title: Molecular cloning and expression of novel metallothionein (MT) gene in the polychaete Perinereis nuntia exposed to metals.
abstract: To report a novel metallothionein (MT) gene and evaluate its potency as a biomarker, we clone this MT gene and measured the expression levels in the metal-exposed polychaete Perinereis nuntia. Accumulated metal contents and metallothionein-like proteins (MTLPs), which have been recognized as potential biomarkers, were compared with the relative mRNA expressions of the MT gene of P. nuntia (Pn-MT). In addition, the metal-binding affinity was estimated by recombinant Pn-MT protein. Pn-MT having high cysteine residues with three metal response elements in the promoter region closely clusters with those of other invertebrates. The accumulation patterns of metals were dependent on the exposure times in lead (Pb), cadmium (Cd), and copper (Cu) exposure. Particularly, both MTLP levels and relative mRNA expressions of MT were increased with accumulated metal contents and exposure time in P. nuntia exposed to Pb and Cd. There was no significant modulation of the Pn-MT gene in polychaetes exposed to Zn and As. However, the metal-binding ability of the recombinant Pn-MT protein provides a clear evidence for a high affinity of MT to several metal elements. These results suggest that Pn-MT would play an important role in the detoxification and/or sequestration of specific metals (e.g., Pb and Cd) in P. nuntia and have potential as a molecular biomarker in the monitoring of the marine environment using a polychaete.
authors: Department of Chemistry, College of Natural Sciences, Hanyang University, Seoul, 133-791, South Korea.
authors: Eun-Ji
authors: EJ
authors: Won
authors: Jae-Sung
authors: JS
authors: Rhee
authors: Kongtae
authors: K
authors: Ra
authors: Kyung-Tae
authors: KT
authors: Kim
authors: Doris W T
authors: DW
authors: Au
authors: Kyung-Hoon
authors: KH
authors: Shin
authors: Jae-Seong
authors: JS
authors: Lee
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D005786:Gene Expression Regulation / Q000187:drug effects*; D008668:Metallothionein / Q000235:genetics / Q000378:metabolism*; D008670:Metals / Q000737:chemistry / Q000633:toxicity*; D008969:Molecular Sequence Data; D010802:Phylogeny; D011077:Polychaeta / Q000187:drug effects* / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D014131:Trace Elements / Q000737:chemistry / Q000633:toxicity; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000633:toxicity
chemical_list: D008670:Metals; D012333:RNA, Messenger; D014131:Trace Elements; D014874:Water Pollutants, Chemical; D008668:Metallothionein