人Nmi mRNA编码区存在变异形式  

An Alternative Form in mRNA Coding Region of Human Nmi Gene

作　　者：王玉刚[1] 刘红涛[1] 马大龙[1] 

机构地区：[1]北京医科大学卫生部医学免疫学重点实验室

出　　处：《中国生物化学与分子生物学报》1998年第6期680-683,共4页Chinese Journal of Biochemistry and Molecular Biology

摘　　要：Ｎｍｉ基因编码一种可与Ｍｙｃ相互作用的蛋白质．在人红白血病细胞系ＴＦ－１细胞去细胞因子ＧＭ－ＣＳＦ后８ｈ，发现ＮｍｉＲＮＡ表达水平升高．利用ＰＣＲ方法从中扩增ＮｍｉｃＤＮＡ编码区，发现除正常大小的扩增片段外，还有一比公布核酸序列小约１００～２００ｂｐ的扩增片段．序列分析表明该片段为编码区第３３７～５０９位的碱基缺失，由ＧＴＴＣＣＡＴＴＧＣＧ１１个碱基取代，形成一个开放读码框架，编码２５４个氨基酸，比野生型Ｎｍｉ编码的３０７个氨基酸少５３个氨基酸．Nmi gene encodes a protein which can interact with Myc protein.Although Myc protein is thought to play an important role in cell proliferation,differentiation and apoptosis,the Nmi protein's function and biochemical properties in the network of Myc cross interacting factors are still unknown.In a hunan premyeloid cell line,TF 1 cell,Nmi RNA expression level increased after GM CSF deprivation for 8 hours.It indirectly suggests that Nmi may have some functions in the process of TF 1 cell apoptosis.To reveal the possible role of Nmi,Nmi coding region sequence was amplified by PCR method for being subcloned into an eukaryotic expression vector .An additional fragment was discovered which had a 100～200 shorter length than published sequence.Sequence analysis revealed that Nmi coding region 337～509 base was deleted and replaced by GTTCCATTGCG.The alternative form of Nmi cDNA encoded an open reading frame with 254 amino acids,53 amino acids shorter compared with wild type Nmi protein.This phenomenon supports the notion that Nmi gene has an isoform and may regulate Nmi proteins role.

关 键 词：Nmi基因 变异体 凋亡 TF-1细胞 

分 类 号：Q754[生物学—分子生物学]