Abstract
Trocarin D from the Tropidechis carinatus venom (TrTD) is a prothrombin activator sharing similar structure and function with blood coagulation factor Xa (FXa). It is probaly evolved from its plasma counterpart (TrFX) by gene duplication. The gene sequences of TrTD and TrFX are highly similar, except for the promoter and intron 1 regions. The insertion in the promoter region of TrTD (VERSE—VEnom Recruitment/Switch Element) accounts for elevated but not tissue specific expression of TrTD. The insertions/deletions intron 1 were examined for their “silencing” role in non-venom gland cells. Using a series of deletion luciferase reporter assays, the strongest silencing cis-elements were located in a 193 bp fragment within the insertion 2 segment (1975 bp). This segment has multiple silencing cis-elements that turn off gene expression synergistically. Several silencer binding transcription factors (TFs) were identified using DNA affinity chromatography and mass spectrometry. The findings here highlight the importance of intron 1 for TrTD venom gland-specific expression, and will contribute to understanding the transcriptional silencing mechanisms of TrTD in non venom gland tissues.
Original language | English |
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Journal | FASEB Journal |
Publication status | Published - 1 Apr 2013 |
Externally published | Yes |