Abstract
Generally, there are two major isoforms of metallothionein (MT) in mammals. In this study two cDNAs of metallothionein, MT-A and MT-B, in a fresh-water fish, crucian carp (Carassius cuvieri), were cloned by the rapid amplification of cDNA ends (RACE). The homology of their reading frame is about 92.3%. The sequence analysis of both cDNAs gave the structures of coding regions corresponding to 60 amino acid residues, and the structures of complete 3′-untranslated regions in which a significant difference in the size of their 3′-untranslated regions (130 bp for MT-A and 280 bp for MT-B) exists. The results of amino acid sequencing of both MT-1 and MT-2 purified by HPLC are identical to those deduced from MT cDNA genes, indicating that MT-1 is from MT-A gene and MT-2 is from MT-B gene respectively. No blocking in the N-terminal of MT-2 isoform was the first case found in vertebrates, most of which were blocked by acetylation. These results suggest that there were differential controls at the transcription level and after translation of these two MT isoforms. And this gives a clue to understand the diversities of their functions.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Margoshes, M., Vallee, B. L., A cadmium protein from equine kidney cortex, J. Am. Chem. Soc., 1957, 79: 4813.
Lazo, J. S., Kuo, S. M., Woo, E. S., The protein thiol metallothionein as an antioxidant and protectant against antineoplastic drugs, Chem. Biol. Interact, 1998, 24: 111.
Yutaka, K., Definitions and nomenclature of metallothioneins, Methods in Enzymology, 1991, 205: 8.
Stuart, G. W., Searle, P. E., Palmiter, R. D., Identification of multiple metal regulatory elements in mouse metallothionein-I promoter by assaying synthetic sequences, Nature, 1985, 317: 828.
Kelly, J. E., Sandgren, P. E., Trinster, R. L. et al., A pair of adjacent glucocorticoid response elements regulate expression of two mouse metallothionein genes, Proc. Natl. Acad. Sci. USA, 1997, 94: 10045.
Karin, M., Haslinger, A., Holtgreve, H. et al., Characterization of DNA sequences through which cadmium and glucocorticoid hormones induce human metallothionein-II A gene, Nature, 1984, 308: 513.
Kille, P., Stephens, P. E., Kay, J., Elucidation of cDNA sequences for metallothioneins from rainbow trout, stone loach and pike liver using the polymerase chain reaction, Biochim. Biophys. Acta, 1991, 1089: 407.
Brown, M. W., Shurben, D., Solbe, H. F. et al., Sequestration of environmental cadmium by metallothionein in the roach (Rutilus rutilus) and the stone loach (Noemacheilus barbatulus), Comp. Biochem. Physiol., 1987, 87C: 65.
Zafarullah, M., Bonham, K., Gedamu, L., Structure of the rainbow trout metallothionein B gene and characterization of its metal-responsive region, Mol. Cell Biol., 1988, 8: 4469.
Chan, K. M., PCR-cloning of goldfish and tilapia metallothionein complementary DNAs, Biochem. Biophys. Res. Commun., 1994, 205: 368.
Chenchik, A., Diachenko, L., Moqadam, F. et al., Full-length cDNA cloning and determination of mRNA 5′ and 3′ ends by amplification of adaptor-ligated cDNA, Biotechniques, 1996, 21: 526.
Schutte, B. C., Ramade, K., Rruessnev, J. et al., Optimized conditions for cloning PCR products into an Xcml T-vector, Biotechniques, 1997, 22: 40.
Muto Norio, Ren, H. W., Itoh Norio. et al., Induction patterns of two metallothionein isoforms on crucian carp (Carassius cuvieri) by air-pumping stress, dexamethasone and metals, Comp. Biochem. Physiol. (C), 1999, 122: 75.
Lin, L. Y., Lin, W. C., Huang, P. C., Pigeon metallothionein consists of two species, Biochim. Biophys. Acto., 1990, 1037: 248.
Olsson, P. E., Kille, P., Functional comparison of the metal-regulated transcriptional control regions of metallothionein genes from cadmium-sensitive and tolerant fish species, Biochim. Biophys. Acta, 1997, 1350: 325.
Lerch, K., Ammer, D., Olafson, R. W., Crab metallothionein, Primary structures of metallothioneins 1 and 2, J. Biol. Chem., 1982, 257: 2420.
Kille, P., Kay, J., Sweeney, G. E., Analysis of regulatory elements flanking metallothionein genes in Cd-tolerant fish (pike and stone loach), Biochim. Biophys. Acta, 1993, 1216: 55.
Foley, R. C., Liang, Z. M., Singh, K. B., Analysis of type 1 metallothionein cDNAs inVicia faba, Plan. Mol. Biol., 1997, 33: 583.
Mahon, P., Partridge, K., Beattie, J. H. et al., The 3′ untranslated region plays a role in the targeting of metallothioneinI mRNA to the perinuclear cytoplasm and cytoskeletal-bound polysomes, Biochim. Biophys. Acta, 1997, 1358: 153.
Author information
Authors and Affiliations
Corresponding author
About this article
Cite this article
Ren, H., Norio, M., Norio, I. et al. Identification of two metallothionein isoforms by molecular cloning of their cDNAs in fresh-water fish, crucian carp (Carassius-cuvieri). Chin.Sci.Bull. 46, 53–57 (2001). https://doi.org/10.1007/BF03183209
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF03183209