C. Gamby et al., GROWTH-ASSOCIATED PROTEIN-43 (GAP-43) FACILITATES PEPTIDE-HORMONE SECRETION IN MOUSE ANTERIOR-PITUITARY ATT-20 CELLS, The Journal of biological chemistry, 271(17), 1996, pp. 10023-10028
The neuronal growth-associated protein (GAP)-43 (neuromodulin, B-50, F
1), which is concentrated in the growth cones of elongating axons duri
ng neuronal development and in nerve terminals in restricted regions o
f the adult nervous system, has been implicated in the release of neur
otransmitter. To study the role of GAP-43 in evoked secretion, we tran
sfected mouse anterior pituitary AtT-20 cells with the rat GAP-43 cDNA
and derived stably transfected cell lines. Depolarization-mediated be
ta-endorphin secretion was greatly enhanced in the GAP-43-expressing A
tT-20 cells without a significant change in Ca2+ influx; in contrast,
expression of GAP-43 did not alter corticotropin releasing factor-evok
ed hormone secretion. The transfected cells also displayed a flattened
morphology and extended processes when plated on laminin-coated subst
rates. These results suggest that AtT-20 cells are a useful model syst
em for further investigations on the precise biological function(s) of
GAP-43.