STTM (Short Tandem Mock Target) Technology

A non-coding protein gene, IPS1 (Induced by Phosphate Starvation 1), was first identified by Franco. Zorrillat 1 et al. in their study of Arabidopsis miR399. IPS1 is able to recognize and bind to miR399, and form incompletely complementary vesicle structures at the miRNA cleavage site (Figure 1), preventing miR399 from efficiently cleaving IPS1 RNA. In plants, cleavage of target mRNAs is an important mechanism of action for plant miRNAs, which can have a direct impact on the amount of protein accumulation 2 . The results of this study showed 3 that IPS1 overexpression could significantly inhibit the silencing effect of miR399 on the target gene PH02, i.e., IPS1 inhibited the function of miR399 (Figure II).

Artificial target mimicry of miRNA is the artificial design of the corresponding complementary oligonucleotide chain based on the nucleic acid sequence of miRNA. On the basis of this technique, the optimized design of MIMIC is carried out to form a non-cleaved MIMIC, specifically a MIMIC that is recognized and interacted with by miRNAs but cannot be cleaved by miRNAs.

Yan 4 et al. improved a new and more efficient miRNA silencing method based on the theoretical basis of the TM technique, short tandem target mimicry, which is a new method of miRNA silencing, and the short tandem target mimicry (short tandem target mimic, short tandem target mimic, short tandem target mimic). Based on the theory of TM technology, Yan 4 et al. improved a new and more efficient miRNA silencing method, the short tandem target mimic (STTM) technology, which consists of a 48-nt sequence that bridges two TMs, and a 3-base raised structure at the mi RNA cutting site of both TMs, which allows the mi RNAs to bind to them but not to cut them. In Yan et al.'s experiment, they constructed the STTM165/166 sequence in Arabidopsis thaliana (Figure 3), and inhibited the function of the mi RNA165/166 family by this simulated target sequence, and found that the control Arabidopsis thaliana grew in an upright position, with regularly shaped leaves and stems, whereas the mutant plants were short, curved, and had irregular leaves; and the STTM165/166 mutant was found to have an irregular shape when compared with the mutant constructed by the traditional TM technology. By comparing with the mutants constructed by the traditional TM technology, we found that the STTM mutants had more obvious phenotypes and deeper inhibition of mi RNA.