Young leaves of tobacco, systemically infected by tobacco etch potyvirus (TEV), were examined for the presence and distribution of four virus encoded proteins [capsid, cytoplasmic inclusion (CI) and two nuclear inclusion (NI) proteins] at various time periods after inoculation of expanded leaves of the plants. The analyses were carried out by ELISA and by immunogold electron microscopy of thin sections of the leaves. All four proteins were detected simultaneously in the systemic leaves for the first time on the fifth day after inoculation of the expanded leaves. All four proteins increased in concentration until the seventh day and then showed no further increase with the exception of the capsid protein which continued to accumulate. The CI protein was first detected in association with the plasmalemma/cell wall and was subsequently found mostly in the form of pinwheels in the cytoplasm. The two NI proteins were found at all times after infection within the nucleus, although small concentrations were detected in the cytoplasm. These experiments suggest that both the NIa and NIb proteins are transported into the nucleus immediately after synthesis. At the earliest time periods after infection, high concentrations of these proteins (NIa and NIb) were found in their noninclusion form in the nucleolus. At 14 days after infection, both proteins were found only as inclusions in the nucleus. The capsid protein was found at all stages of infection only in the cytoplasm.
AllisonR.,
JohnstonR. E.,
DoughertyW. G.1986; The nucleotide sequence of the coding region of tobacco etch virus genomic RNA: evidence for the synthesis of a single polyprotein. Virology 154:9–20
AndrewsJ. H.,
ShallaT. A.1974; The origin, development and conformation of amorphous inclusion body components in tobacco etch virus-infected cells. Phytopathology 64:1234–1243
BaunochD. A.,
DasP.,
HariV.1988; Intracellular localization of TEV capsid and inclusion proteins by immunogold labeling. Journal of Ultrastructure and Molecular Structure Research 99:203–212
BaunochD. A.,
DasP.,
HariV.1990; Potato virus Y helper component protein is associated with amorphous inclusions. Journal of General Virology 71:2479–2482
CarringtonJ. C.,
DoughertyW. G.1987; Small nuclear inclusion protein encoded by a plant potyviral genome is a protease. Journal of Virology 61:2540–2548
DeMejiaM. V. G.,
HiebertE.,
PurcifullD. E.1985a; Isolation and partial characterization of the amorphous cytoplasmic inclusions associated with infections caused by two potyviruses. Virology 142:24–33
DeMejiaM. V. G.,
HiebertE.,
PurcifullD. E.,
ThornburyD.,
PironeT. P.1985b; Identification of potyviral amorphous inclusion protein as a non-structural virus-specific protein related to helper component. Virology 142:34–43
GorbalenyaA. E.,
BlinowV. M.,
DochenkoA. P.,
KooninE. V.1989; An NTP-binding motif is the most conserved sequence in a highly diverged monophyletic group of proteins involved in positive strand RNA viral replication. Journal of Molecular Evolution 28:256–268
HiebertE.,
PurcifullD. E.,
ChristieR. G.1984; Purification and immunological analyses of plant viral inclusion bodies. In Methods in Virology vol 8 pp 225–278 Edited by
MaramoroschK.,
KoprowskiH.
New York: Academic Press;
LaínS.,
RiechmannJ. L.,
GarciaJ. A.1989a; Homologous potyvirus and flavivirus proteins belonging to a superfamily of helicase-like proteins. Gene 82:357–362
MurphyJ. F.,
RhoadsR. E.,
HuntA. G.,
ShawJ. G.1990; The VPg of tobacco etch virus RNA is the 49kDa proteinase or the N-terminal 24kDa part of the proteinase. Virology 178:285–288
SopranoK. J.,
GalantiN.,
JonakG. T.,
McKercherS.,
PipasJ. M.,
PedenK. W. C.,
BasergaR.1983; Mutational analysis of simian virus 40 T-antigen: stimulation of cellular DNA synthesis and activation of r-RNA genes by mutation with deletions in the T-antigen gene. Molecular and Cellular Biology 3:214–219
WinstonS. E.,
FullerS. A.,
HurrellJ. G. R.1988; Enzyme-linked immunosorbent assays (ELISA) for detection of antigens. In Current Protocols in Molecular Biology unit 11.2 Edited by
AusubelF. M.
New York: Wiley Interscience;