Double-stranded cleavage by cell extracts near recombinational signal sequences of immunoglobulin genes
Double-stranded cleavage by cell extracts near recombinational signal sequences of immunoglobulin genes
复制标题
免疫球蛋白基因重组信号序列附近细胞提取物的双链切割
DOI：
10.1038/308860a0
复制
发表时间：
1984
期刊：
影响因子：
64.8
通讯作者：
D. Baltimore
中科院分区：
文献类型：
--
作者：
S. Desiderio;D. Baltimore
The genes encoding the variable regions of murine immunoglobulin light chains are present in the germ line in two separate segments, V and J. During B lymphocyte differentiation these segments are brought together to form a single unit (for review see ref. 1). Although much is known about the structures of V and J segments, both in germ-line configuration and after rearrangement2–5, essentially nothing is known about the biochemical mechanism of V–J recombination. One possible step in proposed mechanisms of immunoglobulin gene rearrangement is endonucleolytic cleavage of the participating DNA segments before joining6. In an attempt to detect such an activity, we have developed an assay for the detection of site-specific double- or single-strand endonucleolytic activity in crude soluble extracts. Using this assay we have detected an activity in extracts of nuclei from mouse B-lymphoid lines and from mouse L cells that is capable of introducing duplex breaks near the recombinational signal sequences of immunoglobulin Jκ segments. We report the activity here because of its intrinsic interest although we lack any direct evidence that it has a role in V–J recombination.
