Fu L, Suen C K, Waseem A, White K N
Division of Biochemistry and Molecular Biology, United Medical School, Guy's Hospital, London, U.K.
Biochem Mol Biol Int. 1997 Jun;42(2):329-37. doi: 10.1080/15216549700202731.
Using in situ hybridisation to detect the intracellular localisation of mRNAs we have found that mRNAs expressed from intronless cDNAs of normally intronic genes are expressed well but largely retained in nuclei. The degree of nuclear retention is quite variable but in all cases addition of splicing signals to the expression cassette are required for efficient export of the mRNAs from nucleus to cytoplasm. In contrast mRNAs expressed from the intronless genes of hamster beta-adrenergic receptor and human serotonin receptor type 1A showed very little nuclear accumulation and strong expression in the cytoplasm independently of splicing signals. The data demonstrate a link between splicing and export and dissemble from the idea that splicing enhances mRNA expression by protecting nascent nuclear mRNAs from degradation.
通过原位杂交检测mRNA的细胞内定位，我们发现，正常情况下含内含子基因的无内含子cDNA所表达的mRNA能很好地表达，但大多保留在细胞核中。核滞留程度变化很大，但在所有情况下，都需要向表达盒中添加剪接信号，以使mRNA从细胞核有效输出到细胞质中。相比之下，仓鼠β-肾上腺素能受体和人5-羟色胺1A型受体的无内含子基因所表达的mRNA几乎没有核积累，且在细胞质中强烈表达，与剪接信号无关。这些数据证明了剪接与输出之间的联系，并且与剪接通过保护新生的核mRNA不被降解来增强mRNA表达的观点不同。
