Leader RNA of Rinderpest virus binds specifically with cellular La protein: a possible role in virus replication

Abstract

Rinderpest virus (RPV) is an important member of the Morbillivirus genus in the family Paramyxoviridae and employs a similar strategy for transcription and replication of its genome as that of other negative sense RNA viruses. Cellular proteins have earlier been shown to stimulate viral RNA synthesis by isolated nucleocapsids from purified virus or from virus-infected cells. In the present work, we show that plus sense leader RNA of RPV, transcribed from 3' end of genomic RNA, specifically interacts with cellular La protein employing gel mobility shift assay as well as UV cross-linking of leader RNA with La protein. The leader RNA synthesized in virus-infected cells was shown to interact with La protein by immunoprecipitation of leader RNA bound to La protein and detecting the leader RNA in the immunoprecipitate by Northern hybridization with labeled antisense leader RNA. Employing a minireplicon system, we demonstrate that transiently expressed La protein enhances the replication/transcription of the RPV minigenome in cells. Sub-cellular immunolocalization shows that La protein is redistributed from nucleus to the cytoplasm upon infection. Our results strongly suggest that La protein may be involved in regulation of Rinderpest virus replication.

Polypyrimidine tract-binding protein is relocated to the cytoplasm and is required during dengue virus infection in Vero cells

“…Consequently, it is likely that, during the replicative cycle, viral RNA remains associated with several cellular and viral proteins. This fact correlates with multiple reports regarding the participation of host factors in the replicative cycle of positive-strand RNA viruses (Chang & Lou, 2006;Meerovitch et al, 1993;Paranjape & Harris, 2007;Polacek et al, 2009;Raha et al, 2004). For DENV, one of the proteins that interacts with the 39UTR is PTB (De Nova-Ocampo et al, 2002).…”

The Cellular Protein La Functions in Enhancement of Virus Release through Lipid Rafts Facilitated by Murine Leukemia Virus Glycosylated Gag

“…Ro is a member of the tripartite motif (TRIM) protein family; this protein is an interferon-inducible E3 ligase that ubiquitinates interferon regulatory factor 3 (IRF-3) and IRF-8 (19–21). La is a predominantly nuclear RNA binding protein that binds certain RNA polymerase III (Pol III) transcripts, facilitating their processing and trafficking (22, 23); it also facilitates replication of some viruses (24–30). Two-color immunofluorescence microscopy for Ro and HA-gg88 was carried out with 293T cells.…”

Cellular La Protein Shields Nonsegmented Negative-Strand RNA Viral Leader RNA from RIG-I and Enhances Virus Growth by Diverse Mechanisms

“…Where mentioned, RNP was deproteinized by phenol-chloroform, followed by ethanol precipitation with glycogen carrier, and dissolved in Tris-EDTA. Protein-free leRNA was fractionated on 1.8% agarose morpholinepropanesulfonic acid-formaldehyde gels (56), transferred onto a Hybond-N membrane, UV cross-linked, and probed by 32 P-labeled antisense DNA using stringent conditions as described previously (56). The washed membrane was autoradiographed.…”