CREATING INTRACELLULAR STRUCTURAL DOMAINS - SPATIAL SEGREGATION OF ACTIN AND TROPOMYOSIN ISOFORMS IN NEURONS

Actin microfilaments play a direct role in a variety of cell processes , Distinct populations of microfilaments are associated with different cellular compartments, such as growth cones, filipodia, stress fibers , and lamellipodia. It is becoming clear that these different populati ons are often composed of different isoforms of the two core microfila ment components, actin and tropomyosin. This is particularly true in n eurons, where actin and tropomyosin isoforms are segregated into diffe rent intracellular compartments which correspond to functionally disti nct regions of the neuron. Developmental regulation of this isoform so rting suggests a specific role for some isoforms in growth and for oth ers in stabilization of neuronal structure. This provides a mechanism by which a neuron can create and independently regulate intracellular domains composed of microfilaments with different functional propertie s. (C) 1998 John Wiley & Sons, Inc.