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Isoform‐specific responses of metallothioneins in a marine pollution biomonitor, the green‐lipped mussel Perna viridis , towards different stress stimulations
Author(s) -
Leung Priscilla T. Y.,
Park T. J.,
Wang Yu,
Che C.M.,
Leung Kenneth M.Y.
Publication year - 2014
Publication title -
proteomics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.26
H-Index - 167
eISSN - 1615-9861
pISSN - 1615-9853
DOI - 10.1002/pmic.201300439
Subject(s) - perna viridis , gene isoform , mussel , western blot , biology , cadmium , oxidative stress , metallothionein , catalase , biomarker , proteomics , biochemistry , environmental chemistry , microbiology and biotechnology , chemistry , ecology , gene , organic chemistry
Metallothioneins (MTs) are commonly used as biomarker for metal pollution assessment in marine ecosystems. Using integrated genomic and proteomic analyses, this study characterized two types of MT isoform in the digestive gland of a common biomonitor, the green‐lipped mussel Perna viridis , towards the challenges of a metal (cadmium; Cd) and a non‐metal oxidant (hydrogen peroxide; H 2 O 2 ) respectively. The two isoforms differed in their deduced protein sequences, with 73 amino acids for MT10‐I and 72 for MT10‐II (a novel type), but both consisted of a high percentage (27.4 to 29.2%) of cysteine. Two‐dimensional gel and Western blot showed that the MT proteins were present in multiple isoform spots, and they were further validated to be MT10‐I and MT10‐II using MS analysis coupled with unrestricted modifications searching. Expression of mRNA revealed that MT10‐I responded promptly to Cd but had a lagged induction to H 2 O 2 treatments, while MT10‐II was exclusively induced by Cd treatment over the course of exposure. Expression of the MT proteins also showed a delayed response to H 2 O 2 , compared to Cd treatments. This study uncovered the potential different functional roles of various MTs isoforms in P. viridis and thus advances the resolution of using MTs as biomarkers in future applications.