Characterization of binding sites for oxyntomodulin on a somatostatin-secreting cell line (RIN T3).

The trout metallothionein (MT) genes consist of two members. We describe the structure of the first fish MT (tMT-B) gene which shows an overall resemblance but some remarkable differences with mammalian MT genes. The similarities included (i) tripartite structure of the gene, (ii) conservation of cysteine residues, and (iii) a TATAAA signal and two copies of metal-responsive elements (MREs). The differences consisted of (i) an AT-rich tMT-B promoter compared with highly GC-rich mammalian MT promoters and (ii) a lack of SP1-binding sites in the tMT-B promoter. Functional analysis of the tMT-B 5'-flanking region following fusion with the bacterial chloramphenicol acetyltransferase gene and its transfection into the rainbow trout hepatoma cell line revealed that sequences from positions -600 to +8 are sufficient for regulation by metals. Further deletion analyses of this fragment suggested that a minimum of 100 nucleotides upstream of the transcription initiation site are required for induction by cadmium and zinc. The tMT-B promoter was also functional in the human hepatoblastoma cell line, suggesting that an MT regulatory factor(s) is conserved in phylogenetically distant species like humans and fish.

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Characterization of a Novel Glucose-Responsive Insulin-Secreting Cell Line, BRIN-BD11, Produced by Electrofusion

Diabetes ◽

10.2337/diab.45.8.1132 ◽

1996 ◽

Vol 45 (8) ◽

pp. 1132-1140 ◽

Cited By ~ 191

Author(s):

N. H. McClenaghan ◽

C. R. Barnett ◽

E. Ah-Sing ◽

Y. H. A. Abdel-Wahab ◽

F. P. M. O'Harte ◽

...

Keyword(s):

Cell Line ◽

Secreting Cell

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Structure of the rainbow trout metallothionein B gene and characterization of its metal-responsive region.

Molecular and Cellular Biology ◽

10.1128/mcb.8.10.4469 ◽

1988 ◽

Vol 8 (10) ◽

pp. 4469-4476 ◽

Cited By ~ 71

Author(s):

M Zafarullah ◽

K Bonham ◽

L Gedamu

Keyword(s):

Rainbow Trout ◽

Cell Line ◽

Binding Sites ◽

Transcription Initiation ◽

Hepatoma Cell ◽

Initiation Site ◽

Hepatoma Cell Line ◽

Flanking Region ◽

Chloramphenicol Acetyltransferase Gene

The trout metallothionein (MT) genes consist of two members. We describe the structure of the first fish MT (tMT-B) gene which shows an overall resemblance but some remarkable differences with mammalian MT genes. The similarities included (i) tripartite structure of the gene, (ii) conservation of cysteine residues, and (iii) a TATAAA signal and two copies of metal-responsive elements (MREs). The differences consisted of (i) an AT-rich tMT-B promoter compared with highly GC-rich mammalian MT promoters and (ii) a lack of SP1-binding sites in the tMT-B promoter. Functional analysis of the tMT-B 5'-flanking region following fusion with the bacterial chloramphenicol acetyltransferase gene and its transfection into the rainbow trout hepatoma cell line revealed that sequences from positions -600 to +8 are sufficient for regulation by metals. Further deletion analyses of this fragment suggested that a minimum of 100 nucleotides upstream of the transcription initiation site are required for induction by cadmium and zinc. The tMT-B promoter was also functional in the human hepatoblastoma cell line, suggesting that an MT regulatory factor(s) is conserved in phylogenetically distant species like humans and fish.

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