多发性内分泌肿瘤I型(MEN1)基因是一个抑癌基因,到目前为止人们只发现了它的一种剪接模式.本实验以MEN1基因为研究对象,设计特异性引物,用RT-PCR检测到细胞中MEN1基因的另一种新的剪接体.利用构建好的含有MEN1小基因的重组质粒转染哺乳动物细胞,扩增小基因的转录产物,并进行序列分析,证实新剪接体的剪接位点位于基因组第5183位和第6196位.通过Western blot检测到了对应大小的蛋白在细胞中的表达,表明MEN1基因在细胞中存在两种不同剪接体,这种新的剪接体表达了一个含有351个氨基酸,大小约为39kD的蛋白质.研究结果为进一步探讨MEN1基因在细胞中的功能提供了重要线索.
MEN1 gene is a tumor-suppressor gene.So far,the mRNA transcripted by MEN1 gene only has one type.In this experiment,we designed some specific primers,and detected an alternative transcripts of the MEN1 gene by RT-PCR.Then using the constructed plasmid containing the MEN1 minigene to transfect mammal cells,we amplified the tramscripts of the mini-MEN1 gene,and analysed their sequence.The results of sequence analysis confirmed that the splice sites of the new transcript is from the 5183th to 6196th nucleotide in MEN1 gene in genome.Finally,we have detected the corresponding new protein by Western blotting.These results showed that the MEN1 gene was transcripted into two different transcripts in cells by alternative splicing,and the new transcript was translated into a small protein containing 351 amino acids.The size of this protein was about 39kD.This finding suggested that MEN1 gene might have another function or that the new transcript could be the cause of MEN1 disease.