Bechler K
Institut für Molekularbiologie und Biochemie, Freie Universität Berlin and GSF-Forschungzentrum für Umwelt und Gesundheit, Neuherberg, Germany.
Biochem Biophys Res Commun. 1997 Dec 8;241(1):193-9. doi: 10.1006/bbrc.1997.7789.
In order to investigate the influence of CAP and poly(A)-tail on mRNA expression and on antisense mediated inhibition of gene expression, coinjections of different expression vectors coding for Chloramphenicol-Acetyltransferase (CAT) sense- or antisense RNAs, respectively, were performed. Different in vitro transcribed and modified sense and antisense RNAs were injected into nucleus or cytoplasm of COS7-cells. It can be concluded that the combination of capping and polyadenylation ensures efficient gene expression and is required for transport of mRNA from the nucleus to the cytoplasm. In contrast, antisense experiments suggest that the length of antisense RNAs play an important role for the inhibitory capability of antisense molecules and expression reduction occurs independently of CAP and poly(A) tail. A model for intermolecular hybridization and suppression of gene expression based on the secondary structures of the CAT mRNA and its corresponding antisense RNA is presented.
为了研究帽结构（CAP）和聚腺苷酸尾（poly(A)-tail）对mRNA表达以及反义介导的基因表达抑制的影响，分别进行了共注射编码氯霉素乙酰转移酶（CAT）正义或反义RNA的不同表达载体的实验。将不同的体外转录和修饰的正义及反义RNA注射到COS7细胞的细胞核或细胞质中。可以得出结论，帽化和聚腺苷酸化的结合确保了有效的基因表达，并且是mRNA从细胞核运输到细胞质所必需的。相比之下，反义实验表明，反义RNA的长度对反义分子的抑制能力起着重要作用，并且表达降低与帽结构和聚腺苷酸尾无关。提出了一个基于CAT mRNA及其相应反义RNA二级结构的分子间杂交和基因表达抑制模型。
