Activation of V(D)J recombination induces the formation of interlocus joints and hybrid joints in scid pre-B-cell lines

作     者：Lew, S Franco, D Chang, Y 

作者机构：Arizona State Univ Dept Microbiol Mol & Cellular Biol Program Tempe AZ 85287 USA 

出 版 物：《MOLECULAR AND CELLULAR BIOLOGY》 (分子生物学与细胞生物学)

年 卷 期：2000年第20卷第19期

页      面：7170-7177页

核心收录：

学科分类：0710[理学-生物学] 071010[理学-生物化学与分子生物学] 07[理学] 

基　　金：NCI NIH HHS [R01 CA073857  CA73857  R29 CA073857] Funding Source: Medline 

主　　题：Abelson鼠白血病病毒/遗传学 Abelson鼠白血病病毒/生理学 细胞凋亡/遗传学 细胞转化 肿瘤/遗传学 细胞转化 病毒 DNA核苷酸转移酶类/代谢 DNA 肿瘤/遗传学 DNA活化蛋白激酶 DNA结合蛋白质类 酶激活 基因表达调控 白血病 基因重排 B淋巴细胞 轻链 基因 免疫球蛋白 基因 bcl-2 基因型 免疫球蛋白J链/遗传学 免疫球蛋白可变区/遗传学 小鼠 SCID 肿瘤蛋白质类/遗传学 肿瘤蛋白质类/代谢 聚合酶链反应 前体B细胞淋巴母细胞白血病淋巴瘤/病理学 蛋白质丝氨酸苏氨酸激酶/缺乏 蛋白质丝氨酸苏氨酸激酶/遗传学 蛋白质丝氨酸苏氨酸激酶/生理学 重症联合免疫缺陷/并发症 重症联合免疫缺陷/遗传学 肿瘤细胞 培养的 VDJ重组酶类 动物 小鼠 

摘      要：V(D)J recombination is the mechanism by which antigen receptor genes are assembled. The site-specific cleavage mediated by RAG1 and RAG2 proteins generates two types of double-strand DNA breaks: blunt signal ends and covalently sealed hairpin coding ends. Although these DNA breaks are mainly resolved into coding joints and signal joints, they can participate in a nonstandard joining process, forming hybrid and open/shut joints that link coding ends to signal ends. In addition, the broken DNA molecules excised from different receptor gene loci could potentially be joined to generate interlocus joints. The interlocus recombination process may contribute to the translocation between antigen receptor genes and oncogenes, leading to malignant transformation of lymphocytes. To investigate the underlying mechanisms of these nonstandard recombination events, we took advantage of recombination-inducible cell lines derived from scid homozygous (s/s) and scid heterozygous (s/+) mice by transforming B-cell precursors with a temperature-sensitive Abelson murine leukemia virus mutant (ts-Ab-MLV). We can manipulate the level of recombination cleavage and end resolution by altering the cell culture temperature. By analyzing various recombination products in scid and s/+ ts-Ab-MLV transformants, we report in this study that scid cells make higher levels of interlocus and hybrid joints than their normal counterparts. These joints arise concurrently with the formation of intralocus joints, as well as,vith the appearance of opened coding ends. The junctions of these joining products exhibit excessive nucleotide deletions, a characteristic of scid coding joints. These data suggest that an inability of scid cells to promptly resolve their recombination ends exposes the ends to a random joining process, which can conceivably lead to chromosomal translocations.