• BMB Reports
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• v.33 no.2
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• pp.184-187
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• 2000

Prostaglandin $E_2$ ($PGE_2$) plays an important role in the regulation of various gastric functions, and the growth-inhibitory activities on tumor cells are studied in vitro and in vivo. Although the mechanisms have attracted many researchers in the past decade, the molecular mechanisms of cell cycle arrest, or induction of apoptosis by $PGE_2$, is unclear. We investigated the effects of $PGE_2$ on the growth of the human gastric carcinoma cell line SNU1 and genes that are regulated by $PGE_2$ and isolated them using differential display RT-PCR (DD RT-PCR). FACS analysis suggested that SNU1 cells were arrested at the G1 phase by $PGE_2$ treatment. This growth inhibitory effect was in a time- and dose-dependent manner. Treatment of SNU1 cells with $10\;{\mu}g/ml$ $PGE_2$, followed by DD RT-PCR analysis, revealed differently expressed bands patterns from the control. Among the differently expressed clones, we found an unidentified cDNA clone (HGP-27) overexpressed in $PGE_2$-treated cells. The full-length cDNA of HGP-27 was isolated using RACE, which consisted of a 30-nt 5'-noncoding region, a 891-nt ORF encoding the 296 amino acid protein, and a 738-nt 3'-noncoding region including a poly(a) signal. This gene was localized on the short arm of chromosome number 11. Using the Motif Finder program, a myb-DNA binding repeat signature was detected on the ORF region. The COOH-terminal half was shown to have similarity with the $NH_3$-terminal domain of thioredoxin (Trx). This relation between HGP-27 and Trx implied a potential role for HGP-27 in modulating the DNA binding function of a transcription factor, myb.

• Animal cells and systems
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• v.13 no.4
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• pp.447-452
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• 2009

We cloned the complete complementary DNA (cDNA) of a Pacific oyster (Crassostrea gigas) cytochrome P450 (CYP450)-related protein using rapid amplification of cDNA ends (RACE). The cDNA included a 1470 bp open reading frame that began with the first ATG codon at position 103 bp and ended with a TAG stop codon at position 1573 bp (GenBank accession EF451959). The sequence had all major functional domains and characteristics of previously characterized CYP450 molecules, including the heme-binding region (FGVGRRRCVG) and putative arginine codon (R) integral to enzymatic function. An NCBI/GenBank database comparison to other CYP450 genes revealed that the deduced C. gigas CYP450 amino acid sequence is similar to that of mouse (Mus musculus) CYP450 2D/II (28%, accession AK078880), rabbit (Oryctolagus cuniculus) CYP450 2D/II (28%, AB008785), and white-tufted-ear marmoset (Callithrix jacchus) CYP450 2D (28%, AY082602). Thus, although the C. gigas CYP450 we cloned appears to belong to the 2D type of the CYP450 group, it has low similarity to this type. CYP450 mRNA expression increased over 6 h in C. gigas gills at $30^{\circ}C$ and $10^{\circ}C$, and then decreased, indicating that CYP450 plays an important role in C. gigas exposed to water temperature changes. This finding can be used as a physiological index for Pacific oysters exposed to changing water temperatures.