Illustration of a circular RNA molecule, depicting the core concept of the article.

Decoding the Circle: How Scientists Are Unraveling the Mysteries of Circular RNA

Lena Kashyap in Science & Nature June 2025 • 5 min read.

"From the Lab to the Body: Exploring the Revolutionary World of Circular RNA and Its Impact on Gene Expression"

For decades, scientists believed that the world of RNA was primarily a linear affair, with molecules following a straightforward path from DNA instructions to protein production. But the scientific landscape is constantly evolving, and this long-held belief is now being challenged by the emergence of circular RNA (circRNA). These unique molecules, found in both plants and animals, are not linear strands, but closed loops, and their discovery is reshaping our understanding of gene expression.

Recent research has revealed that circRNAs are far more prevalent than previously imagined, playing a significant role in various biological processes. These molecules are not merely byproducts of cellular activity; they have the potential to regulate gene expression, act as sponges for microRNAs (miRNAs), and even code for proteins themselves. As researchers delve deeper, they are uncovering the mechanisms behind circRNA biogenesis, their functions, and their potential as therapeutic targets.

This article dives into the fascinating world of circRNAs, exploring their origins, how they differ from traditional RNA, and the latest discoveries that are transforming our understanding of cellular processes. We will examine the work of researchers who are meticulously mapping the pathways of circRNA production and the implications of these findings for our health and well-being. Get ready to explore the revolutionary world of circRNA and its potential to reshape the future of medicine.

What is Circular RNA and How Does It Differ?

Illustration of a circular RNA molecule, depicting the core concept of the article.

Unlike the well-known messenger RNA (mRNA), which carries genetic information from DNA to ribosomes for protein synthesis in a linear fashion, circRNAs form a closed-loop structure. This unique circularity is what sets them apart. Traditional mRNA molecules have a 5' end (the beginning) and a 3' end (the end), while circRNAs lack these free ends, forming a continuous loop. This structural difference grants circRNAs several key advantages, including increased stability and resistance to degradation by cellular enzymes.

The process by which cells create circRNAs is called 'backsplicing', a process where the normal splicing of RNA is reversed. This process involves the joining of the 3' end of an exon (a coding segment) to its own 5' end. This creates the circular structure, and the resulting circRNA can perform various regulatory functions within the cell, such as binding to microRNAs or acting as a template for protein synthesis. The increased stability of circRNAs allows them to persist longer in the cell, influencing cellular processes for extended periods.

Structure: Unlike linear mRNA, circRNAs form a closed loop without free ends.
Biogenesis: Produced through a 'backsplicing' process.
Stability: CircRNAs are more stable and resistant to degradation.
Function: Involved in gene regulation, miRNA sponging, and protein coding.

The discovery of circRNAs has opened a new frontier in molecular biology, and scientists are now racing to unravel their roles in health and disease. The unique structure and stability of these molecules suggest that they may serve as valuable biomarkers, therapeutic targets, and tools for understanding complex biological pathways. Further research is critical to fully understand their functionality and how to use them.

Looking Ahead: The Future of Circular RNA Research

The study of circRNAs is still in its early stages, but the potential implications are immense. As researchers continue to decipher the intricacies of circRNA biogenesis and function, new avenues for diagnostics and therapeutics will likely emerge. From understanding fundamental biological processes to developing innovative treatments for various diseases, the world of circular RNA holds exciting prospects for the future of medicine and molecular biology. The journey has just begun, but the discoveries made so far have set the stage for a remarkable revolution.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.7554/elife.07540, Alternate LINK

Title: Circular Rna Biogenesis Can Proceed Through An Exon-Containing Lariat Precursor

Subject: General Immunology and Microbiology

Journal: eLife

Publisher: eLife Sciences Publications, Ltd

Authors: Steven P Barrett, Peter L Wang, Julia Salzman

Published: 2015-06-09

Everything You Need To Know

What is Circular RNA (circRNA), and how does its structure differ from messenger RNA (mRNA)?

Circular RNA (circRNA) is a unique type of RNA molecule that forms a closed-loop structure, unlike messenger RNA (mRNA), which is linear. mRNA has a 5' end and a 3' end, while circRNA lacks these free ends, creating a continuous loop. This circular structure gives circRNAs greater stability and resistance to degradation by cellular enzymes, setting them apart from their linear counterparts. This allows them to persist longer within the cell, potentially influencing cellular processes for extended periods.

How are Circular RNAs (circRNAs) produced, and what is the 'backsplicing' process?

Circular RNAs (circRNAs) are produced through a process called 'backsplicing'. This is a reversed form of the normal RNA splicing process. During backsplicing, the 3' end of an exon (a coding segment) is joined to its own 5' end. This creates the circular structure of circRNA. This is different from how traditional mRNA is formed, which involves splicing where introns are removed and exons are joined in a linear fashion.

What are the key functions of Circular RNAs (circRNAs) within the cell?

Circular RNAs (circRNAs) have several key functions within the cell. They are involved in gene regulation, helping to control the expression of genes. They can also act as 'sponges' for microRNAs (miRNAs), binding to these small regulatory molecules and preventing them from silencing their target messenger RNAs. Furthermore, some circRNAs can even code for proteins themselves, expanding their functional role in cellular processes. The increased stability of circRNAs contributes to their ability to perform these regulatory functions for extended periods.

Why is the study of Circular RNAs (circRNAs) important for the future of medicine?

The study of Circular RNAs (circRNAs) is crucial for the future of medicine because of their potential as biomarkers, therapeutic targets, and tools for understanding complex biological pathways. The unique structure and stability of circRNAs suggest that they could be used to diagnose diseases. They may also serve as targets for therapies. The discoveries made so far have set the stage for a remarkable revolution in the future of medicine and molecular biology. As researchers continue to decipher the intricacies of circRNA biogenesis and function, new avenues for diagnostics and therapeutics will likely emerge, potentially leading to innovative treatments for various diseases.

How do Circular RNAs (circRNAs) impact gene expression, and what are the implications of this for understanding diseases?

Circular RNAs (circRNAs) play a significant role in gene expression by regulating the activity of other molecules involved in protein synthesis. They can act as 'sponges' for microRNAs (miRNAs), which are small RNA molecules that regulate gene expression by binding to messenger RNAs (mRNAs) and preventing protein production. By binding to miRNAs, circRNAs can alter the levels of proteins produced by a cell. Furthermore, some circRNAs can code for proteins themselves. This impact on gene expression makes circRNAs central to understanding diseases. Dysregulation of circRNA expression can lead to various diseases, highlighting their potential as therapeutic targets. The implications are immense: understanding the role of circRNAs in gene expression could lead to new ways of diagnosing and treating a wide range of illnesses.