Trans-acting siRNA

Trans-acting siRNA is the form small interfering RNA to inhibit gene expression through post-transcriptional gene silencing in land plants (sometimes “tasiRNA” or “TAS”, “TA-Sirna” for short) of (Sirna),. TA-siRNA is transcribed from the genome in order to form receiving polyadenylation occurring segments 21 nucleotide RNA processing is further a segment of double-stranded RNA. These segments are incorporated directly to the cutting of the target mRNA RNA derived muffle complex with (RISC). TA-siRNA is the siRNA is, I obtained double-stranded RNA, such as they are called and so go through the same process from (dsRNA). However, the TA-siRNA, siRNA of the other associated with a sequence specificity thereof is less its target are different. Because they do not require a complete complementary sequences to direct cleavage of the target RNA, they will function as a micro RNA many.

I have found in 2004 by a group of two different laboratory studies of Arabidopsis flowering plant originally presence of TA-siRNA. Thesis of both, was published in October within days of each other. Research lab group proteins and other Argonaute Genki (ZIP), is trying to identify the (Sirna) time specific small interfering RNA. Despite the development of various places, protein inhibition of specific gene silencing 3 (SGS3), research group, found the project and related to the plant enzyme RNA-dependent RNA polymerase 6 (RDR6). It is important for the production of small RNA group called the TA-siRNA of (sRNAs) and RDR6 SGS3, both groups. Because in spite of sharing the similarity of micro RNA (miRNA) dove, siRNA was a new discovery Ta-siRNA is sRNAs distinction significant difference other. miRNA are different, it, siRNA of Ta is that derived from (dsRNA) longer double-stranded RNA, the product is RDR6 dependence was found. The TA-siRNA, siRNA is different transcripts are not identical, because they direct cleavage. Accordingly, TA-siRNA are functionally similar to the miRNA, but was prepared in the same manner as the siRNA.

Generated by antisense transcription by Argonaut guide of the miRNA-mediated cleavage followed by conversion of double-stranded RNA by RDR6 gene silencing to suppress 3 (SGS3) and RNA-dependent RNA polymerase TA-siRNA. In order to obtain the phase sequence of the siRNA of 21-NT, dsRNA produced is processed by a (DCL4) enzyme 4 dicer-like addition. starting from the cleavage site of the miRNA. There are four families of TA-siRNA. Their name from the location of TAS gene family because they have been transferred. The binding site for the mRNA cleavage of TAS3 on release, you need to require the binding sites of two family and TAS1, TAS2 TAS4.

I do not have many similarities to the gene of the draw method of the siRNA is intrinsic TA-siRNA by means straight jamming that the gene is subject to repression and cutting. Or is the same as the cis-acting, they are produced, mute the expression of genes that have many similarities with the gene from there, endogenous siRNA of other running to suppress automatically, this is different have. It miRNA that exhibits hetero jamming had been previously thought. As siRNA other, the TA-siRNA, it is being incorporated RNA-induced silencing complex that inhibits the translation target complex with the target mRNA for cleavage in the middle of locations further (RISCs).

Each member of the Argonaute protein family, is a component of a siren total RNA, an effector complex comprising a catalytic RISCs mRNA cleavage. In Arabidopsis, it plays the role of the time of acting TA-siRNA when subjected to regulation by the TA-siRNA, TAS3 seems AGO7/ZIPPY in particular. It is associated with the target of the cutting thereof by the TAS3 TA-siRNA AGO7/ZIPPY. It does not seem to suggest that different families AGO7/ZIPPY has minor variations of the mechanism in Arabidopsis thaliana, to play the role of TAS1 TAS2 TA-siRNA and mechanism. In addition to participating AGO7, TA-siRNA is able to guide cleavage of the target mRNA, to be loaded into AGO1 complexes in Arabidopsis.

In addition to be present in Arabidopsis, evidence also of the TA-siRNA, it has been found in strains patens, maize, rice Satibaine. Trans-acting short interfering RNA auxin response factor (tasiR-ARF) is an example not only that it does not Arabidopsis, is present in the previous embodiment, all have been proved, the TA-siRNA. The TasiR-ARF, is responsible for regulating the signaling molecule auxin. This is accomplished by directing mRNA encoding auxin response factors of several to decompose (ARF) gene.