Leu T M, Schatz D G
Section of Immunobiology, Yale University School of Medicine, New Haven, Connecticut 06520-8011, USA.
Mol Cell Biol. 1995 Oct;15(10):5657-70. doi: 10.1128/MCB.15.10.5657.
Despite the essential and synergistic functions of the rag-1 and rag-2 proteins in V(D)J recombination and lymphocyte development, little is known about the biochemical properties of the two proteins. We have developed cell lines expressing high levels of the rag proteins and specific, sensitive immunological reagents for their detection, and we have examined the physical properties of the rag proteins in vitro and their subcellular localizations in vivo. rag-1 is tightly associated with nuclear structures, requires a high salt concentration to maintain its solubility, and is a component of large, heterogeneously sized complexes. Furthermore, the presence of rag-1 alters the behavior of rag-2, conferring on it properties similar to those of rag-1 and changing its distribution in the nucleus. We demonstrate that rag-1 and rag-2 are present in the same complex by coimmunoprecipitation, and we provide evidence that these complexes contain more molecules of rag-2 than of rag-1. The demonstration of intracellular complexes containing rag-1 and rag-2 raises the possibility that interaction between these proteins is necessary for their biological function.
尽管rag-1和rag-2蛋白在V(D)J重组和淋巴细胞发育中具有重要的协同功能，但对这两种蛋白的生化特性却知之甚少。我们已经建立了表达高水平rag蛋白的细胞系以及用于检测它们的特异性、灵敏的免疫试剂，并且我们已经在体外研究了rag蛋白的物理性质以及它们在体内的亚细胞定位。rag-1与核结构紧密相关，需要高盐浓度来维持其溶解性，并且是大小各异的大复合物的一个组分。此外，rag-1的存在改变了rag-2的行为，赋予它与rag-1相似的性质并改变其在细胞核中的分布。我们通过共免疫沉淀证明rag-1和rag-2存在于同一复合物中，并且我们提供证据表明这些复合物中rag-2分子比rag-1分子更多。含有rag-1和rag-2的细胞内复合物的证明增加了这些蛋白之间的相互作用对其生物学功能是必需的可能性。
