Post-transcriptional Controls in Virus-infected Cells

真核基因表达在转录、后表达和转录水平上受到调控。 转录和翻译水平。 虽然重要性 转录，机制是理解，后的作用， 翻译控制才刚刚开始被阐明。 几 观察表明虹彩病毒，青蛙病毒3（FV 3），可能 是研究转录后/ 翻译基因调控：（a）FV 3的稳态水平 早期信息在受感染的细胞中不会下降，而宿主细胞则不会。 转录本迅速降解;（B）FV 3信息被翻译 比体外宿主或异源信息更有效;（c） 早期mRNA不降解，提取后， 体外蛋白质合成;以及（d）晚期病毒信息， 体内主要基因产物，在提取物中的翻译很差， 未感染的细胞 这些现象表明，FV 3 基因表达至少部分地在后 转录/翻译水平。 %%% 在这个提议中，假定的转录后/ 将探索翻译控制。 为了做到这一点，两个 已经确定了具体目标。 Sp.目标 FV 3基因的表达是否在 通过顺式作用mRNA控制序列的翻译水平和/或 反式作用mRNA结合蛋白。 Sp.目标 代表性一组FV 3立即应答的核苷酸序列 早期，早期和晚期mRNA，并确定病毒信息是否 具有独特的调控信号， 效率 成功完成这些研究将提供 病毒介导的机制的重要信息 翻译控制以及顺式和反式元件， 调节病毒蛋白质合成。 此外，这些研究将 扩展我们对翻译控制机制的理解， 真核生物系统

Eukaryotic gene expression is regulated at transcriptional, post- transcriptional, and translational levels. Although the importance of transcriptional, mechanisms is understood, the role of post- translational controls is only beginning to be elucidated. Several observations suggest that the iridovirus, frog virus 3 (FV3), may be an excellent model in which to study post-transcriptional/ translational gene regulation: (a) the steady state level of FV3 early messages does not decline in infected cells, whereas host transcripts are rapidly degraded; (b) FV3 messages are translated more efficiently than host or heterologous messages in vitro; (c) early mRNA is not degraded and, after extraction, actively directs protein synthesis in vitro; and (d) late viral messages, which are major gene products in vivo, are translated poorly in extracts from uninfected cells. Taken together these phenomena suggest that FV3 gene expression is controlled, at least in part, at the post- transcriptional/translational level. %%% In this proposal, the nature of putative post transcriptional/ translational controls will be explored. To accomplish this, two specific aims have been established. Sp. Aim whether the expression of FV3 genes is regulated at the translational level by cis-acting mRNA control sequences and/or trans-acting mRNA-binding proteins. Sp. Aim nucleotide sequence of a representative panel of FV3 immediate early, early, and late mRNAs and ascertain whether viral messages possess unique regulatory signals that control translational efficiency. successfully completed these studies will provide important information on the mechanisms of virus-mediated translational control and on the cis and trans elements that regulate viral protein synthesis. In addition, these studies will extend our understanding of translational control mechanisms in eukaryotic systems.