA (538 bp) from P. aspergillum, analyzed its sequence, and examined MT-2 transcription levels by relative quantitative real-time PCR under different concentrations of Cd. The sequence of P. aspergillum MT-2 cDNA and its putative amino acid sequence were highly similar to sequences from other earthworms. The induction with Cd increased the MT-2 gene transcription level in a dose-dependent manner. In addition, earthworm recombinant MT-2 exhibited high Cd bioaccumulation ability in vitro. These results suggested that MT-2 plays an important role in tolerance and accumulation of Cd in P. aspergillum.
authors.affiliation: School of Chinese Materia Medica, Guangzhou University of Chinese Medicine, Guangzhou, China.
authors.forename: L
authors.initials: L
authors.lastname: Gong
authors.affiliation: School of Chinese Materia Medica, Guangzhou University of Chinese Medicine, Guangzhou, China.
authors.forename: W
authors.initials: W
authors.lastname: Li
authors.affiliation: School of Chinese Materia Medica, Guangzhou University of Chinese Medicine, Guangzhou, China.
authors.forename: J
authors.initials: J
authors.lastname: Li
authors.affiliation: School of Chinese Materia Medica, Guangzhou University of Chinese Medicine, Guangzhou, China.
authors.forename: W E
authors.initials: WE
authors.lastname: Li
authors.affiliation: School of Chinese Materia Medica, Guangzhou University of Chinese Medicine, Guangzhou, China.
authors.forename: W R
authors.initials: WR
authors.lastname: Wu
authors.affiliation: School of Chinese Materia Medica, Guangzhou University of Chinese Medicine, Guangzhou, China.
authors.forename: L W
authors.initials: LW
authors.lastname: Yu
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D019256:Cadmium Chloride / Q000494:pharmacology; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D015870:Gene Expression; D005786:Gene Expression Regulation / Q000187:drug effects; D008668:Metallothionein / Q000235:genetics*; D019216:Metals, Heavy / Q000378:metabolism; D008969:Molecular Sequence Data; D009835:Oligochaeta / Q000145:classification / Q000235:genetics*; D010802:Phylogeny; D011993:Recombinant Fusion Proteins; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA
chemical_list: D018076:DNA, Complementary; D019216:Metals, Heavy; D011993:Recombinant Fusion Proteins; D008668:Metallothionein; D019256:Cadmium Chloride