报告题目：细胞内吞作用中的力学问题
报 告 人：马 锐（Yale University）
报告时间：2018年4月23日（星期一），下午4:00
报告地点：威廉希尔六层学术报告厅（致知楼3623）
报告摘要：
Clathrin-mediated endocytosis (CME) is necessary for cells to
internalize extracellular cargo, by invaginating a patch of membrane and
releasing a vesicle into the cytoplasm. In yeast, this process is mediated by
the robust self-assembly of clathrin and over 60 other proteins, including
actin, actin-associated proteins, and membrane proteins. This membrane deformation
is counteracted by membrane tension and high turgor pressure, presenting a
large energy barrier to internalization. Importantly, a dynamic actin meshwork
is required for successful CME in yeast, leading to the conclusion that the
actin machinery produces forces to drive the membrane invagination. In this
talk, I will present our recent simulations on the self-organization rigid
actin filaments in the presence of elastic crosslinkers in conditions relevant
for endocytosis. Our simulations demonstrated that these nanometer-scale
actin structures can store a large amount of elastic energy within the
crosslinkers. This conversion of binding energy into elastic energy is
the consequence of geometric constraints created by the helical pitch of
actin filaments, which results in frustrated configurations of
crosslinkers attached to filaments. We propose that this stored elastic
energy can be used at a later time in the endocytic process. I will
also discuss mechanics of membrane tabulation with turgor pressure, which is
drastically different from pulling a tube from membrane when tension is the
dominant factor. We found a new
branch solution that is able to explain the paradox that spontaneous curvature
of membrane cannot lift the membrane off the cell wall.
报告人简介：
马锐博士2008年本科毕业于吉林大学信息与计算科学专业，后进入清华大学高等研究院师从欧阳钟灿院士从事理论生物物理的研究，其主要研究方向为生物分子马达的动力学和热力学。博士期间，作为交换学生访问德国马普复杂系统物理研究所，师从莱布尼茨奖获得者Frank Jülicher教授。2014年1月取得博士学位后，前往耶鲁大学从事博士后研究至今，研究方向为细胞内吞作用的中的细胞骨架和细胞膜力学。其在国际著名期刊Physical Review Letter，New Journal of Physics等刊物上发表过多篇文章，近五年来，文章引用次数超过百余次。
欢迎广大师生参加！
威廉希尔
2018年4月18日
