Importance of coat protein and RNA silencing in satellite RNA/virus interactions.
RNA silencing is a major defense mechanism plants use to fight an invading virus. The silencing suppressor of Turnip crinkle virus (TCV) is the viral coat protein (CP), which obstructs the DCL2/DCL4 silencing pathway. TCV is associated with a virulent satellite RNA (satC) that represses the accumulation of TCV genomic RNA and whose accumulation is repressed by the TCV CP. To investigate if reduced TCV accumulation due to satC involves RNA silencing and/or the suppressor activity of the CP, TCV was altered to contain a mutation reported to target CP silencing suppressor activity (Deleris et al., Science 313, 68, 2006). However, the mutation did not cause an exclusive defect in silencing suppression, but rather produced a generally non-functional protein. We demonstrate that a functional CP, but not DCL2/DCL4, is required for satC-mediated repression of TCV. In addition, enhancement of satC accumulation in the absence of a functional CP requires DCL2/DCL4.
Manfre
Alicia J
AJ
United States Department of Agriculture-Agricultural Research Service, Appalachian Fruit Research Station, Wiltshire Rd, Kearneysville, WV 25430, USA.
Simon
Anne E
AE
D029681:Arabidopsis Proteins / Q000378:metabolism; D036022:Capsid Proteins / Q000235:genetics / Q000378:metabolism*; D019184:Carmovirus / Q000235:genetics / Q000502:physiology*; D018797:Cell Cycle Proteins / Q000378:metabolism; D009154:Mutation; D010944:Plants / Q000276:immunology* / Q000821:virology*; D034622:RNA Interference; D019244:RNA, Satellite / Q000378:metabolism*; D012367:RNA, Viral / Q000096:biosynthesis; D043244:Ribonuclease III / Q000378:metabolism; D012260:Ribonucleases / Q000378:metabolism
D029681:Arabidopsis Proteins; D036022:Capsid Proteins; D018797:Cell Cycle Proteins; D019244:RNA, Satellite; D012367:RNA, Viral; C504982:DCL4 protein, Arabidopsis; D012260:Ribonucleases; C511919:DCL2 protein, Arabidopsis; D043244:Ribonuclease III