In vivo dynamics and kinetics of pKi-67: Transition from a mobile to an immobile form at the onset of anaphase

Journal Article · Mon Aug 01 04:00:00 EDT 2005 · Experimental Cell Research

DOI:https://doi.org/10.1016/j.yexcr.2005.04.010· OSTI ID:20717635

Saiwaki, Takuya ^[1]; Kotera, Ippei ^[1]; Sasaki, Mitsuho ^[1]; Takagi, Masatoshi ^[1]; Yoneda, Yoshihiro ^[2]

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1. Department of Cell Biology and Neuroscience, Graduate School of Medicine, Osaka University, 2-2 Yamada-oka, Suita, Osaka 565-0871 (Japan)
2. Department of Cell Biology and Neuroscience, Graduate School of Medicine, Osaka University, 2-2 Yamada-oka, Suita, Osaka 565-0871 (Japan) and Department of Frontier Biosciences, Graduate School of Frontier Biosciences, Osaka University, 1-3 Yamada-oka, Suita, Osaka 565-0871 (Japan)

A cell proliferation marker protein, pKi-67, distributes to the chromosome periphery during mitosis and nucleolar heterochromatin in the interphase. We report here on the structural domains of pKi-67 that are required for its correct distribution. While both the LR domain and the conserved domain were involved in localization to the nucleolar heterochromatin, both the LR domain and the Ki-67 repeat domain were required for its distribution to the mitotic chromosome periphery. Using in vivo time-lapse microscopy, GFP-pKi-67 was dynamically tracked from the mitotic chromosome periphery to reforming nucleoli via prenucleolar bodies (PNBs). The signals in PNBs then moved towards and fused into the reforming nucleoli with a thin string-like fluorescence during early G1 phase. An analysis of the in vivo kinetics of pKi-67 using photobleaching indicated that the association of pKi-67 with chromatin was progressively altered from 'loose' to 'tight' after the onset of anaphase. These findings indicate that pKi-67 dynamically alters the nature of the interaction with chromatin structure during the cell cycle, which is closely related to the reformation process of the interphase nucleolar chromatin.

• OSTI ID: 20717635
• Journal Information: Experimental Cell Research, Journal Name: Experimental Cell Research Journal Issue: 1 Vol. 308; ISSN 0014-4827; ISSN ECREAL
• Country of Publication: United States
• Language: English

Related Subjects

60 APPLIED LIFE SCIENCES
CELL CYCLE
CELL PROLIFERATION
CHROMOSOMES
FLUORESCENCE
HETEROCHROMATIN
IN VIVO
KINETICS
MICROSCOPY
MITOSIS
NUCLEOLI
PROTEINS