The informosome-like virus-specific ribonucleoprotein (vRNP) may be involved in the transport of tobacco mosaic virus infection

Intramolecular Complementing Mutations in Tobacco Mosaic Virus Movement Protein Confirm a Role for Microtubule Association in Viral RNA Transport

“…The formation of viral ribonucleoprotein complexes (vRNPs) is supported by the ability of microinjected MPs to mediate the transport of coinjected nucleic acids (23,28,46,62). The existence of vRNPs is also supported by biochemical studies (25,26,34) as well as by elegant microinjection experiments indicating that MP functions in vivo as a cis-acting mediator of plasmodesmal transport, requiring its physical association with the transported molecule (63).To further elucidate the cellular mechanism by which MP facilitates the spread of viral RNA (vRNA) or the proposed vRNP from virus-replicating cells into adjacent cells, several research groups have undertaken the characterization of host components that interact with TMV MP and have shown that a fusion between MP and green fluorescent protein (GFP) accumulates in Pd (31, 48) and also colocalizes with components of the cytoskeleton (30, 44) and endoplasmic reticulum (ER)-derived membranes (31, 54). During infection of leaf epidermal cells or protoplasts derived from tobacco suspension cell line BY-2, ER membranes form aggregates or inclusion bodies (31), and MP seems to be involved in this process (54).…”

“…The formation of viral ribonucleoprotein complexes (vRNPs) is supported by the ability of microinjected MPs to mediate the transport of coinjected nucleic acids (23,28,46,62). The existence of vRNPs is also supported by biochemical studies (25,26,34) as well as by elegant microinjection experiments indicating that MP functions in vivo as a cis-acting mediator of plasmodesmal transport, requiring its physical association with the transported molecule (63).…”

A Non-capsid Protein Associated with Unencapsidated Virus RNA in Barley Infected with Barley Stripe Mosaic Virus

“…Association of virus RNAs with polyribosomes has been reviewed by Atabekov & Morozov (1979). Dorokhov et al (1983Dorokhov et al ( , 1984 have reported a non-virion nucleoprotein containing tobacco mosaic virus RNA, which may be involved in translocation. In contrast to these reports, where the concentration of unencapsidated RNA is small and detected only by use of radioactive labels or other sensitive methods, the concentration of unencapsidated BSMV RNA in acutely infected leaves is large enough for it to be readily detected by density gradient centrifagation of total cellular RNA.…”

Inhibition of Tobacco Mosaic Virus Movement by Expression of an Actin-Binding Protein

“…This protein localizes to PD and modifies the size-exclusion limit of the pores (Tomenius et al, 1987;Wolf et al, 1989;Atkins et al, 1991;Ding et al, 1992a;Moore et al, 1992;Oparka et al, 1997). The MP also has the capacity to bind single-stranded nucleic acids in vitro (Citovsky et al, 1990), and since complexes of MP and viral RNA (vRNA) were isolated from TMV-infected plants (Dorokhov et al, 1983(Dorokhov et al, , 1984, vRNA movement likely occurs in the form of a ribonucleoprotein complex. Indeed, the viral capsid protein is dispensable for cell-to-cell movement (Siegel et al, 1978;Dawson et al, 1988;Saito et al, 1990;Hilf and Dawson, 1993), indicating that the virus moves between cells in a nonencapsidated form.…”