| RRC ID |
47867
|
| 著者 |
Arikawa M, Saito A, Omura G, Mostafa Kamal Khan SM, Suetomo Y, Kakuta S, Suzaki T.
|
| タイトル |
Ca2+-dependent nuclear contraction in the heliozoon Actinophrys sol.
|
| ジャーナル |
Cell Calcium
|
| Abstract |
Ca2+-dependent contractility was found to exist in the nucleus of the heliozoon protozoan Actinophrys sol. Upon addition of Ca2+ ([Ca2+]free = 2.0 x 10(-3) M), diameters of isolated and detergent-extracted nuclei became reduced from 16.5+/-1.7 microm to 11.0+/-1.3 microm. The threshold level of [Ca2+]free for the nuclear contraction was 2.9 x 10(-7) M. The nuclear contraction was not induced by Mg2+, and was not inhibited by colchicine or cytochalasin B. Contracted nuclei became expanded when Ca2+ was removed by EGTA; thus cycles of contraction and expansion could be repeated many times by alternating addition of Ca2+ and EGTA. The Ca2+-dependent nuclear contractility remained even after high salt treatment, suggesting a possible involvement of nucleoskeletal components in the nuclear contraction. Electron microscopy showed that, in the relaxed state, filamentous structures were observed to spread in the nucleus to form a network. After addition of Ca2+, they became aggregated and constructed a mass of thicker filaments, followed by re-distribution of the filaments spread around inside of the nucleus when Ca2+ was removed. These results suggest that the nuclear contraction is induced by Ca2+-dependent transformation of the filamentous structures in the nucleus.
|
| 巻・号 |
38(5)
|
| ページ |
447-55
|
| 公開日 |
2005-11-1
|
| DOI |
10.1016/j.ceca.2005.06.034
|
| PII |
S0143-4160(05)00121-1
|
| PMID |
16099499
|
| MeSH |
Animals
Calcium / pharmacology*
Cell Nucleus / drug effects*
Cell Nucleus / ultrastructure
Egtazic Acid / pharmacology
Eukaryota / ultrastructure*
Microscopy, Electron
Nuclear Matrix / drug effects*
|
| IF |
4.874
|
| 引用数 |
1
|
|
WOS 分野
|
CELL BIOLOGY
|
| リソース情報 |
| 藻類 |
NIES-2497 |
