Nuclear matrix. Isolation and characterization of a framework structure from rat liver nuclei.
Nuclear matrix. Isolation and characterization of a framework structure from rat liver nuclei.
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DOI：
10.1083/jcb.73.3.616
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发表时间：
1977-06
期刊：
影响因子：
--
通讯作者：
Coffey DS
中科院分区：
文献类型：
--
作者：
Berezney R;Coffey DS
一种称为核基质的核框架结构已被分离和表征。这种基质形成了分离细胞核的主要残留结构，主要由蛋白质和少量的RNA、DNA、碳水化合物和磷脂组成。用DNase和RNase联合处理可进一步分解核基质。在提取90%的核蛋白、99.9%的DNA和98%的RNA和磷脂后，剩余的核蛋白结构被称为核蛋白基质。这最终的核蛋白质基质的电子显微镜揭示了一个内部框架结构组成的残留核仁结构与颗粒状和纤维状的内部基质结构。内部基质框架来源于细胞核的染色质间结构，并与周围含有残留核孔复合物结构的残留核被膜层连接。核基质蛋白的十二烷基硫酸钠-丙烯酰胺凝胶电泳显示了三种主要多肽组分，P-1、P-2和P-3，平均分子量约为69，000、66，000和62，000，以及几种次要多肽，其在约50，000和更高分子量（> 100，000）处迁移。分子量与P-1、P-2和P-3相同的多肽也是分离的核膜和核仁的组分，而分离的染色质不含可检测的基质多肽。这表明主要的基质多肽定位于细胞核的特定结构区域，即，核膜、核仁和染色质间结构。细胞色素氧化酶活性在分离的核基质中的存在表明核膜的至少一些整合蛋白与基质相关。
A nuclear framework structure termed the nuclear matrix has been isolated and characterized. This matrix forms the major residual structure of isolated nuclei and consists largely of protein with smaller amounts of RNA, DNA, carbohydrate, and phospholipid. The nuclear matrix can be further resolved by combined treatment with DNase and RNase. The remaining nuclear protein structure, after extraction of 90 percent of the nuclear protein, 99.9 percent of the DNA, and 98 percent of the RNA and phospholipid, is termed the nuclear protein matrix. Electron microscopy of this final nuclear protein matrix reveals an interior framework structure composed of residual nucleolar structures associated with a granular and fibrous internal matrix structure. The internal matrix framework is derived from the interchromatinic structures of the nucleus, and is connected to a surrounding residual nuclear envelope layer containing residual nuclear pore complex structures. Sodium dodecyl sulfate-acrylamide gel electrophoresis of the nuclear matrix proteins demonstrates three major polypeptide fractions, P-1, P-2, and P-3, with average molecular weights of approximately 69,000, 66,000 and 62,000, as well as several minor polypeptides which migrate at approximately 50,000 and at higher molecular weights (>100,000). Polypeptides with molecular weights identical to those of P-1, P-2 and P-3 are also components of isolated nuclear envelopes and nucleoli, whereas isolated chromatin contains no detectable matrix polypeptides. This suggests that the major matrix polypeptides are localized in specific structural regions of the nucleus, i.e., nuclear envelope, nucleoli, and interchromatinic structures. The presence of cytochrome oxidase activity in the isolated nuclear matrix indicates that at least some integral proteins of the nuclear membrane are associated with the matrix.