Factor (s) involved in transport of HBV mRNAs

已有研究表明，乙型肝炎病毒的mRNAs转运可被Rex突变体TAgRex所抑制，该突变体主要通过隔离细胞辅因子来抑制REV/REX功能(S)。此外，我们还发现，与REV/REX功能完全恢复相比，hCRM1的过表达部分恢复了HBVmRNA的转运。这些结果表明，CRM1类似物而不是hCRM1本身参与了HBVmRNAs的转运。今年这项研究的目的是确定可能参与HBVmRNAs转运的因子(S)，特别是hCRM1的类似物。为了克隆hCRM1基因，我们以HeLa基因为模板，在宽松的条件下进行了RT-PCR。对扩增产物的序列分析表明，它们都是hCRM1本身。接下来，我们使用从星形细胞瘤细胞中制备的cDNA作为模板，其中REV不能有效地工作。结果表明，扩增产物与hCRM1cDNA在核苷酸水平上具有%的相似性，在氨基酸水平上具有97%的相似性。我们将这个新基因命名为u-CRM1。目前，我们正在测试它是否参与了乙肝病毒mRNAs的运输。

It has been shown that transport of mRNAs of Hepatitis B virus is inhibited by TAgRex, a Rex mutant, which dominantly inhibits Rev/Rex functions by sequestering the cellular cofactor(s). Moreover we showed that overexpression of hCRM1 partially restored the transport of HBV mRNA in contrast to the complete restoration of Rev/Rex functions. These results suggested that CRM1 analog, but not hCRM1 itself, is involved in the transport of HBV mRNAs. The purpose of the study this year is to identify the factor(s), particularly an analog of hCRM1, which may be involved in transport of HBV mRNAs. To clone it, we performed RT-PCR using primers of the hCRM1 genes with HeLa cDNA as template under the relaxed conditions. Sequence analysis of the PCR products indicated that all were hCRM1 itself. Next, we used cDNA prepared from astrocytoma cells, where Rev does not work efficiently, as template. It has been revealed that the amplified product had the sequence which has 89% similar to the hCRM1 cDNA at nucleotide level and 97% similar in amino acid sequence. We named this new gene as u-CRM1. Currently we are testing it to be involved in transport of HBV mRNAs.