Dagenais A, LeMyre A, Bibor-Hardy V
Institut du cancer de Montréal, Qué., Canada.
Biochem Cell Biol. 1990 May;68(5):827-31. doi: 10.1139/o90-122.
Lamins A, B, and C are the major proteins of the mammalian nuclear lamina and have been well studied in BHK-21 cells. Using in vivo labelling, cell fractionation, and immunoprecipitation, we have found that lamins have different patterns of nuclear transport and solubility. Newly synthesized lamin A is translocated to the nucleus faster than lamin C or B. It is the most tightly bound lamin and cannot be extracted from the lamina by nonionic detergent or high-salt buffers. Lamins B and C migrate more slowly to the nucleus. Partitioning between cytoskeleton and detergent-soluble fractions shows that integration of lamins B and C is not completed before a 1-h chase. For lamin C this process is dependent upon protein synthesis and can be inhibited with cycloheximide. Even though lamins A and C are almost identical, lamin C is never firmly bound to the lamina and can be partially solubilized upon high-salt treatment.
核纤层蛋白A、B和C是哺乳动物核纤层的主要蛋白质，并且已经在BHK - 21细胞中得到了充分研究。通过体内标记、细胞分级分离和免疫沉淀，我们发现核纤层蛋白具有不同的核转运和溶解性模式。新合成的核纤层蛋白A比核纤层蛋白C或B更快地转运到细胞核中。它是结合最紧密的核纤层蛋白，不能通过非离子去污剂或高盐缓冲液从核纤层中提取出来。核纤层蛋白B和C向细胞核迁移的速度较慢。在细胞骨架和去污剂可溶部分之间的分配表明，在1小时的追踪之前，核纤层蛋白B和C的整合尚未完成。对于核纤层蛋白C，这个过程依赖于蛋白质合成，并且可以被环己酰亚胺抑制。尽管核纤层蛋白A和C几乎相同，但核纤层蛋白C从未牢固地结合在核纤层上，并且在高盐处理时可以部分溶解。
