ON THE CELL-FREE ASSOCIATION OF LAMIN-A AND LAMIN-C WITH METAPHASE CHROMOSOMES
ON THE CELL-FREE ASSOCIATION OF LAMIN-A AND LAMIN-C WITH METAPHASE CHROMOSOMES
复制标题
DOI：
10.1016/0014-4827(90)90223-w
复制
发表时间：
1990-01-01
影响因子：
3.7
通讯作者：
BURKE, B
中科院分区：
文献类型：
--
作者：
BURKE, B
此前已证明，在有丝分裂的中国仓鼠卵巢细胞的无细胞匀浆中，核膜可自发地围绕内源染色体组装。为了进一步分析核膜重组的机制和单个核纤层蛋白多肽的功能，设计了一种分级分离的无细胞核膜重组装系统，该系统涉及纯化的染色体和染色体后上清液或来自有丝分裂细胞的胞质级分。用该分级系统获得的结果表明，在没有核纤层蛋白B和膜的情况下，核纤层蛋白A和C将与染色体表面结合，这种结合可被ATP-γ-S抑制。然而，在没有膜的情况下，染色质解缩永远不会发生。利用缺乏二价阳离子的低离子强度缓冲液中染色体的可逆膨胀作为简单测定的基础，证明核纤层蛋白 A 和 C 与染色体表面的结合对染色质组织具有显着且易于观察的影响。
Nuclear envelopes have previously been shown to assemble spontaneously around endogenous chromosomes in cell-free homogenates of mitotic Chinese hamster ovary cells. In order to further analyze the mechanisms underlying nuclear envelope reformation and the functions of the individual nuclear lamin polypeptides, a fractionated cell-free nuclear envelope reassembly system involving purified chromosomes and either a postchromosomal supernatant or a cytosol fraction from mitotic cells has been devised. Results obtained with this fractionated system show that lamins A and C will associate with the surfaces of chromosomes in the absence of lamin B and membranes, this association being inhibitable by ATP-.gamma.-S. However, in the absence of membranes chromatin decondensation never occurs. Using the reversible swelling of chromomes in low ionic strength buffers lacking divalent cations as the basis of a simple assay, it was demonstrated that the association of lamins A and C with the surfaces of chromosomes has a pronounced and easily observable effect on chromatin organization.