Lewis T L, Matsui S M
Program in Cancer Biology, Stanford University School of Medicine, California, USA.
Arch Virol. 1995;140(6):1127-35. doi: 10.1007/BF01315421.
Expression of the astrovirus RNA-dependent RNA polymerase has been hypothesized to be regulated by (-1) ribosomal frameshifting. Sequence analysis of the 70 nucleotide region between open reading frames 1a and 1b indicates the presence of a shifty heptamer consensus sequence and downstream sequences that may be needed for ribosomal frameshifting. We constructed four astrovirus cassettes that spanned this region and inserted each into the rhesus rotavirus VP4 gene. The constructs were expressed in an in vitro system, and products were immunoprecipitated by rotavirus amino and carboxy terminal-specific monoclonal antibodies. Ribosomal frameshifting, at an efficiency of 6-7%, was demonstrated in all constructs containing the shifty heptamer and stem-loop. Deletion of the downstream sequence potentially involved in pseudoknot formation did not affect frameshifting efficiency. However, deletion of the shifty heptamer resulted in no detectable frameshift activity.
有人提出，星状病毒RNA依赖的RNA聚合酶的表达受（-1）核糖体移码调控。对开放阅读框1a和1b之间70个核苷酸区域的序列分析表明，存在一个可变七聚体共有序列以及核糖体移码可能所需的下游序列。我们构建了跨越该区域的四个星状病毒盒式结构，并将每个结构插入恒河猴轮状病毒VP4基因。这些构建体在体外系统中表达，产物用轮状病毒氨基和羧基末端特异性单克隆抗体进行免疫沉淀。在所有含有可变七聚体和茎环的构建体中都证实了核糖体移码，效率为6%-7%。删除可能参与假结形成的下游序列并不影响移码效率。然而，删除可变七聚体导致无法检测到移码活性。
