Roth J F, Kingsman S M, Kingsman A J, Martin-Rendon E
Retrovirus Molecular Biology Group, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK.
Yeast. 2000 Jul;16(10):921-32. doi: 10.1002/1097-0061(200007)16:10<921::AID-YEA588>3.0.CO;2-#.
The yeast Ty1 retrotransposon encodes proteins and RNA that assemble into virus-like particles (VLPs) as part of the life cycle of the retro-element. The Tya protein, which is equivalent to the retroviral Gag, is the major structural component of these particles. In this work, we demonstrate that Tya proteins fulfil other functions apart from their structural role. We show that Tya interacts in vitro with the Ty1 RNA domain required for RNA packaging, suggesting that this RNA-protein interaction may direct the packaging process. Furthermore, the overexpression of both Tya proteins, i.e. p1, the primary translation product, and p2, the mature form, increases endogenous Ty1 RNA levels in trans without increasing translation significantly. These observations suggest that Tya may exert a regulatory function during transposition. Interestingly, however, only p2, the mature form of Tya, trans-activates transposition of a marked genomic Ty element. This confirms that processing is required for transposition.
酵母Ty1逆转录转座子编码蛋白质和RNA，它们作为逆转录元件生命周期的一部分组装成病毒样颗粒（VLP）。与逆转录病毒Gag等效的Tya蛋白是这些颗粒的主要结构成分。在这项工作中，我们证明Tya蛋白除了其结构作用外还履行其他功能。我们表明Tya在体外与RNA包装所需的Ty1 RNA结构域相互作用，表明这种RNA-蛋白质相互作用可能指导包装过程。此外，两种Tya蛋白，即初级翻译产物p1和成熟形式p2的过表达，在不显著增加翻译的情况下，反式增加内源性Ty1 RNA水平。这些观察结果表明Tya可能在转座过程中发挥调节功能。然而，有趣的是，只有Tya的成熟形式p2反式激活标记的基因组Ty元件的转座。这证实了转座需要加工。
