A-to-I mRNA Editing in Animals Latest News
Researchers from China recently reported that it’s hard to make sense of the widespread persistence of A-to-I mRNA editing in animals.
Concept and Mechanism
- DNA acts like a recipe book for building proteins using 20 amino acids. Each recipe (i.e., gene) is transcribed into messenger RNA (mRNA).
- The mRNA is then read by ribosomes to assemble proteins. The mRNA is composed of four nucleotide bases: A (adenosine), U, G, and C.
- In A-to-I mRNA editing, the adenosine (A) in mRNA is enzymatically converted into inosine (I) by proteins called ADARs (Adenosine Deaminase Acting on RNA).
- The ribosome reads inosine as guanine (G), altering the protein’s amino acid sequence post-transcriptionally, without any change in the DNA.
- Functional Impact: A-to-I editing can change the codon identity, thereby producing a different amino acid in the resulting protein.
- This may lead to functional protein diversification and alteration in protein stability or activity.
- A major risk is misreading stop codons:
- A stop codon like UAG or UGA may be edited to UGG, coding for tryptophan.
- This allows the ribosome to continue protein synthesis, potentially creating abnormally long or malfunctioning proteins.
Discovery of PSC Genes
- Researchers identified 71 genes in F. graminearum that contain premature stop codons (UAG) in their unedited mRNA.
- These were termed PSC (premature stop codon-containing) genes.
- Deleting these genes had:
- No impact during asexual growth.
- But significant disruption during sexual development, proving the essentiality of A-to-I editing in these stages.
A-to-I mRNA Editing in Animals FAQs
Q1: What is A-to-I mRNA editing?
Ans: A-to-I mRNA editing is a post-transcriptional RNA modification where adenosine (A) is converted to inosine (I) by the ADAR (Adenosine Deaminase Acting on RNA) enzyme.
Q2: What is the significance of inosine in mRNA?
Ans: Inosine is read as guanosine (G) by the cellular machinery, which can alter the resulting protein sequence, potentially affecting its function.
Source: TH
Last updated on July, 2025
→ UPSC Notification 2025 was released on 22nd January 2025.
→ UPSC Prelims Result 2025 is out now for the CSE held on 25 May 2025.
→ UPSC Prelims Question Paper 2025 and Unofficial Prelims Answer Key 2025 are available now.
→ UPSC Calendar 2026 is released on 15th May, 2025.
→ The UPSC Vacancy 2025 were released 1129, out of which 979 were for UPSC CSE and remaining 150 are for UPSC IFoS.
→ UPSC Mains 2025 will be conducted on 22nd August 2025.
→ UPSC Prelims 2026 will be conducted on 24th May, 2026 & UPSC Mains 2026 will be conducted on 21st August 2026.
→ The UPSC Selection Process is of 3 stages-Prelims, Mains and Interview.
→ UPSC Result 2024 is released with latest UPSC Marksheet 2024. Check Now!
→ UPSC Toppers List 2024 is released now. Shakti Dubey is UPSC AIR 1 2024 Topper.
→ Also check Best IAS Coaching in Delhi
Tags: a-to-i mrna editing in animals Prelims Pointers upsc current affairs upsc prelims current affairs