Difference between revisions of "Part:BBa K3335010"

Latest revision as of 13:11, 22 October 2020

Expression systems of KRAS, PD-L1 and CD47 siRNA under the control of rtTA and tTS

The rtTA protein is capable of binding the operator only if bound by a tetracycline and activate the expression of TRE-controlled genes in a Tet-On system. Thus the introduction of doxycycline to the system initiates the transcription of the genetic product. On the contrast tetracycline-dependent transcriptional silencer (tTS) binds the tetO inducible promoter in the absence of Dox, thus expression of TRE-controlled genes can be repressed.

The entirety of several TetO sequences with a minimal promoter is called a tetracycline response element (TRE). The rtTA protein is capable of binding the operator only if bound by a tetracycline and activate the expression of TRE-controlled genes in a Tet-On system. Thus the introduction of doxycycline to the system initiates the transcription of the genetic product. On the contrast tetracycline-dependent transcriptional silencer (tTS) binds the tetO inducible promoter in the absence of Dox, thus expression of TRE-controlled genes can be repressed.

iRGD is a 9-amino acid cyclic peptide (sequence: CRGDKGPDC) and a molecular mimicry agent that was originally identified in an in vivo screening of phage display libraries in tumor-bearing mice.The peptide was able to home to tumor tissues, but in contrast to standard RGD (Arginylglycylaspartic acid) peptides, also spread much more extensively into extravascular tumor tissue.This part is intend for expression of targeted iRGD peptide and degradation of KRAS PD-L1 and CD47 mRNA in tumor cells.

The albumin promoter ensures that gene sequences are expressed only in liver cells.At the same time, rtTA and tTs Parts guarantee that the downstream gene will only begin to be expressed when DOX enters.Downstream gene expression IRGD-LAMP2B completes exosome targeting and simultaneously expresses siRNA targeting CD47, KRAS and PD-L1.

Sequence and Features