What is circular RNA?

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What is circular RNA? Blog Image


Recently, researchers from the Indian Institute of Science Education and Research Bhopal (IISER Bhopal) identified a specific circular RNA (circRNA) called ‘ciTRAN’, which plays a crucial role in the multiplication of the AIDS-causing HIV-1 virus within the human body.

About circular RNA:

  • Ribonucleic acid is a molecule in living cells that carries genetic information and helps in the production of proteins.
  • RNAs are in general straight-chain, free-end structures but these circular RNA (‘circRNA’ ) forms a closed-loop.
  • The circRNA plays a pivotal role in regulating gene expression and is essential for various biological processes.
  • Its role in HIV-1 replication has remained unclear for a long time.
  • Characterizing circular RNA can be tricky because it usually is less abundant, making it further challenging to detect in the native form.
  • During viral infections, there's so much information from the virus that it can make it hard to find the less common ones like circular RNA.


Highlights about the recent findings

  • The researchers developed a novel approach called ‘circDR-Seq’, to successfully capture circRNAs from T-cells (white blood cells) infected with the HIV-1 virus and identified a specific circRNA named ciTRAN, which plays an important role in the multiplication of the virus.
  • HIV-1 viral protein R (VpR) is a multifunctional protein that plays specific roles at multiple stages of the HIV-1 viral life cycle and affects anti-HIV functions of the immune cells.
  • Further found that HIV-1 infection induces ciTRAN expression in a Vpr-dependent manner and that ciTRAN interacts with serine/arginine-rich splicing factor 1 (SRSF1), a protein known to repress HIV-1 transcription,”
  • How does this work?
    • The results suggest that HIV-1 hijacks ciTRAN which is generally altered during immunological signaling, inflammation, and viral infection.
    • It further prevents (SRSF1) from doing its job, thereby promoting efficient viral transcription. 
    • In addition, researchers demonstrated that an SRSF1-inspired mimic can inhibit viral transcription regardless of ciTRAN induction.
    • The hijacking of a host circRNA thus represents a previously unknown facet of primate lentiviruses in overcoming transmission bottlenecks.


Q1) What is Gene?

It is a fundamental unit of heredity in biology. It is a segment of DNA (deoxyribonucleic acid) that contains the instructions for building and maintaining an organism. Genes carry the information needed to create and regulate proteins, which are the building blocks of cells and perform various functions in the body.

Source: IISER Bhopal scientists develop novel molecule that can hinder viral transcription of HIV-1 virus