Microtuble

From The School of Biomedical Sciences Wiki
Jump to: navigation, search

Microtubules are fibres that make up part of the cytoskeleton (along with intermediate filaments, actin and spectrin). They have three primary functions: moving chromosomes in cell division, positioning organelles and driving cilia and flagella (by either sliding filaments or bending them). All microtubule processes occur because of their motor proteins, which include dyneins and kinesins. By moving across the tube surface, these can move molecules, other microtubules or even entire organelles. Microtubules are polar, and their motor proteins move relative to this - kinesins move toward the plus end and dyneins toward the minus end[1].

Microtubules are cylinders comprised of repeating alpha and beta units (which are dimers) that are made up using GTP. Their positive end grows while their negative end breaks down, which results in a treadmill effect - they are rapidly changing and unstable. They grow out of centrosomes, spindle pores (for mitotic spindle formation) or Basal bodies (for cilia and flagella formation) and are found in the cytoplasm(1). They are 25nm in diameter and are the largest of the cytoskeleton filaments[2].

References

  1. Alberts, Bruce, Alexander. Johnson, Julian. Lewis, David. Morgan, Martin. Raff, Keith. Roberts, Peter. Walter, John. Wilson, and Tim. Hunt. Molecular Biology of the Cell. 6th ed. New York, NY: Garland Science, Taylor and Francis Group, 2015.
  2. Alberts, Bruce, Alexander. Johnson, Julian. Lewis, David. Morgan, Martin. Raff, Keith. Roberts, Peter. Walter, John. Wilson, and Tim. Hunt. Molecular Biology of the Cell. 6th ed. New York, NY: Garland Science, Taylor and Francis Group, 2015.
Personal tools
Namespaces
Variants
Actions
Navigation
Toolbox