Alkema M J, Wiegant J, Raap A K, Berns A, van Lohuizen M
Division of Molecular Genetics, University of Amsterdam, The Netherlands Cancer Institute.
Hum Mol Genet. 1993 Oct;2(10):1597-603. doi: 10.1093/hmg/2.10.1597.
The proto-oncogene bmi-1 is frequently activated by Moloney murine leukemia proviral insertions in E mu-myc transgenic mice1,2. Using a mouse bmi-1 cDNA probe a transcript of 3.3 kb was detected on Northern blots of human Burkitt's lymphoma cell lines. We have isolated and sequenced cDNA clones from a human erythroleukemia cell line (K562) derived cDNA library, using different mouse bmi-1 cDNA fragments as a probe. Analysis of genomic BMI-1 sequences reveals a gene structure which is very similar to that of the mouse, consisting of at least 10 exons. The human cDNA is 3203 bp in length and shows 86% identity to the mouse nucleotide sequence. The open reading frame encodes a protein of 326 amino acids which shares 98% identity to the amino acid sequence of mouse bmi-1 protein. In vitro translation experiments show that human cDNA derived RNA translates into a protein with a mobility of 44-46 kD on SDS polyacrylamide gels. Fluorescence in situ hybridization (FISH) on metaphase chromosome spreads located the human BMI-1 gene to the short arm of chromosome 10 (10p13), a region known to be involved in translocations in various leukemias.
原癌基因bmi-1在Eμ-myc转基因小鼠中常被莫洛尼鼠白血病病毒前病毒插入激活1,2。使用小鼠bmi-1 cDNA探针，在人伯基特淋巴瘤细胞系的Northern印迹上检测到一个3.3 kb的转录本。我们以不同的小鼠bmi-1 cDNA片段为探针，从人红白血病细胞系（K562）来源的cDNA文库中分离并测序了cDNA克隆。对基因组BMI-1序列的分析揭示了一种与小鼠非常相似的基因结构，由至少10个外显子组成。人cDNA长度为3203 bp，与小鼠核苷酸序列的同一性为86%。开放阅读框编码一个326个氨基酸的蛋白质，与小鼠bmi-1蛋白的氨基酸序列同一性为98%。体外翻译实验表明，人cDNA来源的RNA在SDS聚丙烯酰胺凝胶上翻译出一种迁移率为44 - 46 kD的蛋白质。中期染色体铺片的荧光原位杂交（FISH）将人BMI-1基因定位到染色体10的短臂（10p13），该区域已知在各种白血病的易位中起作用。
