Lentiviral delivery of designed shRNAs and the mechanism of RNA interference in mammalian cells
RNA interference (RNAi) is a biological process in which RNA molecules are involved in sequence-specific suppression of gene expression by double-stranded RNA, through translational or transcriptional repression. Historically, RNAi was known by other names, including co-suppression, post-transcriptional gene silencing (PTGS), and quelling. The detailed study of each of these seemingly different processes elucidated that the identity of these phenomena were all actually RNAi. Andrew Fire and Craig C. Mello shared the 2006 Nobel Prize in Physiology or Medicine for their work on RNAi in the nematode worm Caenorhabditis elegans, which they published in 1998. Since the discovery of RNAi and its regulatory potentials, it has become evident that RNAi has immense potential in suppression of desired genes. RNAi is now known as precise, efficient, stable and better than antisense therapy for gene suppression.[1] Antisense RNA produced intracellularly by an expression vector may be developed and find utility as novel therapeutic agents.[2]
Two types of small ribonucleic acid (RNA) molecules, microRNA (miRNA) and small interfering RNA (siRNA), are central to components to the RNAi pathway. Once mRNA is degraded, post-transcriptional silencing occurs as protein translation is prevented. Transcription can be inhibited via the pre-transcriptional silencing mechanism of RNAi, through which an enzyme complex catalyzes DNA methylation at genomic positions complementary to complexed siRNA or miRNA. RNAi has an important role in defending cells against parasitic nucleotide sequences (e.g., viruses or transposons) and also influences development of organisms.
The RNAi pathway is a naturally occurring process found in many eukaryotes and animal cells. It is initiated by the enzyme Dicer, which cleaves long double-stranded RNA (dsRNA) molecules into short double-stranded fragments of approximately 21 to 23 nucleotide siRNAs. Each siRNA is unwound into two single-stranded RNAs (ssRNAs), the passenger (sense) strand and the guide (antisense) strand. The passenger strand is then cleaved by the protein Argonaute 2 (Ago2). The passenger strand is degraded and the guide strand is incorporated into the RNA-induced silencing complex (RISC). The RISC assembly then binds and degrades the target mRNA. Specifically, this is accomplished when the guide strand pairs with a complementary sequence in a mRNA molecule and induces cleavage by Ago2, a catalytic component of the RISC. In some organisms, this process spreads systemically, despite the initially limited molar concentrations of siRNA.[3]
RNAi is a valuable research tool, both in cell culture and in living organisms, because synthetic dsRNA introduced into cells can selectively and robustly induce suppression of specific genes of interest. RNAi may be used for large-scale screens that systematically shut down each gene (and the subsequent proteins it codes for) in the cell, which can help to identify the components necessary for a particular cellular process or an event such as cell division. The pathway is also used as a practical tool for food, medicine and insecticides.[4]
^Saurabh S, Vidyarthi AS, Prasad D (March 2014). "RNA interference: concept to reality in crop improvement". Planta. 239 (3): 543–64. Bibcode:2014Plant.239..543S. doi:10.1007/s00425-013-2019-5. PMID 24402564.
^Weiss B, Davidkova G, Zhou LW (March 1999). "Antisense RNA gene therapy for studying and modulating biological processes". Cellular and Molecular Life Sciences. 55 (3): 334–58. doi:10.1007/s000180050296. PMC 11146801. PMID 10228554. S2CID 9448271.
^Cite error: The named reference Matranga was invoked but never defined (see the help page).
^Kupferschmidt K (August 2013). "A lethal dose of RNA". Science. 341 (6147): 732–3. Bibcode:2013Sci...341..732K. doi:10.1126/science.341.6147.732. PMID 23950525.
RNAinterference (RNAi) is a biological process in which RNA molecules are involved in sequence-specific suppression of gene expression by double-stranded...
20–24 (normally 21) base pairs in length, similar to miRNA, and operating within the RNAinterference (RNAi) pathway. It interferes with the expression of...
RNA silencing or RNAinterference refers to a family of gene silencing effects by which gene expression is negatively regulated by non-coding RNAs such...
transfer RNA (tRNA), microRNA (miRNA), small interfering RNA (siRNA), small nucleolar RNA (snoRNAs), Piwi-interacting RNA (piRNA), tRNA-derived small RNA (tsRNA)...
some of which are topical and some of which are absorbed by the crop. RNAinterference is under study for use in spray-on insecticides (RNAi insecticides)...
first appeared in the literature in 1994 RNAinterference (RNAi) is a means of silencing genes by way of mRNA degradation. Gene knockdown by this method...
Dicer facilitates the activation of the RNA-induced silencing complex (RISC), which is essential for RNAinterference. RISC has a catalytic component Argonaute...
the catalytic functions of the RNA-induced silencing complex (RISC). In the well-known cellular process of RNAinterference, the argonaute protein in the...
predicted a role for the RNA transcript of spacers on target recognition in a mechanism that could be analogous to the RNAinterference system used by eukaryotic...
RNAinterference (RNAi). Expression of shRNA in cells is typically accomplished by delivery of plasmids or through viral or bacterial vectors. shRNA is...
other during meiosis RNAinterference, a process within living cells that moderates the activity of their genes Vaccine interference, interaction between...
resemble the small interfering RNAs (siRNAs) of the RNAinterference (RNAi) pathway, except miRNAs derive from regions of RNA transcripts that fold back on themselves...
sterility helps plant breeders make hybrid crops. RNAinterference (RNAIi) is the process in which a cell's RNA to protein mechanism is turned down or off in...
sense, the CRISPR-Cas9 mechanism has a number of parallels with the RNAinterference (RNAi) mechanism in eukaryotes. Apart from its original function in...
as RNAinterference (RNAi). Argonaute proteins bind different classes of small non-coding RNAs, including microRNAs (miRNAs), small interfering RNAs (siRNAs)...
sRNAs by RNAinterference such as Host-Induced Gene Silencing (HIGS). The transport of RNA between plants and fungi seems to be bidirectional as sRNAs...
Physiology or Medicine, along with Craig C. Mello, for the discovery of RNAinterference (RNAi). This research was conducted at the Carnegie Institution of...
Transfer RNA (abbreviated tRNA and formerly referred to as sRNA, for soluble RNA) is an adaptor molecule composed of RNA, typically 76 to 90 nucleotides...
repeats) pathway, the technique provides a complementary approach to RNAinterference. The difference between CRISPRi and RNAi, though, is that CRISPRi regulates...
attributed to the RNAinterference pathway, potentially through cleaving siRNA molecules; to cleavage of transfer RNA; and to interference with the NF-κB...
compounds which are analogous (structurally similar) to naturally occurring RNA and DNA, used in medicine and in molecular biology research. Nucleic acids...
defective in the cell cycle in S. cerevisiae and S. pombe, respectively. RNAinterference (RNAi) screen is essentially a forward genetics screen using a reverse...
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