The Entamoeba histolytica Ehcp112 gene has a distal and weak promoter
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- 作者：Flores-Soto ; E. ; Azuara-Liceaga ; E. ; L??pez-Camarillo ; C. ; Orozco ; E.
- 刊名：Experimental Parasitology
- 出版年：2005
- 出版时间：July, 2005
- 年：2005
- 卷：110
- 期：3
- 页码：286-291
- 全文大小：521 K
文摘
Ehcp112 encodes the Entamoeba histolytica EhCP112 cysteine protease that is part of the EhCPADH complex. By in silico analysis we identified putative transcription factor-binding sites along 837 bp upstream the Ehcp112 gene ATG codon. A TATA-like motif (TATATAAA) was located at −36 to −29 bp, a GAAC box (GAACC) was found at −10 to −14 bp and an Inr sequence (TTCAAC) at −8 to −2 bp. These tripartite promoter elements are in non-canonical positions, downstream the transcription initiation site (−280 bp). We cloned four Ehcp112 promoter fragments in pBSCAT-ACT plasmid to obtain pI (355 bp), pII (681 bp), pIII (833 bp), and pIV (554 bp) constructs. In transfected trophozoites, only pIII drove CAT activity with 44 % efficiency in relation to actin promoter activity. Our results showed the presence of a distal and weak promoter in the Ehcp112 gene. The active DNA region is inside the open reading frame of the Ehrab B gene, suggesting that expression of both genes could be coordinately regulated.