Cloning and Characterization of a New Multi-Stress Inducible Metallothionein Gene in Tetrahymena pyriformis

Fu, Chengjie; Miao, Wei

doi:10.1016/j.protis.2006.02.006

Cited by 29 publications

(42 citation statements)

References 32 publications

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“…The AATATA at nt 457-462 in the 3′UTR of Tpig-MT1 gene, 56 nt before the poly A tail, differs by only one residue from the usual eukaryotic organisms polyadenylation signal and has not been shown in other MT genes. A "TTTT" motif reported in other Tetrahymena MT genes (Piccinni et al, 1999;Santovito et al, 2001;Dondero et al, 2004;Fu and Miao, 2006), which was suggested to function in rapid degradation of certain short-lived mRNAs as revealed in mammals, was also found in Tpig-MT1 gene 3′ UTR. However, since the average GC content of the Tetrahymena genome is 22% and intergenic sequences tend to be even more ATrich (Eisen et al, 2006), such AT-rich motifs are easily found throughout the genome.…”

Section: The Characterization Of Tpig-mt1 Genementioning

confidence: 73%

“…Tetrahymena MTs are proposed to function in both heavy metal homeostasis and detoxification, and different isoforms exhibit unique expression patterns in response to exposure to different metals (Boldrin et al, 2002). Previous studies indicated that Tetrahymena CdMTs are induced to the highest level of expression by Cd (Boldrin et al, 2002;Fu and Miao, 2006). In this study, the transcriptional activation of Tpig-MT1 mRNA was determined after a short exposure (1 h) to different heavy metals.…”

Section: Induction Of Tpig-mt1 Transcription By Heavy Metals and Hydrmentioning

confidence: 92%

“…Cd-MTs have been previously reported in T. pyriformis, T. pigmentosa, T. thermophila and T. tropicalis (Piccinni et al, 1994(Piccinni et al, , 1999Shang et al, 2002;Boldrin et al, 2003;Fu and Miao, 2006;Diaz et al, 2007, Shuja andShakoori, 2007). The Tpig-MT1 gene is unusually long (521 bp), uses TGA as the stop codon, and is intronless.…”

Section: The Characterization Of Tpig-mt1 Genementioning

confidence: 94%

“…In this study, the transcriptional activation of Tpig-MT1 mRNA was determined after a short exposure (1 h) to different heavy metals. The time was chosen according to the reported plateau of expression for Cd-MT (Santovito et al, 2001;Shang et al, 2002;Fu and Miao, 2006).The concentration of the various heavy metals was in a sublethal range and did not affect normal cell growth rates (unpublished observations).…”

Section: Induction Of Tpig-mt1 Transcription By Heavy Metals and Hydrmentioning

confidence: 99%

“…Different MT isoforms have been described in the unicellular ciliated protozoan genus Tetrahymena (T. pyriformis, T. pigmentosa, T. thermophila and T. tropicalis; Piccinni et al, 1999;Shang et al, 2002;Boldrin et al, 2003;Fu and Miao, 2006;Diaz et al, 2007, Shuja andShakoori, 2007). According to their phylogenetic relationships, the pattern of clustering of Cys residues, and which metal inducer they preferentially respond to, they were grouped into Cd-MTs (subfamily 7a) or Cu-MTs (subfamily 7b), showing little sequence identity with one another.…”

Section: Introductionmentioning

confidence: 99%

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Cloning, characterization, and gene expression analysis of a novel cadmium metallothionein gene in Tetrahymena pigmentosa

Guo

Miao

2008

Gene

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Section: The Characterization Of Tpig-mt1 Genementioning

confidence: 73%

Section: Induction Of Tpig-mt1 Transcription By Heavy Metals and Hydrmentioning

confidence: 92%

Section: The Characterization Of Tpig-mt1 Genementioning

confidence: 94%

Section: Induction Of Tpig-mt1 Transcription By Heavy Metals and Hydrmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Cloning, characterization, and gene expression analysis of a novel cadmium metallothionein gene in Tetrahymena pigmentosa

Guo

Miao

2008

Gene

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From heavy metal‐binders to biosensors: Ciliate metallothioneins discussed

2009

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Metallothioneins (MTs) are ubiquitous proteins with the capacity to bind heavy metal ions (mainly Cd, Zn or Cu), and they have been found in animals, plants, eukaryotic and prokaryotic micro-organisms. We have carried out a comparative analysis of ciliate MTs (Tetrahymena species) to well-known MTs from other organisms, discussing their exclusive features, such as the presence of aromatic amino acid residues and almost exclusive cysteine clusters (CCC) present in cadmium-binding metallothioneins (CdMTs), higher heavy metal-MT stoichiometry values, and a strictly conserved modular-submodular structure. Based on this last feature and an extensive gene duplication, we propose a possible model for the evolutionary history of T. thermophila MTs. We also suggest possible functions for these MTs from consideration of their differential gene expressions and discuss the potential use of these proteins and/or their gene promoters for designing molecular or whole-cell biosensors for a fast detection of heavy metals in diverse polluted ecosystems.

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Isolation and characterization of a novel copper‐inducible metallothionein gene of a ciliate, Tetrahymena tropicalis lahorensis

Chaudhry

Shakoori

2010

J of Cellular Biochemistry

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The two isoforms of copper metallothionein (CuMT) gene of a copper resistant ciliate, Tetrahymena tropicalis lahorensis (Ttl), have been isolated and characterized. The molecular cloning and nucleotide sequencing of cDNAs coding for the two CuMT isoforms revealed that TtlCuMT1 gene has 300, while TtlCuMT2 has 327 nucleotides, both with ATG as the initiation codon and TGA as the translational termination codon. TAG codes for glutamine in TtlCuMT2 gene which is peculiar to Tetrahymena. The deduced or translated TtlCuMT1 and TtlCuMT2 peptide sequences contain 100 and 108 amino acid residues including 28 and 32 cysteine residues, respectively. The amino acid sequences of TtlCuMT1 and TtlCuMT2 have special features of two and three CXCXXCXCXXCXC intragenic tandem repeats with a conserved structural pattern of cysteine, respectively. The predicted tertiary structures of these two isoforms indicate two domains. Domain I and the initial part of domain II showed >98% homology with other Tetrahymena CuMT. On the basis of the differences in the domain II, the metallothionein subfamily 7b can be divided into two groups, one (TtlCuMT1) comprising >100 amino acids and the other (TtlCuMT2) comprising <100 amino acids. This is a novel finding of the present study as no such report on this type of classification exists at the moment. TtlCuMT1 has 95%, while TtlCuMT2 has 97% resemblance with the previously reported CuMT genes of Tetrahymena spp. SDS-PAGE analysis using fluorescent probe as well as coomassie brilliant blue staining also confirmed the presence of metallothionein.

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Cloning and Characterization of a New Multi-Stress Inducible Metallothionein Gene in Tetrahymena pyriformis

Cited by 29 publications

References 32 publications

Cloning, characterization, and gene expression analysis of a novel cadmium metallothionein gene in Tetrahymena pigmentosa

Cloning, characterization, and gene expression analysis of a novel cadmium metallothionein gene in Tetrahymena pigmentosa

From heavy metal‐binders to biosensors: Ciliate metallothioneins discussed

Isolation and characterization of a novel copper‐inducible metallothionein gene of a ciliate, Tetrahymena tropicalis lahorensis

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