HIGHER-PLANT MICROTUBULE-ASSOCIATED PROTEINS (MAPS) - A SURVEY

Microtubule-associated proteins (MAPs) are one of the factors which re gulate the different properties of microtubules during cell cycle and differentiation. They have been characterized as proteins which promot e tubulin assembly in a concentration-dependent manner and bind to the outer surface of the polymers in vitro. Most of our knowledge comes f rom studies of neural microtubule-associated proteins and recent resul ts highlight their implication in neuronal morphogenesis. In contrast, until recently, few data are available about the proteins that associ ate with plant tubulins. This is due principally to the fact that plan t microtubule associated proteins cannot be purified by the standard p rocedures used for neural microtubule-associated proteins. First, we w ill describe methods which have been used to isolate these proteins in plant cells. We will then discuss the biochemical and immunological p roperties of the plant microtubule-associated proteins which have been isolated. From these results, putative functions can be proposed for these proteins in the particular plant cytoskeleton activities.