Cloning, expression, and characterization of cadmium-induced metallothionein-2 from the earthworms Metaphire posthuma and Polypheretima elongata

Shih Hsiung Liang, Yu Ping Jeng, Yun-Wen Chiu, Jiun Hong Chen, Bao Sen Shieh, Chien Yen Chen, Chien Cheng Chen

Research output: Contribution to journalArticle

12 Citations (Scopus)

Abstract

In this study we report the sequences of MT-2 cDNA from two species of Megascoleidae earthworms, Metaphire posthuma and Polypheretima elongata, by mRNA differential display after exposure of the organisms to cadmium. Complementary (c)DNA was verified as the MT-2 gene by the characteristics of its predicted translation product, namely a high cysteine content, conserved CXC motifs, and a molecular weight of around 8 kDa. Amino acid sequence alignment revealed a conserved TKCCG in the cloned MT-2 of both megascolecid earthworms instead of the corresponding conserved TQCCG found in lumbricid earthworms. The cDNAs corresponding to the two megascolecid MT-2 genes were expressed, and the MT-2 proteins were purified for biochemical characterization. The binding of Cu2+ exhibited monophasic kinetics and those of Zn2+ and Cd2+ biphasic kinetics. The proteins bound more tightly to Cd2+ than to Zn2+ and more tightly still to Cu2+. Zn-MT and apo-MT were the most effective at scavenging free radicals, followed by Cd-MT. In conclusion, MT-2s from M. posthuma and P. elongata showed unique sequence features compared to those of lumbricid earthworms. These earthworms could be used to evaluate heavy-metal pollution in soil due to the inducible MT-2 by cadmium exposure.

Original languageEnglish
Pages (from-to)349-357
Number of pages9
JournalComparative Biochemistry and Physiology - C Toxicology and Pharmacology
Volume149
Issue number3
DOIs
Publication statusPublished - 2009 Apr 1

Fingerprint

Oligochaeta
Metallothionein
Cloning
Cadmium
Organism Cloning
Complementary DNA
Genes
Kinetics
Scavenging
Heavy Metals
Free Radicals
Cysteine
Proteins
Pollution
Molecular weight
Display devices
Soils
Amino Acids
Messenger RNA
DNA

All Science Journal Classification (ASJC) codes

  • Physiology
  • Biochemistry
  • Toxicology
  • Cell Biology
  • Health, Toxicology and Mutagenesis

Cite this

Liang, Shih Hsiung ; Jeng, Yu Ping ; Chiu, Yun-Wen ; Chen, Jiun Hong ; Shieh, Bao Sen ; Chen, Chien Yen ; Chen, Chien Cheng. / Cloning, expression, and characterization of cadmium-induced metallothionein-2 from the earthworms Metaphire posthuma and Polypheretima elongata. In: Comparative Biochemistry and Physiology - C Toxicology and Pharmacology. 2009 ; Vol. 149, No. 3. pp. 349-357.
@article{8bf367a072be45e8a93cdb4936f21474,
title = "Cloning, expression, and characterization of cadmium-induced metallothionein-2 from the earthworms Metaphire posthuma and Polypheretima elongata",
abstract = "In this study we report the sequences of MT-2 cDNA from two species of Megascoleidae earthworms, Metaphire posthuma and Polypheretima elongata, by mRNA differential display after exposure of the organisms to cadmium. Complementary (c)DNA was verified as the MT-2 gene by the characteristics of its predicted translation product, namely a high cysteine content, conserved CXC motifs, and a molecular weight of around 8 kDa. Amino acid sequence alignment revealed a conserved TKCCG in the cloned MT-2 of both megascolecid earthworms instead of the corresponding conserved TQCCG found in lumbricid earthworms. The cDNAs corresponding to the two megascolecid MT-2 genes were expressed, and the MT-2 proteins were purified for biochemical characterization. The binding of Cu2+ exhibited monophasic kinetics and those of Zn2+ and Cd2+ biphasic kinetics. The proteins bound more tightly to Cd2+ than to Zn2+ and more tightly still to Cu2+. Zn-MT and apo-MT were the most effective at scavenging free radicals, followed by Cd-MT. In conclusion, MT-2s from M. posthuma and P. elongata showed unique sequence features compared to those of lumbricid earthworms. These earthworms could be used to evaluate heavy-metal pollution in soil due to the inducible MT-2 by cadmium exposure.",
author = "Liang, {Shih Hsiung} and Jeng, {Yu Ping} and Yun-Wen Chiu and Chen, {Jiun Hong} and Shieh, {Bao Sen} and Chen, {Chien Yen} and Chen, {Chien Cheng}",
year = "2009",
month = "4",
day = "1",
doi = "10.1016/j.cbpc.2008.09.004",
language = "English",
volume = "149",
pages = "349--357",
journal = "Comparative Biochemistry and Physiology Part - C: Toxicology and Pharmacology",
issn = "1532-0456",
publisher = "Elsevier Inc.",
number = "3",

