Related Experiment Video
Updated: Aug 15, 2026

Particle Agglutination Method for Poliovirus Identification
Published on: April 20, 2011
Poly(rC) binding proteins mediate poliovirus mRNA stability
K E Murray1, A W Roberts, D J Barton
1Department of Microbiology, University of Colorado Health Sciences Center, Denver 80262, USA.
Abstract:
The 5'-terminal 88 nt of poliovirus RNA fold into a cloverleaf RNA structure and form ribonucleoprotein complexes with poly(rC) binding proteins (PCBPs; AV Gamarnik, R Andino, RNA, 1997, 3:882-892; TB Parsley, JS Towner, LB Blyn, E Ehrenfeld, BL Semler, RNA, 1997, 3:1124-1134). To determine the functional role of these ribonucleoprotein complexes in poliovirus replication, HeLa S10 translation-replication reactions were used to quantitatively assay poliovirus mRNA stability, poliovirus mRNA translation, and poliovirus negative-strand RNA synthesis. Ribohomopoly(C) RNA competitor rendered wild-type poliovirus mRNA unstable in these reactions. A 5'-terminal 7-methylguanosine cap prevented the degradation of wild-type poliovirus mRNA in the presence of ribohomopoly(C) competitor. Ribohomopoly(A), -(G), and -(U) did not adversely affect poliovirus mRNA stability. Ribohomopoly(C) competitor RNA inhibited the translation of poliovirus mRNA but did not inhibit poliovirus negative-strand RNA synthesis when poliovirus replication proteins were provided in trans using a chimeric helper mRNA possessing the hepatitis C virus IRES. A C24A mutation prevented UV crosslinking of PCBPs to 5' cloverleaf RNA and rendered poliovirus mRNA unstable. A 5'-terminal 7-methylguanosine cap blocked the degradation of C24A mutant poliovirus mRNA. The C24A mutation did not inhibit the translation of poliovirus mRNA nor diminish viral negative-strand RNA synthesis relative to wild-type RNA. These data support the conclusion that poly(rC) binding protein(s) mediate the stability of poliovirus mRNA by binding to the 5'-terminal cloverleaf structure of poliovirus mRNA. Because of the general conservation of 5' cloverleaf RNA sequences among picornaviruses, including C24 in loop b of the cloverleaf, we suggest that viral mRNA stability of polioviruses, coxsackieviruses, echoviruses, and rhinoviruses is mediated by interactions between PCBPs and 5' cloverleaf RNA.
Insights
Poliovirus mRNA stability is mediated by poly(rC) binding proteins (PCBPs) interacting with the 5' cloverleaf structure. This interaction protects viral RNA from degradation, crucial for poliovirus replication.
Area of Science:
- Virology
- Molecular Biology
- RNA Biology
Background:
- Poliovirus RNA features a 5'-terminal cloverleaf structure forming ribonucleoprotein complexes with poly(rC) binding proteins (PCBPs).
- The functional role of these ribonucleoprotein complexes in poliovirus replication remains to be fully elucidated.
Purpose of the Study:
- To determine the functional role of PCBP-RNA complexes in poliovirus replication.
- To investigate the impact of PCBP binding on poliovirus mRNA stability, translation, and RNA synthesis.
Main Methods:
- Utilized HeLa S10 translation-replication reactions to assay poliovirus mRNA stability, translation, and negative-strand RNA synthesis.
- Employed ribohomopoly(C) RNA competitor and a C24A mutation to disrupt PCBP binding.
- Assessed the effect of a 5'-terminal 7-methylguanosine cap on mRNA stability.
Main Results:
- Ribohomopoly(C) destabilized wild-type poliovirus mRNA, an effect blocked by the 5' cap.
- PCBP binding, mediated by the 5' cloverleaf structure, is essential for poliovirus mRNA stability.
- A C24A mutation preventing PCBP binding rendered mRNA unstable, but did not affect translation or negative-strand RNA synthesis.
Conclusions:
- Poly(rC) binding proteins (PCBPs) mediate poliovirus mRNA stability through interaction with the 5'-terminal cloverleaf structure.
- This mechanism is likely conserved among picornaviruses, including coxsackieviruses, echoviruses, and rhinoviruses, influencing viral replication.
Related Concept Videos
RNA Stability
RNA Stability
Leaky Scanning
piRNA - Piwi-interacting RNAs
Poliomyelitis
Inhibitors of Viral Protein Synthesis

