Kagawa Naoko, Hori Tetsuya, Hoki Yuko, Hosoya Osamu, Tsutsui Kimiko, Saga Yumiko, Sado Takashi, Fukagawa Tatsuo
Department of Molecular Genetics, National Institute of Genetics and The Graduate University for Advanced Studies, Mishima, Shizuoka, 411-8540, Japan.
Chromosome Res. 2014 Sep;22(3):293-303. doi: 10.1007/s10577-014-9404-1. Epub 2014 Jan 31.
CENP-U (CENP-50) is a component of the CENP-O complex, which includes CENP-O, CENP-P, CENP-Q, CENP-R, and CENP-U and is constitutively localized at kinetochores throughout the cell cycle in vertebrates. Although CENP-U deficiency results in some mitotic defects in chicken DT40 cells, CENP-U-deficient chicken DT40 cells are viable. To examine the functional roles of CENP-U in an organism-dependent context, we generated CENP-U-deficient mice. The CENP-U-deficient mice died during early embryogenesis (approximately E7.5). Thus, conditional CENP-U-deficient mouse ES cells were generated to analyze CENP-U-deficient phenotypes at the cell level. When CENP-U was disrupted in the mouse ES cells, all CENP-O complex proteins disappeared from kinetochores. In contrast, other kinetochore proteins were recruited in CENP-U-deficient mouse ES cells as CENP-U-deficient DT40 cells. However, the CENP-U-deficient ES cells died after exhibiting abnormal mitotic behavior. Although CENP-U was essential for cell viability during mouse early embryogenesis, CENP-U-deficient mouse embryonic fibroblast cells were viable, similar to the DT40 cells. Thus, although both DT40 and ES cells with CENP-U deficiency have similar mitotic defects, cellular responses to mitotic defects vary among different cell types.
着丝粒蛋白U（CENP - U，即CENP - 50）是CENP - O复合体的一个组成部分，该复合体包括CENP - O、CENP - P、CENP - Q、CENP - R和CENP - U，在脊椎动物的整个细胞周期中都组成性地定位于动粒。虽然CENP - U缺陷在鸡DT40细胞中会导致一些有丝分裂缺陷，但CENP - U缺陷的鸡DT40细胞仍可存活。为了在依赖生物体的背景下研究CENP - U的功能作用，我们构建了CENP - U缺陷的小鼠。CENP - U缺陷的小鼠在胚胎早期发育阶段（约E7.5）死亡。因此，我们构建了条件性CENP - U缺陷的小鼠胚胎干细胞，以在细胞水平分析CENP - U缺陷的表型。当在小鼠胚胎干细胞中破坏CENP - U时，所有CENP - O复合体蛋白都从动粒上消失。相反，与CENP - U缺陷的DT40细胞一样，其他动粒蛋白在CENP - U缺陷的小鼠胚胎干细胞中仍被招募。然而，CENP - U缺陷的胚胎干细胞在表现出异常有丝分裂行为后死亡。虽然CENP - U在小鼠胚胎早期发育过程中对细胞存活至关重要，但CENP - U缺陷的小鼠胚胎成纤维细胞与DT40细胞一样仍可存活。因此，虽然CENP - U缺陷的DT40细胞和胚胎干细胞都有类似的有丝分裂缺陷，但不同细胞类型对有丝分裂缺陷的细胞反应有所不同。
