Induction of abnormal nuclear shapes in two distinct modes by overexpression of serine/threonine protein phosphatase 5 in Hela cells
✍ Scribed by Hirokazu Fukuda; Naoto Tsuchiya; Kaori Hara-Fujita; Sachiyo Takagi; Minako Nagao; Hitoshi Nakagama
- Publisher
- John Wiley and Sons
- Year
- 2007
- Tongue
- English
- Weight
- 364 KB
- Volume
- 101
- Category
- Article
- ISSN
- 0730-2312
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
Okadaic acid‐sensitve serine/threonine protein phosphatase 5 (PP5) is expressed ubiquitously in various tissues and is considered to participate in many cellular processes. PP5 has a catalytic domain in the C‐terminal region and three tetratricopeptide repeat (TPR) motifs in the N‐terminal region, which are suspected to function as a protein–protein interaction domain. Physiological roles of PP5 are still largely unknown, although several PP5‐binding proteins were reported and a few in vivo functions of PP5 were suggested. In the present study, the effects of expression of the full‐length wild‐type PP5 fused with EGFP (EGFP‐PP5~WT~) and its phosphatase‐dead mutant EGFP‐PP5~H304A~ were investigated. Transient expression of either EGFP‐PP5~WT~ or EGFP‐PP5~H304A~ in HeLa cells induced deformed nuclei with a 10‐fold frequency compared to that of EGFP. Abnormal‐shaped nuclei were also substantially increased by induced moderate expression of PP5 in tet‐on HeLa cells. Many HeLa cells expressing EGFP‐PP5~WT~ possessed multi‐nuclei separated from each other by nuclear membrane, while expression of EGFP‐PP5~H304A~ induced deformed nuclei which were multiple‐like in shape, but not separated completely and were surrounded by one nuclear membrane. These results suggest that PP5 plays important roles at the M‐phase of the cell cycle, especially in separation of chromosomes and formation of nuclear membrane. J. Cell. Biochem. 101: 321–330, 2007. © 2006 Wiley‐Liss, Inc.