}

Cloning, expression, and characterization of cadmium-induced metallothionein-2 from the earthworms Metaphire posthuma and Polypheretima elongata. / Liang, Shih Hsiung; Jeng, Yu Ping; Chiu, Yun-Wen; Chen, Jiun Hong; Shieh, Bao Sen; Chen, Chien Yen; Chen, Chien Cheng.

In: Comparative Biochemistry and Physiology - C Toxicology and Pharmacology, Vol. 149, No. 3, 01.04.2009, p. 349-357.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Cloning, expression, and characterization of cadmium-induced metallothionein-2 from the earthworms Metaphire posthuma and Polypheretima elongata

AU - Liang, Shih Hsiung

AU - Jeng, Yu Ping

AU - Chiu, Yun-Wen

AU - Chen, Jiun Hong

AU - Shieh, Bao Sen

AU - Chen, Chien Yen

AU - Chen, Chien Cheng

PY - 2009/4/1

Y1 - 2009/4/1

N2 - In this study we report the sequences of MT-2 cDNA from two species of Megascoleidae earthworms, Metaphire posthuma and Polypheretima elongata, by mRNA differential display after exposure of the organisms to cadmium. Complementary (c)DNA was verified as the MT-2 gene by the characteristics of its predicted translation product, namely a high cysteine content, conserved CXC motifs, and a molecular weight of around 8 kDa. Amino acid sequence alignment revealed a conserved TKCCG in the cloned MT-2 of both megascolecid earthworms instead of the corresponding conserved TQCCG found in lumbricid earthworms. The cDNAs corresponding to the two megascolecid MT-2 genes were expressed, and the MT-2 proteins were purified for biochemical characterization. The binding of Cu2+ exhibited monophasic kinetics and those of Zn2+ and Cd2+ biphasic kinetics. The proteins bound more tightly to Cd2+ than to Zn2+ and more tightly still to Cu2+. Zn-MT and apo-MT were the most effective at scavenging free radicals, followed by Cd-MT. In conclusion, MT-2s from M. posthuma and P. elongata showed unique sequence features compared to those of lumbricid earthworms. These earthworms could be used to evaluate heavy-metal pollution in soil due to the inducible MT-2 by cadmium exposure.

AB - In this study we report the sequences of MT-2 cDNA from two species of Megascoleidae earthworms, Metaphire posthuma and Polypheretima elongata, by mRNA differential display after exposure of the organisms to cadmium. Complementary (c)DNA was verified as the MT-2 gene by the characteristics of its predicted translation product, namely a high cysteine content, conserved CXC motifs, and a molecular weight of around 8 kDa. Amino acid sequence alignment revealed a conserved TKCCG in the cloned MT-2 of both megascolecid earthworms instead of the corresponding conserved TQCCG found in lumbricid earthworms. The cDNAs corresponding to the two megascolecid MT-2 genes were expressed, and the MT-2 proteins were purified for biochemical characterization. The binding of Cu2+ exhibited monophasic kinetics and those of Zn2+ and Cd2+ biphasic kinetics. The proteins bound more tightly to Cd2+ than to Zn2+ and more tightly still to Cu2+. Zn-MT and apo-MT were the most effective at scavenging free radicals, followed by Cd-MT. In conclusion, MT-2s from M. posthuma and P. elongata showed unique sequence features compared to those of lumbricid earthworms. These earthworms could be used to evaluate heavy-metal pollution in soil due to the inducible MT-2 by cadmium exposure.

UR - http://www.scopus.com/inward/record.url?scp=60949109009&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=60949109009&partnerID=8YFLogxK

U2 - 10.1016/j.cbpc.2008.09.004

DO - 10.1016/j.cbpc.2008.09.004

M3 - Article

C2 - 18834958

AN - SCOPUS:60949109009

VL - 149

SP - 349

EP - 357

JO - Comparative Biochemistry and Physiology Part - C: Toxicology and Pharmacology

JF - Comparative Biochemistry and Physiology Part - C: Toxicology and Pharmacology

SN - 1532-0456

IS - 3

ER -