Microtubule-Based Pushing Forces

Study Notes

Microtubule-based pushing forces in the cell

Micro-cutting techniques can distinguish between pushing and pulling mechanisms in the cell by perturbing the force balance in the structure of interest.
Microtubules in the budding yeast push against the cell cortex during interphase, propelling the nucleus in the opposite direction.
Microtubules in cylindrically shaped cells of the fission yeast exert a pushing force on the nucleus upon reaching the cell tips, keeping it at the cell center.
The ability of microtubule pushing forces to center the nucleus depends on the arrangement of microtubules, besides its dependence on microtubule dynamics and cell geometry.
In S. pombe, interphase microtubules exert pushing forces against the cell tips to position the duplicated spindle pole body in the cell center during spindle movements.
During anaphase B, astral microtubules grow from the spindle pole bodies and help to align the spindle with the cell axis by pushing against the cell sides.
Microtubules can push on the chromosomes in the spindle, generating polar ejection forces that push chromosome arms away from the proximal spindle pole.
The chromokinesin Kid is the molecular entity generating polar ejection forces by walking towards the microtubule plus-end, which points away from the spindle pole.
The plus-end directed motor CENP-E binds the chromosome at the kinetochore and slides it along another microtubule bound to the kinetochore of another chromosome.
Microtubule-based pushing forces not only involve pushing an organelle away from the spindle pole, but also sliding an organelle along a microtubule.
Microtubule pushing forces are dependent on the arrangement of microtubules, microtubule dynamics, and cell geometry.
Micro-cutting techniques have been applied to spindles and other microtubule-based structures in a variety of cell systems.

Description

Test your knowledge on microtubule-based pushing forces in the cell with this quiz! From the arrangement of microtubules to the molecular entities generating polar ejection forces, this quiz covers various aspects of the topic. Discover how microtubules push against the cell cortex during interphase, exert a pushing force on the nucleus in cylindrically shaped cells, and help align the spindle with the cell axis during anaphase B. Sharpen your understanding of microtubule dynamics