Related Experiment Video
Updated: Jun 3, 2025
10:38
Large-scale Production of Recombinant RNAs on a Circular Scaffold Using a Viroid-derived System in Escherichia coli
Published on: November 30, 2018
9.6K
Viroids and Retrozymes: Plant Circular RNAs Capable of Autonomous Replication
Alexander A Lezzhov1, Anastasia K Atabekova1, Denis A Chergintsev1
1A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, 119992 Moscow, Russia.
Plants (Basel, Switzerland)
|January 11, 2025
Summary
Circular RNAs (circRNAs) are key regulators in eukaryotic cells. This review details non-replicating circRNAs, and replication-capable plant circRNAs like viroids and retrozymes, exploring their functions and applications.
Area of Science:
- Molecular Biology
- Plant Science
- RNA Biology
Background:
- Circular RNAs (circRNAs) are a distinct class of regulatory molecules produced by pre-mRNA back-splicing.
- Known functions include acting as miRNA sponges, forming R-loops, and encoding proteins.
- Plants possess unique replication-capable circRNAs: viroids and retrozymes, which are evolutionarily related.
Purpose of the Study:
- To review biogenesis and functions of non-replicating circRNAs.
- To detail structural features, replication, cellular interactions, and transport of plant viroids and retrozymes.
- To discuss biotechnological applications of replication-capable plant circRNAs.
Main Methods:
- Literature review and synthesis of existing data.
- Comparative analysis of circRNA types (back-splicing vs. replication-capable).
- Exploration of biotechnological potential.
Main Results:
- Non-replicating circRNAs have diverse regulatory roles.
- Viroids and retrozymes exhibit unique replication and transport mechanisms in plants.
- Replication-capable plant circRNAs offer significant biotechnological potential.
Conclusions:
- Circular RNAs encompass a broad range of structures and functions, from regulatory roles to infectious agents.
- Viroids and retrozymes represent a fascinating evolutionary link and a source of novel biotechnological tools.
- Further research into plant circRNAs can unlock new applications in agriculture and research.
Related Concept Videos
01:10Retrovirus Life Cycles
45.6K
Retroviruses have a single-stranded RNA genome that undergoes a special form of replication. Once the retrovirus has entered the host cell, an enzyme called reverse transcriptase synthesizes double-stranded DNA from the retroviral RNA genome. This DNA copy of the genome is then integrated into the host’s genome inside the nucleus via an enzyme called integrase. Consequently, the retroviral genome is transcribed into RNA whenever the host’s genome is transcribed, allowing the...
45.6K
02:33Retroviruses
12.2K
Retroviruses and retrotransposons both insert copies of their genetic elements into the genome of the host cell. Thus, the viral genes are passed on when the host genome is replicated or translated. A typical retroviral DNA sequence contains 3-4 genes that encode the different proteins required for its structural assembly and function as a molecular parasite. This DNA is transcribed into a single mRNA, which is very similar in structure to conventional mRNAs, i.e., it is capped at the 5’...
12.2K
02:30siRNA - Small Interfering RNAs
16.6K
Small interfering RNAs, or siRNAs, are short regulatory RNA molecules that can silence genes post-transcriptionally, as well as the transcriptional level in some cases. siRNAs are important for protecting cells against viral infections and silencing transposable genetic elements.
In the cytoplasm, siRNA is processed from a double-stranded RNA, which comes from either endogenous DNA transcription or exogenous sources like a virus. This double-stranded RNA is then cleaved by the...
In the cytoplasm, siRNA is processed from a double-stranded RNA, which comes from either endogenous DNA transcription or exogenous sources like a virus. This double-stranded RNA is then cleaved by the...
16.6K
01:23RNA Interference
25.9K
RNA interference (RNAi) is a process in which a small non-coding RNA molecule blocks the post-transcriptional expression of a gene by binding to its messenger RNA (mRNA) and preventing the protein from being translated.
This process occurs naturally in cells, often through the activity of genomically-encoded microRNAs. Researchers can take advantage of this mechanism by introducing synthetic RNAs to deactivate specific genes for research or therapeutic purposes. For example, RNAi could be used...
This process occurs naturally in cells, often through the activity of genomically-encoded microRNAs. Researchers can take advantage of this mechanism by introducing synthetic RNAs to deactivate specific genes for research or therapeutic purposes. For example, RNAi could be used...
25.9K
02:47Ribozymes
11.2K
The term ribozyme is used for RNA that can act as an enzyme. Ribozymes are mainly found in selected viruses, bacteria, plant organelles, and lower eukaryotes. Ribozymes were first discovered in 1982 when Tom Cech’s laboratory observed Group I introns acting as enzymes. This was shortly followed by the discovery of another ribozyme, Ribonulcease P, by Sid Altman’s laboratory. Both Cech and Altman received the Nobel Prize in chemistry in 1989 for their work on ribozymes.
Ribozymes can...
Ribozymes can...
11.2K
03:08LTR Retrotransposons
17.3K
LTR retrotransposons are class I transposable elements with long terminal repeats flanking an internal coding region. These elements are less abundant in mammals compared to other class I transposable elements. About 8 percent of human genomic DNA comprises LTR retrotransposons. Some of the common examples of LTR retrotransposons are Ty elements in yeast and Copia elements in Drosophila.
The internal coding region of LTR retrotransposons and their mechanism of transposition closely resembles a...
The internal coding region of LTR retrotransposons and their mechanism of transposition closely resembles a...
17.3K