Leader RNA binding ability of chandipura virus P protein is regulated by its phosphorylation status: a possible role in genome transcription-replication switch

Basak, Soumen and Raha, Tamal and Chattopadhyay, Debasish and Majumde, Amitabha and Shaila, MS and Chattopadhyay, DJ (2003) Leader RNA binding ability of chandipura virus P protein is regulated by its phosphorylation status: a possible role in genome transcription-replication switch. In: Virology, 307 (2). pp. 372-385.

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Abstract

The molecular events associated with the transcriptive and replicative cycle of negative-stranded RNA viruses are still an enigma. We took Chandipura virus, a member of the Rhabdoviridae family, as our model system to demonstrate that Phosphoprotein P, besides Nucleocapsid protein N, also acts as a leader RNA-binding protein in its unphosphorylated form, whereas CKII-mediated phosphorylation totally abrogates its RNA-binding ability. However, interaction between P protein and leader RNA can be distinguished from N-mediated encapsidation of viral sequences. Furthermore, P protein bound to leader chain can successively recruit N protein on RNA while itself being replaced. We also observed that the accumulation of phosphorylation null mutant of P protein in cells results in enhanced genome RNA replication with concurrent increase in the viral yield. All these results led us to propose a model explaining viral transcription-replication switch where Phosphoprotein P acts as a modulator of genome transcription and replication by its ability to bind to the nascent leader RNA in its unphosphorylated form, promoting read-through of the transcription termination signals and initiating nucleocapsid assembly on the nascent RNA chain.

Item Type:	Journal Article
Publication:	Virology
Publisher:	Elsevier Science
Additional Information:	Copyright of this article belongs to Elsevier Science.
Keywords:	Leader RNA;Phosphoprotein;Transcription;Replication; Chandipura virus.
Department/Centre:	Division of Biological Sciences > Microbiology & Cell Biology
Date Deposited:	31 Aug 2009 08:08
Last Modified:	19 Sep 2010 04:55
URI:	http://eprints.iisc.ac.in/id/eprint/17090

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