RT Journal Article SR Electronic T1 An actin-associated protein present in the microtubule organizing center and the growth cones of PC-12 cells JF The Journal of Neuroscience JO J. Neurosci. FD Society for Neuroscience SP 750 OP 761 DO 10.1523/JNEUROSCI.12-03-00750.1992 VO 12 IS 3 A1 Bearer, EL YR 1992 UL http://www.jneurosci.org/content/12/3/750.abstract AB The pathfinding ability of the growth cone depends upon the integrity of a dynamic actin filament network. However, although a number of actin-binding proteins have been found in growth cones, it is not known how these proteins come to be concentrated there or how they might interact to produce these important actin filaments. In this report, an actin-associated protein recognized by the monoclonal antibody 2E4 is demonstrated to be present in PC-12 cells. In undifferentiated cells, this protein is present in an apparently inactive state in a perinuclear location that corresponds to that of the microtubule organizing center and not of the Golgi apparatus. Conversely, after NGF- induced differentiation, the antigen is found enriched in the neurite and growth cone and disappears from the perinuclear position. This disappearance is directly proportional to the length of the neurite. The antigen-antibody complex binds the ends of actin filaments in vitro in an ATP-sensitive manner, and the antibody stains the outermost edge of the actin filament ruffle in the leading edge of migrating fibroblasts. Hence, it is possibly involved in the membrane-associated polymerization of actin filaments such as that observed in growth cones.