PtK2细胞的核骨架—核纤层——中间纤维体系

本文用选择性系列抽提的方法结合整装细胞电镜技术和DGD包埋-去包埋超薄切片技术,在电镜下清晰地显示了PtK 2细胞的核骨架-核纤层-中间纤维体系的精细结构。处于分裂中期的细胞经抽提后可以看到,染色体残余与中间纤维仍然保持一定的联系。用免疫荧光技术对抽提后的PtK 2细胞进行分析结果表明:其中间纤维能同时与AE1和AE3反应;能与Lamin B反应的单抗可以特异地定位于其核周,而Lamin A(C)的单抗除了与其核纤层蛋白有很强的反应外还与中间纤维有交叉反应。此外,在分裂期细胞中可以看到Lamin A(C)可能与染色体能特异结合;与HeLa细胞不一样。PtK 2细胞的核骨架成份不能与280kD的核骨架蛋白单抗反应。双向电泳结果显示出PtK 2细胞的核骨架-核纤层-中间纤维体系的组成成份与HeLa细胞相比有较大的差异,而且这种差异主要反映在核骨架组份上,TdR的处理也能导致其组份发生变化。

NUCLEAR MATRIX-LAMINA-INTERMEDIATE FILAMENT SYSTEM IN PTK 2 CELLS

Selective extraction, whole mount cell preparation and DGD embeddment-free section were involved in visualizing the nuclear matrix -lamina-intermediate filament system in PtK 2 cells. After extraction the anaphase chromosome residues adjoined to the cytoplasmic intermediate filament in some areas. Immunofluorescent staining showed us that the intermediate filament reacted with AE 1 and AE 3; McAb 223 could be localized specifically on the lamina while McAb C 23 could crossreact with cytoplasmic intermediatefilament beside the lamina location, monoclonal antibody against lamin A (C) could also bind to chromosome residues. Antibody to 280 kD nuclear matrix protein which were positive stained in HeLa cells could not react with the nuclear matrix components of PtK 2 cells. 2-D elec-trophoresis demonstrated that there were some differences in the composition of the nuclear matrix-lamina-intermediate filament system of HeLa and PtK 2 cells. TdR treatment could lead to alteration of nuclear matrix proteins.