La Terra Sabrina, English Christopher N, Hergert Polla, McEwen Bruce F, Sluder Greenfield, Khodjakov Alexey
Wadsworth Center, New York State Department of Health, Albany, NY 12201, USA.
J Cell Biol. 2005 Feb 28;168(5):713-22. doi: 10.1083/jcb.200411126.
It has been reported that nontransformed mammalian cells become arrested during G1 in the absence of centrioles (Hinchcliffe, E., F. Miller, M. Cham, A. Khodjakov, and G. Sluder. 2001. Science. 291:1547-1550). Here, we show that removal of resident centrioles (by laser ablation or needle microsurgery) does not impede cell cycle progression in HeLa cells. HeLa cells born without centrosomes, later, assemble a variable number of centrioles de novo. Centriole assembly begins with the formation of small centrin aggregates that appear during the S phase. These, initially amorphous "precentrioles" become morphologically recognizable centrioles before mitosis. De novo-assembled centrioles mature (i.e., gain abilities to organize microtubules and replicate) in the next cell cycle. This maturation is not simply a time-dependent phenomenon, because de novo-formed centrioles do not mature if they are assembled in S phase-arrested cells. By selectively ablating only one centriole at a time, we find that the presence of a single centriole inhibits the assembly of additional centrioles, indicating that centrioles have an activity that suppresses the de novo pathway.
据报道，在没有中心粒的情况下，未转化的哺乳动物细胞会在G1期停滞（欣奇克利夫，E.，F. 米勒，M. 查姆，A. 霍贾科夫，和G. 斯卢德。2001年。《科学》。291:1547 - 1550）。在这里，我们表明去除驻留中心粒（通过激光消融或针显微手术）并不妨碍HeLa细胞的细胞周期进程。没有中心体出生的HeLa细胞，随后会重新组装数量可变的中心粒。中心粒组装始于S期出现的小的中心蛋白聚集体的形成。这些最初无定形的“前中心粒”在有丝分裂前变成形态上可识别的中心粒。重新组装的中心粒在下一个细胞周期中成熟（即获得组织微管和复制的能力）。这种成熟不仅仅是一个时间依赖性现象，因为如果在S期停滞的细胞中组装，重新形成的中心粒不会成熟。通过每次仅选择性地消融一个中心粒，我们发现单个中心粒的存在会抑制额外中心粒的组装，表明中心粒具有抑制从头组装途径的活性。
