Assembly and positioning of microtubule asters in microfabricated chambers.
نویسندگان
چکیده
Intracellular organization depends on a variety of molecular assembly processes; while some of these have been studied in simplified cell-free systems, others depend on the confined geometry of cells and cannot be reconstructed using bulk techniques. To study the latter processes in vitro, we fabricated microscopic chambers that simulate the closed environment of cells. We used these chambers to study the positioning of microtubule asters. Microtubule assembly alone, without the action of molecular motors, is sufficient to position asters. Asters with short microtubules move toward the position expected from symmetry; however, once the microtubules become long enough to buckle, symmetry is broken. Calculations and experiments show that the bending-energy landscape has multiple minima. Microtubule dynamic instability modifies the landscape over time and allows asters to explore otherwise inaccessible configurations.
منابع مشابه
Dynamics of microtubule asters in microfabricated chambers: the role of catastrophes.
Recent in vivo as well as in vitro experiments have indicated that microtubule pushing alone is sufficient to position a microtubule-organizing center within a cell. Here, we investigate the effect of catastrophes on the dynamics of microtubule asters within microfabricated chambers that mimic the confining geometry of living cells. The use of a glass bead as the microtubule-organizing center a...
متن کاملCortical Dynein Controls Microtubule Dynamics to Generate Pulling Forces that Position Microtubule Asters
Dynein at the cortex contributes to microtubule-based positioning processes such as spindle positioning during embryonic cell division and centrosome positioning during fibroblast migration. To investigate how cortical dynein interacts with microtubule ends to generate force and how this functional association impacts positioning, we have reconstituted the 'cortical' interaction between dynein ...
متن کاملMyosin II-Dependent Cortical Movement Is Required for Centrosome Separation and Positioning during Mitotic Spindle Assembly
The role of myosin II in mitosis is generally thought to be restricted to cytokinesis. We present surprising new evidence that cortical myosin II is also required for spindle assembly in cells. Drug- or RNAi-mediated disruption of myosin II in cells interferes with normal spindle assembly and positioning. Time-lapse movies reveal that these treatments block the separation and positioning of dup...
متن کاملThe importance of catastrophe
or microtubule asters, just as with life in general, sometimes you get stuck in a corner. And, say Cendrine Faivre-Moskalenko and Marileen Dogterom (FOM Institute for Atomic and Molecular Physics, Amsterdam, Netherlands), it can take a catastrophe to get things moving again. Dogterom has been trying to reproduce aster behavior in the minimal environment of a microfabricated chamber. Her beads, ...
متن کاملTubes go apical
or microtubule asters, just as with life in general, sometimes you get stuck in a corner. And, say Cendrine Faivre-Moskalenko and Marileen Dogterom (FOM Institute for Atomic and Molecular Physics, Amsterdam, Netherlands), it can take a catastrophe to get things moving again. Dogterom has been trying to reproduce aster behavior in the minimal environment of a microfabricated chamber. Her beads, ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Proceedings of the National Academy of Sciences of the United States of America
دوره 94 12 شماره
صفحات -
تاریخ انتشار 1997