Processing of pre-microrna to microrna

Processing of Pre-MicroRNA to MicroRNA Processing of Pre-MicroRNA to MicroRNA Introduction Within the body of animals, several developmental processes and pathologies take place. These processes and pathologies are responsible for the normal body functions. One of such process is the conversion of pre-MicroRNA to MicroRNA. To begin with, microRNAs are endogenously articulated nucleotide, characterized by the noncoding of RNAs. In normal biological development, microRNA expression is under snug control by two mechanisms, that is, transcriptional and post-transcriptional. This paper discusses the processing of pre-MicroRNA into MicroRNA. For this to happen, there are over five activities involved. Thus, the paper will also discuss the five activities of the processing of pre-MicroRNA into MicroRNA (Grosshans & Slack, 2002, pp. 17-19).
MicroRNAs Processing
In the study involving photogenic elements, scientists normally use samples from animals before testing their results on human beings. In most biochemical laborites, one would find mice especially the Drosophila, Arabidopsis, and elegans type. These animals provide some useful biochemical samples, which scientists study to inform on certain biological and biochemical issues. Just like human beings, mice also have microRNA. Through cloning and sequencing, scientists extract microRNA for study purposes. Various studies have shown that both human beings and mice have over two hundred to three hundred inimitable microRNA genes. The studies also explain that in organisms, human beings and mice included, microRNAs are homologous in nature. Consequently, this is a clear indication that microRNAs play significant roles by representing comparatively old and essential regulatory pathways (Gallo et al., 2006, pp. 6156-6159).
As seen above, the genome hosts pre-MicroRNA and other photogenic elements. Within the genome, sequence encoding of microRNA takes place. However, since there are mechanisms that control microRNA expression, the encoding of microRNA will involve only known genes. In most cases, these genes occur in various flimsy locations within the human chromosomes, and one of the chief characteristic about them their independently transcription shape. It is imperative to note that the primary microRNA transcripts (pre-microRNA) are the ones that encode strands of microRNA. In general, such encoding produces the microRNAs that have the same orientation as pre-microRNA. Clearly, this is an indication that there is a microRNA promoter, which is responsible for such transcriptions. In most cases, the genome stores microRNA genes, and here, these genes appear in form of cluster. Clustering of microRNA genes is so because during transcription, the microRNA genes change into multi-cistronic transcripts, and through the available mechanisms, they become mature microRNAs. The process of processing an active-stranded pre-microRNA into microRNA involves five major activities (Grosshans & Slack, 2002, pp. 20-12)
MicroRNA Processing and Activity
This is the first activity in the Processing of Pre-MicroRNA to MicroRNA. As already discussed above, pre-microRNA transcripts form the basis of processing pre-microRNA into microRNA. Within the genome, RNA polymerase II transliterates pre-microRNA strands. Other transcription materials include 3’ and 5’ caps poly (A) trails, which together with RNA Polymerase II change the pre-microRNA into hairpins surrounded by dsRNA-specific nuclease hew and some pointers—signals (Gallo et al., 2006, pp. 6160-6162).
Hairpin release in the nucleus
After the formation of the hairpin, the process moves into the second step where dsRNA-specific ribonuclease assimilates pre-microRNA within the nucleus and forms hairpin. The hairpin (precursor MicroRNA) exhibits characteristics such as RNAs, loops, overhangs and stems of specific measurements.
Export to the cytoplasm
From the nucleus, we note that the processed pre-microRNA moves to the cytoplasm for further processing. Exportin-5 is the one that is responsible for transportation, and performs other roles such as synchronization, pre-microRNA biogenesis, and other numerous cytoplasmic doling out activities (Yi, Qin, Macara & Cullen, 2003, pp. 3011-3016).
Dicer processing
Now, in the cytoplasm, another activity known as dice processing takes place. Here, the dice smites the pre-microRNA to produce double-stranded RNA characterized with overhangs at each end. Nevertheless, of the two strands, only one with a sheathing strand qualifies as mature microRNA.
Strand selection by RISC
This is the last activity in the processing of pre-microRNA into microRNA. Two paramount activities happen here: first, translation occurs in order to control the detaching of double-stranded RNA. Secondly, the introduction of RISC ensures that mature microRNA grows to become microRNA (Gallo et al., 2002, p. 3945).
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