Skip to main content
Pearson+ LogoPearson+ Logo
Ch. 18 - Post-transcriptional Regulation in Eukaryotes
Klug - Concepts of Genetics  12th Edition
Klug12th EditionConcepts of Genetics ISBN: 9780135564776Not the one you use?Change textbook
Chapter 18, Problem 17

While circular RNAs were first described long ago, they have only recently been investigated for function. What are their known and suspected functions in the cell?

Verified step by step guidance
1
Understand that circular RNAs (circRNAs) are a type of non-coding RNA characterized by a covalently closed loop structure without 5' caps or 3' poly-A tails, which makes them resistant to exonucleases and more stable than linear RNAs.
Explore the known functions of circRNAs, such as acting as microRNA (miRNA) sponges, where they bind and sequester miRNAs, preventing these miRNAs from downregulating their target messenger RNAs (mRNAs).
Consider their role in regulating transcription and splicing by interacting with RNA-binding proteins or influencing the expression of their parental genes.
Investigate the suspected functions, including their potential involvement in protein translation, as some circRNAs have been found to contain internal ribosome entry sites (IRES) that may allow them to be translated into peptides.
Recognize the emerging evidence that circRNAs may play roles in cellular stress responses, development, and disease processes such as cancer, highlighting the importance of ongoing research to fully elucidate their functions.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
2m
Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Circular RNA Structure and Biogenesis

Circular RNAs (circRNAs) are a type of non-coding RNA characterized by a covalently closed loop structure without 5' or 3' ends. They are generated mainly through back-splicing events where a downstream splice donor joins an upstream splice acceptor, distinguishing them from linear RNAs.
Recommended video:

Functions of Circular RNAs

CircRNAs are known to regulate gene expression by acting as microRNA sponges, binding and sequestering microRNAs to prevent them from repressing target mRNAs. They may also interact with RNA-binding proteins and influence transcription or splicing, and some circRNAs can be translated into peptides.
Recommended video:

Biological Significance and Potential Roles

CircRNAs are implicated in various cellular processes including development, differentiation, and disease states like cancer and neurological disorders. Their stability and abundance suggest roles in post-transcriptional regulation and cellular signaling, though many functions remain under investigation.
Recommended video: