ATP-Dependent Formation and Motility of Aster-Like Structures with Isolated Calf Brain Microtubule Proteins

• Published in: Proceedings of the National Academy of Sciences - PNAS 1986-03, Vol.83 (6), p.1728-1732
• Main Authors: Weisenberg, Richard C., Allen, Robert Day, Inoué, Shinya
• Format: Article
• Language: English
• Subjects: Adenosine Triphosphate - physiology; Aggregation; Animals; Biological and medical sciences; Brain Chemistry; Cattle; Cell aggregates; Cell motility; Cell structures and functions; Cytoskeleton, cytoplasm. Intracellular movements; Fundamental and applied biological sciences. Psychology; Microscopy, Phase-Contrast; Microtubule proteins; Microtubule Proteins - metabolism; Microtubules; Microtubules - ultrastructure; Mitotic spindle apparatus; Molecular and cellular biology; Movement; Neurons; Optics; Particle collisions; Particulate matter
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.83.6.1728

Microtubule proteins isolated from calf brain will undergo gelation-contraction in the presence of ATP. We have now examined this process by video-enhanced contrast microscopy. After ATP addition to steady-state microtubules, slow (1-5 μ m/min), linear movements of particles and microtubules toward aggregation centers occur. The resulting structures resemble mitotic spindle asters. During the time when gel contraction occurs, asters move (at 1-5 μ m/min) toward other nearby asters. This is accompanied by the apparent shortening of the microtubules running between the asters. This is the first example of isolated microtubules undergoing a process that has similarities to half-spindle shortening during anaphase A. Formation of aster-like structures without preformed microtubule organizing centers raises the possibility that a similar process may contribute to microtubule organization in vivo.