Bucala R, Lee A T, Rourke L, Cerami A
Picower Institute for Medical Research, Manhasset, NY 11030.
Proc Natl Acad Sci U S A. 1993 Apr 1;90(7):2666-70. doi: 10.1073/pnas.90.7.2666.
Advanced glycosylation endproducts react with DNA and cause mutations and DNA transposition in bacteria. To investigate the mutagenic effect of advanced glycosylation in mammalian cells, plasmid DNA containing the lacI mutagenesis marker was modified by advanced glycosylation endproducts in vitro, transfected into murine lymphoid cells, recovered, and analyzed for mutations, plasmid size changes, and the presence of shared insertion sequences. An 853-bp host-derived DNA sequence, designated INS-1, was identified as an insertion element common to plasmids recovered from multiple independent transfections. Modification of DNA by advanced glycosylation increased by 60-fold the apparent frequency of INS-1 transposition: from 0.025% to 1.5%. The INS-1 element contains a 180-bp region that is homologous to the Alu repetitive sequence family. INS-1 was also observed to be present within larger insertional mutations and, in two cases, an apparently truncated version of INS-1 that lacks the Alu region was identified. These results demonstrate the experimental induction of DNA transposition involving mammalian chromosomal elements and suggest that advanced glycosylation may play a role in the formation of Alu-containing insertions that have been found to disrupt human genes.
晚期糖基化终产物与DNA发生反应，并在细菌中引起突变和DNA转座。为了研究晚期糖基化在哺乳动物细胞中的诱变作用，将含有lacI诱变标记的质粒DNA在体外通过晚期糖基化终产物进行修饰，转染到小鼠淋巴细胞中，回收后分析其突变情况、质粒大小变化以及共享插入序列的存在情况。一个853碱基对的宿主来源DNA序列，命名为INS-1，被鉴定为从多个独立转染回收的质粒中共同存在的插入元件。晚期糖基化对DNA的修饰使INS-1转座的表观频率增加了60倍：从0.025%增至1.5%。INS-1元件包含一个与Alu重复序列家族同源的180碱基对区域。在较大的插入突变中也观察到INS-1的存在，并且在两个案例中，鉴定出了一个明显缺失Alu区域的INS-1截短版本。这些结果证明了涉及哺乳动物染色体元件的DNA转座的实验诱导，并表明晚期糖基化可能在已发现会破坏人类基因的含Alu插入序列的形成中起作用。
