Tabellini G, Riccio M, Baldini G, Bareggi R, Billi A M, Grill V, Narducci P, Martelli A M
Dipartimento di Morfologia Umana Normale, Università di Trieste, Italy.
Ital J Anat Embryol. 2001 Jul-Sep;106(3):251-60.
We have investigated the intranuclear distribution of High-mobility group proteins I/Y by means of immunofluorescent staining employing a variety of cell lines. Confocal scanning laser microscopy analysis revealed that High-mobility group proteins I/Y are present in an intranuclear fibrogranular network and mitotic chromosomes. In Caski, C4I, Flow 2002, and K562 cell lines, High-mobility group proteins I/Y were absent from nucleoli, whereas in HeLa cells they were present in this nuclear domain. Double immunolabeling studies showed that High-mobility group proteins I/Y co-localize with other key nuclear components such as NuMA, SC-35, and TAF(II)70. Nuclear reactivity for High-mobility group proteins I/Y dramatically decreased in apoptotic nuclei of HL-60 human leukemia cells. Our morphological data correlate well with previous biochemical and functional findings obtained by other investigators, who have demonstrated multiple roles for this class of polypeptides. However, they point to the likelihood that High-mobility group proteins I/Y are involved in as yet unidentified functions, most likely in the speckle domains of the nucleus. They also show that conceivably these proteins are also involved in apoptosis.
我们通过免疫荧光染色，利用多种细胞系研究了高迁移率族蛋白I/Y的核内分布。共聚焦扫描激光显微镜分析显示，高迁移率族蛋白I/Y存在于核内纤维颗粒网络和有丝分裂染色体中。在Caski、C4I、Flow 2002和K562细胞系中，核仁中不存在高迁移率族蛋白I/Y，而在HeLa细胞中，它们存在于这个核区域。双重免疫标记研究表明，高迁移率族蛋白I/Y与其他关键核成分如NuMA、SC-35和TAF(II)70共定位。在HL-60人白血病细胞的凋亡核中，高迁移率族蛋白I/Y的核反应性显著降低。我们的形态学数据与其他研究者先前获得的生化和功能研究结果高度相关，这些研究者已证明这类多肽具有多种作用。然而，这些数据表明高迁移率族蛋白I/Y可能参与了尚未明确的功能，很可能是在细胞核的斑点结构域中。它们还表明，这些蛋白质也可能参与了细胞凋亡。
