Long protein filaments called kinetochore microtubules extend from poles on either end of the cell and attach to the kinetochores. Prometaphase is followed by the third phase of mitosis, known as metaphase.
Which phase in mitosis does the kinetochore disassemble?
Thus, the kinetochore microtubules disassemble from both ends in anaphase. Although it is clear that both microtubule motor proteins and microtubule depolymerization at the kinetochores contribute to chromosome movement during anaphase A, the exact molecular mechanism that drives the movement is still unknown.
What is the second phase of mitosis?
Prometaphase is the second phase of mitosis, the process that separates the duplicated genetic material carried in the nucleus of a parent cell into two identical daughter cells. During prometaphase, the physical barrier that encloses the nucleus, called the nuclear envelope, breaks down.
What are the three types of microtubules?
The overall shape of the spindle is framed by three types of spindle microtubules: kinetochore microtubules (green), astral microtubules (blue), and interpolar microtubules (red). Microtubules are a polarized structure containing two distinct ends, the fast growing (plus) end and slow growing (minus) end.
What are the phases of mitosis?
These phases are prophase, prometaphase, metaphase, anaphase, and telophase. Cytokinesis is the final physical cell division that follows telophase, and is therefore sometimes considered a sixth phase of mitosis.
What proteins are involved in mitosis?
A simple set of microtubule motor proteins — BimC, CENP-E, and cytosolic dynein — are conserved in all spindles. Additional motors are present in more complex organisms. The two centrioles in the centrosome, the MTOC in most animal cells, are replicated during interphase.