Part:BBa_K5310021
T2 hairpin arm
INTRODUCTION
The use of miRNAs as biomarkers and therapeutic molecules is seeing rapid advancements in the last decade. As a continuation of this, it is possible to combine the two functions with a mechanism that detects certain signature miRNAs of the disease and releases miRs with restorative effects based on a technique called Hybridization Chain Reaction.
MECHANISM OVERVIEW
The mechanism consists of two types of nucleic acid hairpins, a set of HCR hairpins and a T-shaped one. The first HCR hairpin is activated by an initiator molecule triggering a series of unbindings and hybridizations resulting in the release of two therapeutic molecules. The T hairpin recognizes the biomarker miRNAs and undergoes gradual unbinding of its arms upon which the initiator is released. It operates as a safety measure to make sure the HCR procedure mentioned above occurs in the right cells or tissue, where the therapeutic miRNAs should execute their function.
Different conditions are characterized by a different miRNA expression profile. It is therefore necessary to carefully select those according to which the hairpins would be designed. In the case of Multiple Sclerosis with the purpose of remyelination, one should examine which miRNAs are overexpressed in patient oligodendroglia (myelin generating cells) and which have the ability to enhance their desired function, while taking hairpin structure requirements into account. Upon literature review, discussions with neurologists and in silico testing, it was concluded that miR-125a-3p and miR-146a-5p are the biomarkers the T hairpin would be based on, whereas miR-219-5p and miR-338-3p are the remyelinating miRNAs released by HCR.
PART FUNCTION
This part design serves the overall function of the T hairpin (which is comprised of three arms; T1,T2,T3). It consists of two modules, T2a that is complementary to T3 and T2b that is complementary to T1. After the T1 arm (BBa_K5310020) is activated by miR-125a-3p and released (becoming an inactive molecule) , T2b is left exposed and binds to the other miRNA biomarker, miR-146a-5p, due to complementarity. The T2 arm is then released (also inactive) and frees the T3 arm which can now act as initiator for the HCR hairpin.
Sequence and Features
- 10INCOMPATIBLE WITH RFC[10]Illegal EcoRI site found at 9
- 12INCOMPATIBLE WITH RFC[12]Illegal EcoRI site found at 9
- 21INCOMPATIBLE WITH RFC[21]Illegal EcoRI site found at 9
- 23INCOMPATIBLE WITH RFC[23]Illegal EcoRI site found at 9
- 25INCOMPATIBLE WITH RFC[25]Illegal EcoRI site found at 9
- 1000COMPATIBLE WITH RFC[1000]
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