Search results
Results from the WOW.Com Content Network
The cellular spindle apparatus includes the spindle microtubules, associated proteins, which include kinesin and dynein molecular motors, condensed chromosomes, and any centrosomes or asters that may be present at the spindle poles depending on the cell type. [4] The spindle apparatus is vaguely ellipsoid in cross
This diagram depicts the organization of a typical mitotic spindle found in animal cells. Chromosomes are attached to kinetochore microtubules via a multiprotein complex called the kinetochore. Polar microtubules interdigitate at the spindle midzone and push the spindle poles apart via motor proteins.
Fluorescence microscopy micrographs, showing the endogenous human protein Mad1 (one of the spindle checkpoint components) in green, along the different phases in mitosis; CENP-B, in red, is a centromeric marker, and DAPI (in blue) stains DNA. The first protein to be assembled on the kinetochore is CENP-A (Cse4 in Saccharomyces cerevisiae).
Unlike other microtubule-associated proteins, motor proteins utilize the energy from ATP hydrolysis to generate mechanical work that moves the protein along the substrate. The major motor proteins that interact with microtubules are kinesin , which usually moves toward the (+) end of the microtubule, and dynein , which moves toward the (−) end.
Biorientation is the phenomenon whereby microtubules emanating from different microtubule organizing centres (MTOCs) attach to kinetochores of sister chromatids.This results in the sister chromatids moving to opposite poles of the cell during cell division, and thus results in both daughter cells having the same genetic information.
These proteins have a conserved C-terminal microtubule-binding domain and variable N-terminal domains projecting outwards, probably interacting with other proteins. MAP2 and tau stabilize microtubules, and thus shift the reaction kinetics in favor of addition of new subunits, accelerating microtubule growth.
Upon microtubule-kinetochore attachment, a mechanism of stripping via a dynein-dynein motor complex transports spindle checkpoint proteins away from the kinetochores. [60] The stripped proteins, which include MAD1, MAD2, MPS1, and CENP-F, are then redistributed to the spindle poles. The stripping process is highly dependent on undamaged ...
Katanin is a microtubule-severing AAA protein. It is named after the Japanese sword called a katana. Katanin is a heterodimeric protein first discovered in sea urchins. It contains a 60 kDa ATPase subunit, encoded by KATNA1, which functions to sever microtubules. This subunit requires ATP and the presence of microtubules for activation.