2012年
mDia1 and formins: Screw cap of the actin filament
Biophysics (Japan)
- ,
- 巻
- 8
- 号
- 開始ページ
- 95
- 終了ページ
- 102
- 記述言語
- 英語
- 掲載種別
- DOI
- 10.2142/biophysics.8.95
Formin homology proteins (formins) are actin nucleation factors which remain bound to the growing barbed end and processively elongate actin filament (F-actin). Recently, we have demonstrated that a mammalian formin mDia1 rotates along the long-pitch helix of Factin during processive elongation (helical rotation) by single-molecule fluorescence polarization. We have also shown processive depolymerization of mDia1-bound Factin during which helical rotation was visualized. In the cell where F-actins are highly cross-linked, formins should rotate during filament elongation. Therefore, when formins are tightly anchored to cellular structures, formins may not elongate F-actin. Adversely, helical rotation of formins might affect the twist of F-actin. Formins could thus control actin elongation and regulate stability of cellular actin filaments through helical rotation. On the other hand, ADP-actin elongation at the mDia1-bound barbed end turned out to become decelerated by profilin, in marked contrast to its remarkably positive effect on mDia1-mediated ATP-actin elongation. This deceleration is caused by enhancement of the offrate of ADP-actin. While mDia1 and profilin enhance the ADP-actin off-rate, they do not apparently increase the ADP-actin on-rate at the barbed end. These results imply that G-actin-bound ATP and its hydrolysis may be part of the acceleration mechanism of formin-mediated actin elongation. © 2012 THE BIOPHYSICAL SOCIETY OF JAPAN.
- ID情報
-
- DOI : 10.2142/biophysics.8.95
- ISSN : 1349-2942
- PubMed ID : 27493525
- SCOPUS ID : 84864268954