RNAs That Behave Like Prions.

Area of Science:

• Molecular Biology
• Genetics
• Biochemistry

Background:

• Prions are traditionally defined as protein-based infectious agents causing neurological disorders.
• Existing definitions focus on protein self-replication and transmission, but not all prions exhibit toxicity or infectivity.
• A broader understanding is needed to encompass diverse self-propagating elements.

Purpose of the Study:

• To propose an expanded definition of prions.
• To include RNA-based entities capable of autocatalytic conversion and transmissible phenotypic effects.
• To re-evaluate naturally occurring RNAs within this expanded prion framework.

Main Methods:

• Conceptual analysis and redefinition of prion characteristics.
• Identification of RNA molecules exhibiting prion-like properties.
• Comparison of RNA behaviors (ribozymes, riboswitches, viroids, retroelements, piRNAs) with proposed prion criteria.

Main Results:

• The study proposes broadening the prion definition to encompass inducible, transmissible entities that undergo autocatalytic conversion.
• It identifies several naturally occurring RNA molecules, including ribozymes and PIWI-interacting RNAs (piRNAs), that fit this expanded definition.
• These RNA molecules demonstrate characteristics analogous to proteinaceous prions, such as self-replication and transmission.

Conclusions:

• The traditional protein-centric view of prions is limiting.
• An expanded definition including RNA-based elements offers a more comprehensive understanding of self-propagating biological entities.
• Naturally occurring RNAs like ribozymes and piRNAs exhibit prion-like characteristics, suggesting a broader role for RNA in biological inheritance and function.