报告时间：2013年10月19下午13：30

报告地点：智能楼小会议室

报 告 人：缪岩松

主要内容：

Assembly of appropriately oriented actin cables nucleated by formin proteins is

necessary for many biological processes in diverse eukaryotes. However, compared to

knowledge of how nucleation of dendritic actin filament arrays by the Arp2/3

complex is regulated, the in vivo regulatory mechanisms for actin cable formation

are less clear. To gain insights into mechanisms for regulating actin cable

assembly, we reconstituted the assembly process in vitro by introducing microspheres

functionalized with the Cterminus of the budding yeast formin Bni1 into extracts

prepared from yeast cells at different cell cycle stages. Electron microscopy

studies showed that unbranched actin filament bundles were successfully

reconstituted in the yeast extracts. Only extracts enriched in the mitotic cyclin

Clb2 were competent for actin cable assembly, and cyclin dependent kinase 1 (Cdk1)

activity was indispensible. Cdk1 activity was also found to regulate cable assembly

in vivo. Evidence that cell cycle regulation of actin cable assembly is conserved

in vertebrates is presented. The cable reconstitution system was used to test roles

for the key actinbinding proteins tropomyosin, capping protein and cofilin,

providing new insights into assembly regulation. Furthermore, using mass

spectrometry, we identified components of the actin cables formed in yeast extracts,

providing the basis for comprehensive understanding of cable assembly and

regulation. Among these actin cable components we have identified several Cdk1 targets.

欢迎大家踊跃参加！

亚热带森林资源培育研究中心

浙江省亚热带森林培育国家重点实验室培育基地

2013年10月17日