| Budget Amount *help |
¥3,200,000 (Direct Cost: ¥3,200,000)
Fiscal Year 2000: ¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 1999: ¥1,800,000 (Direct Cost: ¥1,800,000)
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| Research Abstract |
We have located a new cis-element, trophoblast-specific element 2 (TSE2) is located in the placenta-specific enhancer of the human aromatase gene that dictates its tissue-specific expression. In the minimum enhancer region, an element similar to the trophoblast-specific element (TSE), originally described for the human chorionic gonadotropin alpha-subunit gene, also exists (Yamada, K., et al. 1995 J.Biol.Chem.270, 25064-25069). The co-presence of TSE and TSE2 is required to direct trophoblast-specific expression driven by a heterologous thymidine kinase promoter.
A 2562-base pair cDNA clone encoding a 436-amino acid protein that binds to TSE2 was isolated from a human placental cDNA library using a yeast one-hybrid system with the TSE2 as a reporter sequence. The protein was revealed to be identical to hGCMa, a mammalian homologue of the Drosophila GCM (glia cells missing) protein.
Expression of hGCMa is restricted to the placenta. The protein expressed in Sf 21 cells also binds to PLE1 in the leptin promoter among other cis-elements reported to confer placenta-specific expression, suggesting that hGCMa is a placenta-specific transcription regulator, possibly involved in the expression of multipleplacenta-specific genes.(Yamada, K.et al, 1999 J.Biol.Chem.274 : 32279-86)
We also analyzed the genomic organization, chromosomal localization, and the complete 22 kb DNA sequence of the gene. It contains six exons and five introns, encoding a 2.8 kb cDNA.Overall genomic organization is similar for the human and mouse. Several potential binding sites for transcription factors like GATA, Oct-1, and bHLH proteins were found in the 5'-flanking region of the human gene. A DNA motif for GCM protein binding exists in the 5'-flanking region that is highly homologous with that of the mouse gene. The location of this gene was mapped to chromosome 6 using fluorescence in situ hybridization.(Yamada, k. et al, Biochem Biophys Res Commun 2000 278, 134-139)
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