It has become apparent in recent years that the cytoskeleton and its a
ssociated proteins play a major role in secretion. This review summari
zes recent findings on the cytoskeleton organization and the molecular
topology of its regulatory proteins, as well as the dynamic changes t
hat occur in this organelle during secretion from neurons and secretor
y cells. Although two apparently different ultrastructures and molecul
ar organizations of the cytoskeleton seem to be involved in neuronal a
nd secretory cell secretion, there are similarities between the two sy
stems. In both neurons and secretory cells, Ca2+ plays a pivotal role
in the control of cytoskeleton dynamics, especially in the changes in
actin filament networks observed during secretion.