NEW CONCEPT OF MICROTUBULE DYNAMICS AND MICROTUBULE MOTOR MOVEMENT AND NEW MODEL OF CHROMOSOME MOVEMENT IN MITOSIS

In this study, microtubules are regarded as polymers with positive fre e surface energy. The dynamics of such polymers is complex, consisting of equilibrium, non-equilibrium, and one-directional processes. This view of microtubules enables us to propose a new model of microtubule dynamics both in vitro and in vivo, and to draw a new conclusion on th e role of GTP hydrolysis and calcium cations in microtubule polymeriza tion. The study also offers a new model of chromosome movement in mito sis and a new model of the movement of motor proteins along microtubul es. In the conclusion the similarity and difference between microtubul es and microfilaments is examined. We conclude that microfilaments, li ke microtubules, represent polymers with positive free surface energy, and that the movement of myosins along microfilaments can be realized in the same manner as the movement of motor proteins along microtubul es. (C) 1996 Academic Press Limited.