The beta hairpin structure within ribosomal protein S5 mediates interplay between domains II and IV and regulates HCV IRES function

Bhat, Prasanna and Shwetha, Shivaprasad and Sharma, Divya Khandige and Joseph, Agnel Praveen and Srinivasan, Narayanaswamy and Das, Saumitra (2015) The beta hairpin structure within ribosomal protein S5 mediates interplay between domains II and IV and regulates HCV IRES function. In: NUCLEIC ACIDS RESEARCH, 43 (5). pp. 2888-2901.

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Abstract

Translation initiation in Hepatitis C Virus (HCV) is mediated by Internal Ribosome Entry Site (IRES), which is independent of cap-structure and uses a limited number of canonical initiation factors. During translation initiation IRES-40S complex formation depends on high affinity interaction of IRES with ribosomal proteins. Earlier, it has been shown that ribosomal protein S5 (RPS5) interacts with HCV IRES. Here, we have extensively characterized the HCV IRES-RPS5 interaction and demonstrated its role in IRES function. Computational modelling and RNA-protein interaction studies demonstrated that the beta hairpin structure within RPS5 is critically required for the binding with domains II and IV. Mutations disrupting IRES-RPS5 interaction drastically reduced the 80S complex formation and the corresponding IRES activity. Computational analysis and UV cross-linking experiments using various IRES-mutants revealed interplay between domains II and IV mediated by RPS5. In addition, present study demonstrated that RPS5 interaction is unique to HCV IRES and is not involved in 40S-3 ` UTR interaction. Further, partial silencing of RPS5 resulted in preferential inhibition of HCV RNA translation. However, global translation was marginally affected by partial silencing of RPS5. Taken together, results provide novel molecular insights into IRES-RPS5 interaction and unravel its functional significance in mediating internal initiation of translation.

Item Type:	Journal Article
Publication:	NUCLEIC ACIDS RESEARCH
Publisher:	OXFORD UNIV PRESS
Additional Information:	Copy right for this article belongs to the OXFORD UNIV PRESS, GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND
Keywords:	HEPATITIS-C-VIRUS; ENTRY SITE; TRANSLATION INITIATION; 80S RIBOSOME; MUTATIONAL ANALYSIS; 40S RIBOSOME; RNA; SUBUNIT; HCVIRES; REGIONS
Department/Centre:	Division of Biological Sciences > Molecular Biophysics Unit Division of Biological Sciences > Microbiology & Cell Biology
Date Deposited:	13 May 2015 07:21
Last Modified:	13 May 2015 07:21
URI:	http://eprints.iisc.ac.in/id/eprint/51527

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