Part:BBa_K1456004

Hypoxia Response Element(HRE)

According to the results, in hypoxic conditions comparing with normoxia, HRE been inserted into pTRE-luciferase vector shows 7 times more activity by producing more luciferase in HepG2 cell line. In HEK293 cell line, this activity is measured in hypoxia 1,5 times more than normoxia. This results prove that HRE sequence improves the production rate of desired protein in hypoxia comparing with normal oxygen levels.

• Hypoxia response elements (HREs) are 234 bp long small DNA sequences present in most of the body cells which work as binding domains for hypoxia inducible factor-1α (HIF-1α), a common transcription factor found in our body cells released during hypoxic conditions. (Semenza et al. 1992)
• We intend to add several HREs to the upstream region of weak constitutive promoter, PminiCMV, in order to design a novel hypoxia inducible promoter. We expect that in normal conditions with enough oxygen presence, PminiCMV promoter will express very small amount of mRNA which will be degraded soon conceivably. However, in hypoxic conditions, more transcription factors will hopefully bind to our designed HRE sites to enhance the transcription rate of PminiCMV promoter.
• According to the studies in the literature, HRE sequence has provided significant high transcription rate in hypoxic cells when it was attached on the upstream region of Simian virus 40 (SV40) promoter. (Tang et al. 2002) In this study, plasmids which contain HRE inducible promoters were presented in cell lines and the amount of these plasmids were increased gradually to test whether the detection level and transcription rate of hypoxia would raise. As a result, the production rate of reporter gene attached to HRE promoters increased 410 times more. This result encouraged us to use these sequences as novel, efficient and powerful hypoxic promoters in human cells.

Sequence and Features

Assembly Compatibility:

• 10
  COMPATIBLE WITH RFC[10]
• 12
  COMPATIBLE WITH RFC[12]
• 21
  INCOMPATIBLE WITH RFC[21]

  Illegal XhoI site found at 1
  Illegal XhoI site found at 21
  
• 23
  COMPATIBLE WITH RFC[23]
• 25
  COMPATIBLE WITH RFC[25]
• 1000
  COMPATIBLE WITH RFC[1000]