Processing of the 112 kDa (‘112K’) protein encoded by cowpea mosaic virus RNA 1 was examined in cowpea mesophyll protoplasts using a transient expression system. Cleavage of the 112K protein occurred via two alternative pathways either into VPg and 110K (24K + 87K) or into 26K (VPg + 24K) and 87K proteins. The 26K protein can be further cleaved into VPg and 24K proteins. The results support a model in which the 112K protein functions as the precursor of VPg during initiation of replication.
BlakeM. S.,
JohnstonK. H.,
Russell-JonesG. J.,
GotschlichE. C.1984; A rapid, sensitive method for detection of alkaline phosphate-conjugated antibody on Western blots. Analytical Biochemistry 136:175–179
DessensJ. T.,
LomonossoffG. P.1992; Sequence upstream of the 24K protease enhances cleavage of the cowpea mosaic virus B RNA-encoded polyprotein at the junction between the 24K and 87K proteins. Virology 189:225–232
De VarennesA.,
LomonossoffG. P.,
ShanksM.,
MauleA. J.1986; The stability of cowpea mosaic virus VPg in reticulocyte lysates. Journal of General Virology 67:2347–2354
DorssersL.,
Van der KrolS.,
Van der MeerJ.,
Van KammenA.,
ZabelP.1984; Purification of cowpea mosaic virus RNA replication complex: Identification of a virus-encoded 110,000-dalton polypeptide responsible for RNA chain elongation. Proceedings of the National Academy of Sciences, USA 81:1951–1955
EggenR.,
KaanA.,
GoldbachR.,
Van KammenA.1988; Cowpea mosaic virus RNA replication in crude membrane fractions from infected cowpea and Chenopodium amaranticolor
. Journal of General Virology 69:2711–2720
EggenR.,
VerverJ.,
WellinkJ.,
De JongA.,
GoldbachR.,
Van KammenH.1989; Improvements of the infectivity of in vitro transcripts from cloned cowpea mosaic virus cDNA: impact of terminal nucleotide sequences. Virology 173:447–455
FranssenH.,
GoldbachR.,
BroekhuijsenM.,
MoermanM.,
Van KammenA.1982; Expression of middle-component RNA of cowpea mosaic virus: in vitro generation of a precursor to both capsid proteins by a bottom-component RNA-encoded protease from infected cells. Journal of Virology 41:8–17
GoldbachR.,
RezelmanG.,
ZabelP.,
Van KammenA.1982; Expression of the bottom-component RNA of cowpea mosaic virus. Evidence that the 60-kilodalton VPg precursor is cleaved into single VPg and a 58-kilodalton polypeptide. Journal of Virology 42:630–635
JaegleM.,
WellinkJ.,
GoldbachR.1987; The genome-linked protein of cowpea mosaic virus is bound to the 5′ terminus of virus RNA by a phosphodiester linkage to serine. Journal of General Virology 68:627–632
KuhnR. J.,
WimmerE.1987; The replication of picornaviruses. In The Molecular Biology of the Positive Strand RNA Viruses pp 17–51 Edited by
RowlandsD. J.,
MayoM. A.,
MahyB. W. J.
New York & London: Academic Press;
KunkelT. A.1985; Rapid and efficient site-specific mutagenesis without phenotypic selection. Proceedings of the National Academy of Sciences, USA 82:488–192
LutckeH. A.,
ChowK. C.,
MickelF. S.,
MossK. A.,
KernH. F.,
ScheeleG. A.1987; Selection of AUG initiation codons differs in plants and animals. EM BO Journal 6:43–18
PetersS. A.,
VoorhorstW. G. B.,
WellinkJ.,
Van KammenA.1992a; Processing of VPg-containing polyproteins encoded by the B-RNA from cowpea mosaic virus. Virology 191:90–97
PetersS. A.,
VoorhorstW. G. B.,
WeryJ.,
WellinkJ.,
Van KammenA.1992b; A regulatory role for the 32K protein in proteolytic processing of cowpea mosaic virus polyproteins. Virology 191:81–89
SalasM.1983; A new mechanism for the initiation of replication of 029 and adenovirus DNA: priming by the terminal protein. Current Topics in Microbiology and Immunology 109:89–106
StanleyJ.,
RottierP.,
DaviesJ. W.,
ZabelP.,
Van KammenA.1978; A protein linked to the 5′ termini of both RNA components of the cowpea mosaic virus genome. Nucleic Acids Research 5:4505–4522
StanleyJ.,
GoldbachR.,
Van KammenA.1980; The genome-linked protein of cowpea mosaic virus is coded by RNA from the bottom component. Virology 106:180–182
Van BokhovenH.,
Van LentJ. W. M.,
CustersR.,
VlakJ. M.,
WellinkJ.,
Van KammenA.1992; Synthesis of the complete 200K polyprotein encoded by cowpea mosaic virus B-RNA in insect cells. Journal of General Virology 73:2775–2784
Van BokhovenH.,
Le GallO.,
KasteelD.,
VerverJ.,
WellinkJ.,
Van KammenA.1993a; Cis and tram acting elements in cowpea mosaic virus RNA replication. Virology 195:377–386
Van BokhovenH.,
VerverJ.,
WellinkJ.,
Van KammenH.1993b; Protoplasts transiently expressing the 200K coding sequence of cowpea mosaic virus B-RNA support replication of M-RNA. Journal of General Virology 74:2233–2241
VosP.,
JaegleM.,
WellinkJ.,
VerverJ.,
EggenR.,
Van KammenA.,
GoldbachR.1988a; Infectious RNA transcripts derived from full-length DNA copies of the genomic RNAs of cowpea mosaic virus. Virology 165:33–41
VosP.,
VerverJ.,
JaegleM.,
WellinkJ.,
Van KammenA.,
GoldbachR.1988b; Two viral proteins involved in the proteolytic processing of the cowpea mosaic virus polyproteins. Nucleic Acids Research 16:1967–1985
WellinkJ.,
RezelmanG.,
GoldbachR.,
BeyreutherK.1986; Determination of the proteolytic processing sites in the polyprotein encoded by the bottom-component RNA of cowpea mosaic virus. Journal of Virology 59:50–58
WellinkJ.,
JaegleM.,
GoldbachR.1987; Detection of a novel protein encoded by the bottom component RNA of cowpea mosaic virus, using antibodies raised against a synthetic peptide. Journal of Virology 59:50–58
ZabelP.,
MoermanM.,
LomonossoffG.,
ShanksM.,
BeyreutherK.1984; Cowpea mosaic virus VPg: sequencing of radiochemically modified protein allows mapping of the gene on B RNA. EMBO Journal 3:1629–1634
ZabelP.,
MoermanM.,
Van StraatenF.,
GoldbachR.,
Van KammenA.1982; Antibodies against the genome linked protein VPg of cowpea mosaic virus recognize a 60, 000-Dalton precursor polypeptide. Journal of Virology 41:1083–1088