We recently reported that p28, one of the two turnip crinkle virus (TCV) replication proteins, trans-complemented a defective TCV lacking p28, yet repressed the replication of another TCV replicon encoding wildtype p28 (Zhang et al., 2017). Here we show that p88, the TCV-encoded RNA-dependent RNA polymerase, likewise trans-complemented a p88-defective TCV replicon, but repressed one encoding wild-type p88. Surprisingly, lowering p88 protein levels enhanced trans-complementation, but weakened repression. Repression by p88 was not simply due to protein over-expression, as deletion mutants missing 127 or 224 N-terminal amino acids accumulated to higher levels but were poor repressors. Finally, both trans-complementation andmore »
Repression of turnip crinkle virus replication by its replication protein p88
We recently reported that p28, one of the two turnip crinkle virus (TCV) replication proteins, trans-complemented
a defective TCV lacking p28, yet repressed the replication of another TCV replicon encoding wildtype
p28 (Zhang et al., 2017). Here we show that p88, the TCV-encoded RNA-dependent RNA polymerase,
likewise trans-complemented a p88-defective TCV replicon, but repressed one encoding wild-type p88.
Surprisingly, lowering p88 protein levels enhanced trans-complementation, but weakened repression. Repression
by p88 was not simply due to protein over-expression, as deletion mutants missing 127 or 224 N-terminal amino
acids accumulated to higher levels but were poor repressors. Finally, both trans-complementation and repression
by p88 were accompanied by preferential accumulation of subgenomic RNA2, and a novel class of small TCV
RNAs. Our results suggest that repression of TCV replication by p88 may manifest a viral mechanism that
regulates the ratio of genomic and subgenomic RNAs based on p88 abundance.
- Award ID(s):
- 1758912
- Publication Date:
- NSF-PAR ID:
- 10112999
- Journal Name:
- Virology
- Volume:
- 526
- Page Range or eLocation-ID:
- 165-172
- ISSN:
- 0042-6822
- Sponsoring Org:
- National Science Foundation
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