Roland Brandt

Institute of Neurobiology, University of Heidelberg, INF 364, 69120 Heidelberg, Germany.

Received 05/21/96; Accepted 07/05/96; On-line 08/01/96

More than twenty years after the isolation and identification of tau as a microtubule-associated protein, its function during neuronal development is still not fully understood. It is increasingly clear that the role of tau in neurons is more complex than initially thought. Recent data on the subcellular distribution of tau and the function of its aminoterminal projection domain suggest that tau's prime role in neurons may not be to promote microtubule assembly or to stabilize axonal microtubules. Recent data raise the possibility that tau may be an integral part of the molecular machinery which underlies the development and maintenance of the polarity of neurons and may regulate the translation of extracellular cues into the structural changes during axonal outgrowth and pathfinding. For a complete understanding of the role of tau in neurons, it will be critical to identify the component(s) with which tau interacts at the distal axon and to analyze their interaction during neuronal development.