The developmentally-regulated neuron-specific protein, drebrin A, is expressed first at the time of outgrowth and maturation of dendrites, and is localized within dendrites of the adult brain. A cDNA clone of adult rat drebrin A was isolated and sequenced. There is no overall homology with other reported protein sequences except chicken drebrins. We constructed the expression vector MIW-DA containing the drebrin A cDNA. Transfection of nonneuronal cells with MIW-DA induced the formation of highly branched neurite-like cell processes. In these process-bearing transfectants, expressed debrin A is concentrated in submembraneous regions of the cell. Furthermore, actin concentration is higher in these cells than other fibroblasts. These results suggest a possible role of drebrin A in neurite outgrowth.