Induction of the RI cAMP-binding protein in the "neurite-minus" N1A-103 mouse neuroblastoma cell line.

We examined the effects of agents/conditions that raise intracellular cAMP concentration in the induction of the 47,000-dalton RI cAMP-binding protein in the "neurite-minus" N1A-103 mouse neuroblastoma cells. The amount of RI in cell extracts was quantitated by photoaffinity labeling with 8-N3-[32P]cAMP and by ELISA and Western blot. Our results showed that treatment of the N1A-103 neuroblastoma cells with 20 microM forskolin or 1 mM dibutyryl cAMP, or reducing the serum concentration in the culture medium from 10% to 1% caused a 3-4 fold increase in the amount of RJ. Our results suggest that the induction of RJ can occur independent of morphological differentiation in the mouse neuroblastoma cells.