| Cloning and characterization of a new multi-stress inducible metallothionein gene in Tetrahymena pyriformis | |
| Fu, Chengjie; Miao, Wei; Miao, W, Chinese Acad Sci, Inst Hydrobiol, State Key Lab Freshwater Ecol & Biotechnol, Wuhan 430072, Peoples R China | |
| 2006-06-01 | |
| Source Publication | PROTIST
 |
| ISSN | 1434-4610 |
| Volume | 157Issue:2Pages:193-203 |
| Abstract | A new multi-stress-inducible metallothionein (MT) gene isoform has been cloned and characterized from the ciliate Tetrahymena pyriformis. Both the 5'- and 3'-UT regions of the Tp-MT2 gene are very different from the previously reported Tp-MT1 isoform in this organism and from other described MT genes in Tetrahymena pigmentosa and Tetrahymena thermophila. The putative protein sequence of Tp-MT2 contains cysteine clusters with characteristics of the typical Tetrahymena Cd-inducible MT genes. However, the sequence has a special feature of four intragenic tandem repeats within its first half, with a conserved structural pattern x(5/8)CCCx(6)CCx(6)CxCxNCxCCK. To investigate the transcriptional activities of both Tp-MT2 and Tp-MT1 genes toward heavy metals (Cd, Hg, Cu, Zn) and H2O2, the mRNA levels of these two isoforms were evaluated by means of real-time quantitative PCR. Results showed that Tp-MT2 had a higher basal expression level than Tp-MT1 and both genes were induced by Cd, Hg, Cu, and Zn ions after short exposure (I h), although to different extents. Cd was the most effective metal inducer of both two isoforms, but the relative expression level of Tp-MT2 was much lower than that of Tp-MT1. Different expression patterns were also shown between the two genes when treated with Cd over a period of 24 h. We suggest that TpMT-1 plays the role of a multi-inducible stress gene, while TpMT-2 may have a more specific function in basal metal homeostasis although it may have undergone a functional differentiation process. The putative functional significance and evolutionary mode of the TpMT-2 isoform are discussed. (c) 2006 Elsevier GmbH. All rights reserved.; A new multi-stress-inducible metallothionein (MT) gene isoform has been cloned and characterized from the ciliate Tetrahymena pyriformis. Both the 5'- and 3'-UT regions of the Tp-MT2 gene are very different from the previously reported Tp-MT1 isoform in this organism and from other described MT genes in Tetrahymena pigmentosa and Tetrahymena thermophila. The putative protein sequence of Tp-MT2 contains cysteine clusters with characteristics of the typical Tetrahymena Cd-inducible MT genes. However, the sequence has a special feature of four intragenic tandem repeats within its first half, with a conserved structural pattern x(5/8)CCCx(6)CCx(6)CxCxNCxCCK. To investigate the transcriptional activities of both Tp-MT2 and Tp-MT1 genes toward heavy metals (Cd, Hg, Cu, Zn) and H2O2, the mRNA levels of these two isoforms were evaluated by means of real-time quantitative PCR. Results showed that Tp-MT2 had a higher basal expression level than Tp-MT1 and both genes were induced by Cd, Hg, Cu, and Zn ions after short exposure (I h), although to different extents. Cd was the most effective metal inducer of both two isoforms, but the relative expression level of Tp-MT2 was much lower than that of Tp-MT1. Different expression patterns were also shown between the two genes when treated with Cd over a period of 24 h. We suggest that TpMT-1 plays the role of a multi-inducible stress gene, while TpMT-2 may have a more specific function in basal metal homeostasis although it may have undergone a functional differentiation process. The putative functional significance and evolutionary mode of the TpMT-2 isoform are discussed. (c) 2006 Elsevier GmbH. All rights reserved. |
| Subtype | Article |
| Keyword | Gene Expression Intragenic Tandem Repeats Metallothionein Metal Stress Tetrahymena Pyriformis |
| Department | Chinese Acad Sci, Inst Hydrobiol, State Key Lab Freshwater Ecol & Biotechnol, Wuhan 430072, Peoples R China; Chinese Acad Sci, Grad Sch, Wuhan Branch, Wuhan 430072, Peoples R China |
| Subject Area | Microbiology |
| DOI | 10.1016/j.protis.2006.02.006 |
| WOS Headings | Science & Technology ; Life Sciences & Biomedicine |
| Indexed By | SCI |
| Language | 英语 |
| WOS Research Area | Microbiology |
| WOS Subject | Microbiology |
| WOS ID | WOS:000239827700007 |
| WOS Keyword | DIFFERENTIAL EXPRESSION ; CADMIUM ; PROTEIN ; THERMOPHILA ; PIGMENTOSA ; MT ; PROTISTS ; FAMILY ; OYSTER ; TOOL |
| Citation statistics | |
| Document Type | 期刊论文 |
| Identifier | http://ir.ihb.ac.cn/handle/152342/8868 |
| Collection | 期刊论文 |
| Corresponding Author | Miao, W, Chinese Acad Sci, Inst Hydrobiol, State Key Lab Freshwater Ecol & Biotechnol, Wuhan 430072, Peoples R China |
| Affiliation | 1.Chinese Acad Sci, Inst Hydrobiol, State Key Lab Freshwater Ecol & Biotechnol, Wuhan 430072, Peoples R China 2.Chinese Acad Sci, Grad Sch, Wuhan Branch, Wuhan 430072, Peoples R China |
| Recommended Citation GB/T 7714 | Fu, Chengjie,Miao, Wei,Miao, W, Chinese Acad Sci, Inst Hydrobiol, State Key Lab Freshwater Ecol & Biotechnol, Wuhan 430072, Peoples R China. Cloning and characterization of a new multi-stress inducible metallothionein gene in Tetrahymena pyriformis[J]. PROTIST,2006,157(2):193-203. |
| APA | Fu, Chengjie,Miao, Wei,&Miao, W, Chinese Acad Sci, Inst Hydrobiol, State Key Lab Freshwater Ecol & Biotechnol, Wuhan 430072, Peoples R China.(2006).Cloning and characterization of a new multi-stress inducible metallothionein gene in Tetrahymena pyriformis.PROTIST,157(2),193-203. |
| MLA | Fu, Chengjie,et al."Cloning and characterization of a new multi-stress inducible metallothionein gene in Tetrahymena pyriformis".PROTIST 157.2(2006):193-203. |
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