Interaction between tobacco Ribulose-l,5-biphosphate Carboxylase/Oxygenase large subunit (RubisCO-LSU) and the PVY Coat Protein (PVY-CP)

Abstract

A 54 kDa band (P54) was continually detected with the 30 kDa viral capsid protein (CP) on the SDS-PAGE migration profile of purified potato virus Y (PVY). P54 was observed following the use of two different procedures for the purification of the PVY from infected tobacco. It was a constitutively expressed tobacco protein. The analysis of the PVY preparation showed that P54 has aggregation properties and precipitates, thus pulling down the virus. We used an enzyme-linked immunosorbent assay (ELISA) to study the relationship between P54 and the PVY particles. We performed an inhibition test with monoclonal antibodies (mAb) directed against the PVY-CP, to show that these two components interact. This result was confirmed by western blot. The internal sequence of five major peptides, obtained by C-lysine endoprotease digestion of the P54 followed by HPLC separation, showed 100% homology with the large subunit of the ribulose-1,5-biphosphate carboxylase/oxygenase (RubisCO-LSU) of tobacco. MAb directed against RubisCO-LSU were produced and used to reveal the RubisCO-LSU/PVY complex in infected tobacco extracts. A phage library displaying random heptapeptides was used to isolate several peptides that specifically bound to the native form of the PVY. The sequences of thirty-three phage-displayed peptides, which bound specifically to this virus, present further discontinuous sequence homologies with the RubisCO-LSU. Five peptides (p1 to p5) corresponding to the RubisCO-LSU homologous regions were used for a bacterial two-hybrid system to confirm in vivo direct interactions between the selected RubisCO-LSU regions and the PVY-CP. We propose that the PVY-CP may be involved in the production of mosaics and yellowing symptoms in tobacco through its interaction with RubisCO-LSU. Abbreviations: AC

A study of viral coat protein accumulation in lily chloroplasts from mixed virus infections of Lily mottle virus and Cucumber mosaic virus

“…Earlier research confirmed that Tobacco mosaic virus (TMV) CP and CMV CP accumulate in the respective chloroplasts of systemically infected tobacco and cucumber leaves, and the severity of the symptoms is positively related to the amount of CPs in the host chloroplasts (Reinero & Beachy, 1989;Zhu & Francki, 1992). Subsequently, CPs of Turnip mosaic virus (TuMV), Potato virus Y (PVY), Potato virus X (PVX) and Rice stripe virus (RSV) were similarly found to accumulate in the chloroplasts of host plants (Fu et al, 2004;Feki et al, 2005;Qiao et al, 2009;Cheng et al, 2011).…”

Insights into Alternanthera mosaic virus TGB3 Functions: Interactions with Nicotiana benthamiana PsbO Correlate with Chloroplast Vesiculation and Veinal Necrosis Caused by TGB3 Over-Expression

“…Chloroplast phosphoglycerate kinase (cPGK) was found to interact with the 3′-untranslated region (UTR) of Bamboo mosaic virus (BaMV), another member of the genus Potexvirus ; when cPGK was silenced by VIGS with TRV, accumulation of BaMV CP was also reduced, suggesting that the replication site of BaMV is associated with the chloroplast and that cPGK may target the RNA to the chloroplast membrane (Lin et al, 2007). Tomato mosaic virus CP interacts with a thylakoid membrane protein IP-L (Zhang et al, 2008), while PVY ( Potyvirus ) CP has been shown to interact with the large subunit of Rubisco (Feki et al, 2005), and PVY HC-Pro with the domain of the nuclear-encoded chloroplast-division related protein MinD required for dimerization (Jin et al, 2007). TuMV CP interacts with an otherwise unidentified 37 kDa chloroplast protein (McClintock et al, 1998).…”

The Rubisco Small Subunit Is Involved in Tobamovirus Movement and Tm-22-Mediated Extreme Resistance

“…The Rubisco holoenzyme is a heteropolymer consisting of eight large subunits (RbCLs) and eight small subunits (RbCSs). RbCL was reported to interact with the coat protein of Potato virus Y (Feki et al, 2005). Both RbCS and RbCL were reported to interact with the P3 proteins encoded by several potyviruses, including Shallot yellow stripe virus, Onion yellow dwarf virus, Soybean mosaic virus, and Turnip mosaic virus (Lin et al, 2011).…”